KR102522265B1 - Photo sensor and display incuding the same - Google Patents

Abstract

Embodiments of the present invention, in a photosensor including a plurality of photosensor units for detecting light and a sensing signal output circuit for outputting a sensing signal in response to the light sensed by the photosensor unit, the photosensor unit, A photodiode receiving a first driving voltage and generating a first current by detecting light, a first switching transistor receiving the first current and selectively outputting a first sensing voltage in response to a switch signal, and a second driving voltage It is possible to provide a photosensor including a second switching transistor that receives the second current and selectively outputs a second sensing voltage in response to a switch signal, and a display device using the same.

Description

Photosensor and display device including the same {PHOTO SENSOR AND DISPLAY INCUDING THE SAME}

Embodiments of the present invention relate to a photosensor and a display device including the same.

As the information society develops, the demand for display devices for displaying images is increasing in various forms, and liquid crystal display devices (LCD: Liquid Crystal Display Device), plasma display devices, organic light emitting display devices ( Various types of display devices such as organic light emitting display devices (OLEDs) are being utilized.

Such a display device may be used in a smart phone or the like. In the smart phone, various sensors such as a photo sensor, a roughness sensor, a gravity sensor, and a touch sensor are used so that various applications can be driven. Some of these sensors can be manufactured using a semiconductor device, so the sensor can be implemented in a very thin and small size, which is advantageous in implementing a thin display device.

However, since the characteristics of a semiconductor device may be changed by heat, a problem may occur in which sensing is not accurately performed due to ambient temperature or heat generated from a smartphone. Therefore, there is a need for a method of implementing a sensor capable of accurately sensing regardless of temperature change.

An object of embodiments of the present invention is to provide a photosensor capable of more accurately detecting light and a display device including the same.

In addition, another object of embodiments of the present invention is to provide a photosensor that can be implemented in various sizes and a display device including the same.

Embodiments of the present invention on one side, in a photosensor including a plurality of photosensor units for detecting light, and a sensing signal output circuit for outputting a sensing signal in response to the light sensed by the photosensor unit, the photosensor The unit includes a photodiode receiving a first driving voltage and generating a first current by sensing light, a first switching transistor receiving the first current and selectively outputting a first sensing voltage in response to a switch signal, and a second It is possible to provide a photosensor including a second switching transistor that receives the driving voltage and selectively outputs the second sensing voltage in response to the second current corresponding to the switch signal.

In another aspect, embodiments of the present invention include a gate electrode disposed on a substrate, a gate insulating film disposed above the gate electrode, and a first active layer disposed in a first region above the gate insulating film and overlapping the gate electrode. , The second active layer disposed in the second region above the gate insulating film and disposed to overlap the gate electrode, the first source electrode and the first drain electrode disposed on the first active layer, and the second source electrode disposed on the second active layer and a second drain electrode, a first source electrode, a first planarization film disposed on the second source electrode, the first drain electrode and the second drain electrode, and a first planarization film disposed on the first planarization film and connected to the first drain electrode. A first conductive layer, a second conductive layer disposed on the first planarization film and connected to the second drain electrode, a photosensitive layer disposed on the first conductive layer, and disposed on the second conductive layer, except for the first area Provide a photosensor including a second planarization film disposed on, a third conductive layer disposed over the photosensitive layer and the planarization film, disposed to contact the photosensitive layer, and an encap disposed over the third conductive layer and the planarization film. can do.

In another aspect, embodiments of the present invention include a display panel, a photosensor including a plurality of photosensor units disposed in at least one area below the display panel, and outputting a sensing signal in response to a switch signal, and a sensing signal. Including a controller that outputs sensing data in response, the photosensor unit receives a first driving voltage, receives a photodiode that senses light and generates a first current, receives the first current, and selectively responds to a switch signal A display device including a first switching transistor outputting a first sensing voltage and a second switching transistor receiving a second driving voltage and selectively outputting a second sensing voltage in response to a second current in response to a switch signal. can

According to embodiments of the present invention, it is possible to provide a photosensor capable of more accurately detecting light and a display device including the same.

According to embodiments of the present invention, it is possible to provide a photosensor that can be implemented in various sizes and a display device including the same.

1 is a structural diagram showing the structure of a display device according to embodiments of the present invention.
2 is a structural diagram showing a first embodiment of a photosensor according to embodiments of the present invention.
3 is a structural diagram showing a second embodiment of a photosensor according to embodiments of the present invention.
4 is a timing diagram illustrating an example of a switch signal output from a switch driver according to embodiments of the present invention.
5 is a circuit diagram showing a photosensor unit according to embodiments of the present invention.
6 is a circuit diagram showing a photosensor unit according to embodiments of the present invention.
7 is a circuit diagram showing a first embodiment of the configuration of a sensing signal output circuit according to embodiments of the present invention.
8 is a circuit diagram showing a second embodiment of the configuration of a sensing signal output circuit according to embodiments of the present invention.
9 is a cross-sectional view showing a photosensor unit according to embodiments of the present invention.
10 is a plan view showing a first embodiment of a photosensor unit according to embodiments of the present invention.
11 is a plan view showing a second embodiment of a photosensor unit according to embodiments of the present invention.
12 is a structural diagram showing a controller in embodiments according to the present invention.
13 is a graph showing a relationship between a first reference temperature and a corresponding amount of light.
14 is a circuit diagram illustrating an example of a pixel employed in a display device according to example embodiments.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, only these embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention belongs. It is provided to fully inform the holder of the scope of the invention, and the present invention is only defined by the scope of the claims.

In addition, since the shape, size, ratio, angle, number, etc. disclosed in the drawings for explaining the embodiments of the present invention are exemplary, the present invention is not limited to the matters shown. Like reference numbers designate like elements throughout the specification. In addition, in describing the present invention, if it is determined that a detailed description of related known technologies may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. When 'includes', 'has', 'consists of', etc. mentioned in this specification is used, other parts may be added unless 'only' is used. In the case where a component is expressed in the singular, it may include the case of including the plural unless specifically stated otherwise.

In addition, in interpreting the components in the embodiments of the present invention, even if there is no separate explicit description, it should be interpreted as including an error range.

Also, terms such as first, second, A, B, (a), and (b) may be used in describing the components of the present invention. These terms are only used to distinguish the component from other components, and the nature, sequence, order, or number of the corresponding component is not limited by the term. When an element is described as being “connected,” “coupled to,” or “connected” to another element, that element is or may be directly connected to that other element, but intervenes between each element. It will be understood that may be "interposed", or each component may be "connected", "coupled" or "connected" through other components. In the case of a description of a positional relationship, for example, 'on top of', 'on top of', 'at the bottom of', 'next to', etc. Or, unless 'directly' is used, one or more other parts may be located between the two parts.

Also, components in the embodiments of the present invention are not limited by these terms. These terms are only used to distinguish one component from another. Therefore, the first component mentioned below may also be the second component within the technical spirit of the present invention.

In addition, the features (configurations) in the embodiments of the present invention can be partially or entirely combined, combined or separated from each other, technically various interlocking and driving operations are possible, and each embodiment is implemented independently of each other. It may be possible or it may be possible to implement together in an association relationship.

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

1 is a structural diagram showing the structure of a display device according to embodiments of the present invention.

Referring to FIG. 1 , the display device 100 may include a display panel 110 and a photosensor 120 .

The display panel 110 may include a plurality of data lines DL1 , ..., DLm disposed in a first direction and a plurality of gate lines GL1 , ... , GLn disposed in a second direction. The plurality of data lines DL1, ..., DLm and the plurality of gate lines GL1, ..., GLn are illustrated as orthogonal to each other, but are not limited thereto. In addition, the wiring disposed on the display panel 110 is not limited to the plurality of data lines DL1, ..., DLm and the plurality of gate lines GL1, ..., GLn.

The display panel 110 may include a plurality of pixels 101 formed corresponding to an area where the plurality of gate lines GL1 , ..., GLn and the plurality of data lines DL1 , ..., DLm intersect. A plurality of pixels may be arranged in a matrix form including a plurality of pixel rows in a horizontal direction and a plurality of pixel columns in a vertical direction. Pixels disposed in one pixel row may be connected to the same gate line. However, it is not limited thereto.

The photosensor 120 may be disposed below the display panel 110 . The photosensor 120 may be disposed to correspond to the display panel 110 . Corresponding to the display panel 110 may mean having an area corresponding to the entire area of the display panel 110 and being disposed under the display panel 110 . However, it is not limited thereto, and may be disposed in one area under the display panel 110 . The photosensor 120 may directly contact the display panel 1100 at a lower portion of the display panel 110. However, the present invention is not limited thereto. 110) may be detected, but since the light generated from the display panel 110 is radiated upward of the display panel 110, it may not be radiated to the photosensor 120. Therefore, , The photosensor 120 can detect light generated outside the display panel 110 and passing through the display panel 110 from the top to the bottom.

In addition, the display device 100 may include a data driver 130 , a gate driver 140 , and a timing controller 150 to drive the display panel 110 .

The data driver 130 may apply data signals to the plurality of data lines DL1, ..., DLm. The data signal may correspond to a gray level, and a voltage level of the data signal may be determined according to the corresponding gray level. A voltage of the data signal may be referred to as a data voltage. Here, the number of data drivers 130 is illustrated as one, but is not limited thereto and may be two or more corresponding to the size and resolution of the display panel 110 . Also, the data driver 130 may be implemented as an integrated circuit.

The gate driver 140 may apply gate signals to the plurality of gate lines GL1, ..., GLn. Pixels 101 corresponding to the plurality of gate lines GL1 , ..., GLn to which gate signals are applied may receive data signals. Here, the number of gate drivers 140 is illustrated as one, but is not limited thereto and may be at least two. In addition, the gate drivers 140 are disposed on both sides of the display panel 110, one gate driver 140 is connected to an odd-numbered gate line among the plurality of gate lines GL1, ..., GLn, and the other gate driver 140 may be connected to even-numbered gate lines among the plurality of gate lines GL1, ..., GLn. However, it is not limited thereto.

Also, the signal output from the gate driver 140 is not limited to the gate signal. The gate driver 140 may include a gate signal generating circuit disposed on the display panel 110 to output a gate signal, and a level shifter supplying voltage and signals to the gate signal generating circuit. However, it is not limited thereto.

The timing controller 150 may control the data driver 130 and the gate driver 140 . Also, the timing controller 150 may transmit an image signal corresponding to the data signal to the data driver 130 . The video signal may be a digital signal. The timing controller 150 may correct the image signal and transmit it to the data driver 130 .

2 is a structural diagram showing a photosensor according to a first embodiment according to embodiments of the present invention, and FIG. 3 is a structural diagram showing a second embodiment of a photosensor according to embodiments of the present invention.

2 and 3, the photosensor 120 may include a plurality of photosensor units PUa and PUb, and the photosensor units PUa and PUb are arranged in a matrix form in a plurality of rows and columns. can be arranged In addition, the photosensor 120 may include switch drivers 121a and 121b for transmitting a switch signal to each of the photosensor units PUa and PUb. In addition, the photosensor 120 may include sensing signal output circuits SOCa and SOCb for outputting sensing signals. In addition, although it is shown that 3*4 photosensor units PUa and PUb are arranged, this is illustrative and not limited thereto, and the photosensors 120a and 120b exist up to the k-th row and the i-th column. In this case, the number of switch signal lines may be k, and the number of first sensing signal lines and second sensing signal lines may be i, respectively.

Referring to FIG. 2 , the photosensor 120a includes a plurality of first sensing signal lines 1SL1a, 2SL1a, 3SL1a, and 4SL1a arranged in a vertical direction, and a plurality of first sensing signal lines 1SL1a, 2SL1a, 3SL1a, and 4SL1a. ) and a plurality of second sensing signal lines 1SL2a, 2SL2a, 3SL2a, and 4SL2a disposed in parallel, and a plurality of driving power lines disposed parallel to the plurality of second sensing signal lines 1SL2a, 2SL2a, 3SL2a, and 4SL2a ( 1VLa, 2VLa, 3VLa, 4VLa). And, a plurality of switch signal lines (SWL1a, SWL2a, SWL3a) for transmitting the switch signal in the horizontal direction may be disposed. Here, the switch signal lines SWL1a, SWL2a, and SWL3a are first sensing signal lines 1SL1a, 2SL1a, 3SL1a, and 4SL1a, second sensing signal lines 1SL2a, 2SL2a, 3SL2a, and 4SL2a, and driving power lines 1VLa and 2VLa. , 3VLa, 4VLa), but is not limited thereto. In addition, the photosensor 120a may include a driving power bus BBa connected to a plurality of driving power lines 1VLa, 2VLa, 3VLa, and 4VLa in a horizontal direction. Here, the horizontal direction and the vertical direction are illustrative and not limited thereto.

The photo sensor 120 includes first sensing signal lines 1SL1a, 2SL1a, 3SL1a, and 4SL1a, second sensing signal lines 1SL2a, 2SL2a, 3SL2a, and 4SL2a, and a driving power supply for each of the plurality of photo sensor units PUa and PUb. Lines (1VLa, 2VLa, 3VLa, 4VLa) may be connected. For example, as shown in FIG. 2, one photosensor unit PUa includes first sensing signal lines 1SL1a, 2SL1a, 3SL1a, and 4SL1a, and second sensing signal lines 1SL2a, 2SL2a, 3SL2a, and 4SL2a. And driving power lines (1VLa, 2VLa, 3VLa, 4VLa) may be connected to each one. However, as shown in FIG. 3 according to the characteristics of the photosensor units PUa and PUb, the first sensing signal lines 1SL1b, 2SL1b, 3SL1b and 4SL1b and the second sensing signal are connected to one photo sensor unit PUb. The lines 1SL2b, 2SL2b, 3SL2b, and 4SL2b may be connected one by one, and the first driving power lines 1VL1b, 2VL1b, 3VLb, and 4VL1b and the second driving power lines 1VL1b, 2VL1b, 3VLb, and 4VL1b may be connected one by one.

Referring to FIG. 2 , the photosensor unit PUa may detect irradiated light. The photosensor unit PUa may output a predetermined voltage corresponding to detected light in response to driving power received from the driving power lines 1VLa, 2VLa, 3VLa, and 4VLa. A predetermined voltage output from the photosensor unit PUa may be transmitted to the first sensing signal lines 1SL1a, 2SL1a, 3SL1a, and 4SL1a and the second sensing signal lines 1SL2a, 2SL2a, 3SL2a, and 4SL2a. A predetermined voltage transmitted to the first sensing signal lines 1SL1a, 2SL1a, 3SL1a, and 4SL1a is referred to as a first sensing voltage V1, and a predetermined voltage transmitted to the second sensing signal lines 1SL2a, 2SL2a, 3SL2a, and 4SL2a is referred to as a first sensing voltage V1. The voltage may be referred to as the second sensing voltage V2.

The switch driver 121a is connected to a plurality of switch signal lines SWL1a, SWL2a, and SWL3a disposed in the horizontal direction and can sequentially output a plurality of switch signals. Accordingly, after the switch signal is transmitted to the first switch signal line SWL1a among the plurality of switch signal lines SWL1a, SWL2a, and SWL3a, the switch signal may be transmitted to the second switch signal line SWL2a. In this way, switch signals can be transferred to all switch signal lines SWL1a, SWL2a, and SWL3a. The switch signal driven by the switch driver 121a may be selectively transmitted to the photosensor unit PUa, and the photosensor unit PUa receiving the switch signal may output a predetermined voltage.

The sensing signal output circuit SOCa may receive a predetermined voltage from the photosensor unit PUa and output a sensing signal. The sensing signal output circuit SOCa includes the first sensing voltage V1 transmitted to the first sensing signal lines 1SL1a, 2SL1a, 3SL1a, and 4SL1a and the voltage V1 transmitted to the second sensing signal lines 1SL2a, 2SL2a, 3SL2a, and 4SL2a. A sensing signal may be output in response to the second sensing voltage V2. In addition, the sensing signal output circuit SOCa outputs a first sensing signal in response to the first sensing voltage V1 and the reference voltage Vref transmitted to the first sensing signal lines 1SL1a, 2SL1a, 3SL1a, and 4SL1a. A second sensing signal may be output in response to the second sensing voltage V2 and the reference voltage Vref transmitted to the second sensing signal lines 1SL2a, 2SL2a, 3SL2a, and 4SL2a.

The sensing signal output circuit SOCb shown in FIG. 3 may also operate in a similar manner to receive a predetermined voltage from the photosensor unit PUb and output a sensing signal. The sensing signal output circuit SOCb includes the first sensing voltage V1 transmitted to the first sensing signal lines 1SL1b, 2SL1b, 3SL1b, and 4SL1b and the voltage V1 transmitted to the second sensing signal lines 1SL2b, 2SL2b, 3SL2b, and 4SL2b. A sensing signal may be output in response to the second sensing voltage V2. In addition, the sensing signal output circuit SOCa outputs a first sensing signal in response to the first sensing voltage V1 and the reference voltage Vref transmitted to the first sensing signal lines 1SL1b, 2SL1b, 3SL1b, and 4SL1b. A second sensing signal may be output in response to the second sensing voltage V2 and the reference voltage Vref transmitted to the second sensing signal lines 1SL2a, 2SL2a, 3SL2a, and 4SL2a. However, the sensing signal output circuit SOCb shown in FIG. 3 includes a first power bus BBb1 transmitting the first driving voltage Vcc1 and a second power bus BBb2 transmitting the second driving voltage Vcc2. can include The voltage level of the first driving voltage Vcc1 may be different from that of the second driving voltage Vcc2. Voltage levels of the first driving voltage Vcc1 and the second driving voltage Vcc2 may be determined corresponding to the characteristics of the photosensor unit PUb.

In addition, the first driving power lines 1VL1b, 2VL1b, 3VL1b, and 4VL1b are connected to the first power bus BBb1, and the second driving power lines 1VL2b, 2VL2b, 3VL2b, and 4VL2b are connected to the second power bus BBb2. can be connected

4 is a timing diagram illustrating an example of a switch signal output from a switch driver according to embodiments of the present invention. ,… ,

Referring to FIG. 4 , the switch driving units 121a and 121b shown in FIG. 2 or 3 may output a plurality of switch signals SSW1 , SSW2 , SSW3 , ..., SSWk. And, it is assumed that the photosensor 120 includes k photosensor rows. The switch signal may include a first switch signal to a k-th switch signal.

Here, description will be made using the switch driver 121a shown in FIG. 2 . However, the switch driver 121b shown in FIG. 3 may also operate in the same way. However, the operation of the switch driving units 121a and 121b is not limited thereto. The first switch signal SSW1 may be generated and transmitted to the first switch signal line SWL1a. Also, the second switch signal SSW2 may be generated and transmitted to the second switch signal line SWL2a. Also, the third switch signal SSW3 may be generated and transmitted to the third switch signal line SWL3a. In this way, switch signals are generated, and after the first switch signal SSW1 is generated, switch signals are sequentially generated, and finally, the k-th switch signal SSWk is generated and transmitted to the k-th switch signal line.

5 is a circuit diagram showing a photosensor unit according to embodiments of the present invention.

Referring to FIG. 5 , the photosensor unit PUa is a photodiode PDa having an anode electrode connected to the driving power line VLa and a cathode electrode connected to the first node N1a, and a first electrode connected to the first node N1a. (N1a), a second electrode is connected to the first sensing signal line (SL1a), a gate electrode is connected to the switch signal line (SWLa), and a first switching transistor (ST1a), and the first electrode is connected to the driving power line It may include a second switching transistor ST2a connected to (VLa), a second electrode connected to the second sensing signal line SL2a, and a gate electrode connected to the switch signal line SWLa. Here, the first sensing signal line SL1a and the second sensing signal line SL2a are the plurality of first sensing signal lines 1SL1a, 2SL1a, 3SL1a, and 4SL1a and the second sensing signal line 1SL2a shown in FIG. 2, respectively. , 2SL2a, 3SL2a, 4SL2a). The driving power line VLa may be one of the plurality of driving power lines 1VLa, 2VLa, 3VLa, and 4VLa shown in FIG. 2 . Also, the switch signal line SWLa may be one of the plurality of switch signal lines SWL1a, SWL2a, and SWL3a shown in FIG. 2 . However, it is not limited thereto.

In the photodiode PDa, current may flow from the anode electrode to the cathode electrode in response to the detected light intensity. The photodiode PDa may generate a first current I1a by receiving the driving voltage Vcc and detecting light. When the first driving voltage Vcc is transmitted to the anode electrode of the photodiode PDa, the first current I1a may flow in the cathode direction in response to the sensed intensity of light.

The first switching transistor ST1a may receive the first current I1a and transmit the first current I1a to the first sensing signal line SL1a in response to the switch signal. The first current I1a transferred from the photodiode PDa is transferred to the first electrode of the first switching transistor ST1a, and the voltage of the first switching transistor ST1a corresponds to the switch signal SSW transferred to the gate electrode. It may be transmitted to the first sensing signal line SL1a connected to the second electrode. The first sensing signal line SL1a to which the first current I1a is transferred may be referred to as a first sensing voltage V1. Since the characteristics of the first switching transistor ST1a may change in response to temperature, the first current I1a transmitted to the second electrode may include noise corresponding to the temperature. Here, the first electrode may be a source electrode and the second electrode may be a drain electrode. However, it is not limited thereto.

The second switching transistor ST2a may selectively receive the driving voltage Vcc in response to the switch signal SSW and transfer the second current I2a to the second sensing signal line SL2a. The voltage of the second sensing signal line SL2a to which the second current I2a is transferred may be referred to as a second sensing voltage V2. The driving voltage Vcc may be transmitted to the first electrode of the second switching transistor ST2a and the switch signal SSW may be transmitted to the gate electrode of the second switching transistor ST2a. In response to the switch signal SSW transmitted to the gate electrode, the second current I2a may flow from the first electrode to the second electrode. Here, the first electrode may be a source electrode and the second electrode may be a drain electrode. However, it is not limited thereto.

Since the characteristics of the second switching transistor ST2a can be changed in response to light and temperature, the second current I2a transmitted to the second electrode is included in the first current I1a by the first switching transistor ST1a. Noise corresponding to the set temperature may be included.

Also, since the first switching transistor ST1a and the second switching transistor ST2a are connected to the same switch signal line, they can be turned on/off at the same time. Here, simultaneous does not mean that they occur at exactly the same point in time, but may include the existence of a slight time difference. If the noise generated by the first switching transistor ST1a is removed using the noise generated by the second switching transistor ST2a, the sensing signal can be generated only with the current generated by the photodiode PDa, and the sensing signal is It can respond more accurately to the amount of light.

Also, the first switching transistor ST1a and the second switching transistor ST2a may have the same photoreactivity. Having the same photoreactivity may mean that the characteristics of the first switching transistor ST1a and the second switching transistor ST2a, which are changed by light and heat, are the same. Here, the same does not mean exactly the same and may include minor differences. Having the same photoreactivity may be that the active layers of the first switching transistor ST1a and the second switching transistor ST2a include an oxide semiconductor. However, it is not limited thereto.

Also, the first switching transistor ST1a and the second switching transistor ST2a may have different photoreactivity. Having different photoreactivity may mean that the characteristics of the first switching transistor ST1a and the second switching transistor ST2a, which are changed by light and heat, are different. Different photoreactivity may be that the active layer of the first switching transistor ST1a includes an oxide semiconductor, and the active layer of the second switching transistor ST2a includes amorphous silicon.

Also, the first switching transistor ST1a and the second switching transistor ST2a may share a gate electrode. Here, sharing the gate electrode may mean that the gate electrode of the first switching transistor ST1a and the gate electrode of the second switching transistor ST2a are connected to each other.

6 is a circuit diagram showing a photosensor unit according to embodiments of the present invention.

Referring to FIG. 6, the photosensor unit PUb shown in FIG. 3 includes a photodiode PDb having an anode electrode connected to the first driving power line VL1b and a cathode electrode connected to the first node N1b; A first switching transistor ST1b having a first electrode connected to the first node N1b, a second electrode connected to the first sensing signal line SL1b, and a gate electrode connected to the switch signal line SWLb; and A second switching transistor ST2b having a first electrode connected to the second driving power line VL2b, a second electrode connected to the second sensing signal line SL2b, and a gate electrode connected to the switch signal line SWLb. can include Here, the first sensing signal line SL1b and the second sensing signal line SL2b are the plurality of first sensing signal lines 1SL1b, 2SL1b, 3SL1b, and 4SL1b shown in FIG. 3 and the second sensing signal line 1SL2b, respectively. , 2SL2b, 3SL2b, 4SL2b). The first driving power line VL1b and the second driving power line VL2b are each one of the plurality of first driving power lines 1VL1b, 2VL1b, 3VL1b, and 4VL1b shown in FIG. 3 and the second driving power line 1VL2b , 2VL2b, 3VL2b, 4VL2b). Also, the switch signal line SWLb may be one of the plurality of switch signal lines SWL1b, SWL2b, and SWL3b shown in FIG. 3 . However, it is not limited thereto.

In the photodiode PDb, current may flow from the anode electrode to the cathode electrode in response to the sensed intensity of light. The photodiode PDb may generate a first current I1b by receiving the first driving voltage Vcc1 and detecting light. When the first driving voltage Vcc1 is transmitted to the anode electrode of the photodiode PDb, the first current I1b may flow from the anode electrode to the cathode electrode in response to the sensed intensity of light.

The first switching transistor ST1b may receive the first current I1b and transmit it to the first sensing signal line SL1b in response to the switch signal. The first current I1b transferred from the photodiode PDb is transferred to the first electrode of the first switching transistor ST1b and the voltage of the first switching transistor ST1b corresponds to the switch signal SSW transferred to the gate electrode. It may be transmitted to the first sensing signal line SL1b connected to the second electrode. The first sensing signal line SL1b to which the first current I1b is transferred may be referred to as a first sensing voltage V1. Since the characteristics of the first switching transistor ST1b may be changed in response to light and temperature, the first current I1b transmitted to the second electrode may include noise corresponding to light and temperature. Here, the first electrode may be a source electrode and the second electrode may be a drain electrode. However, it is not limited thereto.

The second switching transistor ST2b may selectively receive the second driving voltage Vcc2 in response to the switch signal SSW and transfer the second current I2b to the second sensing signal line SL2b. The voltage of the second sensing signal line SL2b to which the second current I2b is transferred may be referred to as a second sensing voltage V2. The second driving voltage Vcc2 may be transmitted to the first electrode of the second switching transistor ST2b and the switch signal SSW may be transmitted to the gate electrode of the second switching transistor ST2b. In response to the switch signal SSW transmitted to the gate electrode, the second current I2b may flow from the first electrode to the second electrode. Here, the first electrode may be a source electrode and the second electrode may be a drain electrode. However, it is not limited thereto.

Since the characteristics of the second switching transistor ST2b can be changed in response to light and temperature, the second current I2b transmitted to the second electrode is included in the first current I1b by the first switching transistor ST1b. It may include noise corresponding to the light and temperature.

Also, since the first switching transistor ST1b and the second switching transistor ST2b are connected to the same switch signal line, they can be turned on/off at the same time. Here, simultaneous does not mean that they occur at exactly the same point in time, but may include the existence of a slight time difference. If the noise generated by the first switching transistor ST1b is removed using the noise generated by the second switching transistor ST2b, the sensing signal can be generated only with the current generated by the photodiode PDb, and the sensing signal is the amount of light. can respond more accurately.

Also, the first switching transistor ST1b and the second switching transistor ST2b may have the same photoreactivity. Having the same photoreactivity may mean that the characteristics of the first switching transistor ST1b and the second switching transistor ST2b, which are changed by light and heat, are the same. Here, the same does not mean exactly the same and may include minor differences. Having the same photoreactivity may be that the active layers of the first switching transistor ST1b and the second switching transistor ST2b include an oxide semiconductor. However, it is not limited thereto.

Also, the first switching transistor ST1b and the second switching transistor ST2b may have different photoreactivity. Having different photoreactivity may mean that the characteristics of the first switching transistor ST1b and the second switching transistor ST2b, which are changed by light and heat, are different. Different photoreactivity may be that the active layer of the first switching transistor ST1b includes an oxide semiconductor, and the active layer of the second switching transistor ST2b includes amorphous silicon.

Also, the first switching transistor ST1b and the second switching transistor ST2b may share a gate electrode. Here, sharing the gate electrode may mean that the gate electrode of the first switching transistor ST1b and the gate electrode of the second switching transistor ST2b are connected to each other.

7 is a circuit diagram showing a first embodiment of the configuration of a sensing signal output circuit according to embodiments of the present invention.

Referring to FIG. 7 , the sensing signal output circuit SOCa shown in FIG. 2 receives a first sensing voltage V1 from a first input terminal and a second sensing voltage V2 from a second input terminal, thereby performing first sensing. A first sensing signal output circuit 710 outputting a sensing signal SS corresponding to the voltage V1 and the second sensing voltage V2 may be included. The first sensing voltage V1 may be transmitted through the first sensing signal line SL1a shown in FIG. 5 and the second sensing voltage V2 may be transmitted through the second sensing signal line SL2a.

The first sensing signal output circuit 710 may include an amplifier 711 and a capacitor CFa, and the first sensing voltage V1 is connected to the first input terminal (-) of the amplifier 711 and the second input terminal. The second sensing voltage V2 may be transmitted to (+). The first sensing signal line SL1a may be connected to the first input terminal (-) of the amplifier 711 and the second sensing signal line SL2a may be connected to the second input terminal (+). Also, the capacitor CFa may be connected between the output terminal (out) of the amplifier 711 and the first input terminal (-). The first sensing signal output circuit 710 compares the first sensing voltage V1 and the second sensing voltage V2 input to the first input terminal (-) and the second input terminal (+), and corresponds to the difference. A sensing signal SS may be output in response to the current. In addition, the sensing signal SS may be output corresponding to the amount of current output through the output terminal (out) of the amplifier 711 . The first sensing signal output circuit 710 may be an integrator. However, it is not limited thereto.

The first sensing voltage V1 may be generated in response to light and heat, and the second sensing voltage V2 may be generated in response to heat. The first sensing voltage V1 includes information about light and temperature, and the second sensing voltage V2 includes information about temperature. Since the first sensing voltage V1 and the second sensing voltage V2 are generated under the same temperature condition, the first sensing signal output circuit 710 outputs the first sensing voltage V1 and the second sensing voltage V2. Since the sensing signal SS can be output by comparison, the sensing signal SS can be generated in response to light. That is, noise caused by temperature can be removed.

8 is a circuit diagram showing a second embodiment of the configuration of a sensing signal output circuit according to embodiments of the present invention.

Referring to FIG. 8, the sensing signal output circuit SOCa shown in FIG. 2 receives a first sensing voltage V1 through a first input terminal (-) and supplies a reference voltage Vref to a second input terminal (+). The first sensing signal output circuit 811 receiving and outputting the first sensing signal SS1 receives the second sensing voltage V2 at the first input terminal (-) and the reference voltage Vref at the second input terminal (+). ) may be supplied and a second sensing signal output circuit 812 outputting the second sensing signal SS2. The first sensing voltage V1 may be transmitted to the first sensing signal line 1SL1a and the second sensing voltage V2 may be transmitted to the second sensing signal line SL2a.

The first sensing signal output circuit 811 may include a first amplifier 811a and a first capacitor CFa1, and a first sensing voltage V1 is applied to a first input terminal (-) of the first amplifier 811a. is connected, and the reference voltage Vref may be transmitted to the second input terminal (+) of the first amplifier 811a. In addition, a first capacitor CFa1 may be connected between the output terminal and the first input terminal (-) of the first amplifier 811a. The second sensing signal output circuit may include a second amplifier 812a and a second capacitor CFa2, and the second sensing voltage V2 is connected to the first input terminal (-) of the second amplifier 812a. The reference voltage Vref may be transmitted to the second input terminal (+) of the second amplifier 812a. In addition, a second capacitor CFa2 may be connected between the output terminal of the second amplifier 812a and the first input terminal (-). Each of the first sensing signal output circuit 811 and the second sensing signal output circuit 812 may be an integrator. However, it is not limited thereto.

The first sensing signal SS1 and the second sensing signal SS2 may be transmitted to the controller 1200 shown in FIG. 12 below, and the controller 1200 may transmit the first sensing signal SS1 and the second sensing signal SS2. Sensing data SD may be output in response to the signal SS2. The first sensing signal SS1 includes information about light and temperature, and the second sensing signal SS2 includes information about temperature. Since the first sensing signal SS1 and the second sensing signal SS2 are generated under the same temperature condition, the controller 1200 uses the first sensing signal SS1 and the second sensing signal SS2 to determine the temperature Components may be removed and sensing data SD may be generated using only information about light.

Although the sensing signal output circuit SOCa shown in FIG. 2 is described in FIGS. 7 and 8, it can also be applied to the sensing signal output circuit SCOb shown in FIG.

9 is a cross-sectional view showing a photosensor unit according to embodiments of the present invention.

Referring to FIG. 9 , the photosensor units PUa and PUb shown in FIGS. 2 and 3 include a gate metal 920 disposed on a substrate 910 and a gate insulating film disposed on the gate metal 920 ( 930), the first active layer 940a disposed in the first region above the gate insulating film 930 and overlapping the gate metal 920, and disposed in the second region above the gate insulating film 930 and the gate metal ( 920) disposed overlapping with the second active layer 940b, the first source electrode 941a and the first drain electrode 942a disposed on the first active layer 940a, and disposed on the second active layer 940b disposed on the second source electrode 941b, the second drain electrode 942b, the first source electrode 941a, the second source electrode 941b, the first drain electrode 942a, and the second drain electrode 942b A first planarization layer 950 disposed on the first planarization layer 950 and connected to the first drain electrode 942a, a first conductive layer 960a disposed on the first planarization layer 950 and connected to the first drain electrode 942a. A second conductive layer 960b connected to the second drain electrode 942b, a photoresist layer 961 disposed on the first conductive layer 960a, and a second planarization disposed in an area where the photoresist layer 961 is not disposed. A third conductive layer 980 and a third conductive layer 980 disposed over the film 970, the photoresist layer 961, and the second planarization film 970, but contacting the photoresist layer 961. 2 It may include an encap 990 disposed on the planarization layer 970 .

The substrate 910 may be flexible. That is, the substrate 910 may be bent. The substrate 910 may include PET and/or poly amide (PI). However, it is not limited thereto. The first conductive layer 960a, the photosensitive layer 961 disposed on the first conductive layer 960a, and the third conductive layer 980 disposed on the photosensitive layer 961 are illustrated in FIGS. 5 and 6 . It may be included in the illustrated photodiodes PDa and PDb. Here, the photosensitive layer 961 is illustrated as being disposed only on the first conductive layer 960a, but is not limited thereto. The photosensitive layer 961 may be a layer that detects light and allows current to flow. The photoresist layer 961 may include at least one organic layer. Here, each of the first active layer 940a and the second active layer 940b may include an oxide semiconductor. Also, the first active layer 940a may include an oxide semiconductor and the second active layer 940b may include amorphous silicon. However, it is not limited thereto. The encap 990 may protect the photosensitive layer 961 . The encap 990 may include an organic layer and an inorganic layer. However, it is not limited thereto. Here, the gate metal 920 is illustrated as being disposed under the first active layer 940a and the second active layer 940b, but is not limited thereto.

Here, the gate metal 920 may correspond to the gate electrodes of the first switching transistors ST1a and ST1b and the second switching transistors ST2a and ST2b shown in FIGS. 5 and 6 . In addition, the first conductive layer 960a and the second conductive layer 960b may correspond to the first sensing signal lines SL1a and SL1b and the second sensing signal lines SL2a and SL2b shown in FIGS. 5 and 6, respectively. can

10 is a plan view showing a first embodiment of a photosensor unit according to embodiments of the present invention, and FIG. 11 is a plan view showing a second embodiment of a photosensor unit according to embodiments of the present invention.

Referring to FIG. 10 , a first active layer 940a and a second active layer 940b may be respectively disposed on the upper surface of the photosensor unit shown in FIG. 9 to correspond to the first area and the second area. In addition, a first conductive layer 960a and a second conductive layer 960b may be respectively disposed on the upper surface of the photosensor unit to correspond to the first area and the second area. A photoresist layer 961 may be disposed on the first conductive layer 960a. A planarization film (not shown) may be disposed in another area including the second area where the photoresist layer 961 is not disposed. A third conductive layer (not shown) may be disposed on the photosensitive layer 940a. Accordingly, the photodiodes PDa and PDb shown in FIG. 5 or 6 may be formed by the first conductive layer 960a, the photosensitive layer 961, and the third conductive layer. However, as shown in FIG. 11 , the entire photoresist layer 961 may be applied and disposed in other regions including not only the upper portion of the first conductive layer 960a but also the upper portion of the second conductive layer 960b. . If the entire photoresist layer 961 is applied, the application of the second planarization film 970 shown in FIG. 9 may not be necessary. However, it is not limited thereto. In addition, the third conductive layer 980 shown in FIG. 9 is formed corresponding to the first region where the first conductive layer 960a is disposed, thereby forming the photodiodes PDa and PDb shown in FIG. 5 or 6. may be disposed only at positions corresponding to the first region.

12 is a structural diagram showing a controller in embodiments according to the present invention, and FIG. 13 is a graph showing a relationship between a first reference temperature and a corresponding amount of light.

Referring to FIGS. 12 and 13 , the controller 1200 includes a first lookup table 1210 storing a first reference temperature corresponding to an amount of current and a second lookup table 1210 storing a quantity of light corresponding to the first reference temperature Temp_ref. It may include a table 1220 and an arithmetic unit 1230 that outputs sensing data SD corresponding to the amount of current.

The first lookup table 1210 may store a function of a plurality of amounts of current and first reference temperatures corresponding to each amount of current. For example, the curve (a) shown in FIG. 13 may correspond to 0.10 mA, the curve (b) may correspond to 0.15 mA, and the curve (c) may correspond to 0.20 mA. However, this is illustrative and not limited thereto. Also, the second lookup table 1220 may store the amount of light corresponding to the amount of current.

The calculation unit 1230 receives a function from the first lookup table 1210 in response to the information on the first amount of current included in the second sensing signal SS2, and receives the first reference temperature from the second lookup table 1220. Information on the second amount of current included in the first sensing signal SS1 may be received corresponding to (Temp_ref). In addition, the calculation unit 1230 may receive information about the amount of light corresponding to the second amount of current and output sensing data SD. For example, information on the curve (b) is received from the first lookup table 1210, and information on the second amount of current calculated from the first reference temperature Temp_ref is obtained from the second lookup table 1220. After that, the information on the second amount of current can be output as sensing data SD corresponding to the curve (b).

In addition, the arithmetic unit 1230 converts the first sensing signal SS1 and the second sensing signal SS2 output from the sensing signal output circuits SOCa and SOCb shown in FIGS. 2 and 3 into an analog-to-digital converter (not shown). It can be transmitted as a digital signal through

The controller 1200 may be a micro controller unit (MCU). Also, the controller 1200 may be an application processor (AP) included in the external set. However, it is not limited thereto. Also, the controller 1200 may control the switch driving units 121a and 121b shown in FIG. 2 or 3 .

14 is a circuit diagram illustrating an example of a pixel employed in a display device according to example embodiments.

Referring to FIG. 14 , a pixel 101a may include an organic light emitting diode (OLED) and a pixel circuit driving the organic light emitting diode (OLED). The pixel circuit may include a first transistor M1, a second transistor M2, and a capacitor Cst.

The first transistor M1 has a gate electrode connected to the first node N1 and a first electrode connected to a second node N2 connected to the pixel power line VL1 to which the first pixel power EVDD is delivered. and the second electrode may be connected to the third node N3. The first transistor M1 may allow current to flow through the third node N3 in response to the voltage transmitted to the first node N1. The first electrode of the first transistor M1 may be a drain electrode, and the second electrode may be a source electrode. However, it is not limited thereto. The first transistor M1 may be referred to as a driving transistor.

A current flowing through the third node N3 may correspond to Equation 1 below.

Here, Id means the amount of current flowing through the third node N3, k means the electron mobility of the transistor, and V _GS means the voltage difference between the gate electrode and the source electrode of the first transistor M1. and Vth means the threshold voltage of the first transistor M1.

The second transistor M2 has a first electrode connected to the data line DL, a gate electrode connected to the gate line GL, and a second electrode connected to the first node N1. Accordingly, the second transistor M2 may transmit the data voltage Vdata corresponding to the data signal to the first node N1 in response to the gate signal transmitted through the gate line GL. The first electrode of the second transistor M2 may be a drain electrode, and the second electrode may be a source electrode. However, it is not limited thereto.

In the capacitor C1, a first electrode may be connected to the first node N1 and a second electrode may be connected to the third node N3. The capacitor C1 may keep the voltage of the gate electrode and the source electrode of the first transistor M1 constant.

The organic light emitting diode (OLED) may have an anode electrode connected to the third node N3 and a cathode electrode connected to the second pixel power source EVSS. Here, the voltage level of the second pixel power source EVSS may be lower than that of the first pixel power source EVSS. Also, the second pixel power source EVSS may be a ground. However, it is not limited thereto. The second pixel power EVSS may be supplied through a low power line. The second pixel power source EVSS may be commonly supplied to at least two organic light emitting diodes OLED. An organic light emitting diode (OLED) can emit light in response to the amount of current when a current flows from an anode electrode to a cathode electrode. The organic light emitting diode (OLED) may emit light of any one color among red, green, blue, and white. However, the color emitted by the organic light emitting diode (OLED) is not limited thereto. The pixels shown here are exemplary, and the pixels shown in FIG. 1 are not limited thereto.

The above description and accompanying drawings are merely illustrative of the technical idea of the present invention, and those skilled in the art can combine the configuration within the scope not departing from the essential characteristics of the present invention. , various modifications and variations such as separation, substitution and alteration will be possible. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed according to the claims below, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

100: organic light emitting display device
101: pixel
110: display panel
120: photosensor
130: data driver
140: gate driver
150: timing controller

Claims (20)

In a photosensor including a plurality of photosensor units that sense light and a sensing signal output circuit that outputs a sensing signal in response to the light sensed by the photosensor unit,
The photosensor unit is
a photodiode receiving a first driving voltage and sensing light to generate a first current;
a first switching transistor that receives the first current and selectively outputs a first sensing voltage in response to a switch signal; and
A photosensor comprising: a second switching transistor that receives a second driving voltage and selectively outputs a second sensing voltage by generating a second current in response to the switch signal.
According to claim 1,
The sensing signal output circuit receives the first sensing voltage supplied to a first input terminal and the second sensing voltage supplied to a second input terminal, and outputs the sensing signal corresponding to the first sensing voltage and the second sensing voltage. A photosensor comprising a first sensing signal output circuit.
According to claim 1,
The sensing signal output circuit includes a first sensing signal output circuit for outputting a first sensing signal by receiving the first sensing voltage supplied to a first input terminal and a reference voltage supplied to a second input terminal, and the second sensing signal output circuit to a first input terminal. A photosensor comprising a second sensing signal output circuit that receives a voltage and receives a reference voltage from a second input terminal and outputs a second sensing signal.
According to claim 1,
The first switching transistor and the second switching transistor are transistors having the same photoreactivity.
According to claim 1,
The first switching transistor and the second switching transistor are transistors having different photoreactivity.
According to claim 1,
The plurality of photosensor units are arranged in a matrix form arranged in a plurality of rows and columns,
The photosensor that sequentially outputs the switch signal and receives the switch signal at different times from the photosensor units arranged in different rows among the plurality of photosensor units.
According to claim 1,
The first switching transistor and the second switching transistor share a gate electrode.
According to claim 1,
The photosensor unit is
a photodiode having an anode electrode connected to the first driving power line and a cathode electrode connected to the first node;
a first switching transistor having a first electrode connected to the first node, a second electrode connected to a first sensing signal line, and a gate electrode connected to a switch signal line; and
A photosensor comprising a second switching transistor having a first electrode connected to a second driving power line, a second electrode connected to a second sensing signal line, and a gate electrode connected to the switch signal line.
A gate electrode disposed on the substrate;
A gate insulating layer disposed on the upper portion of the gate electrode;
a first active layer disposed in a first region above the gate insulating layer and overlapping the gate electrode;
a second active layer disposed in a second region above the gate insulating layer and overlapping the gate electrode;
a first source electrode and a first drain electrode disposed on the first active layer;
a second source electrode and a second drain electrode disposed on the second active layer;
a first planarization layer disposed on the first source electrode, the second source electrode, the first drain electrode, and the second drain electrode;
a first conductive layer disposed on the first planarization film and connected to the first drain electrode;
a second conductive layer disposed on the first planarization film and connected to the second drain electrode;
a photosensitive layer disposed on the first conductive layer;
a second planarization film disposed on the second conductive layer and disposed in an area other than the first area;
a third conductive layer disposed over the photosensitive layer and the second planarization film, and disposed to contact the photosensitive layer; and
A photosensor comprising an encap disposed on the third conductive layer and the second planarization layer.
According to claim 9,
The first active layer and the second active layer are oxide semiconductor photosensors.
According to claim 9,
The first active layer includes an oxide semiconductor, and the second active layer includes amorphous silicon.
display panel;
a photosensor disposed in at least one region below the display panel and including a plurality of photosensor units outputting a sensing voltage and a sensing signal output circuit outputting a sensing signal in response to a switch signal; and
Including a controller that outputs sensing data in response to the sensing signal,
The photosensor unit is
a photodiode receiving a first driving voltage and sensing light to generate a first current;
a first switching transistor that receives the first current and selectively outputs a first sensing voltage in response to the switch signal; and
A display device comprising a second switching transistor configured to receive a second driving voltage and selectively output a second sensing voltage by generating a second current in response to the switch signal.
According to claim 12,
The sensing signal output circuit receives the first sensing voltage supplied to a first input terminal and the second sensing voltage supplied to a second input terminal, and outputs the sensing signal corresponding to the first sensing voltage and the second sensing voltage. A display device including a first sensing signal output circuit.
According to claim 12,
The sensing signal output circuit includes a first sensing signal output circuit configured to receive the first sensing voltage through a first input terminal, receive a reference voltage through a second input terminal, and output a first sensing signal corresponding to the sensing signal; A display device comprising a second sensing signal output circuit that receives the second sensing voltage at an input terminal, receives a reference voltage at a second input terminal, and outputs a second sensing signal corresponding to the sensing signal.
According to claim 12,
The first switching transistor and the second switching transistor are transistors having the same photoreactivity.
According to claim 12,
The first switching transistor and the second switching transistor are transistors having different photoreactivity.
According to claim 12,
The plurality of photosensor units are arranged in a matrix form arranged in a plurality of rows and columns on at least a portion of the display panel,
The display device of claim 1 , wherein the switch signal is sequentially output so that the photo sensor units arranged in different rows among the plurality of photosensor units receive the switch signal at different times.
According to claim 12,
The first switching transistor and the second switching transistor share a gate electrode.
According to claim 14,
The controller
a first lookup table storing a first reference temperature corresponding to a first amount of current;
a second look-up table for storing the amount of light corresponding to the second amount of current;
Including a calculation unit for outputting the sensing data in response to the first amount of current and the second amount of current,
The calculation unit,
The first reference temperature is received from the first look-up table in response to information on the amount of first current included in the second sensing signal, and the first reference temperature is received from the second look-up table in correspondence to the first reference temperature. A display device configured to receive information on the amount of light in response to information on the amount of second current included in one sensing signal and output the sensing data.
According to claim 12,
The photosensor unit is
a photodiode having an anode electrode connected to the first driving power line and a cathode electrode connected to the first node;
a first switching transistor having a first electrode connected to the first node, a second electrode connected to a first sensing signal line, and a gate electrode connected to a switch signal line; and
A display device including a second switching transistor having a first electrode connected to a second driving power line, a second electrode connected to a second sensing signal line, and a gate electrode connected to the switch signal line.

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