Display devices and mobile terminals including display devices

Abstract

A display device and a mobile terminal including the display device are discussed. The display device may include: a display panel including a first pixel region and a second pixel region; a cover glass disposed on a first surface of the display panel in the second pixel region; an optical module disposed below the second surface of the display panel facing the second pixel region and configured to guide infrared light to a light-transmitting portion of the second pixel region; and a diffractive optical element disposed at a position corresponding to the light-transmitting portion of the second pixel region on or within at least one of the cover glass and the display panel. The diffractive optical element can separate infrared light from the optical module into multiple point beams.

Description

Technical Field

[0001] This disclosure relates to display devices and mobile terminals including display devices, and more specifically to display devices having optical devices disposed below a display panel and mobile terminals including display devices. Background Technology

[0002] Based on the material of the light-emitting layer, electroluminescent display devices are generally divided into inorganic light-emitting display devices and organic light-emitting display devices. Active matrix organic light-emitting display devices include self-emissive organic light-emitting diodes (hereinafter referred to as "OLEDs") and have the advantages of fast response speed, high luminous efficiency, high brightness and wide viewing angle.

[0003] In organic light-emitting diode (OLED) displays, OLEDs are formed within pixels. Because OLEDs have a fast response time, excellent luminous efficiency, brightness, and viewing angle, and can represent black grayscale levels in full black, they excel in contrast and color reproduction.

[0004] Recently, various optical devices have been added to mobile terminals. Examples of mobile terminals may include smartphones or tablets. Optical devices may include sensors or lighting devices required to support multimedia functions or perform biometric identification. These optical devices can be implemented as optical modules and assembled below the display panel of the mobile terminal.

[0005] To enlarge the screen of a mobile terminal, the light-emitting and light-receiving surfaces of the optical module can be set in a recessed area at the top of the display panel screen, or in a perforation within the screen of the mobile terminal. However, due to the recessed area or perforation, there may be many limitations in screen design, and the thickness of the mobile terminal may increase due to the relatively thick characteristics of the optical module. Summary of the Invention

[0006] This disclosure is intended to address or resolve the aforementioned needs and / or problems associated with the relevant technologies.

[0007] This disclosure provides a display device that increases the freedom of screen design and makes the optical module thinner, as well as a mobile terminal including such a display device.

[0008] The problems or limitations to be solved or addressed in this disclosure are not limited to those described above, and other problems or limitations not mentioned will be clearly understood by those skilled in the art from the following description.

[0009] A display device according to an exemplary embodiment of the present disclosure may include: a display panel in which an input image is reproduced in a first pixel region and a second pixel region including one or more light-transmitting portions; a cover glass disposed on a front surface of the display panel; a light source disposed below a rear surface of the display panel facing the second pixel region; and a diffractive optical element disposed on at least one of the cover glass and the display panel at a position facing the light-transmitting portion of the second pixel region, and configured to separate infrared light from the light source into a plurality of point beams.

[0010] A mobile terminal according to an exemplary embodiment of the present disclosure may include: a display panel in which an input image is reproduced in a first pixel region and a second pixel region including one or more light-transmitting portions; a display panel driver configured to write pixel data of the input image to the pixels of the display panel; a cover glass disposed on a front surface of the display panel; a light source disposed below a rear surface of the display panel facing the second pixel region; a diffractive optical element disposed on at least one of the cover glass and the display panel at a position of the light-transmitting portion facing the second pixel region, and configured to split infrared light from the light source into a plurality of point beams; an infrared camera disposed below the rear surface of the display panel and configured to convert infrared light incident through the display panel into electrical signals to output facial pattern data; and a host system configured to send pixel data of the input image to the display panel driver and to process user authentication with respect to facial pattern data received from the infrared camera.

[0011] A display device according to one embodiment of the present disclosure may include: a display panel including a first pixel region and a second pixel region adjacent to the first pixel region, the second pixel region including one or more light-transmitting portions; a cover glass disposed on a first surface of the display panel in the second pixel region; an optical module disposed below the second surface of the display panel facing the second pixel region and configured to guide infrared light to one or more light-transmitting portions of the second pixel region; and a diffractive optical element disposed on or in at least one of the cover glass and the display panel at a position corresponding to at least one of the light-transmitting portions of the second pixel region, the diffractive optical element being configured to separate infrared light from the optical module into a plurality of point beams.

[0012] These and other objectives of this application will become more apparent from the detailed description given below. However, it should be understood that while the detailed description and specific examples indicate preferred embodiments of this disclosure, they are given by way of illustration only, as various changes and modifications within the spirit and scope of this disclosure will become apparent to those skilled in the art in light of the following detailed description. Attached Figure Description

[0013] The above and other objects, features, and advantages of this disclosure will become more apparent to those skilled in the art from the detailed description of exemplary embodiments thereof with reference to the accompanying drawings, in which:

[0014] Figure 1 This is a schematic cross-sectional view illustrating a display panel according to an exemplary embodiment of the present disclosure;

[0015] Figure 2 This is a diagram illustrating an optical device that overlaps with the second pixel area of ​​the display panel;

[0016] Figure 3 This is a diagram illustrating an example of an optical device disposed in the second pixel region and the notch region;

[0017] Figure 4 This is an illustration of the pixel arrangement in the first pixel region;

[0018] Figure 5 This is an illustration of the pixel arrangement in the second pixel region;

[0019] Figures 6 to 8 These are circuit diagrams illustrating various pixel circuits applicable to the display devices of this disclosure;

[0020] Figure 9 It is an instance driver Figure 8 The waveform diagram of the pixel circuit method shown;

[0021] Figure 10 This is a block diagram illustrating a display device according to an exemplary embodiment of the present disclosure;

[0022] Figure 11 This is a diagram illustrating an example of a display device applied to a mobile device according to an exemplary embodiment of the present disclosure;

[0023] Figure 12 This is a cross-sectional view illustrating a display device according to a first exemplary embodiment of the present disclosure;

[0024] Figure 13 This is a cross-sectional view illustrating a display device according to a second exemplary embodiment of the present disclosure;

[0025] Figure 14AThis is a plan view illustrating an example of multiple diffractive optical elements dispersedly arranged on the cover glass of a mobile terminal;

[0026] Figure 14B It is along Figure 14A A cross-sectional view taken from line "AA" in the diagram;

[0027] Figure 15A This is a plan view illustrating an example of a wide diffractive optical element disposed on the cover glass of a mobile terminal;

[0028] Figure 15B It is along Figure 15A A cross-sectional view taken from line "BB" in the diagram;

[0029] Figure 16 This is a cross-sectional view illustrating a display device according to a third exemplary embodiment of the present disclosure;

[0030] Figure 17 This is a cross-sectional view illustrating a display device according to a fourth exemplary embodiment of the present disclosure;

[0031] Figure 18 This is a cross-sectional view illustrating a display device according to a fifth exemplary embodiment of the present disclosure;

[0032] Figure 19A and Figure 19B Detailed examples Figure 13 A diagram showing an example of a collimating lens;

[0033] Figure 20 This is a cross-sectional view illustrating an example of a lens being mounted on a display panel;

[0034] Figure 21 This is a cross-sectional view illustrating a display device according to a sixth exemplary embodiment of the present disclosure;

[0035] Figure 22 This is a cross-sectional view illustrating a display device according to a seventh exemplary embodiment of the present disclosure;

[0036] Figure 23 This is a cross-sectional view illustrating a display device according to an eighth exemplary embodiment of the present disclosure; and

[0037] Figure 24 This is a cross-sectional view illustrating a display device according to a ninth exemplary embodiment of the present disclosure. Detailed Implementation

[0038] The advantages and features of this disclosure, as well as the methods for implementing this disclosure, will become clearer from the embodiments described below with reference to the accompanying drawings. However, this disclosure is not limited to the following embodiments, but can be implemented in various different forms. Rather, the present embodiments are intended to complete the disclosure and allow those skilled in the art to fully understand its scope. This disclosure is limited only to the scope of the appended claims.

[0039] The shapes, dimensions, ratios, angles, quantities, etc., illustrated in the accompanying drawings for describing embodiments of the present disclosure are merely examples, and the present disclosure is not limited thereto. The same reference numerals generally denote the same elements throughout the specification. Furthermore, in describing the present disclosure, detailed descriptions of known prior art may be omitted to avoid unnecessarily obscuring the subject matter of the disclosure.

[0040] The terms “including,” “containing,” “having,” and “consisting of” used in this document are generally intended to allow for the addition of other components, unless used in conjunction with the term “only.” Unless otherwise expressly stated, any singular reference may include the plural.

[0041] Even if not explicitly stated, components are interpreted as including a normal error range.

[0042] When using terms such as “on top of,” “above,” “below,” and “immediately following” to describe the positional relationship between two components, one or more components may be positioned between the two components unless these terms are used with the terms “immediately” or “directly.”

[0043] Terms such as "first," "second," etc., can be used to distinguish components from each other, but the function or structure of a component is not limited by its number or name. These terms do not require any specific order.

[0044] Throughout this disclosure, the same reference numerals may refer to substantially the same elements.

[0045] The following implementations may be combined or integrated with each other in part or in whole, and may be linked and operated in technically different ways. These implementations may be performed independently of each other or in conjunction with each other.

[0046] In each display device of this disclosure, each pixel may include multiple sub-pixels of different colors to reproduce the colors of an image on the screen of the display panel. Each sub-pixel includes a transistor that functions as a switching element or a driving element. Such a transistor may be implemented as a TFT (thin-film transistor).

[0047] Each display device of this disclosure has a driving circuit that writes pixel data of an input image to pixels on a display panel. For this purpose, the driving circuit of the display device may include a data driving circuit configured to provide data signals to data lines, a gating driving circuit configured to provide gating signals to gating lines, and the like.

[0048] In each display device of this disclosure, the pixel circuit and the gating drive circuit may include a plurality of transistors. The transistors may be implemented as oxide thin-film transistors (oxide TFTs) including oxide semiconductors, low-temperature polycrystalline silicon (LTPS) TFTs including low-temperature polycrystalline silicon, etc. Each transistor may be implemented as a p-channel TFT or an n-channel TFT.

[0049] Typically, a transistor is a three-electrode device consisting of a gate, a source, and a drain. The source is the electrode that supplies charge carriers to the transistor. In a transistor, charge carriers begin to flow from the source. The drain is the electrode through which charge carriers leave the transistor. In a transistor, charge carriers can flow from the source to the drain.

[0050] In the case of an n-channel transistor, since the charge carriers are electrons, the source voltage is lower than the drain voltage, allowing electrons to flow from the source to the drain. The n-channel transistor has a current direction from the drain to the source. In the case of a p-channel transistor, since the charge carriers are holes, the source voltage is higher than the drain voltage, allowing holes to flow from the source to the drain. In a p-channel transistor, since holes flow from the source to the drain, the current flows from the source to the drain. It should be noted that the source and drain of a transistor are not fixed. For example, the source and drain can change depending on the applied voltage. Therefore, this disclosure is not limited by the source and drain of the transistor. In the following description, the source and drain of the transistor will be referred to as the first electrode and the second electrode.

[0051] The strobe signal oscillates between the gate on-voltage and the gate off-voltage. The gate on-voltage is set to be higher than the transistor's threshold voltage, and the gate off-voltage is set to be lower than the transistor's threshold voltage.

[0052] A transistor turns on in response to a gate on-voltage and turns off in response to a gate off-voltage. In the case of an n-channel transistor, the gate on-voltage can be the gate high voltage VGH and VEH, and the gate off-voltage can be the gate low voltage VGL and VEL. In the case of a p-channel transistor, the gate on-voltage can be the gate low voltage VGL and VEL, and the gate off-voltage can be the gate high voltage VGH and VEH.

[0053] In the following description, various embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In these embodiments, the display device will be described with emphasis on an organic light-emitting display device, but the present disclosure is not limited thereto. Furthermore, all components of each display device according to all embodiments of the present disclosure are operatively connected and configured.

[0054] Figure 1 This is a schematic cross-sectional view illustrating a display panel (or a portion thereof) according to an embodiment of the present disclosure, and Figure 2 This is an example and Figure 1 The diagram shows the optical device overlapping the second pixel area of ​​the display panel. Furthermore, Figure 3 This is an example diagram illustrating an optical device disposed in the second pixel area and the notch area of ​​the display panel. Figure 2 and Figure 3 The display panel can be the display panel of various mobile terminals.

[0055] Reference Figure 1 and Figure 2 The display panel 100 of the display device includes a screen for reproducing the input image.

[0056] The screen of the display panel 100 may include a first pixel area DA and a second pixel area CA. The first pixel area DA is a display area in which multiple pixels are arranged and an input image is reproduced. The first pixel area DA is preferably larger than the second pixel area CA and constitutes the majority of the main display area of ​​the screen in which the image is displayed. The second pixel area CA is a display area in which multiple pixels are arranged and an input image is reproduced. The pixels per inch (PPI) or resolution of the second pixel area CA is equal to or lower than the resolution of the first pixel area DA. Hereinafter, the PPI of the second pixel area CA will be described as lower than the PPI of the first pixel area DA.

[0057] The second pixel region CA may include multiple light-transmitting portions without a medium for blocking light. These light-transmitting portions may be positioned between sub-pixels of the second pixel region CA. Light can pass through the light-transmitting portions with minimal loss. When the PPI or resolution of the second pixel region CA is smaller than that of the first pixel region DA, the light-transmitting portions in the second pixel region CA can be larger.

[0058] Each of the first pixel region DA and the second pixel region CA includes pixels in which pixel data of the input image is written. Therefore, the input image can be displayed in the first pixel region DA and / or the second pixel region CA.

[0059] Each pixel in the first pixel region DA and the second pixel region CA includes sub-pixels of different colors to achieve the color of the image. Such sub-pixels may include red sub-pixels, green sub-pixels, and blue sub-pixels. Each pixel in pixel P may also include a white sub-pixel, or may include known combinations of sub-pixels of different colors. Furthermore, each sub-pixel in the pixel may include pixel circuitry for driving the corresponding light-emitting element.

[0060] When the PPI or resolution of the second pixel region CA is lower than that of the first pixel region DA, an image quality compensation algorithm can be applied to compensate for the brightness and color coordinates of the pixels in the second pixel region CA.

[0061] One or more optical devices (or modules) 200 may be disposed below the rear surface of the display panel 100 and may overlap with the second pixel region CA. The optical device 200 may include an image sensor (or camera), a proximity sensor, a white light illuminator, optical elements for facial recognition, etc.

[0062] As an example of the optical device 200, the optical elements for facial recognition may include an infrared light source, an infrared camera, an infrared illuminator, etc., located below the second pixel region CA of the display panel 100. Figure 1 As shown.

[0063] exist Figure 2 In the attached drawing, reference numeral 201 indicates an infrared light source, and reference numeral 202 indicates an infrared camera. Thus, Figure 1 The optical device 200 shown, positioned below the second pixel region CA, can be Figure 2 The infrared light source 201 and / or infrared camera 202, but not limited to these. For example, such as Figure 3 As in the example, the infrared light source 201 can be placed only below the second pixel area CA, or the image sensor, proximity sensor, white light illuminator, infrared illuminator, etc. can also be placed below the second pixel area CA.

[0064] The infrared light source 201 may include a vertical cavity surface emitting laser (VCSEL), a lens for expanding and collimating the light emitted from the laser, and a light guide.

[0065] Reference Figure 1 and Figure 2 The transparent cover glass 20 can be attached to the front surface of the display panel 100. The second pixel region CA of the display panel 100 or the cover glass 20 includes a diffractive optical element 203 disposed at a position facing the infrared light source 201. The diffractive optical element 203 may include one or more diffractive optical elements (DOE) and holographic optical elements (HOE).

[0066] exist Figure 2 and Figure 3 In the example, the diffractive optical element is disposed in the second pixel region CA, and the infrared light source is disposed below the rear surface of the display panel 100 to face the diffractive optical element 203. Figure 3 In this design, an ambient light sensor 204, a proximity sensor 205, a flood illuminator 206, an infrared camera 202, and a front-facing camera 207 are disposed in the notch region NA of the mobile terminal, and a diffractive optical element 203 and an infrared light source 201 are disposed in the second pixel region CA. The notch region NA is a non-display area at the top of the screen without any pixels. The mobile terminal may also include known components such as a communication unit configured to transmit and receive signals to and from the mobile terminal, a user input unit (e.g., a touch area) configured to receive user input, a memory / storage unit configured to store data, and a controller / processor configured to control components of the mobile terminal.

[0067] Infrared illuminators enable facial recognition even in dark environments using floodlights that produce infrared (IR) flashes. Diffractive optics diffract infrared light from infrared source 201 using diffraction or holographic patterns, separating the infrared light into hundreds to thousands of point beams. Infrared camera 202 captures these point beams of infrared wavelengths focused on the human face. Infrared camera 202 can convert the infrared wavelengths of light passing through display panel 100 into electrical signals, and then convert these electrical signals into digital data to generate facial pattern data. Therefore, when the point beams separated from the diffractive optics are illuminated onto the user's face, and the infrared point beams reflected from the face are received by infrared camera 202, user authentication can be processed in the biometric authentication module of the host system.

[0068] In the display device of this disclosure, since the optical device 200 is disposed below the rear surface of the display panel 100 to overlap with the second pixel region CA, the display area of ​​the screen is not limited by the optical device 200. Therefore, the display device of this disclosure can achieve a full-screen display by expanding the display area of ​​the screen and increase the freedom of screen design.

[0069] The display panel 100 has a width along the X-axis, a length along the Y-axis, and a thickness along the Z-axis. For example... Figure 1 The display panel 100 shown may include a circuit layer 12 disposed on a substrate 10 and a light-emitting element layer 14 disposed on the circuit layer 12. A polarizer 18 may be disposed on the light-emitting element layer 14, and a cover glass 20 may be disposed on the polarizer 18.

[0070] Circuit layer 12 may include pixel circuitry connected to lines such as data lines, gating lines, power lines, etc., and gating drive portions connected to the gating lines. Circuit layer 12 may include circuit elements such as transistors implemented with thin-film transistors (TFTs), capacitors, etc. The lines and circuit elements of circuit layer 12 may be implemented using multiple insulating layers, two or more metal layers spaced apart from each other by the insulating layers therebetween, and active layers comprising semiconductor materials.

[0071] The light-emitting element layer 14 may include light-emitting elements driven by pixel circuitry. The light-emitting elements may be implemented using an organic light-emitting diode (OLED). An OLED includes an organic compound layer formed between an anode and a cathode. The organic compound layer may include a hole injection layer (HIL), a hole transport layer (HTL), an emissive layer (EML), an electron transport layer (ETL), and an electron injection layer (EIL), but this disclosure is not limited thereto. When a voltage is applied to the anode and cathode of the OLED, holes passing through the hole transport layer (HTL) and electrons passing through the electron transport layer (ETL) move to the emissive layer (EML) and then form excitons, thus emitting visible light from the emissive layer (EML).

[0072] OLEDs used as light-emitting elements (ELs) can have a stacked structure in which multiple light-emitting layers are stacked. OLEDs with stacked structures can improve pixel brightness and lifespan. The light-emitting element layer 14 can be disposed on pixels capable of selectively transmitting red, green, and blue wavelengths, and may also include a color filter array.

[0073] The light-emitting element layer 14 can be covered by a protective film, and the protective film can be covered by an encapsulation layer. The protective layer and encapsulation layer can have a structure in which organic and inorganic films are alternately stacked. The inorganic film blocks the penetration of moisture or oxygen. The organic film flattens the surface of the inorganic film. When organic and inorganic films are stacked in multiple layers, the channels for moisture or oxygen are longer than those for moisture or oxygen in a single layer, thus effectively blocking the penetration of moisture or oxygen that could affect the light-emitting element layer 14.

[0074] A touch sensor layer can be formed on an encapsulation layer, and a polarizer 18 or a color filter layer can be disposed on the touch sensor layer. The touch sensor layer can include a capacitive touch sensor that senses touch input based on capacitance changes before and after touch input. The touch sensor layer can include a metal wiring pattern forming the capacitance of the touch sensor and an insulating film. The insulating film can insulate portions intersecting with the metal wiring pattern and can planarize the surface of the touch sensor layer. The polarizer 18 can improve visibility and contrast by converting the polarization of external light reflected by the metal of the touch sensor layer and the circuit layer. The polarizer 18 can be implemented as a polarizer in which a linear polarizer and a phase retardation film are joined, or a circular polarizer. A cover glass 20 can be attached to the polarizer 18. The color filter layer can include a red color filter, a green color filter, and a blue color filter. The color filter layer can also include a black matrix pattern. The color filter layer can absorb a portion of the wavelength of light reflected from the circuit layer and the touch sensor layer, replacing the function of the polarizer 18 and increasing the color purity of the image reproduced in the pixel array. In this case, the polarizer 18 is not needed and is omitted from the display panel.

[0075] Figure 4 This is a diagram illustrating an example of the pixel arrangement in the first pixel region. Figure 5 This is an example diagram illustrating the pixels and light-transmitting portion within the second pixel region. For clarity, in... Figure 4 and Figure 5 The wiring connecting the pixels is omitted. The first and second pixel regions here can be... Figures 1 to 3 Examples of the first pixel region DA and the second pixel region CA.

[0076] Reference Figure 4 The first pixel region DA comprises pixels arranged with a high PPI. Each pixel in the pixel can be implemented as a real pixel, wherein the R sub-pixels, G sub-pixels, and B sub-pixels of the three primary colors are configured as one pixel. Each pixel in the pixel may also include W sub-pixels, which are omitted from the attached figure.

[0077] Within each pixel, a subpixel coloring algorithm can be used to treat two subpixels as one pixel. For example, the first pixel can be composed of an R subpixel and a first G subpixel, and the second pixel can be composed of a B subpixel and a second / next G subpixel. The insufficient color representation in each pixel of the first and second pixels can be compensated for by averaging the corresponding color data between neighboring pixels.

[0078] Within a subpixel, the luminous efficiency of the light-emitting element may differ for each color. Taking this into account, the size of the subpixel may differ for each color. For example, among the R, G, and B subpixels, the B subpixel can have the largest size, and the G subpixel can have the smallest size.

[0079] Reference Figure 5 The second pixel region CA includes pixel groups spaced apart at a predetermined distance and a light-transmitting portion AG disposed between adjacent pixel groups PG. The pixel group PG includes a portion disposed between adjacent pixel groups PG. Figure 5 The dashed lines indicate the sub-pixels within the region.

[0080] External light is received by a lens of an optical device (e.g., 200) through the light-transmitting portion AG. The light-transmitting portion AG may comprise a transparent medium with high transmittance and no metal, allowing light to enter with minimal light loss and be transmitted to the optical device (e.g., 200) positioned below the second pixel region CA. In other words, the light-transmitting portion AG may be formed of a transparent insulating material that does not include metal wiring or pixels. Due to the light-transmitting portion AG, the PPI of the second pixel region CA is lower than that of the first pixel region DA.

[0081] In the second pixel region CA, a pixel group may include one or two pixels. Each pixel in a pixel group may include two to four sub-pixels. For example, a pixel in a pixel group may include an R sub-pixel, a G sub-pixel, and a B sub-pixel, or two sub-pixels, and also a W sub-pixel. Figure 5 In the example, the first pixel is composed of R sub-pixels and G sub-pixels, and the second pixel is composed of B sub-pixels and G sub-pixels, but this disclosure is not limited thereto.

[0082] The shape of the translucent part AG is in Figure 5 The shape shown is circular, but it is not limited to this. For example, the light-transmitting part AG can be designed in any shape, such as circular, elliptical, or polygonal.

[0083] Due to process variations and component characteristic changes in the manufacturing process of display panels, the electrical characteristics of the driving elements between pixels may differ, and this difference may increase over time. Internal or external compensation techniques can be applied to organic light-emitting display devices to compensate for these variations in the electrical characteristics of the driving elements between pixels.

[0084] Internal compensation techniques use internal compensation circuitry implemented in each pixel circuit to sense the threshold voltage of the driving element in each sub-pixel and compensate for the gate-source voltage Vgs of the driving element using this threshold voltage. External compensation techniques use external compensation circuitry to sense the current or voltage of the driving element in real time, which varies according to the electrical characteristics of the driving element. External compensation techniques modulate the pixel data (digital data) of the input image by sensing the deviation (or variation) of the electrical characteristics of the driving element in each pixel, thereby compensating for the deviation (or variation) of the electrical characteristics of the driving element in each pixel in real time.

[0085] Figures 6 to 8 These are circuit diagrams illustrating various pixel circuits that can be applied to any display device of this disclosure.

[0086] In the first example, refer to Figure 6 The pixel circuit includes a light-emitting element EL, a driving element DT configured to supply current to the light-emitting element EL, a switching element M01 configured to connect a data line DL to a second node n2 in response to a scan pulse SCAN, and a capacitor Cst connected between the second node n2 and the third node n3. The driving element DT and the switching element M01 can be implemented as an n-channel transistor.

[0087] The driving element DT includes a gate connected to the second node n2, a first electrode connected to the first node n1, and a second electrode connected to the third node n3. A VDD line PL, to which a pixel driving voltage ELVDD is applied, is connected to the first node n1. The light-emitting element EL includes an anode connected to the third node n3 and a cathode connected to a VSS line to which a low-potential power supply voltage ELVSS is applied.

[0088] The driving element DT drives the light-emitting element EL by supplying current to it according to the gate-source voltage Vgs. The light-emitting element EL conducts and emits light when the forward voltage between the anode and cathode is equal to or greater than the threshold voltage. A capacitor Cst is connected between the gate and source of the driving element DT to maintain the gate-source voltage Vgs of the driving element DT.

[0089] Figure 7 A second example of a pixel circuit is shown.

[0090] Reference Figure 7 ,Apart from Figure 6 In addition to the pixel circuit configuration shown, the pixel circuit also includes a second switching element M02 connected between the reference voltage line REFL and the second electrode of the driving element DT. In this pixel circuit, the driving element DT and the switching elements M01 and M02 can be implemented as n-channel transistors.

[0091] The second switching element M02 applies a reference voltage VREF to the third node n3 in response to either the scan pulse SCAN or the individual sensing pulse SENSE. The reference voltage VREF is applied to the pixel circuit via the REF line REFL.

[0092] In sensing mode, the current flowing through the channel of the driving element DT or the voltage between the driving element DT and the light-emitting element EL can be sensed via the reference line REFL. The current flowing through the reference line REFL is converted into voltage by an integrator and then into digital data by an analog-to-digital converter (hereinafter referred to as "ADC"). This digital data is sensing data that includes threshold voltage or mobility information of the driving element DT. The sensor data is sent to the data processing section. The data processing section can receive the sensing data from the ADC and compensate for pixel drive deviations and degradation by adding a compensation value selected based on the sensing data to the pixel data or multiplying the compensation value selected based on the sensing data by the pixel data.

[0093] Figure 8 This is a circuit diagram illustrating the third example of a pixel circuit. Figure 9 It is an instance driver Figure 8 The waveform diagram shows the pixel circuit method.

[0094] Reference Figure 8 and Figure 9 The pixel circuit includes a light-emitting element EL, a driving element DT configured to supply current to the light-emitting element EL, and a switching circuit configured to switch the voltage applied to the light-emitting element EL and the driving element DT.

[0095] The switching circuit is connected to power lines PL1, PL2, and PL3, data line DL, and gating lines GL1, GL2, and GL3, which are supplied with pixel drive voltage ELVDD, low-potential power supply voltage ELVSS, and initialization voltage Vini. It switches the voltages applied to the light-emitting element EL and the driving element DT in response to gating signals. The gating signals may include scan pulses SCAN(N-1) and SCAN(N) and a light-emitting control pulse (hereinafter referred to as the "EM pulse") EM(N). Here, N is, for example, a positive integer.

[0096] The switching circuit includes an internal compensation circuit that uses multiple switching elements M1 to M6 to sample the threshold voltage Vth of the driving element DT and store the voltage in a capacitor Cst, and compensates for the gate voltage of the driving element DT using the threshold voltage Vth. Each of the driving element DT and the switching elements M1 to M6 can be implemented as a p-channel TFT.

[0097] The driving period of a pixel circuit can be divided into the initialization period Tini, the sampling period Tsam, and the emission period Tem, such as Figure 9 As shown.

[0098] During the sampling period Tsam, the Nth scan pulse SCAN(N) is generated as the gate on-state voltage VGL and applied to the first gating line GL1. During the initialization period Tini preceding the sampling period, the (N-1)th scan pulse SCAN(N-1) is generated as the gate on-state voltage VGL and applied to the second gating line GL2. During both the initialization period Tini and the sampling period Tsam, the EM pulse EM(N) is generated as the gate off-state voltage VEH and applied to the third gating line GL3.

[0099] During the initialization period Tini, the (N-1)th scan pulse SCAN(N-1) is generated as the gate on-state voltage VGL, and each voltage in the Nth scan pulse SCAN(N) and the EM pulse EM(N) is the gate off-state voltage VGH / VEH. During the sampling period Tsam, the Nth scan pulse SCAN(N) is generated as the gate on-state voltage VGL, and each voltage in the (N-1)th scan pulse SCAN(N-1) and the EM pulse EM(N) is the gate off-state voltage VGH / VEH. During at least a portion of the emission period Tem, the EM pulse EM(N) is generated as the gate on-state voltage VEL, and each voltage in the (N-1)th scan pulse SCAN(N-1) and the Nth scan pulse SCAN(N) is generated as the gate off-state voltage VGH.

[0100] During the initialization period Tini, the fifth switching element M5 is turned on according to the gate turn-on voltage VGL of the (N-1)th scan pulse SCAN(N-1) to initialize the pixel circuit. During the sampling period Tsam, the first switching element M1 and the second switching element M2 are turned on according to the gate turn-on voltage VGL of the Nth scan pulse SCAN(N), and the data voltage Vdata compensated by the threshold voltage of the driving element DT is stored in the capacitor Cst. Simultaneously, during the sampling period Tsam, the sixth switching element M6 is turned on and the voltage of the fourth node n4 is reduced to the reference voltage VREF to suppress the emission of the light-emitting element EL.

[0101] When the light-emitting period Tem begins, EM line GL3 is inverted to the gate on-state voltage VGL. During the light-emitting period Tem, scan lines GL1 and GL2 maintain the gate off-state voltage VGH. During the light-emitting period Tem, the light-emitting element EL can emit light because the third switching element M3 and the fourth switching element M4 are turned on. During the light-emitting period Tem, in order to accurately represent the brightness of low gray levels, the voltage level of the EM pulse EM(N) can be inverted at a predetermined duty cycle between the gate on-state voltage VGL and the gate off-state voltage VGH. In this case, the third switching element M3 and the fourth switching element M4 can be repeatedly turned on / off according to the duty cycle of the EM pulse EM(N) during the light-emitting period Tem.

[0102] The anode of the light-emitting element EL is connected to a fourth node n4 between the fourth switching element M4 and the sixth switching element M6. The fourth node n4 is connected to the anode of the light-emitting element OLED, the second electrode of the fourth switching element M4, and the second electrode of the sixth switching element M6. The cathode of the light-emitting element EL is connected to the VSS line PL3, to which a low-potential power supply voltage ELVSS is applied. The light-emitting element EL emits light using a current Ids flowing according to the gate-source voltage Vgs of the driving element DT. The current path of the light-emitting element EL is switched by the third switching element M3 and the fourth switching element M4.

[0103] The storage capacitor Cst is connected between the VDD line PL1 and the second node n2. The data voltage Vdata, compensated by the threshold voltage Vth of the driving element DT, is charged in the capacitor Cst. Since the data voltage Vdata in each sub-pixel is compensated by the threshold voltage Vth of the driving element DT, the characteristic deviation of the driving element DT in the sub-pixel is compensated.

[0104] The first switching element M1 is turned on in response to the gate turn-on voltage VGL of the Nth scan pulse SCAN(N) to connect the second node n2 to the third node n3. The second node n2 is connected to the gate of the driving element DT, the first electrode of the capacitor Cst, and the first electrode of the first switching element M1. The third node n3 is connected to the second electrode of the driving element DT, the second electrode of the first switching element M1, and the first electrode of the fourth switching element M4. The gate of the first switching element M1 is connected to the Nth scan line GL1 to receive the Nth scan pulse SCAN(N). The first electrode of the first switching element M1 is connected to the second node n2, and the second electrode of the first switching element M1 is connected to the third node n3.

[0105] Because the first switching element M1 is turned on during a very short horizontal period (1H) of the Nth scan signal SCAN(N) generated as the gate on-state voltage VGL in a frame time period, leakage current may occur in the off state. To limit the leakage current of the first switching element M1, the first switching element M1 can be implemented with a transistor having a dual-gate structure with two transistors connected in series.

[0106] The second switching element M2 is turned on in response to the gate turn-on voltage VGL of the Nth scan pulse SCAN(N) to provide a data voltage Vdata to the first node n1. The gate of the second switching element M2 is connected to the Nth scan line GL1 to receive the Nth scan pulse SCAN(N). The first electrode of the second switching element M2 is connected to the first node n1. The second electrode of the second switching element M2 is connected to the data line DL of the first pixel region DA, where the data voltage Vdata is applied. The first node n1 is connected to the first electrode of the second switching element M2, the second electrode of the third switching element M3, and the first electrode of the driving element DT.

[0107] The third switching element M3 is turned on in response to the gate turn-on voltage VEL of the EM pulse EM(N) to connect the VDD line PL1 to the first node n1. The gate of the third switching element M3 is connected to the EM line GL3 to receive the EM pulse EM(N). The first electrode of the third switching element M3 is connected to the VDD line PL1. The second electrode of the third switching element M3 is connected to the first node n1.

[0108] The fourth switching element M4 is turned on in response to the gate turn-on voltage VEL of the EM pulse EM(N) to connect the third node n3 to the anode of the light-emitting element OLED. The gate of the fourth switching element M4 is connected to the EM line GL3 to receive the EM pulse EM(N). The first electrode of the fourth switching element M4 is connected to the third node n3, and the second electrode is connected to the fourth node n4.

[0109] The fifth switching element M5 is turned on in response to the gate turn-on voltage VGL of the (N-1)th scan pulse SCAN(N-1), connecting the second node n2 to the Vini line PL2. The gate of the fifth switching element M5 is connected to the (N-1)th scan line GL2 to receive the (N-1)th scan pulse SCAN(N-1). The first electrode of the fifth switching element M5 is connected to the second node n2, and the second electrode is connected to the Vini line PL2. To limit the leakage current of the fifth switching element M5, the fifth switching element M5 is implemented using a transistor with a dual-gate structure having two transistors connected in series.

[0110] The sixth switching element M6 is turned on in response to the gate turn-on voltage VGL of the Nth scan pulse SCAN(N) to connect the Vini line PL2 to the fourth node n4. The gate of the sixth switching element M6 is connected to the Nth scan line GL1 to receive the Nth scan pulse SCAN(N). The first electrode of the sixth switching element M6 is connected to the Vini line PL2, and the second electrode of the sixth switching element M6 is connected to the fourth node n4.

[0111] In another embodiment, the gates of the fifth switching element M5 and the sixth switching element M6 can be connected together to the (N-1)th scan line GL2 to which the (N-1)th scan pulse SCAN(N-1) is applied. In this case, the fifth switching element M5 and the sixth switching element M6 can be turned on simultaneously in response to the (N-1)th scan pulse SCAN(N-1).

[0112] The driving element DT drives the light-emitting element EL by controlling the current flowing through the light-emitting element EL according to the gate-source voltage Vgs. The driving element DT includes a gate connected to the second node n2, a first electrode connected to the first node n1, and a second electrode connected to the third node n3. Figure 9 In this context, "DTG" refers to the gate voltage of the driving element DT, which is the voltage of the second node n2.

[0113] It should be noted that the configuration of the pixel circuits in the display device of this disclosure is not limited to... Figures 6 to 8 Examples. For instance, a data voltage Vdata can be applied to the gate of the driving element DT or to the first or second electrode of the driving element DT. The gamma characteristic curve of the data voltage Vdata can be set as a positive gamma curve or an inverse gamma curve depending on the channel characteristics of the driving element DT or the electrode to which the data voltage Vdata is applied. The data voltage Vdata can be applied to the first or second electrode of the n-channel driving element DT, or the data voltage Vdata can be applied to the gate of the p-channel driving element DT. The data voltage Vdata applied to the gate of the n-channel driving element DT is a voltage determined by a positive gamma curve. The data voltage Vdata applied to the first or second electrode of the n-channel driving element DT is a voltage determined by an inverse gamma curve. The data voltage Vdata applied to the gate of the p-channel driving element DT is a voltage determined by an inverse gamma curve. The data voltage Vdata applied to the first or second electrode of the p-channel driving element DT is a voltage determined by a positive gamma curve.

[0114] Figure 10 This is a block diagram illustrating a display device according to an exemplary embodiment of the present disclosure. Figure 11 This is a diagram illustrating an example of applying a display device according to an embodiment of the present disclosure to a mobile device.

[0115] Reference Figure 10 The display device according to this embodiment of the present disclosure includes: a display panel 100; display panel drivers 110 and 120 configured to write pixel data of an input image to a pixel P of the display panel 100; a timing controller 130 configured to control the display panel drivers 110 and 120; and a power supply unit 150 configured to generate power required to drive the display panel 100.

[0116] The display panel 100 includes a pixel array for displaying an input image on the screen. As described above, the pixel array can be divided into a first pixel region DA and a second pixel region CA. Each sub-pixel in the pixel array sub-pixels of the display panel 100 can be used... Figures 6 to 8 The pixel circuit shown drives the light-emitting element EL. As a variation, the pixel array may include one or more first pixel regions DA and one or more second pixel regions CA.

[0117] The touch sensor can be disposed on the screen of the display panel 100. The touch sensor can be implemented as an on-cell touch sensor or an additional touch sensor disposed on the screen of the display panel, or it can be implemented as an in-cell touch sensor embedded in the pixel array.

[0118] Display panel 100 can be made into a flexible display panel, wherein pixels P are disposed on a flexible substrate such as a plastic substrate or a metal substrate. In a flexible display, the size and shape of the screen can be changed by rolling, folding, or bending the flexible display panel. Flexible displays can include sliding displays, rollable displays, bendable displays, foldable displays, etc.

[0119] The display panel driver reproduces the input image on the screen of the display panel 100 by writing the pixel data of the input image to subpixels. The display panel driver includes a data driver 110 and a gating driver 120. The display panel driver may also include a demultiplexer 112 disposed between the data driver 110 and the data line DL.

[0120] Each display panel driver can operate in a low-speed drive mode under the control of the timing controller 130. In low-speed drive mode, by analyzing the input image, the power consumption of the display device can be reduced when the input image does not change within a preset time. In low-speed drive mode, when a still image is input for a predetermined time or longer, power consumption can be reduced by lowering the refresh rate of pixel P and extending the data writing period of pixel P. Low-speed drive mode is not limited when a still image is input. For example, when the display device operates in standby mode, or when a user command or input image is not input to the display panel driver circuit for a predetermined time or longer, the display panel driver circuit can operate in low-speed drive mode.

[0121] Data driver 110 uses a digital-to-analog converter (hereinafter referred to as "DAC") to generate a data voltage Vdata for the pixel data (which is digital data) of the input image. The DAC receives the pixel data (which is digital data) and receives a gamma voltage from the gamma voltage generation circuit of power supply unit 150. DACs are provided in each channel of data driver 110. The DAC uses an array of switching elements to convert the pixel data into a data voltage Vdata, the switching elements selecting the voltage in response to the bits of the pixel data. The data voltage output from each channel of data driver 110 can be provided to the data line DL of display panel 100 via demultiplexer 112.

[0122] Demultiplexer 112 time-divisions the data voltage Vdata output from the channels of data driver 110 and distributes it to multiple data lines DL. Due to demultiplexer 112, the number of channels in data driver 110 can be reduced. Demultiplexer 112 can be omitted. In this case, the channels of data driver 110 are directly connected to the data lines DL.

[0123] The gate driver 120 can be implemented as an in-panel gate (GIP) circuit directly formed on the bezel area BZ of the display panel 100 along with the TFT array of the pixel array. Under the control of the timing controller 130, the gate driver 120 outputs a gate signal to the gate line GL. The gate driver 120 can sequentially provide the gate signal to the gate line GL by shifting the gate signal using a shift register. The voltage of the gate signal oscillates between the gate cutoff voltage VGH and the gate on voltage VGL. The gate signal may include scan pulses, EM pulses, sensing pulses, etc. Figures 6 to 8 As shown.

[0124] The gating driver 120 can be disposed on each of the left and right bezels (or two opposite sides) of the display panel 100 to provide a gating signal to the gating line GL in a dual-feed manner. In the dual-feed manner, the gating drivers 120 on both sides are synchronized, so that gating signals can be applied simultaneously from both ends of a gating line. In another exemplary embodiment, the gating driver 120 can be disposed on either the left and right bezels (or two opposite sides) of the display panel 100 and can provide a gating signal to the gating line GL in a single-feed manner.

[0125] The gating driver 120 may include a first gating driver 121 and a second gating driver 122. The first gating driver 121 outputs scan pulses and sensing pulses, and shifts the scan pulses and sensing pulses according to a shift clock. The second gating driver 122 outputs pulses of the EM signal, and shifts the EM pulses according to a shift clock. In the case of a borderless model, at least some of the switching elements constituting the first gating driver 121 and the second gating driver 122 may be distributed in the pixel array.

[0126] The timing controller 130 receives pixel data of the input image and timing signals synchronized with the pixel data from the host system. The timing signals include a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, a clock CLK, and a data enable signal DE. One period of the vertical synchronization signal Vsync is one frame period. One period of each of the horizontal synchronization signal Hsync and the data enable signal DE is one horizontal period 1H. The pulse of the data enable signal DE is synchronized with a row of data of pixel P to be written to a pixel row. Since the frame period and horizontal period can be determined by counting the data enable signal DE, the vertical synchronization signal Vsync and the horizontal synchronization signal Hsync can be omitted.

[0127] The timing controller 130 transmits pixel data of the input image to the data driver 110 and synchronizes the data driver 110, demultiplexer 112, and gating driver 120. The timing controller 130 may include a data processing unit that receives sensing data from pixels P in a display panel driver with applied external compensation technology and modulates the pixel data. In this case, the timing controller 130 can transmit the pixel data modulated by the data processing unit to the data driver 110.

[0128] The timing controller 130 can control the operation timing of the display panel drivers 110, 112, and 120 by multiplying the input frame rate by i to obtain a frame rate of input frame rate × i Hz (where i is a positive integer greater than 0). The input frame rate is 60 Hz in the National Television Standards Committee (NTSC) scheme and 50 Hz in the Phase-Alternating Line (PAL) scheme. The timing controller 130 can reduce the frame rate to a frequency between 1 Hz and 30 Hz to reduce the refresh rate of pixel P in low-speed drive mode.

[0129] The timing controller 130 generates a data timing control signal for controlling the operation timing of the data driver 110, a switch control signal for controlling the operation timing of the demultiplexer 112, and a gating timing control signal for controlling the operation timing of the gating driver 120 based on the timing signals Vsync, Hsync, and DE received from the host system.

[0130] The gating timing signal may include a start pulse, a shift clock, etc. The voltage level of the gating timing control signal output from the timing controller 130 can be converted into a gate high voltage VGH / VEH and a gate low voltage VGL / VEL by a level shifter (omitted in the figure), and then provided to the gating driver 120. The level shifter can convert the low-level voltage of the gate timing control signal into a gate low voltage VGL, and the high-level voltage of the gate timing control signal into a gate high voltage VGH / VEH.

[0131] Power supply unit 150 may include a charge pump, regulator, buck converter, boost converter, gamma voltage generation circuit, etc. Power supply unit 150 generates the power required to drive the display panel driver and display panel 100 by regulating the DC input voltage from the host system. Power supply unit 150 can output DC voltages such as gamma reference voltage, gate cutoff voltage VGH / VEH, gate on-voltage VGL / VEL, pixel drive voltage ELVDD, low-level supply voltage ELVSS, initialization voltage Vini, and reference voltage VREF. The gamma voltage generation circuit can be implemented as a programmable gamma IC (P-GMAIC). The programmable gamma IC can change the gamma voltage according to register settings. The gamma voltage is provided to data driver 110. Gate cutoff voltage VGH / VEH and gate on-voltage VGL / VEL are provided to level shifter and gating driver 120. Pixel drive voltage ELVDD, low-level supply voltage ELVSS, initialization voltage Vini, and reference voltage VREF are typically provided to the pixel circuit via power lines. The pixel drive voltage ELVDD is set to a voltage higher than the low-potential supply voltage ELVSS, the initialization voltage Vini, and the reference voltage VREF.

[0132] The host system can be a TV system, set-top box, navigation system, personal computer (PC), vehicle system, home theater system, mobile device, or wearable device's main circuit board. In the mobile device or wearable device, the timing controller 130, data driver 110, and power supply unit 150 can be integrated into a driver integrated circuit (D-IC) in the display panel of the mobile terminal, such as... Figure 11 As shown. In Figure 11 In the accompanying drawings, reference numeral 200 denotes the host system. The host system 200 includes an authentication module. The authentication module includes circuitry, programs, and / or a processor for executing a facial recognition algorithm that processes user authentication by comparing facial pattern data received from an infrared camera 202 with preset feature points of a user's facial pattern.

[0133] Figure 12 This is a cross-sectional view illustrating a display device according to a first exemplary embodiment of the present disclosure. Figure 13 This is a cross-sectional view illustrating a display device according to a second exemplary embodiment of the present disclosure.

[0134] Reference Figure 12 and Figure 13 The cover glass 20 may include one or more diffraction patterns (DOEs) disposed at a position facing the light-transmitting portion AG of the second pixel region CA. A diffraction pattern (DOE) is a diffractive optical element that splits infrared light (IR) into multiple point beams.

[0135] The emitter 201a of the infrared light source 201 can be positioned below the light-transmitting portion AG of the second pixel region CA, and can illuminate the second pixel region CA with infrared light IR. The infrared light source 201 can be implemented as an optical module / device without light guides and lenses, but is not limited thereto. The infrared light IR emitted from the infrared light source 201 can be incident at an angle perpendicular to the XY plane of the display panel 100 and the cover glass 20, in order to increase the diffraction efficiency of the diffraction pattern DOE. For this purpose, as... Figure 13 As shown, the collimating lens 201b can be disposed on the light emitting surface of the emitter 201a of the infrared light source (optical device).

[0136] The diffraction pattern DOE separates the infrared light IR incident through the light-transmitting portion AG of the second pixel region CA into multiple point beams.

[0137] When the diffractive optical element 203 overlaps with the pixels below the display panel 100, the dot beam passing through the diffractive optical element 203 is masked by the pixel circuitry and metal wiring, potentially reducing the facial recognition rate. The diffractive optical element 203 of this disclosure is disposed in the light-transmitting portion AG without a metal layer or semiconductor layer, and the dot beam passing through the diffractive optical element 203 is projected onto the front of the display panel 100 without interference or masking, thereby improving the transmittance of infrared light IR used for facial recognition.

[0138] The emitter 201a and the diffraction pattern DOE of the infrared light source 201 can be set Figure 12 and Figure 13 In the second pixel region CA of the display device, there is a light-transmitting portion AG.

[0139] Figure 14A This is a plan view illustrating an example of multiple diffractive optical elements dispersedly arranged on the cover glass of a mobile terminal, and Figure 14B It is along Figure 14A The cross-sectional view taken from line "AA" in the diagram. Furthermore, Figure 15A This is a plan view illustrating an example of a wide diffraction optical element disposed on the cover glass of a mobile terminal, and Figure 15B It is along Figure 15A The cross-sectional view taken from line "BB".

[0140] like Figures 14A to 15B As shown, multiple emitters 201a and multiple diffraction patterns DOE of the infrared light source 201 can be disposed in the second pixel region CA of the display device to improve the diffraction efficiency of the diffraction optical element 203 and project a wider point beam. The optical module (optical device) may include multiple emitters 201a arranged in an array. Each emitter in the emitter 201a may be driven by the infrared light source 201. In this case, the multiple diffraction patterns DOE are spaced apart at predetermined intervals in the cover glass 20 and face each light-transmitting portion AG, and each emitter in the emitter 201a of the optical module may be disposed below the rear surface of the display panel 100 to face each light-transmitting portion AG.

[0141] Reference Figure 14A and Figure 14B The diffraction pattern DOE can be set one after another on the light-transmitting portion AG of the second pixel region CA. The emitter 201a of the infrared light source 201 can be matched one-to-one with the diffraction optical element 203 and is set below the rear surface of the display panel 100 so as to face the light-transmitting portion AG of the second pixel region CA.

[0142] In another example, such as Figure 15A and Figure 15BAs shown, the diffraction pattern DOE can be extensively extended and formed in the second pixel region CA, and can overlap with the pixels and the light-transmitting portion AG of the second pixel region CA. Therefore, the diffraction pattern DOE can be patterned on the cover glass 20 to match the size of the emitter 201a of the infrared light source 201, or it can be patterned in or on the cover glass 20 in a wide dimension to face two or more emitters 201a spaced apart from each other at a predetermined interval. Collimating lens (e.g., Figure 13 201b) can be set in Figures 14A to 15B In each of the transmitters 201a of the infrared light source 201 or on each transmitter.

[0143] Figure 16 This is a cross-sectional view illustrating a display device according to a third exemplary embodiment of the present disclosure. Figure 17 This is a cross-sectional view illustrating a display device according to a fourth exemplary embodiment of the present disclosure. Figure 18 This is a cross-sectional view illustrating a display device according to a fifth exemplary embodiment of the present disclosure.

[0144] Reference Figures 16 to 18 The holographic film 21 can be attached to the front or rear surface of the cover glass 20 of the display device. The holographic film 21 may include one or more holographic diffraction patterns HOE recorded at a position on the light-transmitting portion AG facing the second pixel region CA. The holographic diffraction patterns HOE are formed on the holographic film 21 by a transmission-type recording method, and separate the infrared light IR incident through the light-transmitting portion AG into multiple point beams. The holographic film 21 can be as follows: Figure 16 The shown arrangement is on the cover glass 20, or as... Figure 17 The infrared light source 201 is positioned under the cover glass. The emitter 201a of the infrared light source 201 is positioned below the rear surface of the display panel 100, facing the light-transmitting portion AG. Infrared light IR can be incident on the recording surface of the holographic diffraction pattern at an angle perpendicular to the plane of the display panel 100 and the cover glass 20.

[0145] In yet another example, the holographic diffraction pattern HOE of the holographic film 21 can be set on the cover glass 20 and can cover one or more pixels and one or more light-transmitting portions AG, such as Figure 18 As shown. Each emitter in the emitter 201a of the infrared light source 201 is disposed below the rear surface of the display panel 100, so as to face the light-transmitting portion AG respectively.

[0146] exist Figures 16 to 18 In the middle, the collimating lens (e.g., Figure 13201b) can be set in each transmitter or on each transmitter in the transmitter 201a of the infrared light source 201.

[0147] Figure 13 The collimating lens 201b shown can achieve the following: Figure 19A The Fresnel lens shown, or as... Figure 19B The image shows a gradient index (GRIN) lens. In a GRIN lens, the refractive index changes gradually.

[0148] Meanwhile, to increase the diffraction efficiency of the DOE and HOE diffraction patterns, the lens layer 17 can be disposed on the display panel 100, such as... Figure 20 As shown. Lens layer 17 may include a collimating lens 17a formed at a position facing the light-transmitting portion AG of the second pixel region CA. Lens layer 17 may be formed between polarizer 18 and touch sensor layer 16. Figure 20 In the process, instead of the diffraction pattern DOE, the holographic diffraction pattern HOE can be attached to the cover glass 20.

[0149] Figure 21 This is a cross-sectional view illustrating a display device according to a sixth exemplary embodiment of the present disclosure.

[0150] Reference Figure 21 The diffraction pattern DOE can be formed in at least one light-transmitting portion of the light-transmitting portion AG of the second pixel region CA in the display panel 100.

[0151] By patterning a thin film layer formed on the circuit layer 12 or the light-emitting element layer 14 of the display panel 100, a diffraction pattern DOE can be embedded in the light-transmitting portion AG of the display panel 100. For example, the diffraction pattern DOE can be embedded in the light-transmitting portion AG without increasing the manufacturing process of the display panel 100 by patterning either the cathode or anode of the light-emitting element or the interface between layers with different refractive indices (such as semiconductor layers or insulating layers). In another exemplary embodiment, the diffraction pattern DOE can be embedded in the light-transmitting portion AG by inserting a separate diffraction optical element 203, in which the diffraction pattern DOE is formed, into the light-transmitting portion AG during the manufacturing process of the display panel 100.

[0152] Multiple emitters 201a of the infrared light source 201 can be positioned below the light-transmitting portion AG of the second pixel region CA to illuminate the second pixel region CA with infrared light IR. The infrared light source 201 can be implemented as an optical module / device without light guides and lenses, but is not limited thereto. The infrared light IR emitted from the infrared light source 201 can be incident at an angle perpendicular to the XY plane of the display panel 100 to increase the diffraction efficiency of the diffraction pattern DOE.

[0153] The diffraction pattern DOE separates the infrared light IR incident through the light-transmitting portion AG of the second pixel region CA into multiple point beams. Figure 21 In the process, infrared light IR transmitted through the diffraction pattern DOE propagates to the outside through polarizer 18, but is not limited to this. For example, a color filter can be used instead of polarizer 18, and polarizer 18 can be removed, for example, polarizer 18 can be removed only from the light-transmitting portion AG.

[0154] In another exemplary embodiment, instead of a diffraction pattern DOE, a holographic diffraction pattern HOE can be embedded in the light-transmitting portion AG, for example in... Figures 21 to 24 In the example.

[0155] When the diffractive optical element 203 overlaps with pixels in the display panel 100, the dot beam passing through the diffractive optical element 203 is masked by the pixel circuitry and metal wiring, potentially reducing the facial recognition rate. The diffractive optical element 203 of this disclosure is disposed in a light-transmitting portion AG without metal or semiconductor layers, and the dot beam passing through the diffractive optical element 203 is projected onto the front of the display panel 100 without interference or masking, thereby improving the transmittance of infrared (IR) light used for facial recognition.

[0156] Figure 22 This is a cross-sectional view illustrating a display device according to a seventh exemplary embodiment of the present disclosure.

[0157] Reference Figure 22 ,Apart from Figure 21 In addition to the display panel configuration, the display panel 100 also includes a first reflector 32 configured to reflect infrared light IR from the infrared light source 201. The infrared light source 201 also includes a second reflector 31 configured to reflect the infrared light IR from the first reflector 32 onto the light-transmitting portion AG. The first reflector 32 and the second reflector 31 reflect the infrared light IR, which is blocked by the pixel circuitry and wiring of the display panel 100, toward the light-transmitting portion AG of the second pixel region CA. The infrared light IR reflected by the first reflector 32 and the second reflector 31, as well as the infrared light IR emitted from the emitter 201a, are concentrated on the light-transmitting portion AG. Therefore, the efficiency of infrared light used for facial recognition can be improved by using the first reflector 32 and the second reflector 31.

[0158] The first reflector 32 can be formed on the substrate 10 of the display panel 100. The first reflector 32 reflects infrared light IR incident from the infrared light source 201 toward the second reflector 31. The first reflector 32 can be formed on the substrate 10 below the pixel group in the second pixel region CA. When the first reflector 32 is close to the light-transmitting portion AG, the first reflector 32 can be patterned to have a lower thickness, for example, a wedge shape or a cone shape.

[0159] The second reflector 31 is disposed on the infrared light source 201 below the light-transmitting portion AG, facing the first reflector 32. Infrared light IR reflected from the first reflector 32 is reflected by the second reflector 31 and propagates into the light-transmitting portion AG. The infrared light IR reflected by the second reflector 31 is incident on the diffraction pattern DOE in the light-transmitting portion AG at an angle perpendicular to the XY plane of the display panel 100. The second reflector 31 can be patterned into a wedge shape or a cone shape with a small thickness on the side near the first reflector 32. At least a portion of the reflective surfaces of the first reflector 32 and the second reflector 31 can be concavely patterned.

[0160] Figure 23 This is a cross-sectional view illustrating a display device according to an eighth exemplary embodiment of the present disclosure.

[0161] Reference Figure 23 ,Apart from Figure 21 In addition to the display panel configuration, the display panel 100 also includes light collecting portions 10a and 10b and collimating portions 40a and 40b. Each of the light collecting portions 10a and 10b and the collimating portions 40a and 40b includes a low-refractive medium and a high-refractive medium bonded together, and includes a lens surface. A plurality of emitters 201a of the infrared light source 201 can be disposed below the light-transmitting portion AG of the second pixel region CA to illuminate the second pixel region CA with infrared light IR. The combined width of the areas of the emitters 201a can correspond to the width of the light-transmitting portion AG.

[0162] Light collecting portions 10a and 10b can be formed on the substrate of the display panel 100. Light collecting portions 10a and 10b include a low-refractive-index substrate 10a with a concave lens and a high-refractive-index layer 10b filled in the concave lens to flatten the substrate surface. The centers of light collecting portions 10a and 10b can coincide with the centers of the light-transmitting portion AG and the collimating portions 40a and 40b. The size of each light collecting portion in light collecting portions 10a and 10b is set to be larger than the size of the light-transmitting portion AG. Light collecting portions 10a and 10b concentrate infrared light IR from the infrared light source 201 and infrared light IR propagating towards the peripheral pixel group of the light-transmitting portion AG through the refractive index difference between the media and the lens shape, directing it towards the light-transmitting portion AG. The infrared light IR passing through light collecting portions 10a and 10b is concentrated onto the collimating portions 40a and 40b embedded in the light-transmitting portion AG.

[0163] Collimation portions 40a and 40b are embedded in the light-transmitting portion AG between the diffraction pattern DOE and the light-collecting portions 10a and 10b. Collimation portions 40a and 40b can be formed by patterning thin films with refractive index differences in an organic / inorganic thin film layer constituting the circuit layer 12 and the light-emitting element layer 14. Collimation portions 40a and 40b include a convex high-refractive-index layer 40b and a low-refractive-index layer 40a covering the convex surface of the high-refractive-index layer 40b. The size of each collimation portion in collimation portions 40a and 40b can be substantially the same as the size of the light-transmitting portion AG. Collimation portions 40a and 40b collimate the infrared light IR passing through the light-collecting portions 10a and 10b at an angle perpendicular to the plane of the diffraction pattern DOE through the refractive index difference between the media and the lens shape. Therefore, the infrared light IR emitted from the infrared light source 201 is incident perpendicularly onto the diffraction pattern DOE in the light-transmitting portion AR without loss, thereby improving the efficiency of the infrared light IR used for facial recognition.

[0164] Figure 24 This is a cross-sectional view illustrating a display device according to a ninth exemplary embodiment of the present disclosure.

[0165] Reference Figure 24 The display panel 100 includes a first lens 51 facing the infrared light source 201 and a second lens 52 embedded in the light-transmitting portion AG.

[0166] The first lens 51 has a higher refractive index than the air layer 54 and includes a convex lens surface facing the infrared light source 201. The air layer 54 can be formed by an air space. The first lens 51 can be formed by patterning the back side of the substrate of the display panel 100 into a convex lens shape. The center of the first lens 51 can coincide with the center of the second lens 52 embedded in the light-transmitting portion AG and the diffraction pattern DOE. The size (e.g., width) of the first lens 51 is set to be larger than the size of the light-transmitting portion AG. The first lens 51 concentrates the infrared light IR from the infrared light source 201 and the infrared light IR propagating toward the peripheral pixel group of the light-transmitting portion AG towards the light-transmitting portion AG by means of the refractive index difference with air and the lens shape. The infrared light IR passing through the first lens 51 is concentrated on the second lens 52 embedded in the light-transmitting portion AG.

[0167] The second lens 52 is embedded in the light-transmitting portion AG between the diffraction pattern DOE and the first lens 51. The second lens 52 has a higher refractive index than the low-refractive-index layer 53 embedded in the light-transmitting portion AG and includes a convex lens surface facing the diffraction pattern DOE. The second lens 52 and the low-refractive-index layer 53 can be formed by patterning thin films with a refractive index difference in the organic / inorganic thin film layers constituting the circuit layer 12 and the light-emitting element layer 14. The size of the second lens 52 can be substantially the same as the size of the light-transmitting portion AG. The second lens 52 collimates the infrared light IR passing through the first lens 51 at an angle perpendicular to the plane of the diffraction pattern DOE by means of the refractive index difference between the media and the lens shape. Therefore, the infrared light IR emitted from the infrared light source 201 is incident perpendicularly onto the diffraction pattern DOE in the light-transmitting portion AR without loss, thereby improving the efficiency of the infrared light IR used for facial recognition.

[0168] exist Figure 21 and Figure 22 In this context, the diffraction pattern DOE can be replaced by the holographic diffraction pattern HOE (e.g., Figures 16 to 18 (HOE) is used instead.

[0169] According to this disclosure, since the optical module / device is positioned below the screen displaying the image, full-screen display can be achieved.

[0170] According to this disclosure, the size of the optical module / device can be reduced by embedding a diffractive optical element configured to separate infrared light into multiple point beams for facial recognition in the display panel or by forming a diffractive optical element on the cover glass, thereby making the mobile terminal thinner and increasing the design freedom of the mobile terminal.

[0171] According to this disclosure, the diffractive optical element is embedded in the light-transmitting portion of the pixel area, or the diffractive optical element is disposed on the cover glass covering the pixel area, thereby improving the infrared light transmittance for facial recognition without being limited by the loss of point beams passing through the diffractive optical element due to the circuit layers and wiring of the display panel.

[0172] According to this disclosure, by converging and collimating the light incident on the pixel toward the diffractive optical element, the loss of infrared light due to pixel circuitry and wiring can be minimized or prevented, thereby improving the efficiency of infrared light for facial recognition.

[0173] The advantages and effects of this disclosure are not limited to those described above, and other advantages and effects not mentioned will be clearly understood by those skilled in the art from the following description and the appended claims.

[0174] The purpose of this disclosure, the means for achieving the above-mentioned purpose, advantages and effects of this disclosure, do not specify the essential features of the claims, therefore the scope of the claims is not limited to the content of this disclosure.

[0175] Although embodiments of the present disclosure have been described in more detail with reference to the accompanying drawings, the present disclosure is not limited thereto and can be implemented in many different forms without departing from the technical concept of the present disclosure. Therefore, the embodiments disclosed herein are provided for illustrative purposes only and are not intended to limit the technical concept of the present disclosure. The scope of the technical concept of the present disclosure is not limited thereto. Therefore, it should be understood that the above embodiments are illustrative in all respects and do not limit the present disclosure. The scope of protection of the present disclosure should be interpreted based on the appended claims, and all technical concepts within their equivalent scope should be interpreted as falling within the scope of the present disclosure.

[0176] Cross-references to related applications

[0177] This application claims priority and benefit to Korean Patent Application No. 10-2021-0145329, filed in Korea on October 28, 2021, the disclosure of which is incorporated herein by reference in its entirety.

Claims

1. A display device, the display device comprising: The display panel includes a first pixel region and a second pixel region adjacent to the first pixel region, the second pixel region including one or more light-transmitting portions; Cover glass, the cover glass being disposed on the first surface of the display panel in the second pixel region; An optical module is disposed below the second surface of the display panel to face the second pixel region and is configured to guide infrared light toward one or more light-transmitting portions of the second pixel region; as well as A diffractive optical element is disposed on at least one of the cover glass and the display panel, or disposed within at least one of the cover glass and the display panel, at a position corresponding to at least one of the one or more light-transmitting portions of the second pixel region. The diffractive optical element is configured to separate the infrared light from the optical module into multiple point beams.

2. The display device according to claim 1, wherein The pixel per inch (PPI) of the second pixel region is smaller than that of the first pixel region.

3. The display device according to claim 1, wherein The diffractive optical element includes at least one of a diffractive optical element (DOE) disposed on the cover glass or embedded in each light-transmitting portion and a holographic optical element (HOE).

4. The display device according to claim 3, wherein, The optical module is a light source, which includes an emitter for emitting light and a collimating lens disposed on the emitter of the light source.

5. The display device according to claim 4, wherein, The infrared light from the emitter of the light source is incident on the diffractive optical element at an angle perpendicular to the plane of the cover glass and the display panel.

6. The display device according to claim 3, wherein, Multiple diffractive optical elements are spaced apart at predetermined intervals and face the light-transmitting portion accordingly. The optical module is a light source comprising multiple emitters, each of which generates the infrared light. The plurality of emitters are disposed below the second surface of the display panel, each facing the light-transmitting portion.

7. The display device according to claim 3, wherein, The diffractive optical element covers multiple pixels in the second pixel region and the light-transmitting portion. The optical module is a light source comprising multiple emitters, each of which generates the infrared light. The plurality of emitters are disposed below the second surface of the display panel, each facing the light-transmitting portion.

8. The display device according to claim 1, wherein, The diffractive optical element includes one or more holographic diffraction patterns recorded on a holographic film attached to the front or rear surface of the cover glass.

9. The display device according to claim 8, wherein, The infrared light from the optical module is incident on the holographic diffraction pattern at an angle perpendicular to the plane of the cover glass and the display panel.

10. The display device according to claim 8, wherein, Multiple holographic diffraction patterns are spaced apart at predetermined intervals and face the light-transmitting portion accordingly. The optical module is a light source comprising multiple emitters, each of which generates the infrared light. The plurality of emitters are disposed below the second surface of the display panel, each facing the light-transmitting portion.

11. The display device according to claim 8, wherein, The holographic diffraction pattern covers one or more pixels in the second pixel region and the one or more light-transmitting portions. The optical module is a light source comprising multiple emitters, each of which generates the infrared light. The plurality of emitters are disposed below the second surface of the display panel, each facing the light-transmitting portion.

12. The display device according to claim 1, wherein, The display panel includes: Touch sensor layer; Polarizing plate; and A lens layer is disposed between the touch sensor layer and the polarizing plate. The lens layer includes a collimating lens facing at least one of the one or more light-transmitting portions.

13. The display device according to claim 3, wherein, The display panel further includes a first reflector, which is disposed on the substrate of the display panel below the pixels in the second pixel region. The optical module is a light source, and the light source further includes a second reflector, which is disposed below at least one of the one or more light-transmitting portions and faces the first reflector.

14. The display device according to claim 13, wherein, The infrared light from the optical module is reflected by the first reflector, and the infrared light is further reflected by the second reflector toward the one or more light-transmitting portions.

15. The display device according to claim 3, wherein, The display panel also includes: A light-collecting section, configured to collect the infrared light from the optical module; and A collimation portion, which is embedded in at least one of the one or more light-transmitting portions between the diffractive optical element and the light-collecting portion, and is configured to collimate the infrared light passing through the light-collecting portion to the diffractive optical element.

16. A mobile terminal, the mobile terminal comprising: A communication unit configured to transmit and receive signals to and from the mobile terminal; A memory configured to store data; User input unit, the user input unit being configured to receive user input; The display device according to claim 1, wherein the display device is configured to display an image; and A controller configured to control the communication unit, the memory, the user input unit, and the display device. Wherein, the first pixel area of ​​the display panel in the display device is larger than the second pixel area of ​​the display panel, and The optical module of the display device includes one of an image sensor, a camera, a proximity sensor, a white light illuminator, and an optical element for facial recognition.

17. A mobile terminal, the mobile terminal comprising: The display panel is configured to display an input image and includes a first pixel region and a second pixel region, the second pixel region including one or more light-transmitting portions; A display panel driver is configured to write pixel data of the input image to pixels of the display panel; A cover glass is disposed on the front surface of the display panel; A light source is disposed below the rear surface of the display panel to face the second pixel area and is configured to generate infrared light; A diffractive optical element is disposed on at least one of the cover glass and the display panel at a position corresponding only to at least one of the one or more light-transmitting portions of the second pixel region, and the diffractive optical element is configured to separate the infrared light from the light source into a plurality of point beams. An infrared camera is disposed below the rear surface of the display panel and configured to convert infrared light incident through the display panel into electrical signals to output facial pattern data; as well as A host system configured to send the pixel data of the input image to the display panel driver and process user authentication with respect to the facial pattern data received from the infrared camera.

18. The mobile terminal according to claim 17, wherein, The pixel per inch (PPI) of the second pixel region is smaller than that of the first pixel region.

19. The mobile terminal according to claim 17, wherein, The diffractive optical element includes at least one of a diffractive optical element (DOE) and a holographic optical element (HOE) disposed on the cover glass or embedded in one or more light-transmitting portions of the second pixel region.

20. The mobile terminal according to claim 17, wherein, The display panel further includes a first reflector, which is disposed on the substrate of the display panel below the pixels in the second pixel region. The light source includes a second reflector, which is disposed below at least one of the one or more light-transmitting portions and faces the first reflector.

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