KR100875186B1 - Display - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device, wherein a gate line and a data line formed to define a pixel region, a thin film transistor formed at an intersection of the gate line and the data line, and controlled by switching of the thin film transistor, Gallium Dioxide (GaAs), Gallium Phosphate (GaP), Gallium-arsenic-phosphorus (GaAs1-x Px), Gallium-Aluminum-arsenic (Ga1-xAlxAs), Indium Phosphate (InP), Indium-Gallium-phosphorus (ln1-xGaxP) And a common line for grounding the cathode of the light emitting diode, and a light emitting diode comprising at least one compound semiconductor.

Description

Display device

1 is a schematic perspective view of a liquid crystal display of a general transmissive TN mode.

2 is a schematic circuit diagram of a liquid crystal display.

3 is a schematic circuit diagram of a display device according to the present invention.

4 is a cross-sectional view of the display device of the present invention.

5 is a schematic plan view of a display device of the present invention.

6A to 6E are cross-sectional views of manufacturing a display device according to the present invention.

* Description of the main parts of the drawings *

101: gate line 103: data line

105: thin film transistor 107: light emitting diode

109: common line 111: microlens

113 substrate 115 gate electrode

117: gate insulating film 119: active layer

121a and 121b: source / drain electrodes 123: first passivation layer

125 transparent electrode 127 second protective film

129: reflective electrode 131: insulating film

133: pixel area 135: block                 

137: fixed panel 139: gap

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device, and more particularly, to a display device capable of increasing light efficiency by configuring an active matrix display device using a light emitting diode.

Recently, due to the rapid development of the information and communication field, the importance of the display industry for displaying desired information is increasing day by day, and to date, CRT (cathod ray tube) among information display devices can display various colors and display brightness It has also enjoyed steady popularity so far because of its superiority.

However, there is an urgent need for the development of flat panel displays instead of CRTs that are bulky and bulky due to the desire for large, portable and high resolution displays. These flat panel displays have a wide range of applications from computer monitors to displays used in aircraft and spacecraft.

Currently produced or developed flat panel displays include liquid crystal display (LCD), electro luminescent display (ELD), field emission display (FED), plasma display panel (PDP), etc. In order to achieve an ideal flat panel display, light weight, high brightness, high efficiency, high resolution, high speed response characteristics, low driving voltage, low power consumption, low cost, cost, and color display characteristics are required. Among such flat panel displays, the liquid crystal display device is in the spotlight because of its durability as well as its desire.

A liquid crystal display device is an image display device using optical anisotropy characteristics of liquid crystals. When light is irradiated onto liquid crystals having polarization characteristics according to an applied state of a liquid crystal, the amount of light passing through the liquid crystal display according to the alignment state of the liquid crystals is applied. It is a device that can control and express an image.

As described above, in order to configure the liquid crystal display device, a liquid crystal panel including a liquid crystal formed between two substrates and a driving circuit provided around the liquid crystal panel to apply a signal to the liquid crystal panel and control such a signal are required. Do.

In this case, since the liquid crystal panel does not emit light by itself, the reflective liquid crystal display device is restricted from being used in a dark space when it is reflected from the liquid crystal panel using external light such as sunlight.

Accordingly, the transmissive liquid crystal display device may solve a problem of space limitation by providing a separate backlight under the liquid crystal panel and irradiating parallel rays.

Hereinafter, a liquid crystal display of a general transmissive TN mode will be described with reference to the drawings.

1 is a schematic perspective view of a liquid crystal display of a general transmissive TN mode.

As shown in FIG. 1, the liquid crystal display device includes a liquid crystal panel 10 formed of an upper substrate 11 and a lower substrate 12 for displaying color, and a liquid crystal layer 13 formed between the two substrates. And first and second polarizing plates 14 and 15 disposed to be perpendicular to each other above and below the liquid crystal panel 10.

Although not shown, the liquid crystal panel 10 has a backlight including a light guide plate, a reflecting plate, a diffusion plate, and a prism sheet for transmitting light emitted from a light source such as a fluorescent lamp.

Here, the lower substrate 12 is also called an array substrate, and a thin film transistor (not shown), which is a switching element, and a pixel electrode (not shown) for displaying an image are formed in a matrix type.

The upper substrate 11 is also referred to as a color filter substrate, and has a black matrix for preventing light leakage to the outside of the pixel region, and colors of R (red), G (green), and B (blue) corresponding to the pixel electrodes. And a common electrode (not shown) on the black matrix and the color filter.

Pixel electrodes (not shown) and common electrodes (not shown) respectively formed on the lower substrate 12 and the upper substrate 11 are indium-tin oxides for transmitting light emitted from the backlight. -oxide: It is composed of transparent conductive metal such as ITO). In this case, in the IPS mode liquid crystal display, the common electrode is formed on the lower substrate.

At this time, the liquid crystal molecules 18 of the liquid crystal layer 13 formed between the upper substrate 11 and the lower substrate 12 are lowered by an alignment layer (not shown) respectively formed on the surfaces of the two substrates facing each other. The azimuth angle is twisted 90 degrees from the board | substrate 12 to the said upper board | substrate 11, and is oriented.

On the other hand, the first and second polarizing plates 14 and 15 have the characteristic that the polarization direction is vertical.

That is, white light irradiated from the backlight is polarized in one direction by the first polarizing plate 14, and the light polarized by the first polarizing plate 14 is refracted by the lower substrate 12 and the liquid crystal layer 13. do.

At this time, as shown, the light incident on the liquid crystal layer 13 is refracted to be orthogonal to the direction polarized by the first polarizing plate 14 by rotating the azimuth angle by 90 degrees by the twisting of the liquid crystal molecules 18. . As such, the intensity of transmitted light may be adjusted by adjusting the azimuth or polar angle of the liquid crystal molecules 18 in the liquid crystal layer 13.

In addition, the white light refracted by the liquid crystal layer 13 passes through the upper substrate 11 on which a color filter (not shown) capable of expressing an RGB color is formed, and the upper substrate 11 has a color. Light passes through the second polarizing plate 15 and is represented as an image.

Accordingly, the liquid crystal display device may implement an image by controlling the light incident from the light source as the light receiving element and controlling the light incident from the light source to the color filter by the twist angle of the liquid crystal molecules.

2 is a schematic circuit diagram of a liquid crystal display device, in which a thin film transistor 7 and a gate line 16 formed at a portion where gate lines 16 and data lines 17 perpendicular to each other cross each other. And a common line 9 formed at regular intervals in the same direction as the same direction, and a common electrode (not shown) having one side connected to the thin film transistor 7 and the other side connected to the common line 9. do.

Here, the common line 9 or the common electrode is formed on the same substrate or a separate substrate to induce an electric field according to the voltage (V _data ) of the data signal applied through the thin film transistor.

Although not shown, the display device further includes a storage capacitance formed between the drain electrode of the thin film transistor 7 and the gate line 16 to maintain the liquid crystal capacitor 8 for a predetermined time.

As a result, the liquid crystal display may realize a screen by changing the liquid crystal capacitor 8 by controlling the transmitted light by the switching operation of the thin film transistor 7.

However, such a liquid crystal display device has the following problems.

A liquid crystal display device is a light receiving element using transmitted light or reflected light, and has a disadvantage in that light efficiency is lowered because a screen is transmitted through a polarizing plate, a liquid crystal, and a color filter.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to provide a display device having high light efficiency by configuring pixels of an active matrix display device using a light emitting diode (LED).

The display device of the present invention for achieving the above object is a gate line and data line formed to define a pixel region, a thin film transistor formed at the intersection portion of the gate line and the data line, and switching by the thin film transistor Gallium arsenide (GaAs), gallium phosphide (GaP), gallium-arsenide-phosphorus (GaAs1-x Px), gallium-aluminum-arsenic (Ga1-xAlxAs), indium phosphide (InP), indium-gallium-phosphorus A light emitting diode comprising a compound semiconductor including at least one of (ln1-xGaxP), and a common line for grounding the cathode of the light emitting diode.

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In addition, another feature of the present invention is a substrate having a plurality of micro-lenses formed below, a gate electrode formed on the substrate, a gate insulating film formed on the front surface of the substrate on which the gate electrode is formed, and an island shape on the gate insulating film An active layer formed on the active layer, source / drain electrodes formed on both sides of the active layer, a first passivation layer formed on the substrate to expose the source / drain electrodes, a transparent electrode formed to be connected to the drain electrode, and on the transparent electrode. A light emitting diode formed on the substrate; a second passivation layer formed on the substrate to expose the source electrode and the light emitting diode; and a data line, a reflective electrode, and a common line for electrically connecting the source electrode and the light emitting diode, respectively. The micro lens protrudes from the bottom of the substrate. It is a display device.

The data line, the reflective electrode, and the common line are made of aluminum-based metal.

The transparent electrode is ITO.

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The display device includes a plurality of unit cells.

Further, another aspect of the present invention is to form a gate electrode on a flat substrate, to form a gate insulating film on the entire surface of the substrate on which the gate electrode is formed, and to the gate insulating film on the gate electrode Forming an active layer in an island shape, forming a source / drain electrode at both edges of the active layer, exposing a predetermined portion of the surface of the drain electrode to form a first protective film on the substrate; Forming a transparent electrode on the first passivation layer so as to be electrically connected to the drain electrode, forming a light emitting diode using a compound semiconductor on the transparent electrode, and exposing the surfaces of the source electrode and the light emitting diode. Forming a second passivation film on the substrate, the source electrode and the light emitting die A method of manufacturing a display device, the method comprising: forming a data line, a reflective electrode, and a common line electrically connecting an electrode; and forming a microlens by selectively etching a lower portion of the substrate on which the light emitting diode is formed.

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

3 is a schematic circuit diagram of a display device according to the present invention.

As shown in FIG. 3, the display device of the present invention includes a thin film transistor 105 formed at a portion where the gate line 101 and the data line 103 perpendicular to each other cross, and the same direction as the data line 103. And a common line 109 formed at regular intervals, and a light emitting diode 107 having an anode connected to the thin film transistor 105 and a cathode connected to the common line 109.

Although not shown, a gate IC and a data IC for applying a gate signal and a data signal to one side of each of the plurality of gate lines 101 and the data lines 103 are further included.

Here, the light emitting diode 107 generates a small number of carriers (electrons or holes) injected using a pn junction structure, and emits light by recombination thereof. Also

The light emitting diode 107 may emit visible light, and may be gallium arsenide (GaAs), gallium phosphide (GaP), gallium arsenide-phosphorus (GaAs1-x Px), and gallium aluminum arsenide (Ga1-xAlxAs). , A compound semiconductor such as indium phosphide (InP), indium-gallium-phosphorus (ln1-xGaxP), or the like.

Accordingly, in the display device of the present invention, a light emitting diode 107 using a compound semiconductor is formed, and a thin film transistor 105 is formed to control the light emitting diode 107.

4 is a cross-sectional view of the display device of the present invention.

As shown in FIG. 4, the display device of the present invention includes a substrate 113 having a microlens 111 formed thereon, a gate electrode 115 formed in a predetermined region on the substrate 113, and the gate electrode ( The gate insulating film 117 formed on the entire surface of the substrate 113 on which the 115 is formed, the active layer 119 formed by overlapping the gate electrode 115 in an island shape on the gate insulating film 117, and the active layer ( The first passivation layer 123 formed on the substrate 113 with contact holes to expose the source / drain electrodes 121a and 121b formed on both sides of the 119 and the source / drain electrodes 121a and 121b. And a transparent electrode 125 formed to be connected to the drain electrode 121b through the contact hole, a light emitting diode 107 formed in a predetermined region on the transparent electrode 125, the source electrode 121a, and the Has a contact hole to expose the light emitting diode 107 A second passivation layer 127 formed on the plate 113, a data line 103, a reflective electrode 129, which electrically connect the source electrode 121a and the light emitting diode 107 to each other through the contact hole; It comprises a common line 109.

The insulating layer 131 may be further included on the data line 103, the reflective electrode 129, and the common line 109.

On the other hand, when the light emitting diode 107 emits light using the aluminum metal having excellent reflectivity as the cathode of the light emitting diode 107 as the reflective electrode 129, the luminance is condensed toward the substrate 113. Height plays a role.

In addition, the transparent electrode 125 is an anode electrode of the light emitting diode 107 and transmits the light emitted by the light emitting diode 107 toward the substrate 113 using a conductive metal having a high transmittance such as ITO. Let's do it.

Accordingly, the display device of the present invention has a highly reflective reflecting electrode 129 on one side of the light emitting diode 107 controlled by the thin film transistor (105 in FIG. 3), and a light emitting diode 107 having the reflecting electrode 129 formed thereon. Since the transparent electrode 125 having a high transmittance is formed on the other side of the panel), the light emitted from the light emitting diode 107 can be focused in one direction, thereby improving light efficiency.

In particular, in the display device of the present invention, a microlens 111 is formed under the substrate 113 to increase luminance by expanding and dispersing point emission of the light emitting diode 107.

Therefore, since the light emission of the light emitting diode 107 is directly controlled and transmitted light is emitted to the portion protruding to the lower portion of the substrate 113, the viewing angle can be increased.

In addition, FIG. 5 is a schematic plan view of the display device of the present invention, in which the plurality of pixel areas 133 defined by the plurality of gate lines 101 and the data lines 103 are formed in one display device. The unit cell 135 is formed, and a plurality of unit cells 135 are gathered and arranged in a plane on the panel 137.

Although not illustrated, a gate driving IC and a data driving IC are formed at vertical edges of the panel 137, respectively, and each gate line 101 and data line 103 are formed at edges of the plurality of unit cells 135. TCP is formed as a means of electrically connecting).

That is, since the gaps 139 generated between the unit cell 135 and the unit cell 135 may be overlapped by the microlens 111, when the light emitting diode 107 emits light, May not recognize the division between the unit cell 135 and the unit cell 135.

Furthermore, in the display device of the present invention, since the data line 103 and the common line 109 are located at the outermost side of the substrate 113, the unit cells 135 are arranged in a separate panel 137 to form a tiling ( Easy to Tiling

Accordingly, the display device of the present invention can implement a large screen because the plurality of unit cells 135 can be aligned and tiled on the panel 137.

In this case, the TCP connecting the gate line 101 and the data line 101 between the unit cell 135 and the unit cell 135 is formed between the unit cell 135 and the unit cell 135. Alternatively, the unit cells 135 may be formed to protrude behind the edges of the unit cells 135.

The manufacturing method of the display device according to the present invention configured as described above will be described below.

6A to 6E are cross-sectional views of manufacturing a display device according to the present invention.

First, as shown in FIG. 6A, the display device of the present invention forms a gate electrode 115 protruding from a gate line (101 in FIG. 4) in one direction on a flat substrate 113, and the gate electrode 115. The gate insulating layer 117 is formed on the entire surface of the substrate 113 on which is formed.

As shown in FIG. 6B, a semiconductor layer is formed on the entire surface of the substrate 113 including the gate electrode 115, and the semiconductor layer is selectively removed through photo and etching processes. The active layer 119 is formed on the corresponding gate insulating layer 117, and a metal layer is deposited on the entire surface of the substrate including the active layer 119 and selectively removed to form source / drain electrodes at both edges of the active layer 119. 121a and 121b are formed to form a thin film transistor (105 in FIG. 3).

As illustrated in FIG. 6C, the first passivation layer 123 is formed on the entire surface of the substrate 113 including the thin film transistor 105, and the surface of the drain electrode 121b of the thin film transistor 105 is exposed to a predetermined portion. The first protective layer 123 may be selectively removed to form a first contact hole. Subsequently, after the transparent conductive metal such as ITO is deposited on the entire surface of the substrate 113 including the first contact hole, the transparent electrode is selectively removed to be electrically connected to the sound drain 121b through the first contact hole. Forms 125.

In this case, when the first passivation layer 123 is formed, not only the drain electrode 121b but also the source electrode 121a may also expose a predetermined portion of the surface.

As shown in FIG. 6D, gallium arsenide (GaAs), gallium phosphide (GaP), gallium arsenide-phosphorus (GaAs1-x Px), and gallium-aluminum arsenide (Ga1-xAlxAs) are formed on the transparent electrode 125. ), A compound semiconductor such as indium phosphide (InP), indium-gallium-phosphorus (ln1-xGaxP), or the like, and then a light emitting diode 107 is formed using photo and etching processes.

As shown in FIG. 6E, a second passivation layer 127 is formed on the substrate 113 on which the light emitting diode 107 is formed, and the surface of the source electrode 121a and the light emitting diode 107 are exposed. After selectively removing predetermined portions of the first and second passivation layers 123 and 127, a data line 103 is electrically connected to the source electrode 121a using a conductive metal having excellent reflectivity, and at the same time, the light emission is performed. The reflective electrode 129 and the common line 109, which are cathode electrodes of the diode 107, are formed.

In this case, an additional insulating layer 131 may be further formed and planarized on the substrate including the data line and the reflective electrode.

Finally, as shown in FIG. 6F, the lower portion of the substrate 113 on which the light emitting diode 107 is formed is selectively etched to form the microlens 111.

Accordingly, the display device of the present invention can condense the light emitted by the light emitting diode 107 by passing through the substrate 113 on which the microlens 111 is formed.

Since the display device of the present invention can be manufactured by the small size unit cell 135 and then tiled to implement a large display device, it is possible to secure equipment utilization and manufacturing process stability according to the trend of the large screen.

As a result, the display device of the present invention can increase the light efficiency by using the light emitting diode 107 as a light emitting element, and implements a large display device by tiling a plurality of unit cells 137 using the light emitting diode 107 as a pixel. This can increase productivity.

As described above, the display device of the present invention has the following effects.

The display device of the present invention can increase the light efficiency by forming a pixel of the active matrix display device using a light emitting diode.

Claims (11)

A gate line and a data line formed to define a pixel region, A thin film transistor formed at a portion where the gate line and the data line cross each other; Controlled by switching of the thin film transistor, gallium arsenide (GaAs), gallium phosphide (GaP), gallium-arsenide-phosphorus (GaAs1-x Px), gallium-aluminum-arsenic (Ga1-xAlxAs), indium phosphide (InP) ), A light emitting diode comprising a compound semiconductor containing at least one of indium-gallium-phosphorus (ln1-xGaxP), And a common line for grounding the cathode of the light emitting diode. delete delete A substrate having a plurality of micro lenses formed thereon; A gate electrode formed on the substrate; A gate insulating film formed on an entire surface of the substrate on which the gate electrode is formed; An active layer formed in an island shape on the gate insulating film; Source / drain electrodes formed on both sides of the active layer; A first passivation layer formed on the substrate to expose the source / drain electrodes; A transparent electrode formed to be connected to the drain electrode; A light emitting diode formed on the transparent electrode; A second passivation layer formed on the substrate to expose the source electrode and the light emitting diode; A data line, a reflective electrode, and a common line for electrically connecting each of the source electrode and the light emitting diode; And the micro lens protrudes below the substrate. The method of claim 4, wherein And the data line, the reflective electrode, and the common line are made of aluminum-based metal. The method of claim 4, wherein Labeling apparatus characterized in that the transparent electrode is ITO delete The method of claim 4, wherein And the display device is composed of a plurality of unit cells. The method of claim 8, And a means for electrically connecting the plurality of unit cells is TCP. The method of claim 8, And the unit cells are arranged in a separate fixed panel and tiled. Forming a gate electrode on a flat substrate; Forming a gate insulating film on an entire surface of the substrate on which the gate electrode is formed; Forming an active layer in an island shape on the gate insulating film above the gate electrode; Forming source / drain electrodes on both edges of the active layer; Forming a first passivation film on the substrate by exposing a predetermined portion of the surface of the drain electrode; Forming a transparent electrode on the first passivation layer to be electrically connected to the drain electrode; Forming a light emitting diode using a compound semiconductor on the transparent electrode; Forming a second passivation layer on the substrate by exposing the surfaces of the source electrode and the light emitting diode; Forming a data line, a reflective electrode, and a common line electrically connecting the source electrode and the light emitting diode; And selectively etching a lower portion of the substrate on which the light emitting diode is formed to form a microlens.

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