KR20070026938A - Display apparatus - Google Patents

Abstract

A display device is provided to prevent a main display panel from reflecting a sub display panel by arranging a reflecting film having the same refractivity as that of a polarizer of the sub display panel under a light guide plate. A display device includes a light supply unit(200), a main display panel(300), a sub display panel(400), a receiving container(500), and a reflecting film. The light supply unit supplies light in two directions. The main display panel is located on a first plane of the light supply unit and displays a main image. The sub display panel is located on a second plane of the light supply unit, which is opposite to the first plane, and displays a sub image. The receiving container receives the light supply unit and has a first opening(510) corresponding to the sub display panel. The reflecting film is located between the light supply unit and the receiving container and has a second opening(610) corresponding to the first opening. The reflecting film has predetermined reflectivity. The sub display panel includes a polarizer, and the reflecting film has the same reflectivity as that of the polarizer.

Description

Display device {DISPLAY APPARATUS}

1 is an exploded perspective view illustrating a display device according to an exemplary embodiment of the present invention.

FIG. 2 is a combined cross-sectional view of the display device shown in FIG. 1.

3 is a perspective view illustrating the storage container and the reflective film illustrated in FIG. 1.

4 is a plan view illustrating the main display panel illustrated in FIG. 1.

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

100: display device 200: light supply unit

210: light source 220: light guide plate

230: first optical sheet 240: second optical sheet

300: main display panel 400: sub display panel

500: storage container 510: first opening

600: reflective film 610: second opening

The present invention relates to a display device, and more particularly, to a display device capable of improving appearance quality of an image displayed in both directions.

In general, portable electronic devices such as mobile communication terminals, digital cameras, and electronic organizers are provided with a display device for displaying an image. Various types of display devices may be used. However, due to the characteristics of portable electronic devices, a small and light flat panel display device is mainly used. In particular, a liquid crystal display device (LCD) which displays an image using liquid crystals (Liquid Crystal) is used. : LCD) is widely used. The liquid crystal display device is thinner and lighter than other display devices, and has an advantage of low driving voltage and low power consumption.

Such liquid crystal displays generally display images in only one direction. Recently, however, a two-way liquid crystal display device has been developed that displays the same image or different images in both directions, instead of displaying the image in only one direction.

A bidirectional liquid crystal display for displaying images in both directions includes a main liquid crystal display panel displaying a main image and a sub liquid crystal display panel displaying a sub image, and disposed between the main liquid crystal display panel and the sub liquid crystal display panel. A light supply unit for supplying light to the display panel and the sub liquid crystal display panel, and a storage container for storing the light supply unit. The storage container is formed of a metal material and has an opening corresponding to the sub liquid crystal display panel to supply light to the sub liquid crystal display panel.

In this case, a part of the light provided from the light supply unit toward the sub liquid crystal display panel is reflected by the metal storage container, and the other part is reflected by the polarizing plate of the sub liquid crystal display panel.

However, since the reflectance of the storage container and the reflectance of the polarizing plate are different from each other, when viewed from the main liquid crystal display panel side, there is a problem in that an appearance quality defect occurs in which the sub liquid crystal display panel region is faintly generated.

Accordingly, the present invention has been made in view of the above problems, and the present invention provides a display device capable of improving appearance quality of images displayed in both directions.

The display device according to an aspect of the present invention described above includes a light supply unit for supplying light in both directions, a main display panel, a sub display panel, a storage container, and a reflective film. The main display panel is disposed on the first surface of the light supply unit to display a main image. The sub display panel is disposed on a second surface opposite to the first surface of the light supply unit to display a sub image. The storage container accommodates the light supply unit and has a first opening corresponding to the sub display panel. The reflective film is disposed between the light supply unit and the storage container, has a second opening corresponding to the first opening, and has a predetermined reflectance.

The sub display panel includes a polarizer formed on a surface facing the light supply unit, and the reflective film has a reflectance substantially the same as that of the polarizer.

According to such a display device, the appearance quality of the image displayed in both directions can be improved.

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

1 is an exploded perspective view illustrating a display device according to an exemplary embodiment, and FIG. 2 is a combined cross-sectional view of the display device illustrated in FIG. 1.

1 and 2, a display device 100 according to an exemplary embodiment of the present invention may include a light supply unit 200, a main display panel 300, a sub display panel 400, a storage container 500, and Reflective film 600.

The light supply unit 200 is disposed between the main display panel 300 and the sub display panel 400 to supply light in both directions.

The light supply unit 200 includes a light source 210 for generating light, a light guide plate 220 for guiding light from the light source 210, a first optical sheet 230 and a light guide plate disposed on the light guide plate 220. And a second optical sheet 240 disposed below the 220.

The light source 210 is disposed on one side of the light guide plate 220 and generates light in response to a driving power source applied from the outside. The light source 210 includes one or more light emitting diodes (LEDs). Since the light emitting diode has a characteristic of emitting light within a predetermined angle range, a plurality of light emitting diodes are provided to allow uniform light to enter the light guide plate 220. The number of light emitting diodes may vary depending on the exit angle and the size of the light guide plate 220.

Alternatively, the light source 210 may be formed of a long cylindrical cold cathode fluorescent lamp (CCFL).

The light guide plate 220 guides a traveling path of the light incident from the light source 210, and changes the light incident in the form of a point light source into light in the form of a surface light source.

The light guide plate 220 is made of a transparent material to minimize the loss of light. For example, the light guide plate 220 is formed of a polymethyl methacrylate (PMMA) material.

In contrast, the light guide plate 220 may be formed of a polycarbonate (PC) material. Polycarbonate material has a lower hardness than polymethyl methacrylate material, but has excellent heat resistance. Therefore, when the light guide plate 220 made of polycarbonate is used, the thickness of the light guide plate 220 may be reduced.

A predetermined reflection pattern (not shown) for scattering reflection of light is formed on the bottom surface of the light guide plate 220. For example, the reflective pattern consists of a printing pattern or an uneven pattern. Light incident from the light source 210 into the light guide plate 220 is scattered and reflected by a reflection pattern, and light exceeding a specific critical angle is emitted through the top and bottom surfaces of the light guide plate 220.

The first optical sheet 230 is disposed above the light guide plate 220, that is, between the light guide plate 220 and the main display panel 300. The first optical sheet 230 improves luminance characteristics of light emitted from the light guide plate 220 toward the main display panel 300.

The first optical sheet 230 may include a diffusion sheet for diffusing light emitted from the light guide plate 220 to improve luminance uniformity. In addition, the first optical sheet 230 may include a prism sheet for concentrating the light emitted from the light guide plate 220 in the front direction to improve the front brightness of the light. In addition, the first optical sheet 230 may include a reflective polarizing sheet for increasing the brightness of the light by recycling the light in a manner that transmits the light satisfying a specific condition and reflects the remaining light.

The second optical sheet 240 is disposed under the light guide plate 220, that is, between the light guide plate 220 and the sub display panel 400. The second optical sheet 240 improves luminance characteristics of light emitted from the light guide plate 220 toward the sub display panel 400.

The second optical sheet 240 may include a diffusion sheet for diffusing light emitted from the light guide plate 220 to improve luminance uniformity. In addition, the second optical sheet 240 may include a prism sheet for condensing the light emitted from the light guide plate 220 in the front direction to improve the front brightness of the light. In addition, the second optical sheet 240 may include a reflective polarizing sheet that increases the brightness of the light by recycling the light in a manner of transmitting the light satisfying a specific condition and reflecting the remaining light.

The main display panel 300 is disposed on the first surface corresponding to the upper portion of the light supply unit 200. The main display panel 300 displays a main image by using light supplied from the light supply unit 200.

The main display panel 300 is formed of a first substrate 310, a second substrate 320 coupled to face the first substrate 310, and a first substrate 310 disposed between the first substrate 310 and the second substrate 320. 1 liquid crystal layer (not shown).

In addition, the main display panel 300 includes a first polarizing plate 330 formed on the outer surface of the first substrate 310 and a second polarizing plate 340 formed on the outer surface of the second substrate 320. The first polarizing plate 330 and the second polarizing plate 340 transmit only the light oscillating in the direction coinciding with the transmission axis, and the light oscillating in the remaining direction reflects or absorbs the light.

The sub display panel 400 is disposed on a second surface opposite to the first surface of the light supply unit 200. The sub display panel 400 displays a sub image using light supplied from the light supply unit 200.

The sub display panel 400 may include a third substrate 410, a fourth substrate 420 coupled to face the third substrate 410, and a third substrate 410 disposed between the third substrate 410 and the fourth substrate 420. 2 liquid crystal layer (not shown).

In addition, the sub display panel 400 includes a third polarizer 430 formed on the outer surface of the third substrate 410 and a fourth polarizer 440 formed on the outer surface of the fourth substrate 420. The third polarizer 430 and the fourth polarizer 440 transmit only light that vibrates in a direction coinciding with the transmission axis, and light that vibrates in the other direction reflects or absorbs light.

The storage container 500 accommodates the light supply unit 200 and is formed of a metal material. The storage container 500 has a first opening 510 corresponding to the sub display panel 400. Light emitted downward from the light supply unit 200 is supplied to the sub display panel 400 through the first opening 510.

The reflective film 600 is disposed between the light supply unit 200 and the storage container 500. The reflective film 600 may include a second opening corresponding to the first opening 510 of the storage container 500 so that light emitted downward from the light supply unit 200 may be supplied to the sub display panel 400. 610.

The reflective film 600 has substantially the same reflectance as the third polarizing plate 430 of the sub display panel 400 facing the light supply unit 200. Among the light emitted from the light supply unit 200 in a downward direction, part of the light corresponding to the area of the sub display panel 400 is reflected by the third polarizer 430, except for the area of the sub display panel 400. Light corresponding to the area is reflected by the reflective film 600. In this case, since the light reflectance of the reflective film 600 is substantially the same as the light reflectance of the third polarizing plate 430, the amount of light reflected in the direction of the main display panel 300 becomes uniform over the entire area. Therefore, the phenomenon in which the area of the sub display panel 400 is reflected in the main display panel 300 is removed, thereby improving appearance quality.

3 is a perspective view illustrating the storage container and the reflective film illustrated in FIG. 1.

1 and 3, the storage container 500 may include a bottom surface 520 that covers the second surface of the light supply unit 200, that is, a bottom part 520, and a side part that covers the side surface of the light supply unit 200. 530).

The sub display panel 400 is disposed on an outer surface of the bottom part 520 of the storage container 500. Accordingly, a first opening 510 corresponding to the sub display panel 400 is formed at the bottom 520 so that the light from the light supply unit 200 can be supplied to the sub display panel 400.

The reflective film 600 is disposed on the bottom portion 520 of the storage container 500 and has a second opening 610 corresponding to the first opening 510.

Although not shown, the reflective film 600 is attached to the bottom 520 of the storage container 500 through an adhesive member such as a double-sided tape. In contrast, an adhesive layer for attaching to the bottom part 520 may be integrally formed on the bottom surface of the reflective film 600.

4 is a plan view illustrating the main display panel illustrated in FIG. 1.

1 and 4, the main display panel 300 includes a first substrate 310, a second substrate 320 coupled to the first substrate 310, and a first substrate 310 and a second substrate. It includes a first liquid crystal layer (not shown) disposed between the substrate 320.

The main display panel 300 is substantially divided into a display area DA displaying an image and a peripheral area PA surrounding the display area DA.

In response to the display area DA, a plurality of gate lines GL1 to GLn and a plurality of data lines DL1 to DLm intersecting the gate lines GL1 to GLn are formed on the first substrate 310. do. Where n and m are one or more natural numbers. The gate lines GL1 to GLn and the data lines DL1 to DLm are provided on different layers and cross each other insulated from each other.

In response to the display area DA, a plurality of thin film transistors (TFTs) and a plurality of pixel electrodes are formed in a matrix on the first substrate 310. For example, the gate electrode of the first thin film transistor TFT1 is connected to the first gate line GL1 of the gate lines GL1 to GLn, and the source electrode is the first data of the data lines DL1 to DLm. The drain electrode is connected to the line DL1 and the drain electrode is connected to the first pixel electrode 314.

In response to the peripheral area PA, a gate driving circuit 312 for driving the gate lines GL1 to GLn is formed in the first substrate 310. The gate driving circuit unit 312 includes a shift register composed of a plurality of driving transistors.

The gate driving circuit unit 312 sequentially outputs the gate driving signals to the gate lines GL1 to GLn in response to a gate control signal applied from the outside.

The gate driving circuit unit 312 is simultaneously formed by a thin film process for forming the gate lines GL1 to GLn, the data lines DL1 to DLm, and the thin film transistor.

The second substrate 320 includes a color filter layer (not shown) for realizing color and a common electrode (not shown) facing the pixel electrode of the upper substrate 310. Alternatively, the color filter layer may be formed on the first substrate 310.

The liquid crystal layer disposed between the first substrate 310 and the second substrate 320 is composed of liquid crystal molecules having electrical and optical characteristics such as anisotropic dielectric constant and anisotropic refractive index. For example, the liquid crystal layer is composed of twisted nematic liquid crystal molecules tilted at a predetermined angle by an electric field formed by the pixel electrode and the common electrode.

The main display panel 300 further includes a driving chip 350 mounted in the peripheral area PA of the first substrate 310. The driving chip 350 is electrically connected to the first substrate 310 through, for example, an anisotropic conductive film (ACF).

The driving chip 350 outputs a data driving signal to the data lines DL1 to DLm in response to a control signal applied from the outside.

When power is applied to the gate terminal of the thin film transistor and the thin film transistor is turned on, an electric field is formed between the pixel electrode and the common electrode. By the electric field, the arrangement of the liquid crystal molecules of the liquid crystal layer disposed between the first substrate 310 and the second substrate 320 is changed, and the transmittance of light is changed according to the arrangement of the liquid crystal molecules to display an image of a desired gray scale. Done.

Meanwhile, since the sub display panel 400 has a structure substantially similar to that of the main display panel 300, detailed description thereof will be omitted.

According to the display device, a reflective film having substantially the same reflectance as that of the polarizing plate of the sub display panel is disposed under the light guide plate, thereby improving appearance quality by eliminating the phenomenon of the sub display panel shining on the main display panel.

In the detailed description of the present invention described above with reference to a preferred embodiment of the present invention, those skilled in the art or those skilled in the art having ordinary knowledge in the scope of the invention described in the claims to be described later It will be understood that various modifications and variations can be made in the present invention without departing from the scope of the present invention.

Claims (5)

A light supply unit for supplying light in both directions; A main display panel disposed on a first surface of the light supply unit to display a main image; A sub display panel disposed on a second surface opposite to the first surface of the light supply unit to display a sub image; A storage container accommodating the light supply unit and having a first opening corresponding to the sub display panel; And And a reflective film disposed between the light supply unit and the storage container and having a second opening corresponding to the first opening and having a predetermined reflectance. The method of claim 1, The sub display panel includes a polarizer formed on a surface facing the light supply unit, And the reflective film has a reflectance substantially the same as that of the polarizing plate. The method of claim 2, wherein the storage container A bottom portion covering a second surface of the light supply unit; And It includes a side covering the side of the light supply unit, The first opening is formed in the bottom portion. The display device of claim 3, wherein the reflective film is attached to the bottom portion through an adhesive member. The method of claim 2, wherein the light supply unit A light source for generating light; A light guide plate for guiding light from the light source; A first optical sheet disposed on the light guide plate corresponding to the first surface; And And a second optical sheet disposed under the light guide plate corresponding to the second surface.

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