Display device

Abstract

The invention provides a display device. The display device includes a display panel and a readout circuit. The display panel includes light emitting pixels and light sensing pixels. Each of the light emitting pixels includes a light emitting element, and each of the light sensing pixels includes a photoelectric conversion element. The readout circuit is connected to the light sensing pixel through a readout line. When operating in a photoplethysmography (PPG) sensing mode, the readout circuit may receive a first sensing current from one or more of the light sensing pixels in a first sensing region adjacent to a sensing light emitting region emitting light, a second sensing current from one or more of the light sensing pixels in a second sensing region spaced apart from the first sensing region may be received, and a PPG signal may be generated based on the first sensing current and the second sensing current.

Description

Technical Field

[0001] One or more embodiments described herein relate to a display device. Background Art

[0002] Electronic devices (e.g., smart phones, smart watches, etc.) that perform biometric sensing operations have been developed. Examples of biometric sensing operations include fingerprint sensing operations and photoplethysmography (PPG) sensing operations. The electronic device may perform the biometric sensing operation using a sensor that is separate from the display device. In this case, the size of the display area of ​​the electronic device or display device may be reduced, and additionally, the size of the frame may be increased. In an attempt to address this problem, in-cell light sensor technology has been developed. In-cell light sensor technology employs optical sensors or light sensing pixels within the display area of ​​the display device. Summary of the invention

[0003] One or more embodiments described herein provide a display device with improved sensing accuracy. These embodiments may be applied during detection of a user's biosignal, such as but not limited to a photoplethysmography (PPG) signal.

[0004] Additional features of the inventive concept will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the inventive concept.

[0005] A display device according to an embodiment may include a display panel including light-emitting pixels and light-sensing pixels. Each of the light-emitting pixels includes a light-emitting element, and each of the light-sensing pixels includes a photoelectric conversion element. The display device may also include a readout circuit connected to the light-sensing pixels through a readout line. When operating in a photoplethysmography (PPG) sensing mode, the readout circuit may receive a first sensing current from one or more of the light-sensing pixels in a first sensing area adjacent to the light-emitting sensing light-emitting area, may receive a second sensing current from one or more of the light-sensing pixels in at least one second sensing area spaced apart from the first sensing area, and may generate a PPG signal based on the first sensing current and the second sensing current.

[0006] In an embodiment, the at least one second sensing area may be spaced apart from the sensing light emitting area. The reflected light emitted from the sensing light emitting area and reflected from the blood vessels of the user's finger may be incident into the first sensing area. The reflected light may not be incident into the second sensing area.

[0007] In an embodiment, the at least one second sensing region may be located at one side of the sensing light emitting region.

[0008] In an embodiment, the display device may include a plurality of second sensing regions, and the plurality of second sensing regions may be located at different sides of the sensing light emitting region.

[0009] In an embodiment, a size of the second sensing region may be larger than a size of the first sensing region.

[0010] In an embodiment, in a plan view, the sensing light emitting area may surround at least a portion of the first sensing area.

[0011] In an embodiment, a distance between the sensing light emitting region and the one or more second sensing regions may be greater than or equal to a width of the sensing light emitting region.

[0012] In an embodiment, the readout circuit may include: a sensing circuit, which receives a first sensing current and a second sensing current through a readout line, generates a first sensing signal corresponding to the first sensing current, and generates a first noise signal corresponding to the second sensing current; a low-pass filter, which receives the first noise signal from the sensing circuit and generates a second noise signal; and a noise eliminator, which receives the first sensing signal from the sensing circuit, receives the second noise signal from the low-pass filter, and generates a second sensing signal based on the first sensing signal and the second noise signal.

[0013] In an embodiment, the first sensing region may include a first-first sensing region and a first-second sensing region spaced apart from each other, and reflected light is incident on each of the first-first sensing region and the first-second sensing region. The readout circuit may receive a first-first sensing current from a light sensing pixel in the first-first sensing region, may receive a first-second sensing current from a light sensing pixel in the first-second sensing region, and may generate a PPG signal based on the first-first sensing current, the first-second sensing current, and the second sensing current.

[0014] In an embodiment, the readout circuit may include: a sensing circuit, receiving a first-first sensing current, a first-second sensing current, and a second sensing current through a readout line; generating a first sensing signal corresponding to the first-first sensing current; generating a second sensing signal corresponding to the first-second sensing current; and generating a first noise signal corresponding to the second sensing current; a low-pass filter, receiving the first noise signal from the sensing circuit and generating a second noise signal; a band-stop filter, receiving the second sensing signal from the sensing circuit and generating a third noise signal; and a noise eliminator, receiving the first sensing signal from the sensing circuit, receiving the second noise signal from the low-pass filter, receiving the third noise signal from the band-stop filter, and generating a third sensing signal based on the first sensing signal, the second noise signal, and the third noise signal.

[0015] In an embodiment, the readout circuit may further include: a bandpass filter, which receives the second sensing signal from the sensing circuit and generates a fourth sensing signal; and an operational amplifier, which receives the third sensing signal from the noise eliminator, receives the fourth sensing signal from the bandpass filter, and generates a fifth sensing signal based on the third sensing signal and the fourth sensing signal.

[0016] In an embodiment, the second sensing area may be adjacent to the sensing light emitting area. Reflected light emitted from the sensing light emitting area and reflected from a blood vessel of the user's finger may be incident into each of the first sensing area and the second sensing area.

[0017] In an embodiment, the readout circuit may include: a sensing circuit, which receives a first sensing current and a second sensing current through a readout line, generates a first sensing signal corresponding to the first sensing current, and generates a first noise signal corresponding to the second sensing current; a band-stop filter, which receives the second sensing signal from the sensing circuit and generates a noise signal; and a noise eliminator, which receives the first sensing signal from the sensing circuit, receives the noise signal from the band-stop filter, and generates a third sensing signal based on the first sensing signal and the noise signal.

[0018] In an embodiment, the readout circuit may include a bandpass filter and an operational amplifier, wherein the bandpass filter receives the second sensing signal from the sensing circuit and generates a fourth sensing signal, the operational amplifier receives the third sensing signal from the noise eliminator, receives the fourth sensing signal from the bandpass filter, and generates a fifth sensing signal based on the third sensing signal and the fourth sensing signal.

[0019] In an embodiment, in the PPG sensing mode, in the sensing luminescent area, the luminescent pixels may be turned on and the light sensing pixels may be turned off. In the PPG sensing mode, in the first sensing area, the luminescent pixels may be turned off and the light sensing pixels may be turned on. In the PPG sensing mode, in the second sensing area, the luminescent pixels may be turned off and the light sensing pixels may be turned on.

[0020] In an embodiment, the light-emitting pixels and the light-sensing pixels may be arranged in the entire display area of ​​the display panel. The display area may include a sensing light-emitting area, a first sensing area, a second sensing area, and a shut-off area. In the PPG sensing mode, the light-emitting pixels and the light-sensing pixels in the shut-off area may be shut off.

[0021] In an embodiment, each of the light-emitting pixels may include: a first transistor that generates a driving current; a second transistor that transmits a data signal in response to a write signal; a third transistor that diode-connects the first transistor in response to a compensation signal; a fourth transistor that transmits an initialization voltage to the gate of the first transistor in response to an initialization signal; a fifth transistor that connects a line of a first power supply voltage and the first transistor in response to an emission signal; a sixth transistor that connects the first transistor and a light-emitting element in response to the emission signal; a seventh transistor that transmits an anode initialization voltage to the light-emitting element in response to a bypass signal; an eighth transistor that transmits a bias voltage to a terminal of the first transistor in response to the bypass signal; a storage capacitor that is connected between the line of the first power supply voltage and the gate of the first transistor; and the light-emitting element that emits light based on the driving current.

[0022] In an embodiment, each of the light sensing pixels may include: a ninth transistor that generates a sensing current based on the voltage of the anode of the photoelectric conversion element; a tenth transistor that transmits a reset voltage to the anode of the photoelectric conversion element in response to a global reset signal; an eleventh transistor that connects the ninth transistor and a readout line in response to a write signal; and the photoelectric conversion element.

[0023] In an embodiment, the display device may further include a main processor that receives the PPG signal from the readout circuit and determines a biomarker of the user based on the PPG signal.

[0024] The display device according to the embodiment may include a display panel including a light-emitting pixel and a light-sensing pixel. Each light-emitting pixel includes a light-emitting element, and each light-sensing pixel includes a photoelectric conversion element. The display device also includes a readout circuit connected to the light-sensing pixel through a readout line, and provided to generate a photoplethysmography (PPG) signal based on a sensing current received from the light-sensing pixel in a PPG sensing mode. In the PPG sensing mode, the light-emitting pixels in the sensing light-emitting area may be turned on, the light-sensing pixels in the sensing light-emitting area may be turned off, and the reflected light emitted from the sensing light-emitting area and reflected from the blood vessels of the user's finger may be incident on a partial area of ​​the display panel. In the PPG sensing mode, in the first sensing area where the reflected light is incident, the light-emitting pixel may be turned off, and the light-sensing pixel may be turned on. In the PPG sensing mode, in the second sensing area where the reflected light is not incident, the light-emitting pixel may be turned off, and the light-sensing pixel may be turned on.

[0025] According to one or more embodiments, a display device includes a first pixel for emitting light reflected by a user's finger; a light sensing pixel at a position where the reflected light is sensed; a second pixel at a position where the reflected light is not sensed; a sensing circuit that generates a first sensing signal based on a sensing current output from the light sensing pixel and generates a noise signal based on the sensing current output from the second pixel; and a noise canceller that subtracts the noise signal from the first sensing signal to generate a bio-signal of the user. The finger overlaps the first pixel and the second pixel and the light sensing pixel. The bio-signal may be a photoplethysmography (PPG) signal. The first pixel may be configured to emit green light. The sensing current output from the second pixel may be generated based on one of a motion artifact, micro-motion, mispositioning, ambient light, and breathing of the user.

[0026] According to one or more of the embodiments described herein, the display device according to the embodiment can operate in a normal mode to display an image or in a PPG sensing mode to sense the volume of a blood vessel of a user's finger. The display device can generate a PPG signal based on a signal sensed in each of a first sensing area and a second sensing area spaced apart from each other. Therefore, the PPG sensing accuracy of the display device can be improved.

[0027] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention.

[0029] Figure 1 is a block diagram showing a display device according to an embodiment.

[0030] Figure 2 is a plan view showing an example of arrangement of light emitting pixels and light sensing pixels according to an embodiment.

[0031] Figure 3 is a circuit diagram showing an example of a light emitting pixel and a light sensing pixel according to an embodiment.

[0032] Figure 4 and Figure 5 is a diagram for explaining a sensing operation of a display device in a photoplethysmography (PPG) sensing mode according to an embodiment.

[0033] 6A to 6F It is used to explain Figure 4 and Figure 5 FIG. 1 is a diagram of an example of an arrangement of a sensing area and a sensing light-emitting area of ​​a display device.

[0034] Figure 7 It is shown that the Figure 4 and Figure 5 FIG. 1 is a diagram of an example of a readout circuit in a display device.

[0035] Figure 8 is a diagram for explaining a sensing operation of a display device in a photoplethysmography (PPG) sensing mode according to another embodiment.

[0036] 9A to 9D It is used to explain Figure 8 FIG. 1 is a diagram of an example of an arrangement of a sensing area and a sensing light-emitting area of ​​a display device.

[0037] Fig.10 It is shown that the Figure 8 FIG. 1 is a diagram of an example of a readout circuit in a display device.

[0038] Fig.11 is a diagram showing another example of a readout circuit included in a display device according to another embodiment.

[0039] Fig.12 is a diagram for explaining a sensing operation of a display device in a photoplethysmography (PPG) sensing mode according to still another embodiment.

[0040] FIG. 13A to FIG. 13E It is used to explain Fig.12 FIG. 1 is a diagram of an example of an arrangement of a sensing area and a sensing light-emitting area of ​​a display device.

[0041] Fig.14 It is shown that the Fig.12 FIG. 1 is a diagram of an example of a readout circuit in a display device.

[0042] Fig.15 is a diagram showing another example of a readout circuit included in a display device according to another embodiment. DETAILED DESCRIPTION

[0043] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which various embodiments are shown. However, the present invention may be implemented in many different forms and should not be construed as being limited to the embodiments described herein. On the contrary, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. The same reference numerals represent the same elements throughout.

[0044] It will be understood that when an element is referred to as being associated with another element, such as "on" another element, it can be directly on the other element, or intervening elements may exist between them. Conversely, when an element is referred to as being associated with another element, such as "directly on the other element," there are no intervening elements.

[0045] As used herein, "about" or "approximately" is inclusive of the stated value and means within an acceptable range of deviation for a particular value as determined by one of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system). For example, "about" can mean within one or more standard deviations of the stated value, or within ±30%, ±20%, ±10%, or ±5%.

[0046] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless explicitly so defined herein.

[0047] Embodiments are described herein with reference to cross-sectional illustrations that are schematic illustrations of idealized embodiments. As such, variations from the illustrated shapes are expected as a result of, for example, manufacturing techniques and / or tolerances. Therefore, the embodiments described herein should not be construed as limited to the specific regional shapes shown herein, but rather to include shape deviations that result, for example, from manufacturing. For example, a region shown or described as flat may typically have rough and / or nonlinear features. In addition, the sharp angles shown may be rounded. Therefore, the regions shown in the figures are schematic in nature, and their shapes are not intended to illustrate the precise shape of the regions, and are not intended to limit the scope of the claims set forth.

[0048] Illustrative, non-limiting embodiments will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings.

[0049] Figure 1 is a block diagram showing a display device 10 according to an embodiment. Figure 2 1 is a plan view showing an example of arrangement of light emitting pixels PX and light sensing pixels PS according to an embodiment.

[0050] Reference Figure 1According to the embodiment, the display device 10 may include a display panel 100, a panel driver, and a main processor 400, wherein the display panel 100 includes a light-emitting pixel PX and a light-sensing pixel PS, and the panel driver drives the display panel 100. The panel driver may include a plurality of drivers. For example, the panel driver may include a scan driver 210, an emission driver 220, and a data driver 230. The scan driver 210 provides a scan signal SS to the light-emitting pixel PX and the light-sensing pixel PS. The emission driver 220 provides an emission signal EM[n] to the light-emitting pixel PX. The data driver 230 provides a data signal DS to the light-emitting pixel PX. A display controller 240 that controls the operation of each of the scan driver 210, the emission driver 220, and the data driver 230, and a readout circuit 300 connected to the light-sensing pixel PS through a readout line RL are also included.

[0051] In an embodiment, the display device 10 can operate in the following modes: operating in a normal mode to display an image, operating in a fingerprint sensing mode to sense a user's fingerprint, or operating in a photoplethysmography (PPG) sensing mode to sense the volume of a blood vessel of a user's finger. This will be described in more detail later.

[0052] The display panel 100 may include a display area DA and a non-display area surrounding the display area DA. The light-emitting pixels PX and the light-sensing pixels PS may be arranged in the display area DA. In an embodiment, the light-emitting pixels PX and the light-sensing pixels PS may be arranged throughout the entire display area DA. Each of the light-emitting pixels PX may include a light-emitting element, and may emit light using the light-emitting element. For example, Figure 2 As shown in , the light-emitting pixel PX may include a red light-emitting pixel PX-R that emits red light, a green light-emitting pixel PX-G that emits green light, and a blue light-emitting pixel PX-B that emits blue light. In another embodiment, the light-emitting pixel PX may emit light of different color combinations. As explained in more detail below, a predetermined combination of red light-emitting pixels PX-R, green light-emitting pixels PX-G, and blue light-emitting pixels PX-B may form a pixel unit PU. Each of the light-sensing pixels PS may include a photoelectric conversion element, and the photoelectric conversion element may be used to sense light.

[0053] In an embodiment, the display panel 100 may include one light sensing pixel PS for each light emitting pixel PX. In another embodiment, the display panel 100 may include one light sensing pixel PS corresponding to a plurality of light emitting pixels PX constituting one pixel unit PU. Figure 2As shown in the plan view of FIG. 1 , in the display panel 100, one red light-emitting pixel PX-R, two green light-emitting pixels PX-G, and one blue light-emitting pixel PX-B may be arranged in a predetermined (e.g., diamond) shape, and one light-sensing pixel PS may be arranged between (e.g., at the center of) the four light-emitting pixels PX arranged in a diamond shape, but the embodiment is not limited thereto. In this case, one light-sensing pixel PS and four light-emitting pixels PX may form one pixel unit PU.

[0054] The scan driver 210 may generate a scan signal SS based on a scan control signal SCTRL received from the display controller 240. The scan signal SS may be sequentially provided to the display panel 100 row by row. In an embodiment, the scan control signal SCTRL may include a scan start signal and a scan clock signal, but the embodiment is not limited thereto. In an embodiment, the scan driver 210 may generate a scan signal SS, such as a write signal GW[n], a compensation signal GC[n], an initialization signal GI[n], and a bypass signal GB[n], may provide the write signal GW[n], the compensation signal GC[n], the initialization signal GI[n], and the bypass signal GB[n] to the light-emitting pixel PX, and may provide the write signal GW[n] to the light-sensing pixel PS. In addition, in an embodiment, the scan driver 210 may be integrated or formed in the display panel 100. In another embodiment, the scan driver 210 may be implemented as one or more integrated circuits.

[0055] The emission driver 220 may generate an emission signal EM[n] based on an emission control signal EMCTRL received from the display controller 240, and may sequentially provide the emission signal EM[n] to the display panel 100 row by row. In an embodiment, the emission control signal EMCTRL may include an emission start signal and an emission clock signal, but the embodiment is not limited thereto. In addition, in an embodiment, the emission driver 220 may be integrated or formed in the display panel 100. In another embodiment, the emission driver 220 may be implemented as one or more integrated circuits.

[0056] The data driver 230 may generate a data signal DS based on the data control signal DCTRL and the output image data ODAT received from the display controller 240, and may provide the data signal DS to the corresponding light-emitting pixel PX through the data line DL. In an embodiment, the data control signal DCTRL may include an output data enable signal, a horizontal start signal, and a load signal, but the embodiment is not limited thereto. In an embodiment, the data driver 230 and the display controller 240 may be implemented as a single integrated circuit, and the single integrated circuit may be referred to as a timing controller embedded data driver (TED) integrated circuit. In another embodiment, the data driver 230 and the display controller 240 may be implemented as separate integrated circuits.

[0057] The display controller 240 can generate a scan control signal SCTRL, an emission control signal EMCTRL, a data control signal DCTRL and an output image data ODAT based on the input image data IDAT and the input control signal CTRL received from the main processor 400. The input image data IDAT can be, for example, RGB image data, including red image data, green image data and blue image data. In another embodiment, the input image data IDAT can include different combinations of color image data. In one embodiment, the input control signal CTRL can include a master clock signal and an input data enable signal. The input control signal CTRL can also include a vertical synchronization signal and a horizontal synchronization signal.

[0058] The readout circuit 300 may receive a sensing current of the light sensing pixel PS through the readout line RL, may generate a PPG signal PPGS based on the sensing current, and may provide the PPG signal PPGS to the main processor 400. In addition, the readout circuit 300 may apply a global reset signal GR to all light sensing pixels PS of the display panel 100 substantially simultaneously. In an embodiment, the readout circuit 300 may provide a reset voltage VRST to the light sensing pixel PS. In another embodiment, the display device 10 may further include a power management circuit (e.g., Figure 7 The power management circuit 500 of the data driver 230 may be provided, and the power management circuit 500 may generate a reset voltage VRST provided to the light sensing pixel PS. In an embodiment, the readout circuit 300 may be implemented as an integrated circuit, and the integrated circuit may be referred to as a readout integrated circuit (ROIC). In another embodiment, the readout circuit 300 may be included in the data driver 230.

[0059] The main processor 400 may control the overall operation of the display device 10. For example, the main processor 400 may provide the display controller 240 with input image data IDAT and input control signals CTRL so that the display panel 100 displays an image. In addition, the main processor 400 may receive touch data from the touch drive circuit, may determine the touch coordinates of the user on the display device 10, and may execute an application indicated by an icon displayed at the touch coordinates specified by the user.

[0060] The main processor 400 may determine a biomarker of the user based on the PPG signal PPGS received from the readout circuit 300. For example, the main processor 400 may determine the user's blood pressure, heart rate, stress level, cardiovascular health, respiratory rate, vascular age (or vascular elasticity), oxygen saturation, or the like based on the PPG signal PPGS, but the embodiment is not limited thereto.

[0061] As described above, the display device 10 may operate in a normal mode, a fingerprint sensing mode, or a PPG sensing mode. The main processor 400 may generate a mode signal SMODE indicating which of the normal mode, the fingerprint sensing mode, and the PPG sensing mode is to be executed. In an embodiment, the main processor 400 may automatically switch from the normal mode to the fingerprint sensing mode or the PPG sensing mode after a predetermined touch event occurs, without the user's additional input action for mode determination. In another embodiment, the main processor 400 may determine the mode after receiving an input action for mode determination from a user or a program of the display device 10. The display controller 240 may receive a mode signal SMODE from the main processor 400, and may control the operation of the scan driver 210, the emission driver 220, and the data driver 230 based on the received mode signal SMODE. The readout circuit 300 may receive a mode signal SMODE from the main processor 400, may generate a PPG signal PPGS or a fingerprint signal based on the received mode signal SMODE, and may provide the PPG signal PPGS or the fingerprint signal to the main processor 400.

[0062] Figure 3 is a circuit diagram showing an example of a light emitting pixel PX and a light sensing pixel PS according to an embodiment.

[0063] Reference Figure 1 and Figure 3 In an embodiment, the light-emitting pixel PX may include a plurality of transistors and at least one capacitor. For example, the light-emitting pixel PX may include a first transistor T1, a second transistor T2, a third transistor T3, a fourth transistor T4, a fifth transistor T5, a sixth transistor T6, a seventh transistor T7, an eighth transistor T8, a storage capacitor CST, and a light-emitting element EL.

[0064] The first transistor T1 may generate a driving current based on a voltage stored in the storage capacitor CST. In an embodiment, the first transistor T1 may include a gate connected to the storage capacitor CST, a first terminal connected to the fifth transistor T5, and a second terminal connected to the sixth transistor T6.

[0065] The second transistor T2 may transmit the data signal DS of the data line DL to the first terminal of the first transistor T1 in response to the write signal GW[n]. In an embodiment, the second transistor T2 may include a gate receiving the write signal GW[n], a first terminal connected to the data line DL, and a second terminal connected to the first terminal of the first transistor T1.

[0066] The third transistor T3 may place the first transistor T1 in a diode connection state in response to the compensation signal GC[n]. In an embodiment, the third transistor T3 may include a gate receiving the compensation signal GC[n], a first terminal connected to the second terminal of the first transistor T1, and a second terminal connected to the gate of the first transistor T1.

[0067] The fourth transistor T4 may transmit the initialization voltage VINT to the gate of the first transistor T1 in response to the initialization signal GI[n]. In an embodiment, the fourth transistor T4 may include a gate receiving the initialization signal GI[n], a first terminal connected to the gate of the first transistor T1, and a second terminal connected to a line of the initialization voltage VINT.

[0068] The fifth transistor T5 may connect a line of a first power supply voltage ELVDD (e.g., a high power supply voltage) and the first transistor T1 in response to an emission signal EM[n]. In an embodiment, the fifth transistor T5 may include a gate receiving the emission signal EM[n], a first terminal connected to the line of the first power supply voltage ELVDD, and a second terminal connected to the first terminal of the first transistor T1.

[0069] The sixth transistor T6 may connect the first transistor T1 and the light emitting element EL in response to the emission signal EM[n]. In an embodiment, the sixth transistor T6 may include a gate receiving the emission signal EM[n], a first terminal connected to the second terminal of the first transistor T1, and a second terminal connected to the anode of the light emitting element EL.

[0070] The seventh transistor T7 may transmit the anode initialization voltage AINT to the light emitting element EL in response to the bypass signal GB[n]. In an embodiment, the seventh transistor T7 may include a gate receiving the bypass signal GB[n], a first terminal connected to the anode of the light emitting element EL, and a second terminal connected to a line of the anode initialization voltage AINT. In an embodiment, the initialization voltage VINT and the anode initialization voltage AINT may be voltages different from each other. In another embodiment, the initialization voltage VINT and the anode initialization voltage AINT may be voltages substantially the same as each other.

[0071] The eighth transistor T8 may transmit the bias voltage VOBS to the first terminal of the first transistor T1 in response to the bypass signal GB[n]. The first transistor T1 may be in a conductive state based on the bias voltage VOBS. In an embodiment, the eighth transistor T8 may include a gate receiving the bypass signal GB[n], a first terminal connected to a line of the bias voltage VOBS, and a second terminal connected to the first terminal of the first transistor T1.

[0072] The storage capacitor CST may be connected between the line of the first power voltage ELVDD and the gate of the first transistor T1. In an embodiment, the storage capacitor CST may include a first electrode connected to the line of the first power voltage ELVDD and a second electrode connected to the gate of the first transistor T1.

[0073] The light emitting element EL may emit light based on the driving current generated by the first transistor T1. In an embodiment, the light emitting element EL may be an organic light emitting diode (OLED), but the embodiment is not limited thereto. In another embodiment, the light emitting element EL may be a nano light emitting diode (NED), a quantum dot (QD) light emitting diode, a micro light emitting diode, an inorganic light emitting diode, or any other suitable light emitting element. In an embodiment, the light emitting element EL may include an anode connected to the sixth transistor T6 and a cathode connected to a line of a second power supply voltage ELVSS (e.g., a low power supply voltage).

[0074] In an embodiment, the first transistor T1 to the eighth transistor T8 may be a P-type metal oxide semiconductor (PMOS) transistor. In another embodiment, the first transistor T1 to the eighth transistor T8 may be an N-type metal oxide semiconductor (NMOS) transistor. In yet another embodiment, some of the first transistor T1 to the eighth transistor T8 may be a PMOS transistor, and the other transistors of the first transistor T1 to the eighth transistor T8 may be an NMOS transistor. For example, Figure 3As shown in FIG. 1 , the first transistor T1 , the second transistor T2 , the fifth transistor T5 , the sixth transistor T6 , the seventh transistor T7 , and the eighth transistor T8 may be PMOS transistors, and the third transistor T3 and the fourth transistor T4 may be NMOS transistors, but the embodiment is not limited thereto. Figure 3 An example of a light-emitting pixel PX including eight transistors (ie, first to eighth transistors T1 to T8) and one capacitor (ie, storage capacitor CST) is shown, but the light-emitting pixel PX of the display device 10 according to the embodiment is not limited to Figure 3 , and can have any structure.

[0075] In an embodiment, the light sensing pixel PS may include a ninth transistor T9, a tenth transistor T10, an eleventh transistor T11 and a photoelectric conversion element PD. In this case, the light sensing pixel PS may share at least one of the power supply voltages used by the light emitting pixel PX, for example, the second power supply voltage ELVSS as a low power supply voltage.

[0076] The ninth transistor T9 may generate a sensing current based on the voltage of the anode of the photoelectric conversion element PD. In an embodiment, the ninth transistor T9 may include a gate connected to the anode of the photoelectric conversion element PD, a first terminal receiving a sensing reference voltage VSENREF, and a second terminal. In an embodiment, the sensing reference voltage VSENREF may have a voltage level substantially the same as the anode initialization voltage AINT, but the embodiment is not limited thereto.

[0077] The tenth transistor T10 may reset the photoelectric conversion element PD (or the voltage of the anode of the photoelectric conversion element PD) to a reset voltage VRST in response to the global reset signal GR. In an embodiment, the tenth transistor T10 may include a gate receiving the global reset signal GR, a first terminal receiving the reset voltage VRST, and a second terminal connected to the anode of the photoelectric conversion element PD.

[0078] The eleventh transistor T11 may transmit the sensing current generated by the ninth transistor T9 to the readout line RL in response to the write signal GW[n]. In an embodiment, the eleventh transistor T11 may include a gate receiving the write signal GW[n], a first terminal connected to the second terminal of the ninth transistor T9, and a second terminal connected to the readout line RL.

[0079] The photoelectric conversion element PD can be used to measure light intensity. For example, the photoelectric conversion element PD can be an organic photodiode, but the embodiment is not limited thereto. After the voltage of the anode of the photoelectric conversion element PD is reset to the reset voltage VRST, the voltage of the anode of the photoelectric conversion element PD can increase by different amounts according to the light intensity. The sensing current of the ninth transistor T9 can be determined according to the voltage of the anode of the photoelectric conversion element PD, and the readout circuit 300 can generate a PPG signal PPGS corresponding to the sensing current. In an embodiment, the photoelectric conversion element PD may include an anode connected to the gate of the ninth transistor T9 and a cathode connected to a line of the second power supply voltage ELVSS as a low power supply voltage.

[0080] In an embodiment, the ninth transistor T9 to the eleventh transistor T11 may be PMOS transistors. In another embodiment, the ninth transistor T9 to the eleventh transistor T11 may be NMOS transistors. In yet another embodiment, some of the ninth transistor T9 to the eleventh transistor T11 may be PMOS transistors, and the other transistors of the ninth transistor T9 to the eleventh transistor T11 may be NMOS transistors. For example, Figure 3 As shown in FIG. 1 , the ninth transistor T9 and the eleventh transistor T11 may be PMOS transistors, and the tenth transistor T10 may be an NMOS transistor, but the embodiment is not limited thereto. Figure 3 An example of a light sensing pixel PS including three transistors (ie, ninth to eleventh transistors T9 to T11) and one photoelectric conversion element PD is shown, but the light sensing pixel PS of the display device 10 according to the embodiment is not limited to Figure 3 , and can have any structure.

[0081] Figure 4 and Figure 5 is a diagram for explaining a sensing operation of the display device 10 in a PPG sensing mode according to an embodiment. 6A to 6F It is used to explain Figure 4 and Figure 5 FIG. 1 is a diagram of an example of an arrangement of sensing areas SA1 and SA2 and a sensing light emitting area SLA of a display device 10 .

[0082] Hereinafter, a sensing operation of the display apparatus 10 according to the embodiment in the PPG sensing mode for sensing the volume of the blood vessel BV of the user's finger FGR will be described in detail.

[0083] Reference Figures 1 to 5In the PPG sensing mode, the display device 10 may drive the light-emitting pixel PX to emit light in the sensing light-emitting area SLA, and may drive the light-sensing pixel PS to sense light in each of the first sensing area SA1 and the second sensing area SA2 separated from each other. In one embodiment, the first sensing area SA1 and the second sensing area SA2 correspond to different areas of the user's finger FGR, as described below. When set at these locations, a PPG signal PPGS may be generated to indicate the user's condition.

[0084] In an embodiment, a sensing light emitting area SLA, a first sensing area SA1, and a second sensing area SA2 may be set in the display area DA. For example, according to the touch coordinates of the user's finger FGR, the sensing light emitting area SLA, the first sensing area SA1, and the second sensing area SA2 may be set to overlap with the finger FGR respectively. The remaining area of ​​the display area DA except the sensing light emitting area SLA, the first sensing area SA1, and the second sensing area SA2 may be referred to as corresponding to the off area OA.

[0085] Hereinafter, the pixel unit PU in the sensing light emitting area SLA may be referred to as the first pixel unit PU1, the pixel unit PU in the first sensing area SA1 may be referred to as the second pixel unit PU2, the pixel unit PU in the second sensing area SA2 may be referred to as the third pixel unit PU3, and the pixel unit PU in the shutdown area OA may be referred to as the fourth pixel unit PU4.

[0086] When operating in the PPG sensing mode, the sensing light emitting area SLA may emit light. In the PPG sensing mode, at least one or a predetermined number of light emitting pixels PX in the sensing light emitting area SLA may be turned on, and the light sensing pixels PS in the sensing light emitting area SLA may be turned off. Figure 2 and Figure 4 As shown in , in the PPG sensing mode, the green light-emitting pixel PX-G (for example, two green light-emitting pixels PX-G) included in each of the first pixel units PU1 in the sensing light-emitting area SLA may be turned on. In this case, in the PPG sensing mode, the red light-emitting pixel PX-R, the blue light-emitting pixel PX-B, and the light-sensing pixel PS included in each of the first pixel units PU1 in the sensing light-emitting area SLA may be turned off. Therefore, in the PPG sensing mode, the sensing light-emitting area SLA may emit green light, but the embodiment is not limited thereto. In other embodiments, light-emitting pixels PX and light-sensing pixels PS of different types or combinations may be turned on to generate different light-emitting signals.

[0087] In the PPG sensing mode, the first sensing area SA1 may sense light, for example, light emitted by pixels turned on in the sensing light-emitting area SLA may be reflected by the finger FGR and detected or sensed by the light-sensing pixels PS in the first sensing area SA1. For example, in the PPG sensing mode, the light-emitting pixels PX in the first sensing area SA1 may be turned off, and the light-sensing pixels PS in the first sensing area SA1 may be turned on. Figure 2 and Figure 4 As shown in , in the PPG sensing mode, the red light-emitting pixel PX-R, the green light-emitting pixel PX-G, and the blue light-emitting pixel PX-B included in each of the second pixel units PU2 in the first sensing area SA1 may be turned off. In the PPG sensing mode, the light-sensing pixel PS included in each of the second pixel units PU2 in the first sensing area SA1 may be turned on.

[0088] like Figure 5 As shown in , in the PPG sensing mode, light (e.g., green light) emitted from the sensing light emitting area SLA may be reflected from the blood vessel BV of the user's finger FGR. The reflected light may be incident into the first sensing area SA1. The light sensing pixels PS in the first sensing area SA1 may sense the reflected light. The light intensity of the reflected light reflected from the blood vessel BV may vary according to the volume of the blood vessel BV. For example, when the user's heart contracts and the volume of the blood vessel BV increases, the amount of hemoglobin in the blood vessel BV may increase, the light intensity absorbed by the hemoglobin may increase, and the light sensing pixels PS may measure the reflected light of relatively low light intensity. On the contrary, when the user's heart expands (or relaxes) and the volume of the blood vessel BV decreases, the amount of hemoglobin in the blood vessel BV may decrease, and the light intensity absorbed by the hemoglobin may decrease. As a result, the light sensing pixels PS may measure the reflected light of relatively high light intensity. The light sensing pixels PS in the first sensing area SA1 may generate a sensing current corresponding to the light intensity of the reflected light.

[0089] In the PPG sensing mode, the second sensing area SA2 may sense light. In the PPG sensing mode, the light-emitting pixels PX in the second sensing area SA2 may be turned off, and the light-sensing pixels PS in the second sensing area SA2 may be turned on. Figure 2 and Figure 4 As shown in , in the PPG sensing mode, the red light-emitting pixel PX-R, the green light-emitting pixel PX-G, and the blue light-emitting pixel PX-B included in each of the third pixel units PU3 in the second sensing area SA2 may be turned off. In the PPG sensing mode, the light-sensing pixel PS included in each of the third pixel units PU3 in the second sensing area SA2 may be turned on.

[0090] like Figure 5As shown in , in the PPG sensing mode, light (e.g., green light) emitted from the sensing light emitting area SLA may be reflected from the blood vessel BV of the user's finger FGR, but the reflected light may not be incident into the second sensing area SA2. The light sensing pixels PS in the second sensing area SA2 may sense incident light that is incident due to various reasons (e.g., motion artifacts, micro-motion, mispositioning, ambient light, breathing, etc.) and is not reflected light. The light sensing pixels PS may output a signal representing a noise component that is not caused by light reflected from the blood vessel BV. For example, the light sensing pixels PS in the second sensing area SA2 may generate a sensing current corresponding to the light intensity of the incident light corresponding to the noise component. As discussed in more detail below, the noise component may be subtracted from a sensing signal generated based on the output of one or more light sensing pixels PS in the first sensing area SA1 (e.g., the current therefrom). In one embodiment, the light sensing pixels PS in the second sensing area SA2 may generate a sensing current based on an effect that is not directly related to the reflected light, but may nonetheless be used to sense the noise component to be used in the process of generating a more accurate biological (e.g., PPG) signal. In this case, the light sensing pixel PS may be located at a pixel unit (eg, Fig.12 PU4).

[0091] The readout circuit 300 can generate a sensing signal based on the sensing current of the light sensing pixel PS in the first sensing area SA1, and can generate a noise signal based on the sensing current of the light sensing pixel PS in the second sensing area SA2. The sensing signal may include not only data of the volume of the blood vessel BV that varies over time (which is obtained by sensing the reflected light), but also noise. The noise signal may include noise caused by the above-mentioned various reasons that do not belong to the reflected light. The readout circuit 300 can effectively remove noise from the sensing signal based on the sensing signal and the noise signal. Therefore, the readout circuit 300 can generate a PPG signal PPGS that represents the volume of the blood vessel BV that varies over time and has a low signal-to-noise ratio (SNR). That is, by reducing or eliminating the influence of noise in the sensing signal, the PPG sensing accuracy (or PPG sensing capability) of the display device 10 can be improved. This will be referred to later. Figure 7 Detailed description.

[0092] In the PPG sensing mode, the red light-emitting pixel PX-R, the green light-emitting pixel PX-G, the blue light-emitting pixel PX-B, and the light-sensing pixel PS included in each of the fourth pixel units PU4 in the turn-off area OA may be turned off.

[0093] like Figure 4 and Figure 5As shown in FIG. 1 , the first sensing area SA1 may be adjacent to the sensing light emitting area SLA so that the reflected light may be incident into the first sensing area SA1. For example, in a plan view, the sensing light emitting area SLA may be adjacent to (or in contact with) the first sensing area SA1. Figure 4 ), the sensing light emitting area SLA may surround at least a portion of the first sensing area SA1. Figure 4 As shown in FIG. 1 , when the first sensing area SA1 has a circular shape in a plan view, the sensing light emitting area SLA may have a ring shape surrounding the first sensing area SA1 in a plan view, but the embodiment is not limited thereto. For example, the planar shape of each of the sensing light emitting area SLA and the first sensing area SA1 may be variously modified, for example, as Fig. 6A , Figure 6B and Figure 6C As shown in .

[0094] The second sensing area SA2 may be spaced apart from the sensing light emitting area SLA so that the reflected light does not enter the second sensing area SA2. The second sensing area SA2 may be set to have various positions, various sizes, and various shapes so that the second sensing area SA2 is located in an area overlapping with the finger FGR at a position where the reflected light does not enter the second sensing area SA2. For example, the distance D between the sensing light emitting area SLA and the second sensing area SA2 may be greater than or equal to the width W of the annular sensing light emitting area SLA, but the embodiment is not limited thereto. For example, in an alternative embodiment, the second sensing area SA2 may be adjacent to the sensing light emitting area SLA, and the reflected light emitted from the sensing light emitting area SLA and reflected from the blood vessel BV of the user's finger FGR may enter each of the first sensing area SA1 and the second sensing area SA2. Figure 4 In the embodiment of the present invention, the distance D between the sensing light emitting area SLA and the second sensing area SA2 may be defined as the minimum distance between the sensing light emitting area SLA and the second sensing area SA2. The width W of the sensing light emitting area SLA may be defined as the distance between a first tangent line TL1 tangent to an outer edge OE of the sensing light emitting area SLA and a second tangent line TL2 tangent to an inner edge IE of the sensing light emitting area SLA adjacent to the first sensing area SA1 and parallel to the first tangent line TL1.

[0095] In an embodiment, Figure 4 As shown in FIG. 1 , the second sensing area SA2 may have a planar shape corresponding to the planar shape of the sensing light emitting area SLA. For example, when the sensing light emitting area SLA has a ring (or annular) shape in a plan view, the second sensing area SA2 may have a curved rectangular shape in a plan view, but the embodiment is not limited thereto. Fig.6DAs shown in , the second sensing area SA2 may have a planar shape that does not correspond to the planar shape of the sensing light emitting area SLA.

[0096] In an embodiment, Figure 4 As shown in , a plurality of second sensing areas SA2 may be provided, and the plurality of second sensing areas SA2 may be located at opposite sides of the sensing light emitting area SLA. In addition, the size of each of the second sensing areas SA2 may be larger than the size of the first sensing area SA1, but the embodiment is not limited thereto. For example, Fig. 6E As shown in , the size of each of the second sensing areas SA2 may be smaller than the size of the first sensing area SA1. Fig. 6F As shown in FIG. 4 , only one second sensing area SA2 may be provided, and the second sensing area SA2 may be located at a predetermined side of the sensing light emitting area SLA.

[0097] Figure 7 It is shown that the Figure 4 and Figure 5 FIG. 1 is a diagram of an example of a readout circuit 300 in the display device 10 .

[0098] refer to Figure 1 and Figure 7 In an embodiment, the readout circuit 300 may include a register 310, a global reset circuit 320, a sensing circuit 330, a noise canceller 340, and a low-pass filter 350. The register 310 may store setting values ​​of the global reset signal GR and the reset voltage VRST in each of the normal mode, the fingerprint sensing mode, and the PPG sensing mode. In addition, the register 310 may receive a mode signal SMODE indicating the normal mode, the fingerprint sensing mode, or the PPG sensing mode from the main processor 400, and may provide one or more setting values ​​corresponding to the driving mode indicated by the mode signal SMODE to the global reset circuit 320 and / or the power management circuit 500.

[0099] The global reset circuit 320 may generate a global reset signal GR provided to the light sensing pixels PS of the display panel 100. In an embodiment, the global reset signal GR may be provided to all or part of the light sensing pixels PS of the display panel 100 substantially simultaneously. The global reset circuit 320 may change at least one of a voltage level, a timing, a waveform, and a conversion rate of the global reset signal GR based on a set value provided from the register 310.

[0100] The power management circuit 500 may change the voltage level of the reset voltage VRST based on one or more set values ​​provided from the register 310. In an embodiment, the power management circuit 500 may be included in an ROIC in which the readout circuit 300 is implemented. In another embodiment, the power management circuit 500 may be implemented as an integrated circuit different from the ROIC, and the integrated circuit may be referred to as a power management integrated circuit (PMIC).

[0101] The sensing circuit 330 may be electrically connected to the light sensing pixels PS of the display panel 100 through corresponding readout lines RL. The sensing circuit 330 may receive a sensing current of the light sensing pixels PS through the readout lines RL, may convert the sensing current into a digital signal, and may output the digital signal.

[0102] like Figure 7 As shown in FIG. 1 , the sensing circuit 330 may receive a sensing current SC1 of at least one of the light sensing pixels PS in the first sensing area SA1 through a first readout line RL1, and may generate a first sensing signal SS1 corresponding to the sensing current SC1. The first sensing signal SS1 may include not only data of the volume of the blood vessel BV over time obtained by detecting light reflected from the blood vessel BV, but may also include a noise component.

[0103] The sensing circuit 330 may also receive a sensing current SC2 of at least one of the light sensing pixels PS in the second sensing area SA2 through a second readout line RL2 and may generate a first noise signal NS1 corresponding to the sensing current SC2. The first noise signal NS1 may include noise components due to various reasons unrelated to the reflected light.

[0104] The low pass filter 350 may receive the first noise signal NS1 from the sensing circuit 330, and may generate a second noise signal NS2 from the first noise signal NS1 by blocking frequency components of a cutoff frequency or more and passing only low frequency components less than the cutoff frequency. The low frequency component may be present in the first sensing signal SS1 and will be removed to generate a more accurate indication of the biological being (e.g., a PPG signal PPGS). For example, the cutoff frequency may be about 0.5 Hz, but the embodiment is not limited thereto.

[0105] The noise canceller 340 may receive the first sensing signal SS1 from the sensing circuit 330, may receive the second noise signal NS2 from the low pass filter 350, and may generate the second sensing signal SS2 based on the first sensing signal SS1 and the second noise signal NS2. For example, the noise canceller 340 may generate the second sensing signal SS2 by subtracting the second noise signal NS2 from the first sensing signal SS1. In an embodiment, the second sensing signal SS2 may be a PPG signal PPGS transmitted to the main processor 400. In another embodiment, the readout circuit 300 may further include various filters (e.g., a band pass filter (BPF), etc.) for additionally filtering the second sensing signal SS2 (e.g., for additionally removing noise from the second sensing signal SS2), and the signal obtained by additionally filtering the second sensing signal SS2 may be the PPG signal PPGS transmitted to the main processor 400.

[0106] The main processor 400 may determine the biomarker of the user based on the PPG signal PPGS received from the readout circuit 300 .

[0107] Figure 8 is a diagram for explaining a sensing operation of the display device 11 in a PPG sensing mode according to another embodiment. 9A to 9D It is used to explain Figure 8 FIG. 1 is a diagram showing an example of arrangement of the sensing areas SA1 - 1 and SA1 - 2 and the sensing light emitting area SLA of the display device 11 . Fig.10 It is shown that the Figure 8 FIG. 1 is a diagram of an example of a readout circuit 301 in a display device 11 of FIG.

[0108] According to reference Figures 8 to 10 The display device 11 of another embodiment described can be used with reference Figures 1 to 7 The display device 10 described is substantially the same or similar except that the readout circuit 301 is partially changed and the sensing light emitting area SLA and the sensing areas SA1-1 and SA1-2 are configured differently in the PPG sensing mode. Therefore, repeated descriptions may be omitted or simplified.

[0109] Reference Figure 1 , Figure 2 , Figure 8 , 9A to 9D as well as Fig.10 In the PPG sensing mode, the display device 11 may drive the light-emitting pixels PX to emit light in the sensing light-emitting area SLA, and may drive the light-sensing pixels PS to sense light in each of the first-first sensing area SA1-1 and the first-second sensing area SA1-2 spaced apart from each other.

[0110] In an embodiment, the sensing light emitting area SLA, the first-first sensing area SA1-1, and the first-second sensing area SA1-2 may be set in the display area DA. For example, according to the touch coordinates of the user's finger FGR, each of the sensing light emitting area SLA, the first-first sensing area SA1-1, and the first-second sensing area SA1-2 may be set to overlap with the finger FGR. The remaining area of ​​the display area DA except the sensing light emitting area SLA, the first-first sensing area SA1-1, and the first-second sensing area SA1-2 may be the off area OA.

[0111] Hereinafter, the pixel unit PU in the sensing light-emitting area SLA may be referred to as the first pixel unit PU1, the pixel unit PU in the first-first sensing area SA1-1 may be referred to as the second-first pixel unit PU2-1, the pixel unit PU in the first-second sensing area SA1-2 may be referred to as the second-second pixel unit PU2-2, and the pixel unit PU in the shutdown area OA may be referred to as the third pixel unit PU3.

[0112] In the PPG sensing mode, the sensing light emitting area SLA may emit light to be reflected by the user's finger FGR (e.g., reflected by the blood vessel BV in the finger FGR). In the PPG sensing mode, one or more of the light emitting pixels PX in the sensing light emitting area SLA may be turned on, and the light sensing pixels PS in the sensing light emitting area SLA may be turned off. For example, Figure 2 and Figure 8 As shown in , in the PPG sensing mode, the green light-emitting pixel PX-G included in each of the first pixel units PU1 in the sensing light-emitting area SLA may be turned on. In the PPG sensing mode, the red light-emitting pixel PX-R, the blue light-emitting pixel PX-B, and the light-sensing pixel PS included in each of the first pixel units PU1 in the sensing light-emitting area SLA may be turned off. Therefore, in the PPG sensing mode, the sensing light-emitting area SLA may emit green light, but the embodiment is not limited thereto.

[0113] In the PPG sensing mode, each of the first-first sensing area SA1-1 and the first-second sensing area SA1-2 may sense light. In the PPG sensing mode, the light emitting pixel PX in each of the first-first sensing area SA1-1 and the first-second sensing area SA1-2 may be turned off, and the light sensing pixel PS in each of the first-first sensing area SA1-1 and the first-second sensing area SA1-2 may be turned on. For example, Figure 2 and Figure 8As shown in , in the PPG sensing mode, the red light emitting pixel PX-R, the green light emitting pixel PX-G, and the blue light emitting pixel PX-B included in each of the second-first pixel units PU2-1 in the first-first sensing area SA1-1 may be turned off. In the PPG sensing mode, the light sensing pixel PS included in each of the second-first pixel units PU2-1 in the first-first sensing area SA1-1 may be turned on. In addition, in the PPG sensing mode, the red light emitting pixel PX-R, the green light emitting pixel PX-G, and the blue light emitting pixel PX-B included in each of the second-second pixel units PU2-2 in the first-second sensing area SA1-2 may be turned off. In the PPG sensing mode, the light sensing pixel PS included in each of the second-second pixel units PU2-2 in the first-second sensing area SA1-2 may be turned on.

[0114] In the PPG sensing mode, light emitted from the sensing light emitting area SLA may be reflected from the blood vessel BV of the user's finger FGR, and the reflected light may be incident on each of the first-first sensing area SA1-1 and the first-second sensing area SA1-2. The light sensing pixels PS in each of the first-first sensing area SA1-1 and the first-second sensing area SA1-2 may sense the reflected light.

[0115] In the PPG sensing mode, the red light emitting pixel PX-R, the green light emitting pixel PX-G, the blue light emitting pixel PX-B, and the light sensing pixel PS included in each of the third pixel units PU3 in the turn-off area OA may all be turned off.

[0116] The first-first sensing area SA1-1 and the first-second sensing area SA1-2 may be spaced apart from each other. Each of the first-first sensing area SA1-1 and the first-second sensing area SA1-2 may be adjacent to the sensing light emitting area SLA so that reflected light may be incident on each of the first-first sensing area SA1-1 and the first-second sensing area SA1-2. For example, in a plan view, the sensing light emitting area SLA may be adjacent to (or in contact with) both the first-first sensing area SA1-1 and the first-second sensing area SA1-2. For example, in a plan view, the sensing light emitting area SLA may surround at least a portion of each of the first-first sensing area SA1-1 and the first-second sensing area SA1-2. For example, as Figure 8As shown in , when the first-first sensing area SA1-1 and the first-second sensing area SA1-2 have circular shapes spaced apart from each other in a plan view, the sensing light emitting area SLA may have a figure 8 or “∞” shape surrounding the first-first sensing area SA1-1 and the first-second sensing area SA1-2 in a plan view, but the embodiment is not limited thereto. For example, the planar shape of each of the sensing light emitting area SLA, the first-first sensing area SA1-1, and the first-second sensing area SA1-2 may be variously modified, for example, as Fig.9A , Fig. 9B , Fig. 9C and Fig.9D As shown in .

[0117] In an embodiment, the readout circuit 301 may include a register 310, a global reset circuit 320, a sensing circuit 331, a noise canceller 341, and a band stop filter 360. The register 310 and the global reset circuit 320 of the readout circuit 301 may be substantially the same as the reference circuit 331. Figure 7 The register 310 and global reset circuit 320 of the readout circuit 300 are depicted as being the same or similar.

[0118] The sensing circuit 331 may receive the sensing current SC1-1 of the light sensing pixel PS in the first-first sensing area SA1-1 through the first-first readout line RL1-1, and may generate a first sensing signal SS1 corresponding to the sensing current SC1-1. The sensing circuit 331 may receive the sensing current SC1-2 of the light sensing pixel PS in the first-second sensing area SA1-2 through the first-second readout line RL1-2, and may generate a second sensing signal SS2 corresponding to the sensing current SC1-2. Each of the first sensing signal SS1 and the second sensing signal SS2 may include not only data of the volume of the blood vessel BV that varies with time, obtained by sensing reflected light, but may also include a noise component.

[0119] The band stop filter 360 may receive the second sensing signal SS2 from the sensing circuit 331, and may generate a noise signal NS from the second sensing signal SS2 by blocking frequency components in a stop band and passing only frequency components in a remaining frequency band except the stop band. For example, the stop band may be 0.7 Hz to 7.2 Hz, but the embodiment is not limited thereto.

[0120] The noise canceller 341 may receive the first sensing signal SS1 from the sensing circuit 331, may receive the noise signal NS from the band stop filter 360, and may generate a third sensing signal SS3 based on the first sensing signal SS1 and the noise signal NS. For example, the noise canceller 341 may generate the third sensing signal SS3 by subtracting the noise signal NS from the first sensing signal SS1, thereby generating a PPG signal PPGS adjusted to exclude noise to generate a more accurate indication of the user's PPG. In an embodiment, the third sensing signal SS3 may be a PPG signal PPGS transmitted to the main processor 400. In another embodiment, the readout circuit 301 may further include various filters (e.g., BPF, etc.) for additionally filtering the third sensing signal SS3 (e.g., for additionally removing noise from the third sensing signal SS3), and the signal obtained by additionally filtering the third sensing signal SS3 may be a PPG signal PPGS transmitted to the main processor 400.

[0121] Fig.11 3 is a diagram showing another example of a readout circuit 302 included in a display device 12 according to another embodiment. Fig.11 The display device 12 of another embodiment described can be used with reference to Fig.10 The display device 11 described is substantially the same or similar except that the readout circuit 302 is partially changed. Therefore, repeated descriptions may be omitted or simplified.

[0122] refer to Fig.11 In an embodiment, the readout circuit 302 may include a register 310, a global reset circuit 320, a sensing circuit 331, a noise canceller 341, a band stop filter 360, a band pass filter 370, and an operational amplifier 380. The sensing circuit 331, the noise canceller 341, and the band stop filter 360 of the readout circuit 302 may be substantially the same as the reference circuit 310. Fig.10 The sensing circuit 331 , the noise canceller 341 , and the band stop filter 360 of the readout circuit 301 are described to be the same or similar.

[0123] The bandpass filter 370 may receive the second sensing signal SS2 from the sensing circuit 331, and may generate a fourth sensing signal SS4 from the second sensing signal SS2 by passing only frequency components in a passband of the bandpass filter 370 and blocking frequency components in a remaining frequency band except the passband. For example, the passband may be 0.7 Hz to 7.2 Hz, but the embodiment is not limited thereto.

[0124] The operational amplifier 380 may receive the third sensing signal SS3 from the noise canceller 341, may receive the fourth sensing signal SS4 from the bandpass filter 370, and may generate a fifth sensing signal SS5 based on the third sensing signal SS3 and the fourth sensing signal SS4. For example, the operational amplifier 380 may generate the fifth sensing signal SS5 by adding the third sensing signal SS3 and the fourth sensing signal SS4. In an embodiment, the fifth sensing signal SS5 may be a PPG signal PPGS transmitted to the main processor 400, which generates a more accurate indication of the user's PPG due to the output of the noise canceller 341. In another embodiment, the readout circuit 302 may further include various filters (e.g., BPF, etc.) for additionally filtering the fifth sensing signal SS5 (e.g., for additionally removing noise from the fifth sensing signal SS5), and the signal obtained by additionally filtering the fifth sensing signal SS5 may be the PPG signal PPGS transmitted to the main processor 400.

[0125] Fig.12 is a diagram for explaining a sensing operation of the display device 13 in a PPG sensing mode according to another embodiment. FIG. 13A to FIG. 13E It is used to explain Fig.12 FIG. 1 is a diagram showing an example of arrangement of the sensing areas SA1 - 1 , SA1 - 2 , and SA2 and the sensing light emitting area SLA of the display device 13 . Fig.14 It is shown that the Fig.12 FIG. 1 is a diagram of an example of a readout circuit 303 in a display device 13 .

[0126] According to reference Figure 12 to Figure 14 The display device 13 of another embodiment described can be used with reference to Figures 8 to 10 The display device 11 described is substantially the same or similar except that the readout circuit 303 is partially changed and the sensing light emitting area SLA and the sensing areas SA1-1, SA1-2, and SA2 are differently set in the PPG sensing mode. Therefore, repeated descriptions may be omitted or simplified.

[0127] Reference Figure 1 , Figure 2 , Fig.12 , FIG. 13A to FIG. 13E as well as Fig.14 In the PPG sensing mode, the display device 13 may drive the light-emitting pixels PX to emit light in the sensing light-emitting area SLA, and may drive the light-sensing pixels PS to sense light in each of the first-first sensing area SA1-1, the first-second sensing area SA1-2, and the second sensing area SA2 spaced apart from each other.

[0128] In an embodiment, a sensing light emitting area SLA, a first-first sensing area SA1-1, a first-second sensing area SA1-2, and a second sensing area SA2 may be set in the display area DA. For example, according to the touch coordinates of the user's finger FGR, the sensing light emitting area SLA, the first-first sensing area SA1-1, the first-second sensing area SA1-2, and the second sensing area SA2 may be set to overlap with the user's finger FGR respectively. The remaining area of ​​the display area DA except the sensing light emitting area SLA, the first-first sensing area SA1-1, the first-second sensing area SA1-2, and the second sensing area SA2 may be an off area OA.

[0129] Hereinafter, the pixel unit PU in the sensing light-emitting area SLA may be referred to as the first pixel unit PU1, the pixel unit PU in the first-first sensing area SA1-1 may be referred to as the second-first pixel unit PU2-1, the pixel unit PU in the first-second sensing area SA1-2 may be referred to as the second-second pixel unit PU2-2, the pixel unit PU in the second sensing area SA2 may be referred to as the third pixel unit PU3, and the pixel unit PU in the shutdown area OA may be referred to as the fourth pixel unit PU4.

[0130] In the PPG sensing mode, one or more of the light-emitting pixels PX in the sensing light-emitting area SLA may emit light. In the PPG sensing mode, one or more of the light-emitting pixels PX in the sensing light-emitting area SLA may be turned on, and the light-sensing pixels PS in the sensing light-emitting area SLA may be turned off.

[0131] In the PPG sensing mode, each of the first-first sensing area SA1-1 and the first-second sensing area SA1-2 may sense light reflected from the user's finger FGR. In the PPG sensing mode, the light-emitting pixels PX in each of the first-first sensing area SA1-1 and the first-second sensing area SA1-2 may be turned off, and the light-sensing pixels PS in each of the first-first sensing area SA1-1 and the first-second sensing area SA1-2 may be turned on. In the PPG sensing mode, light emitted from the sensing light-emitting area SLA may be reflected from the blood vessel BV of the user's finger FGR, and the reflected light may be incident into each of the first-first sensing area SA1-1 and the first-second sensing area SA1-2. The light-sensing pixels PS in each of the first-first sensing area SA1-1 and the first-second sensing area SA1-2 may sense the reflected light.

[0132] In the PPG sensing mode, the second sensing area SA2 may sense light. In the PPG sensing mode, the light-emitting pixels PX in the second sensing area SA2 may be turned off, and the light-sensing pixels PS in the second sensing area SA2 may be turned on. In the PPG sensing mode, light emitted from the sensing light-emitting area SLA may be reflected from the blood vessel BV of the user's finger FGR, but due to the interval between the sensing light-emitting area SLA and the second sensing area SA2, the reflected light may not be incident into the second sensing area SA2. The light-sensing pixels PS in the second sensing area SA2 may sense incident light incident due to various reasons (e.g., motion artifacts, micro-motion, mispositioning, ambient light, breathing, etc.) regardless of the reflected light.

[0133] In the PPG sensing mode, the light emitting pixels PX and the light sensing pixels PS in the off area OA may both be turned off.

[0134] The first-first sensing area SA1-1 and the first-second sensing area SA1-2 may be spaced apart from each other. Each of the first-first sensing area SA1-1 and the first-second sensing area SA1-2 may be adjacent to the sensing light emitting area SLA so that reflected light may be incident into each of the first-first sensing area SA1-1 and the first-second sensing area SA1-2. For example, in a plan view, the sensing light emitting area SLA may be adjacent to (or in contact with) both the first-first sensing area SA1-1 and the first-second sensing area SA1-2. For example, in a plan view, the sensing light emitting area SLA may surround at least a portion of each of the first-first sensing area SA1-1 and the first-second sensing area SA1-2. For example, as Fig.12 As shown in , when the first-first sensing area SA1-1 and the first-second sensing area SA1-2 have circular shapes spaced apart from each other in a plan view, the sensing light emitting area SLA may have a figure 8 or “∞” shape surrounding the first-first sensing area SA1-1 and the first-second sensing area SA1-2 in a plan view, but the embodiment is not limited thereto. For example, the planar shape of each of the sensing light emitting area SLA, the first-first sensing area SA1-1, and the first-second sensing area SA1-2 may be variously modified, for example, as Fig.13A , Fig. 13B and Fig. 13C As shown in .

[0135] The second sensing area SA2 may be spaced apart from the sensing light emitting area SLA so that the reflected light does not enter the second sensing area SA2. The second sensing area SA2 may be set to have various positions, various sizes, and various shapes so that the second sensing area SA2 is located in an area overlapping the finger FGR, but due to the interval between the sensing light emitting area SLA and the second sensing area SA2, the reflected light does not enter the second sensing area SA2.

[0136] In an embodiment, Fig.12 As shown in , a plurality of second sensing areas SA2 may be provided, and the plurality of second sensing areas SA2 may be located at different sides or opposite sides of the sensing light emitting area SLA. In addition, the size of each of the second sensing areas SA2 may be larger than the size of the first-first sensing area SA1-1 and / or the size of the first-second sensing area SA1-2, but the embodiment is not limited thereto. For example, Fig.13D As shown in , the size of each of the second sensing areas SA2 may be smaller than the size of the first-first sensing area SA1-1 or the size of the first-second sensing area SA1-2. Fig.13E As shown in FIG. 1 , a second sensing area SA2 may be provided, and the second sensing area SA2 may be located at one side of the sensing light emitting area SLA.

[0137] In an embodiment, the readout circuit 303 may include a register 310, a global reset circuit 320, a sensing circuit 332, a noise canceller 342, a low pass filter 350, and a band stop filter 360. The register 310 and the global reset circuit 320 of the readout circuit 303 may be substantially the same as the reference circuit 310. Figure 7 The register 310 and global reset circuit 320 of the readout circuit 300 are depicted as being the same or similar.

[0138] The sensing circuit 332 may receive the sensing current SC1-1 of one or more of the light sensing pixels PS in the first-first sensing area SA1-1 through the first-first readout line RL1-1, and may generate a first sensing signal SS1 corresponding to the sensing current SC1-1. The sensing circuit 332 may receive the sensing current SC1-2 of one or more of the light sensing pixels PS in the first-second sensing area SA1-2 through the first-second readout line RL1-2, and may generate a second sensing signal SS2 corresponding to the sensing current SC1-2. The sensing circuit 332 may receive the sensing current SC2 of one or more of the light sensing pixels PS in the second sensing area SA2 through the second readout line RL2, and may generate a first noise signal NS1 corresponding to the sensing current SC2. Each of the first sensing signal SS1 and the second sensing signal SS2 may include not only data of the volume of the blood vessel BV varying with time obtained by sensing the reflected light, but may also include a noise component. The first noise signal NS1 may include noise caused by various reasons regardless of the result of the reflected light.

[0139] The low pass filter 350 may receive the first noise signal NS1 from the sensing circuit 332, and may generate the second noise signal NS2 from the first noise signal NS1 by blocking frequency components of a cutoff frequency or more and passing only low frequency components less than the cutoff frequency. For example, the cutoff frequency may be about 0.5 Hz, but the embodiment is not limited thereto.

[0140] The band stop filter 360 may receive the second sensing signal SS2 from the sensing circuit 332, and may generate a third noise signal NS3 from the second sensing signal SS2 by blocking frequency components in a stop band and passing only frequency components in a remaining frequency band except the stop band. For example, the stop band may be 0.7 Hz to 7.2 Hz, but the embodiment is not limited thereto.

[0141] The noise canceller 342 may receive the first sensing signal SS1 from the sensing circuit 332, may receive the second noise signal NS2 from the low pass filter 350, may receive the third noise signal NS3 from the band stop filter 360, and may generate the third sensing signal SS3 based on the first sensing signal SS1, the second noise signal NS2, and the third noise signal NS3. For example, the noise canceller 342 may generate the third sensing signal SS3 by subtracting the second noise signal NS2 and the third noise signal NS3 from the first sensing signal SS1. In an embodiment, the third sensing signal SS3 may be a PPG signal PPGS transmitted to the main processor 400. In another embodiment, the readout circuit 303 may include various filters (e.g., BPF, etc.) for additionally filtering the third sensing signal SS3 (e.g., for additionally removing noise from the third sensing signal SS3), and the signal obtained by additionally filtering the third sensing signal SS3 may be the PPG signal PPGS transmitted to the main processor 400.

[0142] Fig.15 3 is a diagram showing another example of a readout circuit 304 included in a display device 14 according to another embodiment. Fig.15 The display device 14 of another embodiment described can be used with reference to Fig.14 The display device 13 described is substantially the same or similar except that the readout circuit 304 is partially changed. Therefore, repeated descriptions may be omitted or simplified.

[0143] refer to Fig.15 In an embodiment, the readout circuit 304 may include a register 310, a global reset circuit 320, a sensing circuit 332, a noise canceller 342, a low-pass filter 350, a band-stop filter 360, a band-pass filter 370, and an operational amplifier 380. The sensing circuit 332, the noise canceller 342, the low-pass filter 350, and the band-stop filter 360 of the readout circuit 304 may be substantially the same as the reference circuit 310. Fig.14 The sensing circuit 332 , noise canceller 342 , and band stop filter 360 of the readout circuit 303 are described to be the same or similar.

[0144] The bandpass filter 370 may receive the second sensing signal SS2 from the sensing circuit 332, and may generate a fourth sensing signal SS4 from the second sensing signal SS2 by passing only frequency components in a passband and blocking frequency components in remaining frequency bands other than the passband. For example, the passband may be 0.7 Hz to 7.2 Hz, but the embodiment is not limited thereto.

[0145] The operational amplifier 380 may receive the third sensing signal SS3 from the noise canceller 342, may receive the fourth sensing signal SS4 from the bandpass filter 370, and may generate the fifth sensing signal SS5 based on the third sensing signal SS3 and the fourth sensing signal SS4. For example, the operational amplifier 380 may generate the fifth sensing signal SS5 by adding the third sensing signal SS3 and the fourth sensing signal SS4. In an embodiment, the fifth sensing signal SS5 may be a PPG signal PPGS transmitted to the main processor 400, which has improved accuracy due to the output of the noise canceller 342 and the bandpass filter 370. In another embodiment, the readout circuit 304 may further include various filters (e.g., BPF, etc.) for additionally filtering the fifth sensing signal SS5 (e.g., for additionally removing noise from the fifth sensing signal SS5), and the signal obtained by additionally filtering the fifth sensing signal SS5 may be the PPG signal PPGS transmitted to the main processor 400.

[0146] The methods, processes and / or operations described herein may be performed by a code or instruction to be performed by a computer, processor, controller or other signal processing device. The computer, processor, controller or other signal processing device may be those described herein or elements except for the elements described herein. Because the algorithm of the basis (or the operation of a computer, processor, controller or other signal processing device) of the formation method is described in detail, the code or instruction for realizing the operation of the method embodiment may convert a computer, processor, controller or other signal processing device into a special processor for performing the method herein.

[0147] In addition, another embodiment may include a computer-readable medium, such as a non-transitory computer-readable medium, for storing the above-mentioned code or instructions. The computer-readable medium may be a volatile or non-volatile memory or other storage device, which may be removably or fixedly connected to a computer, processor, controller or other signal processing device that will execute the code or instructions for performing the operations of the method embodiments or device embodiments herein.

[0148] The controllers, processors, circuits, eliminators, filters, amplifiers, and other signal generation and signal processing features of the embodiments disclosed herein may be implemented as, for example, non-transitory logic that may include hardware, software, or both. When implemented at least in part in hardware, the controllers, processors, circuits, eliminators, filters, amplifiers, and other signal generation and signal processing features may be, for example, any of a variety of integrated circuits, including but not limited to application specific integrated circuits, field programmable gate arrays, combinations of logic gates, systems on chips, microprocessors, or other types of processing or control circuits. In some embodiments, these features may be implemented by neural networks, machine learning logic, or other forms of artificial intelligence.

[0149] When implemented at least in part with software, controllers, processors, circuits, eliminators, filters, amplifiers, and other signal generation and signal processing features may include, for example, a memory or other storage device for storing codes or instructions to be executed by, for example, a computer, processor, microprocessor, controller, or other signal processing device. The computer, processor, microprocessor, controller, or other signal processing device may be those described herein or elements other than the elements described herein. Because the algorithm forming the basis of the method (or the operation of a computer, processor, microprocessor, controller, or other signal processing device) is described in detail, the code or instructions for implementing the operation of the method embodiment may convert a computer, processor, microprocessor, controller, or other signal processing device into a special purpose processor for performing the method described herein.

[0150] Although embodiments and implementations have been described herein, other embodiments and modifications will be apparent from this description. Therefore, the present invention is not limited to such embodiments, but rather to the broader scope of the appended claims and various obvious modifications and equivalent arrangements as will be apparent to one of ordinary skill in the art. The embodiments may be combined to form additional embodiments.

Claims

1. Display equipment, including: A display panel including light-emitting pixels and light-sensing pixels, each of the light-emitting pixels including a light-emitting element, and each of the light-sensing pixels including a photoelectric conversion element; as well as A readout circuit, connected to the light sensing pixel via a readout line, Wherein, in the photoplethysmography (PPG) sensing mode, the readout circuit is configured to: receive a first sensing current from one or more of the light sensing pixels in a first sensing area adjacent to a sensing light emitting area configured to emit light, receive a second sensing current from one or more of the light sensing pixels in at least one second sensing area spaced apart from the first sensing area, and generate a PPG signal based on the first sensing current and the second sensing current.

2. The display device according to claim 1, wherein: The at least one second sensing region is spaced apart from the sensing light emitting region, The reflected light emitted from the sensing light emitting area and reflected from the blood vessels of the user's finger is incident on the first sensing area, and The reflected light is not incident on the at least one second sensing region.

3. The display device according to claim 2, wherein: The sensing and luminescent region surrounds at least a portion of the first sensing region in a plan view.

4. The display device according to claim 2, wherein: A distance between the sensing light-emitting area and the second sensing area is greater than or equal to a width of the sensing light-emitting area.

5. The display device according to claim 2, wherein: The readout circuit comprises: a sensing circuit configured to receive the first sensing current and the second sensing current through the readout line, generate a first sensing signal corresponding to the first sensing current, and generate a first noise signal corresponding to the second sensing current; a low pass filter configured to receive the first noise signal from the sensing circuit and generate a second noise signal; and A noise canceller is configured to receive the first sensing signal from the sensing circuit, receive the second noise signal from the low pass filter, and generate a second sensing signal based on the first sensing signal and the second noise signal.

6. The display device according to claim 2, wherein: The first sensing region includes a first-first sensing region and a first-second sensing region that are spaced apart from each other, and the reflected light is incident on each of the first-first sensing region and the first-second sensing region, and The readout circuit is configured to receive a first-first sensing current from one or more light sensing pixels in the first-first sensing area, receive a first-second sensing current from one or more light sensing pixels in the first-second sensing area, and generate the PPG signal based on the first-first sensing current, the first-second sensing current, and the second sensing current.

7. The display device according to claim 1, wherein: The second sensing region is adjacent to the sensing light emitting region, and Reflected light emitted from the sensing light emitting area and reflected from a blood vessel of a user's finger is incident on each of the first sensing area and the second sensing area.

8. The display device according to claim 1, wherein: In the PPG sensing mode, The light sensing area includes the light emitting pixels that are turned on and the light sensing pixels that are turned off. The first sensing area includes the light emitting pixels that are turned off and the light sensing pixels that are turned on, and The second sensing area includes the light emitting pixels that are turned off and the light sensing pixels that are turned on.

9. Display equipment, including: A display panel including light-emitting pixels and light-sensing pixels, each of the light-emitting pixels including a light-emitting element and each of the light-sensing pixels including a photoelectric conversion element; as well as a readout circuit connected to the light sensing pixel through a readout line and configured to generate a PPG signal based on a sensed current received from the light sensing pixel in a photoplethysmography (PPG) sensing mode, Wherein, in the PPG sensing mode, one or more of the light-emitting pixels in the sensing light-emitting area of ​​the display panel are turned on, one or more of the light-sensing pixels in the sensing light-emitting area are turned off, and reflected light emitted from the sensing light-emitting area and reflected from a blood vessel of a finger of a user is incident on a partial area of ​​the display panel, The reflected light is incident into a first sensing area of ​​the display panel, and in the first sensing area, one or more of the light emitting pixels are turned off and one or more of the light sensing pixels are turned on, and The reflected light is not incident into a second sensing region of the display panel, and in the second sensing region, one or more of the light emitting pixels are turned off, and one or more of the light sensing pixels are turned on.

10. Display equipment, including: a first pixel for emitting light reflected by a finger of a user; light sensing pixels, at locations where reflected light is sensed; a second pixel at a position where the reflected light is not sensed; a sensing circuit that generates a first sensing signal based on a sensing current output from the light sensing pixel and generates a noise signal based on a sensing current output from the second pixel; as well as A noise canceller is configured to subtract the noise signal from the first sensing signal to generate a bio-signal of the user.

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