KR20160044161A - Display device - Google Patents

Abstract

According to one embodiment of the present invention, a display device includes a substrate, a display panel formed on the substrate and displaying an image, and a cooling unit in contact with a lower portion of the substrate to adjust a temperature of the substrate. When a temperature of the display device rises, the display device operates the cooling unit positioned in the lower portion of the substrate to prevent the temperature of the substrate or the like from being increased.

Description

Display device {DISPLAY DEVICE}

The present invention relates to a display device

Currently known display devices include a liquid crystal display (LCD), a plasma display panel (PDP), an organic light emitting diode (OLED) device, a field effect display display: FED, and electrophoretic display device.

In particular, an organic light emitting diode display includes two electrodes and an organic light emitting layer disposed therebetween. Electrons injected from one electrode and holes injected from the other electrode are combined in the organic light emitting layer to form excitons excitons are formed, and the excitons emit energy and emit light.

The organic light emitting display device has a self-luminance characteristic, and unlike a liquid crystal display device, a separate light source is not required, so that thickness and weight can be reduced. Further, organic light emitting display devices are attracting attention as next generation display devices because they exhibit high quality characteristics such as low power consumption, high luminance, and fast response speed.

On the other hand, in recent years, such a display device has been applied to flexible or foldable flexible display devices. In the flexible display device, a flexible film is used instead of a conventional glass substrate as the substrate for supporting the display panel.

However, such a flexible film can be deformed or cured by heat.

An embodiment of the present invention is to provide a display device capable of preventing a substrate or a display panel from being damaged by heat.

A display device according to an embodiment of the present invention may include a substrate, a display panel formed on the substrate to display an image, and a cooling unit contacting the bottom of the substrate to adjust the temperature of the substrate.

At this time, the cooling unit may include a plurality of thermoelectric elements.

At this time, each of the plurality of thermoelectric elements may have a bar shape extending in one direction.

At this time, the plurality of thermoelectric elements may be spaced apart from each other at equal intervals.

Meanwhile, the thermoelectric element may be located at the center of the substrate.

The plurality of thermoelectric elements may be arranged in a matrix form.

At this time, the thermoelectric element may be located at the center of the substrate.

The controller may further include a controller for controlling the cooling unit.

On the other hand, the substrate may be flexible.

The display panel may further include a cover member covering the display panel.

In this case, the cover member may include a sealing layer sealing the display panel and a window positioned on the sealing layer.

The apparatus may further include a support plate positioned below the plurality of thermoelectric elements and supporting the plurality of thermoelectric elements.

According to the display device of the embodiment of the present invention, when the temperature of the display device is raised, the cooling part located below the substrate is operated to prevent the temperature of the substrate and the like from rising. Thus, it is possible to prevent the substrate or the light emitting element from being deformed or hardened by heat.

1 is an equivalent circuit diagram of one pixel of an organic light emitting diode display.
2 is a cross-sectional view of an organic light emitting diode display.
3 is a schematic perspective view of a display device according to the first embodiment of the present invention.
4 is a cross-sectional view of the display device cut along the line IV-IV in FIG.
5 is a schematic perspective view of a display device according to a second embodiment of the present invention.
6 is a schematic perspective view of a display device according to a third embodiment of the present invention.
7 is an exploded perspective view of the thermoelectric element.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, the embodiments disclosed herein are provided so that the disclosure can be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

In the drawings, the thicknesses of layers and regions are exaggerated for clarity. Also, when a layer is referred to as being "on" another layer or substrate, it may be formed directly on another layer or substrate, or a third layer may be interposed therebetween. Like numbers refer to like elements throughout the specification.

3 and 4, a display device according to an embodiment of the present invention includes cooling units 310, 330, and 350, a substrate 100, a display panel 200, (Not shown) and a cover member (not shown).

First, the display panel constituting the display device according to the first to third embodiments of the present invention will be described with reference to Figs. 1 and 2. Fig. In other words, in a display device according to an embodiment of the present invention, a substrate and a display panel formed on the substrate will be described first.

The display device described with reference to FIGS. 1 and 2 relates to an organic light emitting diode (OLED).

However, the display device according to one embodiment of the present invention is not limited to this, and may be a liquid crystal display (LCD), a plasma display panel (PDP), a field effect display (FED) ), An electrophoretic display device, or the like can be applied.

1 is an equivalent circuit diagram of one pixel of an organic light emitting diode display. 2 is a cross-sectional view of an organic light emitting diode display.

Referring to FIG. 1, an OLED display includes a plurality of signal lines 121, 171, and 172 and a pixel PX connected to the plurality of signal lines 121, 171, and 172. The pixel PX may be any one of a red pixel R, a green pixel G and a blue pixel B. [

The signal line includes a scanning signal line 121 for transmitting a gate signal (or a scanning signal), a data line 171 for transmitting a data signal, a driving voltage line for transmitting a driving voltage, (172), and the like. The scanning signal lines 121 extend substantially in the row direction, are substantially parallel to each other, the data lines 171 extend in a substantially column direction, and are substantially parallel to each other. Although the driving voltage line 172 is shown extending substantially in the column direction, it may extend in the row direction or the column direction, or may be formed in a net shape.

At this time, one pixel PX includes a thin film transistor including a switching transistor T1 and a driving transistor T2, a storage capacitor Cst and an organic light emitting device element (LD). Although not shown in the drawing, one pixel PX may further include a thin film transistor and a capacitor in order to compensate the current provided to the organic light emitting element.

The switching transistor T1 has a control terminal N1, an input terminal N2 and an output terminal N3. The control terminal N1 is connected to the scanning signal line 121, An input terminal N2 is connected to the data line 171 and an output terminal N3 is connected to the driving transistor T2. The switching transistor T 1 transmits a data signal received from the data line 171 to the driving transistor T 2 in response to a scanning signal received from the scanning signal line 121.

The driving transistor T2 also has a control terminal N3, an input terminal N4 and an output terminal N5. The control terminal N3 is connected to the switching transistor T1, Is connected to the driving voltage line 172 and the output terminal N5 is connected to the organic light emitting diode LD. The driving transistor T2 flows an output current Id whose magnitude varies depending on the voltage applied between the control terminal N3 and the output terminal N5.

At this time, the capacitor Cst is connected between the control terminal N3 and the input terminal N4 of the driving transistor T2. The capacitor Cst charges the data signal applied to the control terminal N3 of the driving transistor T2 and maintains the data signal even after the switching transistor T1 is turned off.

The organic light emitting diode LD is an organic light emitting diode (OLED), for example, and includes an anode connected to the output terminal N5 of the driving transistor T2 and a common electrode Vss, And a cathode connected to the cathode. The organic light emitting diode LD emits light with different intensity according to the output current Id of the driving transistor T2 to display an image.

The organic light emitting diode LD may include an organic material that uniquely emits one or more of primary colors such as red, green, and blue primary colors, and the organic light emitting device may include a spatial sum The desired image is displayed.

The switching transistor Tl and the driving transistor T2 are n-channel field effect transistors (FETs), but at least one of them may be a p-channel field effect transistor. Also, the connection relationship between the transistors T1 and T2, the capacitor Cst, and the organic light emitting diode LD can be changed.

Hereinafter, the organic light emitting diode display will be described with reference to the sectional view shown in FIG.

Referring to FIG. 2, the substrate 123 may be formed of an insulating substrate made of glass, quartz, ceramics, plastic, or the like. More specifically, the substrate 123 may be made of a flexible material. At this time, the substrate 123 may correspond to the substrate 100 of FIG.

A substrate buffer layer 126 is formed on the substrate 123. The substrate buffer layer 126 prevents penetration of impurity elements and serves to planarize the surface.

At this time, the substrate buffer layer 126 may be formed of various materials capable of performing the functions described above. For example, the substrate buffer layer 126 may be any one of a silicon nitride (SiNx) film, a silicon oxide (SiO ₂ ) film, and a silicon oxynitride (SiO x N y) film. However, the substrate buffer layer 126 is not necessarily required, and may be omitted depending on the type of the substrate 123 and the process conditions.

A driving semiconductor layer 137 is formed on the substrate buffer layer 126. The driving semiconductor layer 137 is formed of a polycrystalline silicon film. The driving semiconductor layer 137 also includes a channel region 135 that is not doped with an impurity and a source region 134 and a drain region 136 that are formed by doping both sides of the channel region 135. At this time, the ionic material to be doped is a P-type impurity such as boron (B), and mainly B ₂ H ₆ is used. Here, such impurities vary depending on the type of the thin film transistor.

A gate insulating film 127 formed of a silicon nitride (SiNx) film or a silicon oxide (SiO ₂ ) film is formed on the driving semiconductor layer 137. On the gate insulating film 127, a gate wiring including the driving gate electrode 133 is formed. The driving gate electrode 133 is formed so as to overlap at least a part of the driving semiconductor layer 137, particularly, the channel region 135.

On the other hand, an interlayer insulating film 128 covering the driving gate electrode 133 is formed on the gate insulating film 127. A contact hole 128a is formed in the gate insulating film 127 and the interlayer insulating film 128 to expose the source region 134 and the drain region 136 of the driving semiconductor layer 137. [ The interlayer insulating film 128 may be made of a ceramic material such as silicon nitride (SiNx) or silicon oxide (SiO ₂ ) in the same manner as the gate insulating film 127.

A data line including the driving source electrode 131 and the driving drain electrode 132 is formed on the interlayer insulating film 128. The driving source electrode 131 and the driving drain electrode 132 are connected to the source region 134 of the driving semiconductor layer 137 through the contact hole 128a formed in the interlayer insulating film 128 and the gate insulating film 127, Drain region 136 of the transistor.

The driving thin film transistor 130 including the driving semiconductor layer 137, the driving gate electrode 133, the driving source electrode 131, and the driving drain electrode 132 is formed. The configuration of the driving thin film transistor 130 is not limited to the above-described example, and can be variously changed to a known configuration that can be easily practiced by those skilled in the art.

On the interlayer insulating film 128, a planarization film 124 covering the data lines is formed. The flattened film 124 serves to eliminate the step and planarize the organic light emitting device to improve the luminous efficiency of the organic light emitting device to be formed thereon. The planarization film 124 has an electrode via hole 122a for exposing a part of the drain electrode 132. [

The planarization layer 124 may be formed of a resin such as polyacrylates resin, epoxy resin, phenolic resin, polyamide resin, polyimides resin, at least one of unsaturated polyesters resin, polyphenylenethers resin, polyphenylenesulfides resin, and benzocyclobutene (BCB) may be used.

Here, one embodiment according to the present invention is not limited to the above-described structure, and either the planarizing film 124 or the interlayer insulating film 128 may be omitted in some cases.

At this time, the first electrode of the organic light emitting diode, that is, the pixel electrode 160 is formed on the planarization film 124. That is, the organic light emitting display includes a plurality of pixel electrodes 160 arranged for each of a plurality of pixels. At this time, the plurality of pixel electrodes 160 are disposed apart from each other. The pixel electrode 160 is connected to the drain electrode 132 through the electrode via hole 122a of the planarization layer 124. [

A pixel defining layer 125 having an opening for exposing the pixel electrode 160 is formed on the planarization layer 124. That is, the pixel defining layer 125 has a plurality of openings formed for each pixel. At this time, the organic light emitting layer 170 may be formed for each opening formed by the pixel defining layer 125. Accordingly, a pixel region in which each organic light emitting layer is formed by the pixel defining layer 125 can be defined.

At this time, the pixel electrode 160 is arranged to correspond to the opening of the pixel defining layer 125. However, the pixel electrode 160 is not necessarily disposed only in the opening of the pixel defining layer 125, and the pixel defining layer 125 may be disposed below the pixel defining layer 125 such that a portion of the pixel defining layer 125 overlaps the pixel defining layer 125 .

The pixel defining layer 125 may be made of a resin such as a polyacrylate resin or a polyimide or a silica-based inorganic material.

On the other hand, an organic light emitting layer 170 is formed on the pixel electrode 160.

A second electrode, that is, the common electrode 180, may be formed on the organic light emitting layer 170. Thus, the organic light emitting diode LD including the pixel electrode 160, the organic light emitting layer 170, and the common electrode 180 is formed.

At this time, the pixel electrode 160 and the common electrode 180 may be formed of a transparent conductive material or may be formed of a transflective or reflective conductive material, respectively. Depending on the type of the material forming the pixel electrode 160 and the common electrode 180, the organic light emitting display may be a top emission type, a bottom emission type, or a both-sided emission type.

On the other hand, a cover film 190 covering and protecting the common electrode 180 may be formed on the common electrode 180 as an organic film.

A thin-film encapsulating layer 141 is formed on the lid 190. The thin film sealing layer 141 protects the organic light emitting device LD and the driving circuit portion formed on the substrate 123 from the outside by sealing.

The thin film encapsulating layer 141 includes encapsulating organic films 141a and 141c and encapsulating inorganic films 141b and 141d which are alternately stacked one by one. In FIG. 2, for example, two encapsulating organic films 141a and 141c and two encapsulating inorganic films 141b and 141d are alternately stacked one by one to form the thin film encapsulating layer 141, but the present invention is not limited thereto .

On the other hand, a window (not shown) may be disposed on the thin film encapsulation layer 141 to protect the organic light emitting device and the like on the lower side.

Hereinafter, the display device according to the first embodiment of the present invention will be described with reference to FIGS. 3 and 4. FIG.

According to the first embodiment of the present invention, the cooling part 310 is disposed under the substrate 100. [ The cooling unit 310 functions to cool the substrate 100. Thus, the cooling part 310 can prevent the substrate 100 from being deformed or hardened by heat.

Referring to FIG. 3, the cooling unit may include a plurality of thermoelectric elements 310. According to the first embodiment of the present invention, the plurality of thermoelectric elements 310 may have a bar shape extending in one direction. That is, the plurality of thermoelectric elements 310 may be bar-shaped thermoelectric elements.

The thermoelectric element 310 applied to the first embodiment of the present invention may be the thermoelectric element shown in Fig. Referring to FIG. 7, the thermoelectric element may be composed of a plurality of P-type and N-type semiconductors disposed on a pair of electrically conductive plates, a seramic plate disposed on each electrically conductive plate, and the like.

At this time, when a current is applied from the N-type semiconductor to the P-type semiconductor, the formed ceramics plate is cooled and the ceramic plate formed on the other side generates heat.

More specifically, when two metals of different materials are formed and a semiconductor is connected to form a closed circuit and current is applied, heat other than the row heat is generated or absorbed at the contact. This phenomenon is called the Peltier effect.

Here, the Peltier effect means the release and absorption of heat that occurs when current flows through a junction between two different materials. If heat is generated when the current flows in one direction, the Peltier effect is reversible because it absorbs heat when the current flows in the opposite direction.

That is, reversing the direction of current reverses the generation and absorption of heat. For example, when both ends of iron and copper are connected and a current is supplied to them, heat is radiated to the outside at one contact and heat is absorbed from the other at the other contact to lower the ambient temperature.

The thermoelectric elements applied to the first to third embodiments of the present invention are not limited to the above-described configuration, and various known thermoelectric elements can be applied.

Referring to FIG. 3, each of the thermoelectric elements 310 extended in one direction may be formed of the thermoelectric elements shown in FIG.

More specifically, a plurality of thermoelectric elements 310 are disposed under the substrate 100, so that heat generated in the substrate 100 is discharged to the outside through the thermoelectric elements 310.

At this time, the plurality of thermoelectric elements 310 are arranged at equal intervals. By uniformly arranging the thermoelectric elements 310 at equal intervals, the heat generated in the substrate 100 can be evenly discharged.

Meanwhile, the number, size, arrangement interval, etc. of the thermoelectric elements 310 may be different depending on the size and area of the substrate 100. That is, the number, size, spacing, etc. of the thermoelectric elements 310 can be adjusted according to the amount of heat that the thermoelectric elements 310 should emit.

In the display device according to the first embodiment of the present invention, the plurality of thermoelectric elements 310 are spaced apart from each other at a predetermined interval in a bar shape, so that the substrate 100 can be bent in one direction.

For example, as shown in FIG. 3, the substrate 100 may be bent around the extending direction of the thermoelectric element 310.

Meanwhile, in the first embodiment of the present invention, the support plate 500 may be disposed below the plurality of thermoelectric elements 310. The support plate 500 may function to support a plurality of thermoelectric elements 310.

In addition, the display device according to the first embodiment of the present invention may further include a controller (not shown) for controlling the plurality of thermoelectric elements 310.

At this time, the control unit can measure the temperature of the substrate 100 and operate the plurality of thermoelectric elements 310. [ For example, when the temperature of the substrate 100 is heated to the reference temperature or more, the control unit operates the plurality of thermoelectric elements 310 to cool the temperature of the substrate 100. On the other hand, when the temperature of the substrate 100 is cooled to a certain temperature or lower by the plurality of thermoelectric elements 310, the control unit stops the operation of the plurality of thermoelectric elements 310.

On the other hand, a display panel (not shown) may be disposed on the substrate 100 of FIG. At this time, the display panel is a plurality of thin film structures stacked on the substrate 123 in Fig. 2, and displays an image. The display panel includes a buffer layer 126, a semiconductor layer 137, an organic light emitting diode (LD), and the like.

On the other hand, a cover member may be disposed on the display panel (not shown). At this time, the cover member may include the sealing layer and the window described above.

Hereinafter, a display device according to a second embodiment of the present invention will be described. In explaining the display device of the second embodiment of the present invention, detailed description of the same or similar configuration to the configuration of the display device according to the first embodiment of the present invention will be omitted.

Referring to FIG. 5, the plurality of thermoelectric elements 330 may be arranged in a matrix form.

Unlike the plurality of thermoelectric elements 310 shown in FIG. 3, in the second embodiment of the present invention, each thermoelectric element 310 of the first embodiment of the present invention is separately formed by a plurality of thermoelectric elements 330.

The display device according to the second embodiment of the present invention can be bent not only in the extending direction of the thermoelectric element 310 in Fig. 3, but also in the direction perpendicular to the extending direction. That is, the second embodiment of the present invention can be bent in various directions than the first embodiment.

In the following, a display device according to a third embodiment of the present invention will be described. In explaining the display device of the third embodiment of the present invention, detailed description of the same or similar configuration to the configuration of the display device according to the first embodiment of the present invention will be omitted.

Referring to FIG. 6, a plurality of thermoelectric elements 350 may be disposed at the center of the substrate 100. More specifically, a plurality of thermoelectric elements 350 can be disposed only in the folded region A of the substrate 100. [

In the case where the display device of the third embodiment of the present invention is a foldable display device, the plurality of thermoelectric elements 350 may be located only in the folded area A. When the display device is folded, since the stress is concentrated on the folding region A and the substrate 100 may be deformed, a plurality of thermoelectric elements 350 are disposed in the folding region A to prevent this.

Meanwhile, as shown in FIG. 6, the plurality of thermoelectric elements 350 may have a bar shape extending in one direction. Alternatively, the plurality of thermoelectric elements may be disposed only in the folded region A in a matrix form (not shown).

The display device according to an embodiment of the present invention can prevent the substrate from being deformed or hardened by heat by a plurality of thermoelectric elements disposed under the substrate.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of the right.

100 substrates 310, 330, 350 thermoelectric elements
500 support plate

Claims (12)

Board;
A display panel formed on the substrate and displaying an image;
And a cooling unit contacting the bottom of the substrate to adjust the temperature of the substrate. The method of claim 1,
Wherein the cooling section comprises a plurality of thermoelectric elements. 3. The method of claim 2,
Wherein each of the plurality of thermoelectric elements has a bar shape extending in one direction. 4. The method of claim 3,
Wherein the plurality of thermoelectric elements are spaced apart from each other at equal intervals. 4. The method of claim 3,
Wherein the thermoelectric element is located at the center of the substrate. 3. The method of claim 2,
Wherein the plurality of thermoelectric elements are arranged in a matrix form. The method of claim 6,
Wherein the thermoelectric element is located at the center of the substrate. The method of claim 1,
And a control unit for controlling the cooling unit. The method of claim 1,
Wherein the substrate is flexible. The method of claim 1,
And a cover member covering the display panel. 11. The method of claim 10,
The cover member
An encapsulating layer sealing the display panel and
And a window positioned above the encapsulation layer. The method according to any one of claims 2 to 7,
And a support plate disposed under the plurality of thermoelectric elements and supporting the plurality of thermoelectric elements.

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