KR20060100864A - Liquid crystal device and mobile phone employing the same - Google Patents

Abstract

The present invention relates to a mobile communication terminal using a liquid crystal display device for providing light to an LCD panel using an organic electroluminescent element. The mobile communication terminal including an LCD panel includes a power supply unit, a first organic electroluminescent element, and a second organic electroluminescent element. The power supply unit generates a voltage having a predetermined magnitude. The first organic electroluminescent device displays a predetermined image using the voltage generated from the power supply. The second organic electroluminescent device provides light to the LCD panel according to the voltage generated from the power supply unit. The mobile communication terminal uses an organic electroluminescent device as a device for providing light to the LCD panel, the manufacturing cost can be reduced.

Organic electroluminescent device, mobile communication terminal, LCD, LCD, OLED

Description

Liquid crystal display and mobile communication terminal using same {LIQUID CRYSTAL DEVICE AND MOBILE PHONE EMPLOYING THE SAME}

1 is a block diagram illustrating a conventional mobile communication terminal.

FIG. 2A is a cross-sectional view of the liquid crystal display of FIG. 1.

2B and 2C are cross-sectional views illustrating the backlight of FIG. 2A.

3A is a block diagram illustrating a mobile communication terminal according to an embodiment of the present invention.

3B is a view illustrating the second organic EL device of FIG. 3A according to an exemplary embodiment of the present invention.

3C is a timing diagram illustrating scan signals according to an exemplary embodiment of the present invention.

4 illustrates a second organic electroluminescent device according to another exemplary embodiment of the present invention.

The present invention relates to a liquid crystal display device and a mobile communication terminal using the same. More particularly, the present invention relates to a liquid crystal display device for providing light to an LCD panel using an organic electroluminescent device and a mobile communication terminal using the same.

The mobile communication terminal not only conducts a call between the caller and the called party but also displays a predetermined image through the display element.

In general, a liquid crystal display (“LCD”) is used as a main display device, and an organic electroluminescent device (“”) is used as a sub display device. OLED ") is used.

1 is a block diagram illustrating a conventional mobile communication terminal.

Referring to FIG. 1, a conventional mobile communication terminal includes an LCD 100, an OLED 102, an LCD power supply 104, and an OLED power supply 106.

The LCD power supply 104 provides a power supply, for example, a voltage of 16V to the LCD 100.

OLED power supply 106 provides power to OLED 102, for example a voltage of 18V.

However, since the magnitudes of the voltages provided to the LCD 100 and the OLED 102 are different from each other, the conventional mobile communication terminal has a power supply unit 104 for the LCD 100 and a power supply unit 106 for the OLED 102. ) Had to be included separately.

As a result, the size of the conventional mobile communication terminal is bound to increase.

FIG. 2A is a cross-sectional view illustrating the liquid crystal display of FIG. 1, and FIGS. 2B and 2C are cross-sectional views illustrating the backlight of FIG. 2A.

Referring to FIG. 2A, the conventional LCD 100 includes an LCD panel 180 and a backlight 200.

The LCD panel 180 includes a lower polarizing film 202, an upper polarizing film 204, a lower glass substrate 206, an upper glass substrate 208, a color filter 210, a black matrix 212, and a pixel electrode 214. ), A common electrode 216, a liquid crystal layer 218, and a TFT array 220.

The color filter 210 includes color filters corresponding to red, green, and blue, and generates an image corresponding to red, green, or blue when light is applied.

The TFT array 220 switches the pixel electrode 214 as a switching element.

The common electrode 216 is an electrode which applies a voltage to the color filter 210 in common.

The pixel electrode 214 is an electrode that applies voltages to the red color filter, the green color filter, and the blue color filter, respectively.

The liquid crystal layer 218 is arranged in a predetermined pattern corresponding to the voltage difference between the pixel electrode 214 and the common electrode 216.

The backlight 200 generates plane light by using a cold cathode fluorescent lamp (CCFL) or a light emitting diode (LED).

Generally, the plane light is white light.

Referring to FIG. 2B, the backlight 200 is driven in a direct manner and includes a CCFL 230, a reflector 232, and a diffuser plate 234.

Light emitted from the CCFL 230 is totally reflected by the reflector 230 and is incident on the diffuser plate 234.

Subsequently, the diffuser plate 234 diffuses the light reflected from the reflector plate 230 to generate planar light as shown in FIG. 2B.

Referring to FIG. 2C, the backlight 200 is driven by an edge-light method, and includes a CCFL 240, a reflector 242, a reflective sheet 244, a light guide plate 246, and a diffuser plate 248. ).

The CCFL 242 is located at the side of the backlight 200 unlike FIG. 2B.

Light generated by the CCFL 242 is reflected by the reflecting plate 242 and the reflecting sheet 244, and then the reflected light is uniformly spread throughout the light guide plate 246 as shown in FIG. 2C.

Light uniformly diffused in the light guide plate 246 passes through the diffuser plate 248, resulting in plane light as shown in FIG. 2C.

Hereinafter, the light emission operation of the LCD 100 will be described in detail.

The backlight 200 provides the LCD panel 180 with planar light that is white light.

Subsequently, the TFT array 220 switches the pixel electrode 214.

Subsequently, a predetermined voltage difference is applied between the pixel electrode 214 and the common electrode 216, and as a result, the liquid crystal layer 218 is arranged corresponding to the red color filter, the green color filter, and the blue color filter, respectively.

In this case, the amount of light is adjusted while the plane light provided from the backlight 200 passes through the liquid crystal layer 218, and the plane light whose light amount is adjusted is provided to the color filter 210.

As a result, the color filter 210 implements an image with a predetermined gray scale.

Specifically, the red color filter, the green color filter, and the blue color filter form one pixel, and the red color filter, the green color filter, and the blue color filter implement a predetermined image by the combination of the light passing through. do.

As described above, in the conventional LCD 100, a predetermined image is implemented by passing light generated from the backlight 200 through the LCD panel 180.

In this case, since the CCFL or LED used as the backlight 200 is expensive, the manufacturing cost of the LCD 100 is also expensive.

In short, the conventional mobile communication terminal uses the LCD 100 using the backlight 200 as the main display element, so that the size is thick and the manufacturing cost is high.

Therefore, there is a need for a mobile communication terminal capable of reducing the manufacturing cost while reducing the size.

An object of the present invention is to provide an LCD for providing light to the LCD panel using an organic EL device for the backlight and a mobile communication terminal using the same.

In order to achieve the above object, the mobile communication terminal including the LCD panel according to an embodiment of the present invention includes a power supply, a first organic electroluminescent element and a second organic electroluminescent element. The power supply unit generates a voltage of a predetermined size. The first organic electroluminescent device displays a predetermined image using the voltage generated from the power supply. The second organic electroluminescent device provides light to the LCD panel according to the voltage generated from the power supply unit.

According to an exemplary embodiment of the present invention, an organic light emitting diode for backlight that provides light to an LCD panel includes data lines, scan lines, and subpixels. The data lines correspond to anodes, and positive voltages of the same magnitude are respectively applied. The scan lines correspond to cathodes. The subpixels are formed in regions where the data lines and the scan lines intersect. The subpixels emit full white light.

The liquid crystal display device and the mobile communication terminal using the same according to the present invention uses an organic EL device as a device for providing light to the LCD panel, the manufacturing cost can be reduced.

In addition, the mobile communication terminal according to the present invention provides power to both the LCD and the OLED through one power supply, it can be reduced in size.

Hereinafter, exemplary embodiments of a liquid crystal display and a mobile communication terminal using the same according to the present invention will be described in detail with reference to the accompanying drawings.

3A is a block diagram illustrating a mobile communication terminal according to an embodiment of the present invention.

Referring to FIG. 3A, the mobile communication terminal of the present invention includes a liquid crystal display 300 (hereinafter referred to as "LCD"), a first organic electroluminescent element 302 and a power supply 304.

The power supply unit 304 applies a power source, specifically, a voltage having a predetermined size, to the LCD 300 and the first organic EL device 302.

For example, the power supply unit 304 applies a voltage of 18V to the LCD 300 and the first organic EL device 302.

The LCD 300 is a first display element for displaying a predetermined image, and includes an LCD panel 306 and a second organic electroluminescent element 308.

The second organic electroluminescent element 308 generates full white light according to the voltage provided from the power supply 304, and the generated light is provided to the LCD panel 306.

That is, the second organic electroluminescent element 306 is a light emitting element for backlight.

Although not shown in FIG. 3A, the first organic EL device 302 includes a plurality of first sub pixels and an integrated circuit chip.

The first sub pixels are formed in regions where the first data lines and the second scan lines cross each other.

The integrated circuit chip includes a data driver and a first scan driver, and generates data signals and scan signals using a voltage applied from the power supply unit 304 as a driving voltage.

In detail, the data driver provides the data signals to the first data lines.

The first scan driver sequentially provides the scan signals to the first scan lines. The high logic voltage of the scan signals according to an embodiment of the present invention corresponds to a voltage applied from the power supply 304, and the low logic voltage is a ground voltage.

When the data signals are provided to the first data lines and the scan signals are provided to the first scan lines, the subpixels generate light having a predetermined wavelength.

As a result, the first organic electroluminescent element 302 is a second display element and displays a predetermined image.

In other words, the LCD 300 of the mobile communication terminal of the present invention uses a second organic electroluminescent element 308 as an element for providing light to the LCD panel 306, unlike the LCD of the conventional mobile communication terminal using a backlight. do.

In the case of the backlight, since light is generated using a cold cathode fluorescent lamp (CCFL) or a light emitting diode (LED), the manufacturing cost of the backlight is expensive.

On the other hand, since the second organic electroluminescent element 308 used in the present invention emits full white as described below, the manufacturing cost of the second organic electroluminescent element 308 is lower than that of the backlight.

In addition, in the conventional mobile communication terminal, the LCD power supply for the LCD and the OLED power supply for the organic electroluminescent device are separately required, but in the mobile communication terminal of the present invention, the second organic electroluminescent device 308 is used instead of the backlight. In this case, the LCD 300 and the first organic EL device 302 may be driven even by including only one power supply 304.

Therefore, the mobile communication terminal of the present invention can be made smaller in size than the conventional mobile communication terminal.

The LCD 300 including the second organic electroluminescent element 308 according to another exemplary embodiment of the present invention may be used for other devices using a display element in addition to the mobile communication terminal.

3B is a diagram illustrating the second organic EL device of FIG. 3A according to an exemplary embodiment of the present invention, and FIG. 3C is a timing diagram illustrating scan signals according to an exemplary embodiment of the present invention. 3B illustrates a panel of 5 (number of data lines) x 5 (number of scan lines) for convenience of description.

Referring to FIG. 3B, the second organic EL device 308 includes a panel 310 and a scan driver 312.

The panel 310 includes second subpixels E11 to E55 formed in regions where the second data lines D1 to D5 and the second scan lines S1 to S5 intersect.

Voltages provided from the power supply unit 304, for example, 18V, are respectively applied to the second data lines D1 to D5.

The scan driver 312 sequentially provides the scan signals PS1 to PS5 to the second scan lines S1 to S5 as shown in FIG. 3C. Here, the high logic voltage of each of the scan signals PS1 to PS5 is a voltage provided from the power supply 304.

Hereinafter, the light emission operation of the second sub pixels E11 to E55 will be described in detail.

In the high logic region of the first scan signal PS1, since the reverse voltage is applied to the subpixels E11 to E51 corresponding to the first scan line S1, the subpixels E11 to E51 do not emit light. .

On the other hand, in the low logic region of the first scan signal PS1, the subpixels E11 to E51 emit light because a forward voltage is applied to the subpixels E11 to E51.

However, since a voltage corresponding to 100% gray level (for example, 18V) is applied to the data lines D1 to D5, the subpixels E11 to E51 emit light in full white.

Subsequently, the second scan signal PS2 is provided to the second scan line S2, and the sub pixels E12 to E52 corresponding to the second scan line S2 are low logic of the second scan signal PS2. It emits full white in the area.

That is, the sub pixels E11 to E55 emit full white light in the low logic regions of the scan signals PS1 to PS5.

Light emitted in full white is provided to the LCD panel 306.

As a result, the LCD panel 306 displays a predetermined image.

In short, the LCD 300 of the present invention drives the LCD panel 306 using the second organic electroluminescent element 308 for the backlight.

Here, since the second organic electroluminescent element 308 always emits full white, the second organic electroluminescent element 308 has a simple structure as shown in FIG. 3B.

As a result, the manufacturing cost of the second organic electroluminescent element 308 becomes low, that is, the manufacturing cost of the LCD 300 becomes low.

4 illustrates a second organic electroluminescent device according to another exemplary embodiment of the present invention.

Referring to FIG. 4, voltages (eg, 18 V) provided from the power supply unit 304 are applied to the data lines D1 to D5, and the scan lines S1 to S5 are connected to ground, respectively. .

As a result, the sub pixels E11 to E55 always emit light in full white.

Scan lines PS1 to PS5 according to another embodiment of the present invention may be connected to an electrode having a first voltage instead of ground.

In this case, the difference between the voltage provided from the power supply unit 304 and the first voltage should be equal to or greater than the threshold voltage of the subpixels E11 to E55.

Preferred embodiments of the present invention described above are disclosed for purposes of illustration, and those skilled in the art having ordinary knowledge of the present invention will be able to make various modifications, changes, additions within the spirit and scope of the present invention, such modifications, changes and Additions should be considered to be within the scope of the following claims.

As described above, the liquid crystal display device and the mobile communication terminal using the same according to the present invention uses an organic electroluminescent element as a device for providing light to the LCD panel, there is an advantage that the manufacturing cost is reduced.

In addition, since the mobile communication terminal according to the present invention provides power to both the LCD and the OLED through one power supply, there is an advantage that the size thereof is reduced.

Claims (8)

In the mobile communication terminal comprising an LCD panel, A power supply unit generating a voltage having a predetermined magnitude; A first organic electroluminescent element for displaying a predetermined image using the voltage generated from the power supply unit; And And a second organic electroluminescent device for providing light to the LCD panel according to the voltage generated from the power supply unit. The mobile communication terminal of claim 1, wherein the second organic electroluminescent device provides full white light to the LCD panel according to a voltage generated from the power supply unit. The display device of claim 1, wherein the second organic electroluminescent device includes a plurality of subpixels formed in regions where data lines and scan lines intersect each other. And a voltage generated from the power supply unit is applied to the data lines. The mobile communication terminal of claim 3, wherein the second organic light emitting diode further comprises a scan driver configured to sequentially provide scan signals having the voltage as a high logic voltage to the scan lines. The mobile communication terminal of claim 3, wherein the scan lines are connected to ground. In the organic electroluminescent device for backlight providing light to the LCD panel, Data lines corresponding to anodes, to which voltages of the same magnitude are respectively applied; Scan lines corresponding to the cathode; And Sub-pixels formed in regions where the data lines and the scan lines cross each other, And the sub-pixels emit light in full white. The organic light emitting device of claim 6, further comprising a scan driver configured to sequentially provide scan signals to the scan lines. 7. The organic light emitting device of claim 6, wherein the scan lines are connected to ground.

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