KR20200025078A - Display device with photocells - Google Patents

Abstract

The present invention relates to a display device that receives reflected light of light output from the display device to recognize a user touch. According to an embodiment of the present invention, the display device comprises: a display panel having pixels for each intersection of the scan line and the data line; a plurality of first electrodes and second electrodes that are cross-formed in a lower part the display panel; a photoelectric cell provided between the first electrode and the second electrode and receiving reflected light output from the display panel and reflected by a reflector to form a voltage difference between the first electrode and the second electrode; and a detection part that detects a position of the reflector by detecting a voltage between the first electrode and the second electrode through a detection circuit connected to the first electrode and the second electrode, individually.

Description

Display device with built-in photocell {DISPLAY DEVICE WITH PHOTOCELLS}

The present invention relates to a display device that recognizes a user's touch by receiving reflected light of light output from the display device.

Recently, display devices basically provide a touch recognition function, and in addition, provide a fingerprint recognition function for improving user convenience and security.

The fingerprint recognition function is largely performed by an optical fingerprint sensor or a capacitive fingerprint sensor.

In the method using an optical fingerprint sensor (hereinafter, referred to as an optical sensing method), the light is irradiated by using a separate light source such as a light emitting diode (LED) inside the display device and the light reflected by the ridge of the fingerprint is image sensor. Detect through.

On the other hand, the method using the capacitive fingerprint sensor (hereinafter, capacitive sensing method) is based on the difference in the amount of electricity charged between the ridge and the valley of the fingerprint that the voltage pulse applied to the plurality of sensor electrodes contact the sensor. It is a way of detecting change.

However, according to the conventional optical sensing method, a separate light source for sensing a fingerprint is required. Accordingly, it is difficult to organically combine and use a separate light source in a display device that emits light. In addition, there is a limit in accurately sensing a fingerprint in the entire area of the display device due to the diffusion of the light output from the light source.

On the other hand, according to the capacitive sensing method, when displaying an image of one frame, the time for displaying the image and the time for sensing the fingerprint must be driven separately (time division driving), so the image must be displayed for a relatively short time. As a result, horizontal crosstalk and dim may occur in the display device.

An object of the present invention is to provide a display device that receives a reflected light of the light output from the display device through a photocell to recognize a user touch.

In addition, an object of the present invention is to provide a display device for adjusting the detection resolution by grouping a plurality of electrodes according to the detection target.

Another object of the present invention is to provide a display device using a voltage generated in a photovoltaic cell.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention which are not mentioned above can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

According to an exemplary embodiment of the present invention, a display panel includes a pixel for each intersection of a scan line and a data line, and a plurality of first electrodes and a second intersecting portion formed under the display panel. And a photocell provided between the first electrode and the second electrode to receive a reflected light output from the display panel and reflected by the reflector to form a voltage difference between the first electrode and the second electrode. And a detector configured to detect a position of the reflector by detecting a voltage between the first electrode and the second electrode through a detection circuit connected to the first electrode and the second electrode, respectively.

In addition, the display device according to an exemplary embodiment may include a detector configured to control the detection circuit to group at least one of the plurality of first electrodes and the plurality of second electrodes. do.

In addition, the display device according to an exemplary embodiment controls the detection circuit to short the plurality of first electrodes and the plurality of second electrodes to output a voltage between the first electrode and the second electrode. Characterized in that it comprises a detection unit.

According to the present invention, the user's touch can be recognized by receiving the reflected light of the light output from the display device through a photocell, thereby recognizing the user's touch through an optical sensing method without a separate light source.

In addition, the present invention has the effect of reducing the detection time by preventing unnecessary signal processing by adjusting the detection resolution by grouping a plurality of electrodes according to the detection target.

In addition, the present invention has the effect of providing an energy harvesting function as well as a sensing function by using the voltage generated in the photovoltaic cell.

1 illustrates a display device according to an exemplary embodiment of the present invention.
FIG. 2 is a diagram illustrating an example of an equivalent circuit corresponding to the pixel illustrated in FIG. 1.
3 is a diagram illustrating a state in which light output from a display panel is reflected by a reflector.
4 is a diagram illustrating an example of a light detection module in which the reflected light illustrated in FIG. 3 is received.
5 is a cross-sectional view of the light detection module shown in FIG. 4.
FIG. 6 is a diagram illustrating another example of a light detection module in which the reflected light shown in FIG. 3 is received.
FIG. 7 is a cross-sectional view of the light detection module shown in FIG. 6. FIG.
8 is a diagram illustrating a plurality of electrodes constituting the light detection module grouped according to a driving mode.
9 to 11 each show a detection circuit according to the driving mode shown in FIG. 8;

The above objects, features, and advantages will be described in detail with reference to the accompanying drawings, and thus, those skilled in the art may easily implement the technical idea of the present invention. In describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device for receiving a reflected light of light output from a display device and recognizing a user touch. The present invention relates to a liquid crystal display (LCD), a field emission display (FED), and a plasma display panel. The display panel may be implemented as a flat panel display device such as a plasma display panel (PDP), an organic light emitting display (OLED), an electrophoresis display (EPD), or the like.

Hereinafter, the present invention will be described on the assumption that the present invention is implemented as an OLED, but the present invention is not limited thereto. It may be implemented in any display device that can be transmitted through.

Hereinafter, a display device according to an exemplary embodiment of the present invention will be described in detail with reference to FIGS. 1 to 11.

1 illustrates a display device according to an exemplary embodiment of the present invention. 2 is a diagram illustrating an example of an equivalent circuit corresponding to the pixel illustrated in FIG. 1.

3 is a diagram illustrating a state in which light output from a display panel is reflected by a reflector.

4 is a diagram illustrating an example of a light detection module in which the reflected light shown in FIG. 3 is received, and FIG. 5 is a cross-sectional view of the light detection module illustrated in FIG. 4.

FIG. 6 is a diagram illustrating another example of a light detection module in which the reflected light illustrated in FIG. 3 is received, and FIG. 7 is a diagram illustrating a cross section of the light detection module illustrated in FIG. 6.

8 is a diagram illustrating a plurality of electrodes constituting the optical detection module grouped according to a driving mode, and FIGS. 9 to 11 are diagrams illustrating a detection circuit according to the driving mode illustrated in FIG. 8, respectively.

Referring to FIG. 1, a display device according to an exemplary embodiment includes a timing controller TC, a data driver DD, a gate driver GD, a display panel 10, and a light detection module OD. can do. Here, the light detection module OD may include the light detection panel 20, the detection circuit 30, and the detection unit 40. The display device illustrated in FIG. 1 is according to an exemplary embodiment, and its components are not limited to the exemplary embodiment illustrated in FIG. 1, and some components may be added, changed, or deleted as necessary.

The display panel 10 may include pixels for each intersection area of the scan line 12 and the data line 11. As illustrated in FIG. 1, the scan lines 12 may be arranged side by side in the horizontal direction and the data lines 11 may be arranged side by side in the vertical direction in the display panel 10. In this case, the pixel may be provided in a matrix form in an area where the plurality of scan lines 12 and the data lines 11 cross each other.

In addition, the display panel 10 includes a first driving power line 13 for supplying the first driving power VDD to the plurality of pixels PXL, and a second driving power having a potential lower than that of the first driving power VDD. It may further include a second driving power line for supplying (VSS).

The timing controller TC may rearrange the digital video data RGB input from the outside to match the resolution of the display panel 10 and supply the rearranged digital video data RGB ′ to the data driver DD.

In addition, the timing controller TC of the data driver DD may be configured based on timing signals such as a horizontal sync signal Hsync, a vertical sync signal Vsync, a dot clock signal DCLK, and a data enable signal DE. The data control signal DDC for controlling the operation timing and the gate control signal GDC for controlling the operation timing of the gate driver GD may be supplied.

The data driver DD may convert the rearranged digital video data RGB ′ into an analog data voltage VDATA based on the data control signal DDC. Subsequently, the data driver DD may supply the data voltage VDADA to each pixel PXL through the data lines 11.

The gate driver GD may sequentially supply the scan signal SCAN to the plurality of scan lines 12 based on the gate control signal GDC.

Although not shown in FIG. 1, the display panel 10 may include a pair of substrates that are opposed to each other and an organic light emitting diode array disposed therebetween. In addition, any one of the pair of substrates may be a thin film transistor array substrate for supplying a driving current to the organic light emitting diode OLED in each pixel PXL.

Referring to FIG. 2, each pixel PXL may include an organic light emitting diode OLED, a driving transistor DT, a switching transistor DT, and a storage capacitor Cst.

The driving transistor DT is in series with the organic light emitting diode OLED between the first driving power line 13 supplying the first driving power supply VDD and the second driving power supply line supplying the second driving power supply VSS. It can be arranged as.

The switching transistor ST may be disposed between the data line 11 supplying the data voltage VDATA to each pixel PXL and the node 1 ND1 connected to the gate electrode of the driving transistor DT. The switching transistor ST may be turned on according to the scan signal SCAN supplied to the scan line 12 to supply the data voltage VDATA to the node 1 ND1.

Both ends of the storage capacitor Cst may be connected to a node 1 ND1 and a node 2 ND2 between the driving transistor DT and the organic light emitting diode OLED. The storage capacitor Cst may be charged by the data voltage VDATA supplied to the node 1 ND1 through the turned-on switching transistor ST.

The driving transistor DT is turned on by the voltage charged in the storage capacitor Cst, and supplies a driving current corresponding to the data voltage VDATA to the node 2 ND2, that is, the organic light emitting diode OLED. .

According to the above-described operation, the pixel PXL may output light in the upper direction of the display panel 10.

Referring to FIG. 3, the light output from the display panel 10 may be output to the outside through a transmission body such as a cover glass C / G. In this case, when a reflector such as a fingerprint of a user is positioned on an upper surface of the display device, the light output to the outside may be reflected back to the display panel 10.

The reflected light may be received by the light detection module OD after passing through the display panel 10. Hereinafter, the structure and operation method of the light detection module OD will be described in detail with reference to FIGS. 4 to 11. .

The photodetector module OD is formed under the display panel 10 and may include the photodetector panel 20, the detection circuit 30, and the detector 40, and the photodetector panel 20 may include a first electrode ( 21, a second electrode 22, and a photo cell 23.

Referring to FIG. 4, the first electrode 21 and the second electrode 22 may cross each other under the display panel 10. More specifically, the plurality of first electrodes 21 and the plurality of second electrodes 22 may cross each other perpendicularly.

Accordingly, as shown in FIG. 4, the first electrode 21 and the second electrode 22 may form a cross region C11 ˜ Cmn in a matrix form.

In the present invention, the first electrode 21 and the second electrode 22 are terms for distinguishing two electrodes that cross each other, and one electrode may be defined relative to the other electrode. However, hereinafter, for convenience of explanation, it is assumed that the electrodes arranged side by side in the horizontal direction are assumed to be the first electrodes 21 and the electrodes arranged side by side in the vertical direction are described as the second electrodes 22.

The first electrode 21 and the second electrode 22 may be made of any conductive material. For example, indium tin oxide (ITO), conductive organic molecules, metal mesh, and carbon nanotubes (carbon) NanoTube (CNT), silver nanowires (Ag Nanowire) and the like.

Referring to FIG. 5, the photovoltaic cell 23 is provided between the first electrode 21 and the second electrode 22, and receives the light output from the display panel 10 and reflected by the reflector. A voltage difference may be formed between 21 and the second electrode 22.

In this case, the photovoltaic cell 23 may be formed of any device that converts light energy into electrical energy, and may be, for example, a photovoltaic cell, a photoresister, or the like.

However, in order to improve the flexibility of the substrate, the photovoltaic cell 23 may be preferably composed of OPV (Organic Photo Voltaic solar cell). At this time, OPV may be composed of a single molecule, PCBM, MPc (Methacryloyl Phosphoryl choline), Me-PCT, Pentacene, PTCBI, ICBA, polymers MEH-PPV, PCPDTBT, MDMO-PPV, P3HT, PDTTDABT It may be made of.

As described with reference to FIG. 3, when the reflector is positioned on the upper surface of the display device, the light output from the display panel 10 may be reflected back to the display panel 10. In this case, the photovoltaic cell 23 may receive the reflected light, and the reflected light may generate a current flow in the photocell 23 to form a constant voltage difference between the first electrode 21 and the second electrode 22. .

On the other hand, the photovoltaic cell 23 may receive a light output from an external light source in addition to the above-described reflected light to form a voltage difference between the first electrode 21 and the second electrode 22.

More specifically, the photovoltaic cell 23 converts any light energy received into electrical energy, and thus outputs from an external light source such as a laser pointer in addition to the reflected light by the reflector on the display panel 10 as described above. The received light can be converted into electrical energy.

The photovoltaic cell 23 includes a region where the first electrode 21 and the second electrode 22 cross each other in order to receive light at an arbitrary position provided with the first electrode 21 and the second electrode 22. It may be provided to include.

4 and 5, the single photovoltaic cell 23 may be formed wider than the first electrode 21 to be provided above the first electrode 21. Similarly, a single photovoltaic cell 23 may be formed wider than the second electrode 22 and disposed below the second electrode 22.

Accordingly, when light is incident on at least one of the plurality of intersecting areas C11 to Cmn where the first electrode 21 and the second electrode 22 intersect, the photovoltaic cell 23 may enter the corresponding intersecting area. A voltage difference may be formed between the provided first electrode 21 and the second electrode 22.

Referring to FIG. 4 as an example, when a user inputs a touch on an intersection area of C11, C12, C21, and C22, reflected light may be incident on the intersection area C11, C12, C21, and C22. . In this case, the photovoltaic cell 23 provided to include the corresponding intersection regions C11, C12, C21, and C22 receives the reflected light to receive two first electrodes (2) provided in the corresponding intersection regions C11, C12, C21, and C22. A voltage difference according to the reflected light may be formed between the 21 and the second electrodes 22.

On the other hand, the photovoltaic cell 23 may be provided in a matrix form in each region where the first electrode 21 and the second electrode 22 intersect.

Referring to FIG. 6, the photovoltaic cell 23 may be formed of a plurality of sub photovoltaic cells 23, and the plurality of sub photovoltaic cells 23 may be formed at intersection regions formed by the first electrode 21 and the second electrode 22. C11 to Cmn).

In this case, the plurality of sub-photovoltaic cells 23 may include the first electrode 21 and the second electrode 22 so as to receive light at an arbitrary position provided with the first electrode 21 and the second electrode 22. It may be provided to include the intersecting areas (C11 ~ Cmn) to form.

Referring to FIG. 7, a plurality of sub photovoltaic cells 23 may be formed on the first electrode 21 and provided in the first upper portion. In addition, the plurality of sub photovoltaic cells 23 may have a width wider than that of the second electrode 22, and may be provided under the second electrode 22. Accordingly, each sub photovoltaic cell 23 may be formed to include an intersecting region C11 to Cmn where the first electrode 21 and the second electrode 22 cross each other, and may be separately formed from the adjacent sub photovoltaic cells 23. .

In this structure, when light is incident on at least one of the plurality of intersecting areas C11 to Cmn where the first electrode 21 and the second electrode 22 intersect, the photovoltaic cell 23 is applied to the corresponding area. A voltage difference may be formed between the provided first electrode 21 and the second electrode 22.

Referring to FIG. 6 as an example, when the laser pointer irradiates laser light on an intersection area of C22, C23, C32, and C33, laser light may be incident on the intersection area C22, C23, C32, and C33. In this case, the plurality of sub-photovoltaic cells 23 provided to include the corresponding crossing regions C22, C23, C32, and C33 receive laser light, and thus, the two sub-photovoltaic cells 23 provided in the corresponding crossing regions C22, C23, C32, and C33. The voltage difference according to the laser light may be formed between the first electrode 21 and the two second electrodes 22.

As described above, when the photovoltaic cell 23 is formed of the sub photovoltaic cells 23 arranged in a matrix form, crosstalk between electrodes can be prevented.

Referring again to FIG. 4, when the photovoltaic cell 23 is provided as a single unit to include a region where the first electrode 21 and the second electrode 22 cross each other, the voltage difference due to the received light forms an adjacent crossing region. Can occur between the electrodes.

For example, when light is received on the C12 crossing region, diffusion of electrons and holes may occur in the photocell 23 by the received light. At this time, the electrons and holes can be widely spread to the adjacent C13 crossing region, and thus a voltage difference may occur between the electrode forming the C12 crossing region and the electrode forming the C13 crossing region.

In contrast, referring to FIG. 6, when the photovoltaic cell 23 includes a plurality of sub-photovoltaic cells 23 each including a region where the first electrode 21 and the second electrode 22 intersect with each other, The voltage difference can only occur between the electrodes forming one cross region.

For example, when light is received on the C12 crossing region, diffusion of electrons and holes may occur in the photocell 23 by the received light. However, since the sub-photovoltaic cell 23 and the sub-photovoltaic cell 23 adjacent to the C12 cross region are physically separated, the voltage difference may occur only in the electrode forming the C12 cross region.

Accordingly, as shown in FIG. 6, when the photovoltaic cell 23 is formed of the matrix sub-photovoltaic cell 23, crosstalk between electrodes may not occur.

The detector 40 detects a voltage between the first electrode 21 and the second electrode 22 through a detection circuit 30 connected to the first electrode 21 and the second electrode 22, respectively, and detects the detected voltage. The position of the reflector can be detected based on the voltage.

As shown in FIGS. 4 and 6, the plurality of first electrodes 21 may be connected to the detection circuit 30 through the plurality of first electrode lines HL1 to HLm. In addition, the plurality of second electrodes 22 may be connected to the detection circuit 30 through the plurality of second electrode lines VL1 to VLn.

In the drawing, the detection circuit 30 connected to the first electrode lines HL1 to HLm and the detection circuit 30 connected to the second electrode lines VL1 to VLn are illustrated, respectively, for convenience of description. The electrode lines HL1 to HLm and the second electrode lines VL1 to VLn may be connected to any one detection circuit 30 in position.

5 and 7, the detector 40 is connected to the first electrode lines HL1 to HLm and the second electrode 22 connected to the first electrode 21 through the detection circuit 30. Each of the two electrode lines VL1 to VLn may be connected to detect a voltage between the two electrode lines.

The detector 40 may identify the electrode line where the voltage is detected by comparing the magnitude of the detected voltage with the magnitude of the reference voltage. More specifically, the detector 40 may selectively identify a detection line among the one or more electrode lines from which the voltage is detected, in which the detected voltage is equal to or greater than the reference voltage.

For example, a foreign material such as dust may be positioned on an upper surface of the display device, and the light output from the display panel 10 may be reflected by the foreign material and received by the photovoltaic cell 23. In this case, the voltage difference generated by the reflected light may be less than the reference voltage, and the electrode line having the voltage difference may not be identified by the detector 40.

On the other hand, the user's finger may be positioned on the upper surface of the display device, and the light output from the display panel 10 may be reflected by the finger and received by the photocell 23. In addition, a laser point (laser light) may be positioned on an upper surface of the display device, and the laser light may be received by the photocell 23. In this case, the voltage difference generated by the received light may be greater than or equal to the reference voltage, and the electrode line having the corresponding voltage difference may be identified by the detector 40.

Referring to FIG. 6 as an example, when laser light is input on a cross region of C11, a voltage difference greater than or equal to a reference voltage may occur between the first electrode 21 and the second electrode 22 forming the cross region C11. Can be.

The detector 40 may identify the voltage difference through the first electrode line HL1 located at the top of the horizontal line and the second electrode line VL1 located at the left end of the vertical line. Accordingly, the detector 40 may detect the position where the laser light is input to the region C11 where the first electrode line of HL1 and the second electrode line of VL1 intersect each other.

In another example, when a user inputs a user touch on an intersection area of C11, C12, C21, and C22, the first electrode 21 and the second electrode forming the corresponding intersection area C11, C12, C21, and C22. A voltage difference of more than the reference voltage may occur between the 22.

The detector 40 may identify the voltage difference through two first electrode lines HL1 and HL2 positioned at the top of the horizontal line and two second electrode lines VL1 and VL2 positioned at the left end of the vertical line. have. Accordingly, the detector 40 may detect the position where the user touch is input to the regions C11, C12, C21, and C22 where the first electrode lines of HL1 and HL2 intersect the second electrode line of VL1 and VL2. .

The reference voltage may be set differently according to the driving mode described later, and the reference voltage may be set higher in the laser point mode than in the touch mode and the fingerprint mode.

As described above, the present invention receives the reflected light of the light output from the display device through the photocell 23 to recognize the user touch, so that the user touch can be recognized through the optical sensing method without a separate light source.

The detector 40 may control the detection circuit 30 to group at least one of the plurality of first electrodes 21 and the plurality of second electrodes 22.

Referring to FIG. 8, the detector 40 may control the detection circuit 30 according to a driving mode to group electrodes. Meanwhile, in FIG. 8, for convenience of description, the first electrode 21 arranged horizontally and the second electrode 22 arranged vertically are briefly illustrated with conductive lines.

The resolution of the electrode for detecting a user fingerprint may be higher than the resolution (pixels per inch) of the electrode for detecting a laser point. In addition, the resolution of the electrode for detecting the laser point may be higher than the resolution of the electrode for detecting the user touch.

Accordingly, when an electrode for detecting a user fingerprint or a laser point is used to detect a user touch, unnecessary signal processing must be performed and a detection speed is slowed.

To solve this problem, the detector 40 may control the detection circuit 30 according to the driving mode to group the electrodes, thereby adjusting the resolution of the electrodes.

More specifically, as illustrated in FIG. 8, the detector 40 may adjust the detection resolution to the maximum by not grouping electrodes in the fingerprint mode. Accordingly, the detector 40 can detect the voltage from all the electrodes.

On the other hand, the detector 40 may adjust the detection resolution by grouping the electrodes in the laser pointer mode and the touch mode. For example, the detector 40 may group two adjacent electrodes in the laser pointer mode, and may group four adjacent electrodes in the touch mode.

In the following description, only the contents of grouping the first electrode 21 by controlling the detection circuit 30 by the detector 40 for convenience of explanation will be described. However, the method described below may be applied to the second electrode 22. .

In an example, the detection circuit 30 may be turned on according to the first enable signal to connect the plurality of first electrodes 21 to the detection unit 40 through the first sensing line, respectively. The second switch S2 may be turned on according to the second enable signal to connect two adjacent electrodes of the plurality of first electrodes 21 to the detector 40 through a second sensing line.

9, the detector 40 may group electrodes according to two driving modes. For example, the two driving modes may be a fingerprint mode and a laser point mode.

In this case, the first enable signal may be a fingerprint enable signal, and the second enable signal may be a laser pointer enable signal. The fingerprint enable signal may be supplied when in the fingerprint mode, and the laser pointer enable signal may be supplied when in the laser pointer mode.

The first switch S1 may be turned on according to the fingerprint enable signal to connect the plurality of first electrodes 21 to the first sensing lines F1 to F8. The second switch S2 may be turned on according to the laser pointer enable signal to connect two adjacent electrodes among the plurality of first electrodes 21 to the second sensing lines L1 to L4, respectively.

The first sensing lines F1 to F8 and the second sensing lines L1 to L4 are connected to the detector 40, and the detector 40 is configured to detect each sensing line and the first electrode 21 based on the driving mode. The voltage difference formed between the first electrode 21 and the second electrode 22 may be detected through each sensing line with respect to the second electrode 22.

In another example, the detection circuit 30 may be turned on according to the first enable signal to connect the plurality of first electrodes 21 to the detection unit 40 through the first sensing line, respectively. The second switch S2 may be turned on according to the second enable signal or the third enable signal to connect two adjacent electrodes of the plurality of first electrodes 21 to the first node.

In addition, the detection circuit 30 may be turned on according to the second enable signal to connect the third switch S3 to the detection unit 40 through the second sensing line, respectively, and to the third enable signal. Accordingly, a fourth switch S4 which is turned on to connect two adjacent first nodes to the detector 40 through a third sensing line, respectively.

Referring to FIG. 10, the detector 40 may group electrodes according to three driving modes. For example, the three driving modes may be a fingerprint mode, a laser point mode, and a touch mode.

In this case, the first enable signal may be a fingerprint enable signal, the second enable signal may be a laser pointer enable signal, and the third enable signal may be a touch enable signal. The fingerprint enable signal may be supplied in the fingerprint mode, the laser pointer enable signal may be supplied in the laser pointer mode, and the touch enable signal may be supplied in the touch mode.

The first switch S1 may be turned on according to the fingerprint enable signal to connect the plurality of first electrodes 21 to the first sensing lines F1 to F8.

The second switch S2 may be turned on according to the laser pointer enable signal or the touch enable signal to connect two adjacent electrodes of the plurality of first electrodes 21 to the first node N1, respectively.

The third switch S3 may be turned on according to the laser pointer enable signal to connect the first node to the second sensing lines L1 to L4.

The fourth switch S4 may be turned on according to the touch enable signal to connect two adjacent first nodes to the third sensing lines T1 and T2.

The first sensing lines F1 to F8, the second sensing lines L1 to L4, and the third sensing lines T1 and T2 are connected to the detector 40, and the detector 40 is connected to the first electrode according to the driving mode. A voltage difference formed between the first electrode 21 and the second electrode 22 may be detected through each sensing line for the 21 and each sensing line for the second electrode 22.

On the other hand, the photovoltaic cell 23 used in the present invention may not only receive the reflected light by the user's touch and the laser light output from the laser pointer as described above, but may also receive any external light.

At this time, the photovoltaic cell 23 may generate current flow due to external light. The detector 40 may perform an energy harvesting operation using the generated current.

To this end, the detection unit 40 controls the detection circuit 30 to short the plurality of first electrodes 21 and the plurality of second electrodes 22 so that the first electrode 21 and the second electrode ( It is possible to output the voltage (Vsolar) between the 22).

The detector 40 shorts the plurality of first electrodes 21 to one node, shorts the plurality of second electrodes 22 to another node, and outputs a voltage Vsolar between the two nodes. The voltage can be supplied to internal batteries, external devices, and the like.

More specifically, the detector 40 may short the first electrode 21 and the second electrode 22 in a solar cell mode for energy harvesting.

Referring to the solar cell mode illustrated in FIG. 8, the plurality of first electrodes 21 may be connected to the detector 40 through a first short line in the detection circuit 30 for energy harvesting. Similarly, the plurality of second electrodes 22 may be connected to the detector 40 through the second short line in the detection circuit 30. In this case, the detector 40 may output a voltage Vsolar between the first short line and the second short line.

In addition to the above three driving modes, the detector 40 may group the electrodes according to a total of four driving modes including a mode for energy harvesting.

To this end, the detection circuit 30 may be turned on according to the first enable signal to connect the plurality of first electrodes 21 to the detection unit 40 through the first sensing line, respectively; And a second switch S2 turned on according to the second enable signal, the third enable signal, or the fourth enable signal to connect two adjacent electrodes of the plurality of first electrodes 21 to the first node, respectively. can do.

In addition, the detection circuit 30 may be turned on according to the second enable signal to connect the first node to the detector 40 through the second sensing line, respectively, and a third enable signal or It may include a fourth switch (S4) is turned on according to the fourth enable signal to connect two adjacent first nodes to the second node, respectively.

In addition, the detection circuit 30 may be turned on according to the third enable signal to connect the second node to the detection unit 40 through the third sensing line, respectively, and the fourth enable signal. As a result it may include a sixth switch (S6) is turned on to connect the second node to the short line.

Referring to FIG. 11, the detector 40 may group electrodes according to the three driving modes and the solar cell mode described with reference to FIG. 10.

In this case, the first enable signal may be a fingerprint enable signal, the second enable signal may be a laser pointer enable signal, the third enable signal may be a touch enable signal, and the fourth enable signal may be a touch enable signal. The enable signal may be a solar enable signal.

The fingerprint enable signal may be supplied in the fingerprint mode, the laser pointer enable signal may be supplied in the laser pointer mode, and the touch enable signal may be supplied in the touch mode. In addition, the solar enable signal may be supplied when in the solar cell mode.

The first switch S1 may be turned on according to the fingerprint enable signal to connect the plurality of first electrodes 21 to the first sensing lines F1 to F8.

The second switch S2 may be turned on according to the laser pointer enable signal, the touch enable signal or the solar enable signal to connect two adjacent electrodes of the plurality of first electrodes 21 to the first node, respectively.

The third switch S3 may be turned on according to the laser pointer enable signal to connect the first node to the second sensing lines L1 to L4.

The fourth switch S4 may be turned on according to the touch enable signal or the solar enable signal to connect two adjacent first nodes to the second node, respectively.

The fifth switch S5 may be turned on according to the touch enable signal to connect the second node with the third sensing lines T1 and T2.

The sixth switch S6 may be turned on according to the solar enable signal to connect the second node with the short line S. FIG.

The first sensing lines F1 to F8, the second sensing lines L1 to L4, the third sensing lines T1 and T2, and the short line S are connected to the detector 40, and the detector 40 is driven. According to the mode, the voltage difference formed between the first electrode 21 and the second electrode 22 is detected through each sensing line for the first electrode 21 and each sensing line for the second electrode 22, or The voltage Vsolar between the first electrode 21 and the second electrode 22 may be output.

As described above, according to the present invention, by grouping a plurality of electrodes in accordance with the detection target, it is possible to prevent unnecessary signal processing by adjusting the resolution of the electrode according to the user's needs, and accordingly, such as fingerprint, touch, laser point The detection time can be shortened.

In addition, the present invention outputs the voltage generated in the photovoltaic cell where the power source such as a battery, an external device, there is an advantage that can perform the energy harvesting function as well as the sensing function.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by.

Claims (12)

A display panel including a pixel at each intersection of the scan line and the data line;
A plurality of first and second electrodes intersecting with each other under the display panel;
A photovoltaic cell disposed between the first electrode and the second electrode and receiving a reflected light output from the display panel and reflected by the reflector to form a voltage difference between the first electrode and the second electrode; And
A detection unit detecting a position of the reflector by detecting a voltage between the first and second electrodes through a detection circuit connected to the first and second electrodes, respectively.
Display device.
The method of claim 1,
The photovoltaic cell receives light output from an external light source to form a voltage difference between the first electrode and the second electrode.
The method of claim 1,
The photovoltaic cell is provided to include a region where the first electrode and the second electrode intersect.
The method of claim 1,
The photovoltaic cell includes a plurality of sub-photovoltaic cells provided in a matrix form in each region where the first electrode and the second electrode cross each other.
The method of claim 4, wherein
And the sub-photovoltaic cell includes a region where the first electrode and the second electrode cross each other.
The method of claim 1,
The detection unit controls the detection circuit to group at least one of the plurality of first electrodes and the plurality of second electrodes.
The method of claim 1,
And the detector is configured to control the detection circuit to short the plurality of first electrodes and the plurality of second electrodes to output a voltage between the first electrode and the second electrode.
The method of claim 7, wherein
The plurality of first electrodes are connected to the detection unit through a first short line in the detection circuit,
The plurality of second electrodes are connected to the detection unit through a second short line in the detection circuit,
And the detector outputs a voltage between the first short line and the second short line.
The method of claim 1,
The detection circuit
A first switch turned on according to a first enable signal to connect the plurality of first electrodes to the detector through a first sensing line, respectively;
And a second switch turned on according to a second enable signal to connect two adjacent electrodes of the plurality of first electrodes to the detection unit through a second sensing line, respectively.
The method of claim 1,
The detection circuit
A first switch turned on according to a first enable signal to connect the plurality of first electrodes to the detector through a first sensing line, respectively;
A second switch turned on according to a second enable signal or a third enable signal to connect two adjacent electrodes of the plurality of first electrodes to a first node, respectively;
A third switch that is turned on according to the second enable signal and connects the first node to the detection unit through a second sensing line;
And a fourth switch that is turned on according to the third enable signal and connects the two adjacent first nodes to the detector through a third sensing line, respectively.
The method of claim 1,
The detection circuit
A first switch turned on according to a first enable signal to connect the plurality of first electrodes to the detector through a first sensing line, respectively;
A second switch that is turned on according to a second enable signal, a third enable signal, or a fourth enable signal to connect two adjacent electrodes of the plurality of first electrodes to a first node, respectively;
A third switch that is turned on according to the second enable signal and connects the first node to the detection unit through a second sensing line;
A fourth switch turned on according to the third enable signal or a fourth enable signal to connect the two adjacent first nodes to a second node, respectively;
A fifth switch which is turned on according to the third enable signal and connects the second node to the detection unit through a third sensing line;
And a sixth switch turned on according to the fourth enable signal to connect the second node to the short line.
The method of claim 1,
The detection unit
And a position of the reflector is detected by comparing the voltage between the first electrode and the second electrode with a reference voltage.

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