KR100691141B1 - Liquid crystal display device and mobile station having the same - Google Patents

Abstract

Liquid crystal display device according to the present invention, a transmissive liquid crystal panel; Located in the front portion of the transmissive liquid crystal panel to supply light for image display, a first light guide plate, a first light source disposed on the first light guide plate, and a first provided on the first light guide plate to reflect or transmit the incident light A first light source supply unit having a light adjusting means; A second light source positioned at a rear side of the transmissive liquid crystal panel to supply light for displaying an image, and reflecting or transmitting a second light guide plate, a second light source disposed on the second light guide plate, and a light incident under the second light guide plate; A second light source supply unit having a light adjusting means; It includes.

According to the liquid crystal display device according to the present invention, there is an advantage that the image can be displayed in both the front direction and the rear direction of the liquid crystal panel using one transmissive liquid crystal panel.

In addition, the mobile communication terminal according to the present invention has an advantage of providing a thin mobile communication terminal capable of displaying images in both directions by using a liquid crystal display device employing one transmissive liquid crystal panel.

Description

Liquid crystal display device and mobile communication terminal having same {Liquid crystal display device and mobile station having the same}

1 is a view schematically showing the configuration of a liquid crystal display according to the present invention.

2 is a view for explaining an operation when a voltage is applied to the PDLC applied to the liquid crystal display according to the present invention.

3 is a view for explaining the operation when no voltage is applied to the PDLC applied to the liquid crystal display according to the present invention.

FIG. 4 is a view for explaining that an image is displayed on a rear surface by using light provided from a first light source in the liquid crystal display shown in FIG. 1.

FIG. 5 is a view for explaining that an image is displayed on a front surface by using light provided from a second light source in the liquid crystal display shown in FIG. 1.

FIG. 6 is a view for explaining that an image is displayed on a front surface using an external light source in the liquid crystal display shown in FIG. 1.

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

100 ... liquid crystal panel 110 ... first substrate

111 ... transmission electrode 120 ... second substrate

121 ... Black Matrix 123 ... Color Filter

130 liquid crystal layer 140 first polarizing plate

150 ... 2nd Polarizer 160 ... Micro Lens Sheet

190 ... PDLC 191 ... first transparent electrode

192 ... Second transparent electrode 193 ... Polymer binder

195 ... liquid crystal 210 ... first light source supply unit

211 ... First light guide plate 212 ... First light source

213 ... 1st PDLC 220 ... 2nd light source supply part

221 ... Second light guide plate 222 ... Second light source

223 ... 2nd PDLC

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device capable of displaying an image in both front and rear directions of a liquid crystal panel using one transmissive liquid crystal panel and a mobile communication terminal having the same.

In general, CRT (or CRT: Cathode Ray Tube) has been the most used screen display device for displaying image information on the screen, which is inconvenient to use because it is bulky and heavy compared to the display area. Followed.

Accordingly, a thin film type flat panel display device having a small display area that can be easily used in any place even though the display area is large has been developed, and is gradually replacing the CRT display device. In particular, the liquid crystal display device has superior display resolution than other flat panel display devices, and exhibits a fast response speed as compared with CRTs when a moving image is realized.

As is known, the driving principle of the liquid crystal display device utilizes the optical anisotropy and polarization properties of the liquid crystal. Since the liquid crystal is thin and long in structure, the direction of the molecular arrangement can be controlled by artificially applying an electric field to the liquid crystal molecules having directionality and polarization in the molecular arrangement. Therefore, if the alignment direction is arbitrarily adjusted, light may be transmitted or blocked according to the alignment direction of the liquid crystal molecules by optical anisotropy of the liquid crystal, thereby displaying colors and images.

The active matrix liquid crystal display device adds an active element having a nonlinear characteristic to each pixel arranged in a matrix form, and controls the operation of each pixel by using the switching characteristics of the element. The memory function is implemented through.

On the other hand, in recent years, a variety of researches on a bidirectional display device (dual display) that can display the image in both the front and rear, the liquid crystal display device.

It is an object of the present invention to provide a liquid crystal display device which can display an image in both front and rear directions of a liquid crystal panel using one transmissive liquid crystal panel.

Another object of the present invention is to provide a thin mobile communication terminal capable of displaying images in both directions by using a liquid crystal display device employing one transmissive liquid crystal panel.

In order to achieve the above object, a liquid crystal display device according to the present invention, a transmissive liquid crystal panel; Located in the front portion of the transmissive liquid crystal panel to supply light for displaying an image, the first light guide plate, the first light source disposed on the first light guide plate, and all the incident light provided on the first light guide plate reflects or A first light source supply having a first light adjusting means for transmitting all of the light; Located in the rear portion of the transmissive liquid crystal panel to supply light for displaying an image, and reflects or transmits a second light guide plate, a second light source disposed on the second light guide plate, and the incident light provided under the second light guide plate A second light source supply unit having a second light adjusting means to make a light source; Its features are to include.

In addition, another example of the liquid crystal display device according to the present invention in order to achieve the above object, a transmissive liquid crystal panel; Located in the front portion of the transmissive liquid crystal panel to supply light for displaying an image, the first light guide plate, the first light source disposed on the first light guide plate, and all the incident light provided on the first light guide plate reflects or A first light source supply having a first light adjusting means for transmitting all of the light; Located in the rear portion of the transmissive liquid crystal panel to supply light for displaying an image, the second light guide plate, the second light source disposed on the second light guide plate, and the incident light provided under the second light guide plate to reflect all or A second light source supply having a second light adjusting means for transmitting all of the light; And a first display mode for displaying an image on a front surface of the transmissive liquid crystal panel using light provided from the second light source supply unit and the transmissive liquid crystal using light provided from the first light source supply unit. The characteristic is that the image is displayed in both directions of the second display mode of displaying the image on the rear surface of the panel.

In addition, the mobile communication terminal according to the present invention in order to achieve the above another object, a transmissive liquid crystal panel; Located in the front portion of the transmissive liquid crystal panel to supply light for displaying an image, reflecting or transmitting a first light guide plate, a first light source disposed on the first light guide plate, and the incident light provided on the first light guide plate A first light source supply unit having a first light adjusting means to make a light source; Located in the rear portion of the transmissive liquid crystal panel to supply light for displaying an image, and reflects or transmits a second light guide plate, a second light source disposed on the second light guide plate, and the incident light provided under the second light guide plate A liquid crystal display device having a second light source supply unit having a second light control means for controlling the communication device. The communication means for performing communication with the outside. The control unit controls an image display of the communication means and the liquid crystal display device. Has its features.

According to the present invention, there is an advantage that it is possible to provide a liquid crystal display device for displaying an image in both the front direction and the rear direction of the liquid crystal panel using one transmissive liquid crystal panel.

In addition, according to the present invention, by using a liquid crystal display device employing one transmissive liquid crystal panel, there is an advantage that it is possible to provide a thin mobile communication terminal capable of displaying images in both directions.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a view schematically showing the configuration of a liquid crystal display according to the present invention.

As shown in FIG. 1, the liquid crystal display according to the present invention includes a transmissive liquid crystal panel 100, a first light source supply unit 210 and a second light source supply unit 220 for supplying light for displaying an image, and the first light source. And a micro lens sheet 160 for receiving light from the light source supply unit 210 and condensing the incident light on the transmissive liquid crystal panel 100.

The first light source supply unit 210 may include a first light guide plate 211 for guiding light propagation, a first light source 212 disposed on a side surface of the first light guide plate 211, and the first light guide plate ( The first light control means, for example, the first polymer-dispersed liquid crystal (PDLC), which is provided on the upper portion 211 to reflect or mostly transmit the incident light.

In addition, the second light source supply unit 220 may include a second light guide plate 221 for guiding light propagation, a second light source 222 disposed on a side of the second light guide plate 221, and the second light guide plate ( The second light adjusting means, for example, the second polymer-dispersed liquid crystal (PDLC) which is provided below the 221 and mostly reflects or mostly transmits incident light.

The PDLC (Polymer-Dispersed Liquid Crystal) has been proposed in several kinds of structures such as a large number of liquid crystal molecular grains dispersed in a polymer or a liquid crystal contained in a reticulated polymer. . As illustrated in FIGS. 2 and 3, the PDLC 190 transmits incident light when a voltage is applied between the first transparent electrode 191 and the second transparent electrode 192. When no voltage is applied between the first transparent electrode 191 and the second transparent electrode 192, the incident light is reflected. In this case, the PDLC 190 diffusely reflects incident light when a voltage is not applied. Reference numeral 193 denotes a polymer binder, and reference numeral 195 denotes a liquid crystal, respectively.

In the liquid crystal display according to the present invention, a first light source supply unit 210 is provided at a front side of the transmissive liquid crystal panel 100, and a second light source supply unit 220 is provided at a rear side of the transmissive liquid crystal panel 100. Accordingly, the front and rear parts of the transmissive liquid crystal panel 100 can display images in both directions.

That is, the liquid crystal display according to the present invention provides a first display mode in which an image is displayed on the front surface of the transmissive liquid crystal panel 100 by using light provided from the second light source supply unit 220. In addition, the liquid crystal display according to the present invention provides a second display mode for displaying an image on the rear surface of the transmissive liquid crystal panel 100 by using the light provided from the first light source supply unit 210.

In addition, the liquid crystal display according to the present invention is characterized by including the micro lens sheet 160 on the transmissive liquid crystal panel 100.

The micro lens sheet 160 receives light from the first light source supply unit 210 and condenses the incident light to an opening of a pixel region of the transmissive liquid crystal panel 100. . The micro lens sheet 160 is a transparent film having a micro structure in a pixel unit, and serves as a micro lens array.

Here, the opening indicates a region where the black matrix 121 of the second substrate 120 constituting the transmissive liquid crystal panel 100 is not formed, and the transmissive electrode 111 is formed in the region of the first substrate 110 corresponding to the opening. ) Is provided.

Although not clearly shown in the drawings, the transmissive electrode 111 is formed for each pixel that is the minimum unit for implementing the screen. In addition, the transmission electrode 111 is applied with a voltage by a switching element, for example, a thin film transistor that controls the voltage on / off, thereby controlling the light transmittance in the liquid crystal layer 130.

According to the present invention, the micro lens sheet 160 is provided above the transmissive liquid crystal panel 100 so that the entire light incident on the transmissive liquid crystal panel 100 can be focused and incident on each opening region. do. Accordingly, according to the present invention, it is possible to utilize the light incident more efficiently than the conventional transmissive liquid crystal panel, and as a result, it is possible to improve the brightness of displaying the image. That is, according to the present invention, it is possible to increase the number of the light source provided in the first light source supply unit 210 or not to increase the power applied to the light source, thereby improving the luminance without increasing the power consumption. do.

In addition, the micro lens sheet 160 performs a function of condensing the light incident from the external light source into the opening of the transmissive liquid crystal panel 100 by the same principle.

The micro lens sheet 160 may be formed in the shape of a lenticular lens in the form of a stripe, or may be formed in the shape of a cylindrical lens.

In addition, the micro lens sheet 160 may be configured such that a lens shape is formed at a position corresponding to each pixel unit constituting the transmissive liquid crystal panel 100. When the micro lens sheet 160 having the lens shape is applied to each pixel unit as described above, the position of the unit lens must be aligned to correspond to each pixel area, so that the micro lens sheet 160 is attached on the second polarizing plate 150. There is a higher degree of alignment is required in the process as compared to the other examples. Here, each unit lens provided in the micro lens sheet 160 may be formed in a spherical or aspheric shape. In addition, each unit lens may be formed in a decenter lens shape.

The transmissive liquid crystal panel 100 includes a first substrate 110, a second substrate 120, a liquid crystal layer 130, a first polarizing plate 140, and a second polarizing plate 150. Since details of each of the above components are already well known, only a brief description will be provided herein.

The first substrate 110 includes an array element having a thin film transistor and a transmission electrode 111 formed on the array element to transmit incident light to display an image. The array device may include a plurality of gate lines formed in a first direction, a plurality of data lines formed in a direction perpendicular to the gate line, a pixel region divided by the gate lines and data lines, and a plurality of gate lines and data lines. It comprises a thin film transistor formed in the intersection area.

In addition, the second substrate 120 is provided at a position opposite to the first substrate 110, and a color filter formed at a corresponding position in a region where the transmissive electrode 111 of the first substrate 110 is formed. 123, a black matrix 121 formed between the color filter 123, and a common electrode (not shown) formed under the color filter 123.

The liquid crystal layer 130 is filled between the first substrate 110 and the second substrate 120, and a first polarizing plate is disposed below the first substrate 110 and above the second substrate 120. 140 and the second polarizing plate 150 are provided, respectively.

Then, in the liquid crystal display device having such a configuration, a process of displaying an image on the front part and the rear part of the transmissive liquid crystal panel will be described with reference to FIGS. 4 to 6. Here, the description will be made based on the case where PDLC is applied as a light adjusting means for reflecting or transmitting incident light.

First, a case in which an image is displayed on the rear surface of the liquid crystal panel using light provided from the first light source supply unit 210 will be described with reference to FIG. 4.

In the liquid crystal display according to the present invention, as illustrated in FIG. 4, an image is displayed on the rear surface of the transmissive liquid crystal panel 100 by using light provided from the first light source 212 of the first light source supply unit 210. I can display it.

The light emitted from the first light source 212 is propagated along the first light guide plate 211. At this time, the first PDLC 213 is controlled so that no power is applied. Accordingly, the first PDLC 213 is in a state of reflecting incident light, and reflects light propagating along the first LGP 211 toward the transmissive liquid crystal panel 100. In this case, the first PDLC 213 diffuses the incident light to be incident toward the transmissive liquid crystal panel 100, and such diffuse reflection can provide more advantageous results in terms of reflectance than when total reflection is performed. do.

In addition, the light reflected by the first PDLC 213 is collected by the micro lens sheet 160 in the opening of the pixel region constituting the transmissive liquid crystal panel 100 and transmitted. At this time, by controlling the power to be applied to the second PDLC 223, it may be in a state of transmitting the incident light. Accordingly, an image may be displayed on the rear surface of the transmissive liquid crystal panel 100.

Here, the first light source 212 provided on the side of the first light source supply unit 210 may be composed of LED. The LED may be configured as a white LED, or may be configured as a red LED / green LED / blue LED. In addition, the first light source 212 may be configured as a cold cathode fluorescent lamp (CCFL) or an external electrode fluorescent lamp (EEFL).

Next, a case in which an image is displayed on the front side of the liquid crystal panel using light provided from the second light source supply unit 220 will be described with reference to FIG. 5.

In the liquid crystal display according to the present invention, as illustrated in FIG. 5, an image is formed on the front surface of the transmissive liquid crystal panel 100 using light provided from the second light source 222 of the second light source supply unit 220. Can be displayed.

The light emitted from the second light source 222 is propagated along the second light guide plate 221. In this case, the second PDLC 223 controls not to apply power. Accordingly, the second PDLC 223 is in a state of reflecting incident light, and reflects light propagating along the second LGP 221 toward the transmissive liquid crystal panel 100.

The first PDLC 213 may be controlled so that power is applied to the first PDLC 213 so as to transmit incident light. Accordingly, an image may be displayed on the front surface of the transmissive liquid crystal panel 100.

In addition, as shown in FIG. 6, the liquid crystal display according to the present invention may display an image on a front surface of the transmissive liquid crystal panel 100 using light provided from an external light source such as the sun or an ambient lighting device (see FIG. 6). At this time, the first PDLC 213 is powered to be in a transparent state, the power is not applied to the second PDLC 223 is in an opaque state).

Although not shown in the drawings, the liquid crystal display according to the present invention may display an image on the rear surface of the transmissive liquid crystal panel 100 using light provided from the external light source (in this case, the first PDLC ( 213 and the second PDLC 223 are powered and are in a transparent state).

That is, even when the first light source 212 and the second light source 222 are in an OFF state, images may be displayed in both directions of the transmissive liquid crystal panel 100 using light incident from an external light source. Can be. At this time, the surrounding light is collected by the micro lens sheet 160 to the opening region of the transmissive liquid crystal panel 100 and may be incident, thereby increasing the luminance of the displayed image.

On the other hand, the liquid crystal display device having such a configuration can be utilized as a double-sided display device. Accordingly, when the liquid crystal display device according to the present invention is applied to a mobile communication terminal (mobile portable communication, PDA, etc.), it is possible to display images in both directions of the front part and the rear part of the liquid crystal panel. The video display function can be implemented.

For example, when the liquid crystal display device according to the present invention is applied to a mobile communication terminal equipped with a digital camera function, several users can simultaneously view a picture screen of the same screen size and the same resolution in both directions of the mobile communication terminal. There is usefulness to become.

According to the liquid crystal display device according to the present invention as described above, there is an advantage that the image can be displayed in both the front direction and the rear direction of the liquid crystal panel using one transmissive liquid crystal panel.

In addition, the mobile communication terminal according to the present invention has an advantage of providing a thin mobile communication terminal capable of displaying images in both directions by using a liquid crystal display device employing one transmissive liquid crystal panel. For example, since the PDLC can be manufactured to a thickness of 0.9 mm or less, according to the present invention, the thickness of the PDLC can be made thinner than 4.0 mm when the LCD module for bidirectional image display is manufactured.

Claims (20)

Transmissive liquid crystal panel; Located in the front portion of the transmissive liquid crystal panel to supply light for displaying an image, reflecting or transmitting a first light guide plate, a first light source disposed on the first light guide plate, and the incident light provided on the first light guide plate A first light source supply unit having a first light adjusting means to make a light source; Located in the rear portion of the transmissive liquid crystal panel to supply light for displaying an image, and reflects or transmits a second light guide plate, a second light source disposed on the second light guide plate, and the incident light provided under the second light guide plate A second light source supply unit having a second light adjusting means to make a light source; Liquid crystal display comprising a. Transmissive liquid crystal panel; Located in the front portion of the transmissive liquid crystal panel to supply light for displaying an image, reflecting or transmitting a first light guide plate, a first light source disposed on the first light guide plate, and the incident light provided on the first light guide plate A first light source supply unit having a first light adjusting means to make a light source; Located in the rear portion of the transmissive liquid crystal panel to supply light for displaying an image, and reflects or transmits a second light guide plate, a second light source disposed on the second light guide plate, and the incident light provided under the second light guide plate A second light source supply unit having a second light adjusting means to make a light source; It is configured to include, A first display mode for displaying an image on the front side of the transmissive liquid crystal panel using light provided from the second light source supply unit and an image on the rear side of the transmissive liquid crystal panel using light provided from the first light source supply unit. And an image in both directions of a second display mode for displaying. The method according to claim 1 or 2, And the first light source and the second light source are selected from LEDs, cold cathode fluorescent lamps (CCFL) or external electrode fluorescent lamps (EEFL). The method according to claim 1 or 2, And the first light source and the second light source are composed of white LEDs. The method according to claim 1 or 2, The first light source and the second light source is a liquid crystal display comprising a red LED, a green LED, a blue LED. The method according to claim 1 or 2, The transmissive liquid crystal panel, A first substrate having an array element having a thin film transistor and a transmissive electrode formed on the array element to transmit incident light to display an image; A second substrate provided at an opposite position of the first substrate and having a color filter formed at a corresponding position of a region where the transmissive electrode of the first substrate is formed and a black matrix formed between the color filters; A liquid crystal layer filled between the first substrate and the second substrate; Liquid crystal display comprising a. The method of claim 6, The array device, A plurality of gate lines formed in a first direction; A plurality of data lines formed in a direction perpendicular to the gate line; A pixel region divided by the gate line and the data line; A thin film transistor formed at an intersection of the gate line and the data line; Liquid crystal display comprising a. The method of claim 6, The second substrate further comprises a common electrode formed under the color filter. The method according to claim 1 or 2, And a microlens sheet for receiving light from the first light source supply unit and condensing the incident light onto the transmissive liquid crystal panel. The method according to claim 1 or 2, And a microlens sheet for receiving light from the first light source supply unit and condensing the incident light in an opening of an area of the transmissive liquid crystal panel. The method of claim 9, And the micro lens sheet condenses incident light into an opening of the transmissive liquid crystal panel, and the opening is an area where no black matrix forming the transmissive liquid crystal panel is formed. The method of claim 9, The micro lens sheet is formed in the shape of a lenticular lens (cylindrical lens) or a cylindrical lens (cylindrical lens). The method of claim 9, The micro lens sheet has a lens shape formed at a position corresponding to each pixel unit constituting the transmissive liquid crystal panel. The method of claim 13, And wherein the lens shape is selected from spherical or aspherical or decenter lens shapes. The method according to claim 1 or 2, And the first light control means and the second light control means comprise a polymer-dispersed liquid crystal (PDLC). The method of claim 15, The PDLC transmits incident light when a voltage is applied and reflects incident light when a voltage is not applied. The method of claim 16, And the PDLC diffusely reflects the reflected light when no voltage is applied. The method of claim 15, When light is provided from the first light source, no voltage is applied to the PDLC provided in the first light source supply unit, and a voltage is applied to the PDLC provided in the second light source supply unit, the rear portion of the transmissive liquid crystal panel Liquid crystal display device characterized in that the image is displayed. The method of claim 15, When light is provided from the second light source, no voltage is applied to the PDLC provided in the second light source supply unit, and a voltage is applied to the PDLC provided in the first light source supply unit, the front part of the transmissive liquid crystal panel An image is displayed on the liquid crystal display device. The liquid crystal display device according to claim 1 or 2; Communication means for performing communication with the outside; A control unit controlling image display of the communication means and the liquid crystal display device; Mobile communication terminal comprising a.

Images