DISPLAY PANEL AND DISPLAY DEVICE HAVING THE SAME

A display panel includes: a substrate; a plurality of pixels on the substrate, the plurality of pixels including an emitting element; a power supply line on the substrate, the power supply line being configured to receive power supplied from a power supply; and a temperature sensor at a peripheral region of the power supply line and for sensing a temperature of the power supply line.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application No. 10-2015-0116109, filed on Aug. 18, 2015, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference in their entirety.

BACKGROUND

Embodiments relate to a display panel and a display device having the same.

2. Description of the Related Art

Today, widely used devices such as computer monitors, TVs, mobile phones, and/or the like have display devices. Display devices, which display image using digital data, include a cathode-ray tube display, a liquid crystal display (LCD), a plasma display panel (PDP), an organic light emitting display (OLED) and/or the like. The rate of data transfer for the display device is increasing as the display device becomes more high-resolution and larger.

However, display devices typically use higher voltages than other suitable electronic devices do. Therefore, there is a high possibility for fire or for damage caused by excessive current due to a crack in the display panel or an abnormal short circuiting of the power line.

SUMMARY

Embodiments relate to a display panel capable of sensing and preventing an overcurrent which may arise in case of a crack in the display panel or an abnormal short circuiting of the power supply line.

Embodiments further relate to a thin film transistor (TFT) with a circuit capable of detecting an overcurrent in the display panel mounted inside, leading to implementation at a low cost.

Embodiments further relate to a display panel capable of sensing and preventing an overcurrent based on the determination whether an overcurrent has occurred by sensing the temperature of the power supply line of the power supply and a display device including the same.

Embodiments further relate to a method of preventing an overcurrent capable of saving cost even when the number of power lead-in terminals increases due to an increase in the size of the display panel.

The technological goals contained herein are not limited to those mentioned above, and those not mentioned shall be understood clearly by a person of ordinary skill in the art from the description provided herein.

A display panel according to an embodiment may include: a substrate; a plurality of pixels on the substrate, the plurality of pixels including an emitting element; a power supply line on the substrate, the power supply line being configured to receive power supplied from a power supply; and a temperature sensor at a peripheral region of the power supply line and for sensing a temperature of the power supply line.

The temperature sensor may include a p-type-intrinsic-metal (p-i-m) diode or a p-type intrinsic n-type (p-i-n) diode.

The temperature sensor may be between the substrate and the power supply line.

The power supply line may include a first power supply line for receiving a first power from the power supply and a second power supply line for receiving a second power from the power supply.

The temperature sensor may include a first temperature sensor at a peripheral region of the first power supply line, the first temperature sensor being for detecting a temperature of the first power supply line and a second temperature sensor at a peripheral region of the second power supply line, the second temperature sensor being for sensing a temperature of the second power supply line.

The temperature sensor may include a temperature sensing sensor for changing a leakage current according to the temperature of the power supply line, a detection circuit for converting the leakage current of the temperature sensing sensor into a voltage and a comparator for comparing the voltage with a reference voltage and determine whether an overcurrent is generated.

The comparator may transmit signals to interrupt power supplied from the power supply to the power supply line when the voltage is greater than the reference voltage.

A display device according to an embodiment may include a display panel, a data driver for supplying data signals to the display panel, a scan driver for supplying scan signals to the display panel, and a power supply for supplying power to the display panel. The display panel may include a substrate, a plurality of pixels on the substrate, the plurality of pixels including an emitting element, a power supply line on the substrate, the power supply line being configured to receive a power supplied from the power supply, and a temperature sensor at a peripheral region of the power supply line and for sensing a temperature of the power supply line.

According to an embodiment, a display panel capable of sensing and preventing an overcurrent and a display device including the same may be provided.

Also, a thin film transistor (TFT) with a circuit capable of detecting an overcurrent in the display panel mounted inside may be implemented, leading to implementation at a low cost.

Also, a display panel capable of sensing and preventing an overcurrent based on the determination whether an overcurrent has occurred by sensing the temperature of the power supply line of the power supply and a display device including the same may be provided.

Also, a method of preventing an overcurrent capable of saving cost even when the number of power lead-in terminals increases due to an increase in the size of the display panel may be provided.

The effects which may be obtained here are not limited to those mentioned above, and those not mentioned should be understood clearly by any person of ordinary skill in the art from the description provided herein.

DETAILED DESCRIPTION

It will be understood that when an element or layer is referred to as being “on,” “connected to,” “coupled to,” “connected with,” “coupled with,” or “adjacent to” another element or layer, it can be “directly on,” “directly connected to,” “directly coupled to,” “directly connected with,” “directly coupled with,” or “directly adjacent to” the other element or layer, or one or more intervening elements or layers may be present. Further “connection,” “connected,” etc. may also refer to “electrical connection,” “electrically connect,” etc. depending on the context in which they are used as those skilled in the art would appreciate. When an element or layer is referred to as being “directly on,” “directly connected to,” “directly coupled to,” “directly connected with,” “directly coupled with,” or “immediately adjacent to” another element or layer, there are no intervening elements or layers present.

Like numbers refer to like elements (or components) throughout. As used herein, the term “and/or” includes any and all suitable combinations of one or more of the associated listed items. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. Further, the use of “may” when describing embodiments of the present invention refers to “one or more embodiments of the present invention.” Also, the term “exemplary” is intended to refer to an example or illustration.

FIG. 1is a block diagram of an example of a display device according to an embodiment.

Referring toFIG. 1, a display device according to an embodiment may include a timing controller110, a scan driver120, a data driver130, a display panel140, and a power supply (or power supply unit)160.

The timing controller110may respond to a synchronization signal supplied from outside and control operations of the scan driver120and the data driver130. In other words, the timing controller110may generate a scan drive control signal and supply the scan drive control signal to the scan driver120. The timing controller110may generate a drive control signal and supply the drive control signal to the data driver130. Furthermore, the timing controller110may output data, supplied from outside, to the data driver130.

The scan driver120may respond to a scan driving signal output from the timing controller110and supply scan driving signals sequentially to scan lines S1to Sn.

In addition, the data driver130may, in response to a data drive control signal that is output from the timing controller110, rearrange data output from the timing controller110and supply it to data lines D1to Dm.

The display panel140may include a plurality of rows and columns of pixels150arranged in a matrix structure. The pixels150may be arranged at crossing regions of the data lines D1to Dm and scan line S1to Sn. And the pixels150may include light emitting elements such as organic light emitting diodes (OLED) and/or the like. Light from the pixels150may be emitted using first power supplied from a first power supply line ELVDD, and second power from a second power supply line ELVSS. Here, the power supply160may supply the first power to the first power supply line ELVDD and the second power to the second power supply line ELVSS.

Because a display panel in general uses higher voltage than other electronic appliances do, if there is a crack in the display panel or an abnormal short circuiting of the power line, there is an increased possibility of fire, due to an overcurrent, and that there will be damage caused by the fire. For example, if there is a crack in the display panel, current may flow through the crack, and as a result, an overcurrent may flow through the power supply line.

Some embodiments of the present invention provide an overcurrent sensor at every route that electric current flows to detect an overcurrent. In other words, an overcurrent from the power supply160may be detected by placing a separate current sensor between the power supply160and the display panel140. Here, the overcurrent sensor may include an overcurrent sensing circuit which includes resistance that detects a current, an op-amp, a microprocessor (MCU), and/or the like, and which is capable of determining that there is an overcurrent when current higher than a certain threshold is detected for over a certain amount of time and preventing power from being supplied by the power supply160. Circuits may be located on power/source printed board assembly (PBA), which is bonded to integrated circuit film at the top and bottom of the display panel. An overcurrent sensing circuit may be located at every film lead-in terminal, to which power from the power supply160is supplied. The overcurrent sensing circuit may detect voltage by placing resistance on current routes, which extend from the power supply unit, store it in the microprocessor, and determine whether there is an overcurrent based on it.

An overcurrent sensing circuit is used on every power route by which power from the power supply is provided to the display panel from the PBA. Therefore, the number of power lead-in terminals may increase as display panels become larger, and accordingly costs may increase due to an increase in the number of overcurrent sensing circuits. Also, current sensing fire protection-related costs of material may increase as display panels become larger.

In a display device according to an embodiment of the present invention, a method of internalizing a sensing circuit for determining whether an overcurrent flows in a display panel may be provided.

In a display device according to an embodiment of the present invention, when power from the power supply160is supplied to the panel through film bonded to the power supply160, the power supply160may be coupled to the display panel140through wiring on a bonding pad of the panel. Here, when an overcurrent on a power route from the power supply160occurs, heat may be generated in power wiring. In other words, because the degree to which heat will be generated while operating within normal operational range is taken into consideration when the wiring is being laid out, heat above an allowed level may be generated when there is an overcurrent. Therefore, a temperature sensor170, which detects the temperature of the power wiring, may be provided on a substrate of the display panel, such that it may be determined whether there has been an overcurrent by sensing the temperature of the power wiring.

In other words, the temperature sensor170formed around the power wiring of the display panel may determine that an overcurrent has occurred in the power wiring when heat over a critical temperature (e.g., a predetermined critical temperature) has occurred in the power wiring. Here, according to an embodiment, the temperature sensor170may be implemented with p-i-m (p-type-intrinsic-metal) diode or p-i-n (p-type-intrinsic-n-type) diode. Furthermore, according to an embodiment, the temperature sensor170may be provided below the power wiring, that is, between the substrate of the display panel and the power wiring to sense the temperature of the power wiring.

In further detail, the temperature sensor170formed around the power wiring of the display panel may detect temperature on the display panel by using changes in leakage current caused by changes in the temperature of the power wiring. And the temperature sensor170may determine that there has been an overcurrent when detected heat is greater than (or equal to or greater than) a critical temperature (e.g., a predetermined critical temperature). Here, according to an embodiment, the temperature sensor170may convert leakage current into voltage, compare the converted voltage with the critical voltage (e.g., the predetermined critical voltage), and determine that there has been an overcurrent when the converted voltage is greater than (or equal to or greater than) a critical voltage. In addition, when it is determined that there has been an overcurrent, the temperature sensor170may transmit a signal to the power supply160to interrupt (or block) the power supplied by the power supply160. Accordingly, the power supply160may interrupt (or block) the supplied power according to a signal with information to interrupt (or block) the supplied power when there has been an overcurrent.

Accordingly, having the temperature sensor170formed on the display panel to detect the temperature of the power wiring in order to determine whether there has been an overcurrent may lead to lower costs because the temperature sensor, circuits, and/or the like which determine whether there has been an overcurrent are all implemented on the display panel through thin film process.

FIG. 2illustrates an example of a top view of a display panel with a temperature sensor according to an embodiment.FIG. 3illustrates an example of a sectional view of a display panel with a temperature sensor according to an embodiment.FIG. 4illustrates another example of a top view of a display panel with a temperature sensor according to an embodiment.FIG. 5illustrates another example of a sectional view of a display panel with a temperature sensor according to an embodiment.FIGS. 6A and 6Billustrate perspective views of temperature sensor implemented diodes according to example embodiments.

Referring toFIG. 2, a display panel of a display device according to an embodiment may include a substrate210, a bonding pad240which supplies power from the power supply to the display panel, and power supply lines230and235by which power is supplied from the power supply unit. Temperature sensors220and225may be formed below the power supply lines230and235, respectively. In other words, temperature sensors220and225may be formed between the substrate210of the display panel and the power supply lines230and235. Here, according to an embodiment, the substrate210may include glass.

When, according to an embodiment, the first power and the second power are supplied from the power supply unit, the display panel may include a first power supply line ELVDD230and a second power supply line ELVSS235, which are supplied, respectively, with the first power and the second power from the power supply unit. The display panel may further include a first temperature sensor220and a second temperature sensor225, which are formed below the first power supply line230and the second power supply line235, respectively. The first temperature sensor220may measure the temperature of the first power supply line230, and the second temperature sensor225may measure the temperature of the second power supply line235. The temperature sensors220and225may determine whether there has been an overcurrent in the power supply lines230and235, respectively.

Also,FIG. 3is a sectional view taken along the line A-A′ of a display panel according to an embodiment. Referring toFIG. 3, the temperature sensor320may be formed on the substrate310, and the power wiring330may be formed thereon. The power wiring may be a double-layer structure including a first conductive layer331and a second conductive layer333. The first conductive layer331may be composed of the same or substantially the same material as a source/drain S/D electrode, and the second conductive layer333may be composed of the same or substantially the same material as a gate electrode.

Operations of the temperature sensors220and225will be discussed in further detail. When there is an overcurrent in the power route, heating may occur in the power wiring, for example, first power supply line230and/or the second power supply line235. As stated above, the extent to which heat is generated under normal operation conditions is taken into consideration when wiring layout is designed, so when there is an overcurrent, heat over a critical value (e.g., a predetermined critical value) may occur in the power wiring.

Therefore, when temperature sensors220and225are located below the power supply lines230and235, the temperature sensors220and225may sense the temperature of the power supply lines230and235. The temperature sensors220and225may determine whether there has been an overcurrent based on whether the temperature of the power supply lines230and235is higher than the critical temperature (e.g., the predetermined critical temperature). Or according to an embodiment, the temperature sensors220and225may convert leakage current into voltage, compare the converted voltage with a critical voltage (e.g., a predetermined critical voltage), and determine that there is an overcurrent when the converted voltage is higher than the critical voltage. When it is determined that there has been an overcurrent, the temperature sensors220and225may transmit a signal to interrupt (or block) the power supplied by the power supply unit. Accordingly, the power supply unit, when there is an overcurrent, may interrupt (or block) the power according to the signal with information to interrupt (or block) the power.

When there is a plurality of power supply lines from the power supply unit, for example, when there are two power supply lines, the first power supply line230and the second power supply line235, the first temperature sensor220and the second temperature sensor225may be formed below the first power supply line230and the second power supply line235. In this case, the first temperature sensor220and the second temperature sensor225may detect the temperature of the first power supply line230and the second power supply line235, respectively. Accordingly, whether there is an overcurrent in the first power supply line230and/or the second power supply line235may be determined.

Referring toFIG. 4, a display panel of a display device according to an embodiment may include a bonding pad440which supplies power from the power supply to the display panel and power supply lines430and435, to which power from the power supply is supplied. The temperature sensors420and425may be formed in the peripheral region of the power supply lines430and435. In other words, the temperature sensors420and425may be located, not between the power supply lines430and435and the substrate410, as in the embodiment shown inFIG. 2, but in the peripheral region of the power supply lines430and435. For example, the temperature sensors420and425may be formed in regions where power supply lines430and435are not formed, as shown inFIG. 4. In other words, the temperature sensors420and425may be formed next to the power supply lines430and435and alongside the power supply lines430and435. According to an embodiment, the substrate410may include glass.

According to an embodiment, when the first power and the second power are supplied from the power supply unit, the display panel may include a first power supply line ELVDD430and a second power supply line ELVSS435, to which the first power and the second power are supplied from the power supply unit, respectively. The display panel may include a first temperature sensor420and a second temperature sensor425which are formed in the peripheral region of the first power supply line430and the second power supply line435. The first temperature sensor420may sense the temperature of the first power supply line430, and the second temperature sensor425may detect the temperature of the second power supply line435. The temperature sensors420and425may determine whether there has been an overcurrent in the power supply lines430and435, respectively.

FIG. 5is a sectional view of a cross section of B-B′ of the display panel according to the embodiment ofFIG. 4. Referring toFIG. 5, a temperature sensor520may be formed at a side of the power wiring530in regions different from those where the power wiring530is formed. The power wiring may be a double-layer structure including a first conductive layer531and a second conductive layer533. The first conductive layer531may be composed of the same or substantially the same material as a source/drain S/D electrode, and the second conductive layer533may be composed of the same or substantially the same material as a gate electrode.

The operation of the temperature sensors420and425will be described more fully hereinafter. When there is an overcurrent in the power route, heating may occur in the power wiring, for example, the first power supply line430and/or the second power supply line435. As stated above, the extent to which heat will occur within normal operations is taken into consideration when the wiring is laid out, so when there is an overcurrent, there may be heat over a critical value (e.g., a predetermined critical value). When the temperature sensors420and425are located in the peripheral region of the power supply lines430and435, the temperature sensors420and425may detect the temperature of the power supply lines430and435, respectively, and determine whether there has been an overcurrent by determining whether the temperature of either of the power supply lines430and435is higher than the critical temperature (e.g., the predetermined critical temperature).

According to an embodiment, the temperature sensors420and425may convert leakage current into voltage, compare the converted voltage with a critical voltage (e.g., a predetermined critical voltage), and determine that there is an overcurrent when the converted voltage is higher than the critical voltage. When it is determined that there has been an overcurrent, the temperature sensors420and425may transmit a signal to interrupt (or block) the power supplied from the power supply unit. Accordingly, the power supply unit, when an overcurrent is generated, may interrupt (or block) the power according to a signal having information to interrupt (or block) the power. Here, when there are a plurality of power supply lines from the power supply unit, for example, when there are two power supply lines, the first power supply line430and the second power supply line435, the first temperature sensor420and the second temperature sensor425may be formed in the peripheral region of the first power supply line430and the second power supply line435, respectively. In this case, the first temperature sensor420and the second temperature sensor425may sense the temperature of the first power supply line430and the second power supply line435, respectively, and determine whether there is an overcurrent in the first power supply line430and the second power supply line435, respectively.

Temperature sensors of the temperature sensors220,225,320,420,425and520may be implemented with a p-type-intrinsic-metal (p-i-m) diode or a p-type-intrinsic-n-type (p-i-n) diode.FIG. 6Ashows a p-i-n diode, andFIG. 6Bshows a p-i-m diode.

The p-i-n diode depicted inFIG. 6Amay include a p-type doped region610, an intrinsic semiconductor region620, and an n-type doped region630, and be coupled to metal plates640and650on the p-type doped region610and the n-type doped region630, respectively.

The p-i-m diode depicted inFIG. 6bmay include a p-type doped region610and an intrinsic semiconductor region620and be connected to metal plates640and650on the p-type doped region610and the intrinsic semiconductor region620respectively. In other words, unlike the p-i-n diode, the p-i-m diode does not include an n-type doped poly-Si region. However, the p-i-m diode may perform electrical functions almost the same or substantially the same as those of the p-i-n diode. Furthermore, the p-i-m diode requires only a p-type doping, thereby reducing cost.

FIG. 7illustrates an example of a temperature sensor according to an embodiment, andFIG. 8illustrates an example of leakage current of a temperature sensor according to a temperature according to an embodiment.

Referring toFIG. 7, a temperature sensor710according to an embodiment may be formed on a substrate of the display panel. The temperature sensor may include a temperature sensor711, a detection circuit713, and a comparator715. Here, according to an embodiment, the temperature sensor711may be a thin film diode. The thin film diode may, as stated above, be a p-i-m diode or a p-i-n diode. For example, leakage current of the p-i-m diode711may change according to changes in temperature, as shown inFIG. 8. In other words, leakage current of the p-i-m diode711may increase as temperature increases. Therefore, temperature may be detected on the display panel using this characteristic.

In other words, the temperature of the power wiring on the display panel may change as the amount of the current which flows in the power wiring changes. That is, the temperature of the power wiring may increase when the current in the power wiring increases. Here, according to an embodiment, because temperature sensors are located around the power wiring on the display panel, the amount of the leakage current of the thin film diode711of the temperature sensor may change as the size of the current in the power wiring changes. In other words, when the current in the power wiring increases, the size of the leakage current of the thin film diode711may increase. Here, the detection circuit713may detect the leakage current of the thin film diode711, convert it into voltage, and relay it to the comparator715.

The comparator715may compare the received converted voltage with a reference voltage (e.g., a predetermined reference voltage) and determine whether there has been an overcurrent in the power route. Here, the comparator715may determine that there has been an overcurrent when the received converted voltage is greater than the reference voltage (e.g., the predetermined reference voltage) and transmit a corresponding signal as an enable signal to the power supply750.

Here, according to an embodiment, the signal which the comparator715transmits to the power supply750may be a 1-bit signal which indicates whether there has been an overcurrent. For example, the comparator715may send signal ‘1’ to the power supply750, when the input voltage is greater than the reference voltage (e.g., the predetermined reference voltage), that is, when it is determined that the temperature of the power wiring is higher than the critical temperature (e.g., the predetermined critical temperature). Also, the comparator715may transmit signal ‘0’ to the power supply750, when the input voltage is not greater than the reference voltage (e.g., the predetermined reference voltage), that is, when it is determined that the temperature of the power wiring is lower than the critical temperature.

According to an embodiment, when there is an overcurrent, that is, when the temperature of the power wiring is higher than the critical temperature (e.g., the predetermined critical temperature), or when the voltage converted from leakage current of the thin film diode711is higher than the reference voltage (e.g., the predetermined reference voltage), the comparator715may transmit a signal with information to stop power supplied to the power supply750.

Afterwards, the power supply750may interrupt (or block) or continue power supply according to a signal received from the comparator715. For example, when the power supply750receives a signal from the comparator715which indicates that there has not been an overcurrent, for example, signal ‘0,’ the power supply750may continue power supply to the display panel. When the power supply750receives a signal from the comparator715which indicates that there has been an overcurrent, for example, signal ‘1,’ the power supply750may interrupt (or block) the power to the display panel. In the case in which the comparator715transmits to the power supply750a signal to interrupt (or block) the power only when there has been an overcurrent, the power supply750which has received such a signal may interrupt (or block) the power.

In this case, because the temperature sensor711, the detection circuit713, the comparator715, etc. are all realized on the display panel through the thin film process, there may be significant savings.

FIG. 9is a diagram illustrating another example of an operation of a temperature sensor according to an embodiment.

Referring toFIG. 9, a temperature sensor910may be formed on a substrate of the display panel. The temperature sensor may include a temperature sensor911, a detection circuit913, and a plurality of comparators915. Here, according to an embodiment, the temperature sensor911may be a thin film diode. The thin film diode, as stated above, may be a p-i-m diode, or a p-i-n diode. For example, the leakage current of the p-i-m diode911may change as temperature changes as shown inFIG. 8. In other words, the leakage current of the p-i-m diode911may increase as temperature increases. Therefore, using this characteristic, temperature detection may be possible on the display panel.

In other words, the temperature of the power wiring on the display panel may change as the size of the current in the power wiring changes. That is, the temperature of the power wiring may increase when the current in the power wiring increases. Here, according to an embodiment, because temperature sensors are located around the power wiring on the display panel, the amount of the leakage current of the thin film diode911of a temperature sensor may change depending on the size of the current flowing in the power wiring. In other words, when there is an increase in the current in the power wiring, the amount of the leakage current increases. Here, the detection circuit913may detect the leakage current of the thin film diode911, convert it into voltage, and relay it to the comparator915.

The comparator915may convert voltage received from the detection circuit913and convert it into an n-bit signal using a plurality of comparators. Here n may be the number that is the same as the number of comparators. InFIG. 7, one comparator may compare voltage received from the detection circuit913with the existing stored reference voltage and determine whether there has been an overcurrent. However, inFIG. 9, voltage received from the detection circuit913may be converted to an n-bit signal and transmitted to a microprocessor940outside the display panel.FIG. 9shows three comparators915are included, but 2 or more, or 4 or more comparators915may exist. Here, the plurality of comparators915may form bit of “1” when voltage higher than the reference voltage (e.g., the predetermined reference voltage) is formed, and bit of “0” in other circumstances. For example, when there are 5 comparators915, voltage received from the detection circuit913may be compared with values predetermined by first through fifth comparators respectively. Here, it may be assumed that the received voltage is lower than a first comparison voltage and a second comparison voltage and higher than a third comparison voltage through a fifth comparison voltage. In this case, a first comparator may output “0,” a second comparator “0,” a third comparator “1,” a fourth comparator “1,” and a fifth comparator “1,” resulting in a 5 bit-signal such as “00111.” With this, the comparator915may transmit a more precise voltage value to the microprocessor940. The more the comparators915are, the more precise a value may be transmitted to the microprocessor940.

The microprocessor940may use the received voltage value, the n-bit signal, and determine whether there has been an overcurrent using this value. In other words, the microprocessor940may save the temperature in normal conditions and transmit a signal with information to interrupt (or block) the power supplied from the power supply950when there has been an overcurrent.

Afterwards, the power supply950may, according to signals received from the microprocessor940, interrupt (or block) or continue to supply the power. For example, when the power supply950receives a signal indicating that there has not been an overcurrent (or no signal), the power supply950may continue supplying power to the display panel. When the power supply950receives a signal indicating that there has been an overcurrent, the power supply950may interrupt (or block) the power supplied to the display panel.

In this case, the number of comparators and interface signals may increase, but there may be no reason why reference voltage, which indicates an overcurrent within the display panel, should be saved (or stored).

FIG. 10illustrates an example of a block diagram of a display device according to another embodiment.

Referring toFIG. 10, a display device according to an embodiment may include a timing controller1010, a scan driver1020, a data driver1030, a display panel1040, pixels1050, and a power supply1060. Here, the display device may be substantially the same as the display device shown inFIG. 1, except that it includes a plurality of first power supply lines ELVDD1to ELVDDi and a plurality of second power supply lines ELVSS1to ELVSSi. Therefore, detailed description of those components that are substantially the same may be omitted.

The plurality of the first power supply lines ELVDD1to ELVDDi each may supply the first power to certain corresponding regions of the entire region of the display panel1040. The plurality of the second power supply lines ELVSS1to ELVSSi each may supply the second power to certain corresponding regions of the entire region of the display panel1040. The power supply1060may supply the first power to the plurality of the first power supply lines ELVDD1to ELVDDi, and the second power to the plurality of the second power supply lines ELVSS1to ELVSSi.

In a display device according to an embodiment, a plurality of temperature sensors1070,1073, and1075, which detect the temperature of the plurality of the power wiring ELVDD1to ELVDDi and ELVSS1to ELVSSi from the power supply1060may be provided on the substrate of the display panel, and it may be determined whether there has been an overcurrent by detecting the temperature of the power wiring. In other words, the temperature sensors1070,1073and1075, which were formed around the power wiring of the display panel, may determine that there has been an overcurrent in the power wiring when there is heat over a critical temperature (e.g., a predetermined critical temperature).

FIG. 11is a diagram illustrating an example of a detection circuit based on a thin film transistor according to an embodiment, andFIG. 12is a timing chart of a detection circuit according to an embodiment.

Referring toFIG. 11, a detection circuit of a temperature sensor according to an embodiment may include first transistor T1through eighth transistor T8formed on the display panel, a first capacitor C1, a second capacitor C2, and a p-i-m diode. Here a first electrode of the transistors may be a source or drain electrode, and a second electrode may be a drain or source electrode.

The p-i-m diode may be coupled between the second power Vss and the first electrode of the eighth transistor T8, and the second electrode of the eighth transistor T8may be coupled to a second node B. A gate electrode of the eighth transistor18may be coupled to a TXB signal input line. The second electrode of the fifth transistor T5may be coupled to the second power VSS, the first electrode of the fifth transistor T5may be coupled to the second electrode of the first transistor T1, and a gate electrode of the fifth transistor T5may be coupled to a second signal input line COMPB. The second electrode of the second transistor T2may be coupled to the second electrode of the first transistor T1, the first electrode of the second transistor T2may be coupled to a first node A, and a gate electrode of the second transistor T2may be coupled to a reset signal input line RST. The first capacitor C1may be connected between the second node B and the second power Vss, and the second capacitor C2may be connected between the first node A and the second node B. The second electrode of the first transistor T1may be connected to the second electrode of the second transistor12and the first electrode of the fifth transistor T5, the first electrode of the first transistor T1may be connected to the second electrode of the fourth transistor14, and a gate electrode of the first transistor T1may be connected to the first node A. The second electrode of the third transistor T3may be connected to the second node B, the first electrode of the third transistor T3may be connected to a first reference power VREF1, and a gate electrode of the third transistor13may be connected to the reset signal input line RST. The second electrode of the fourth transistor14may be connected to the first electrode of the first transistor, the first electrode of the fourth transistor T4may be connected to a second reference power VREF2, and a gate electrode of the fourth transistor14may be connected to the first signal input line COMP. The first electrode of the sixth transistor T6may be connected to the first electrode of the seventh transistor T7, the second electrode of the sixth transistor16may be connected to the first electrode of the first transistor T1, and a gate electrode of the sixth transistor T6may be connected to a transmission signal input line Tx. The first electrode of the seventh transistor T7may be connected to the first electrode of the sixth transistor16, the second electrode of the seventh transistor T7may be connected to the first power VDD, and a gate electrode may be connected to a pre-charge signal input line PRE. Load may be connected between the first electrode of the seventh transistor T7and an output terminal.

Referring toFIG. 12, the detection circuit shown inFIG. 11may operate according to a reset period, an integration period and a read-out period. During the reset period, a reset signal RST may be supplied so that the detection circuit may be initialized. During the integration period, a TXB signal may be input to the gate electrode of the eighth transistor T8and the leakage current from the p-i-m diode may be stored in the capacitors C1and C2. During a precharging period included in the integration period, a precharge signal PRE may be supplied to the gate electrode of the seventh transistor T7so that the seventh transistor T7may be turned on. During the read-out period, a voltage corresponding to the above leakage current may be output through the output terminal.

FIG. 13illustrates an example of a comparator using a Schmitt trigger according to an embodiment,FIG. 14is a timing chart of a comparator according to an embodiment, andFIG. 15illustrates an example of an analog-digital converter using a comparator according to an embodiment.

Referring toFIG. 13, a comparator according to an embodiment may include an inverter and a Schmitt trigger. Furthermore, one of the inverters of buffer may be a low logic voltage low Vlogic inverter, so the output voltage of the comparator may be high during a first phase operation as shown inFIG. 14. It may further include an edge trigger switch, preventing fluctuation of the output voltage.

FIG. 15illustrates an example of a multi-channel analog-digital converter (ADC). Here, an n-bit latch and a comparator may be located in each channel, and there may be only one n-bit counter in the multi-channel ADC. Parallel to serial blocks consist of n-bit shift resisters in order to minimize the interface line.

In a display device according to an embodiment, temperature sensors may be formed on the display panel to determine whether an overcurrent is supplied from the power supply unit. In other words, temperature detecting units may be located below or near power supply lines in order to detect temperature increases in the wiring due to an overcurrent. When the temperature of the wiring is at the critical value or higher, it may be determined that there has been an overcurrent. Here, the temperature sensor, a detection circuit, and a comparator circuit may be configured as a TFT and be integrated into a panel. As a result, it may be determined whether an overcurrent has been generated, while also, reducing costs.