Display device and proximity sensing method using input sensor

Abstract

A display device according to one embodiment may include a control unit that executes a proximity sensing mode that detects a proximity signal instead of a touch signal when a start signal is received according to user input, a display unit that reduces the brightness of a display panel to a target brightness when the proximity sensing mode is executed, and a sensor unit that is synchronized with the display unit and detects the proximity signal.

Description

Technology Field

[0001] The present invention relates to a proximity signal sensing method using a display device and an input sensor, and more specifically, to a proximity signal sensing method using a display device and an input sensor with improved reliability. Background Technology

[0002] Display devices include smartphones or mobile phones that display images. Current mobile phones have a feature that turns off the screen when a user enters a call and turns it back on when the call ends, and typically control the screen by detecting the approach of an ear or face via an infrared sensor. Input sensors detect user touch. Input sensors are placed on the display panel that displays the image. Input sensors can detect various input signals in addition to touch. The problem to be solved

[0003] One embodiment of the present invention aims to provide a display device that detects a proximity signal through an input sensor and a proximity signal sensing method using the input sensor.

[0004] One embodiment of the present invention aims to provide a proximity signal sensing method using a display device and an input sensor that reduces noise generated from a display panel during the process of detecting a proximity signal through an input sensor and improves detection performance. means of solving the problem

[0005] Among the embodiments, the display device includes a control unit that executes a proximity sensing mode that detects a proximity signal instead of a touch signal when a start signal is received according to user input, a display unit that reduces the brightness of a display panel to a target brightness when the proximity sensing mode is executed, and a sensor unit that is synchronized with the display unit and detects the proximity signal.

[0006] The above initiation signal may be a call mode entry signal based on the user's call button input.

[0007] The above display unit includes the display panel and a display driving circuit electrically connected to the display panel, and the display driving circuit can reduce the brightness of the display panel to the target signal.

[0008] The above display unit includes a first frame and a second frame that alternate with each other, and the first brightness of the display panel in the first frame may be higher than the second brightness of the display panel in the second frame.

[0009] The driving voltage applied to the display panel from the display driving circuit in the second frame may be smaller than the driving voltage applied in the first frame.

[0010] The second driving time of the second frame may be smaller than the first driving time of the first frame.

[0011] The driving voltage and driving time of the second frame may be smaller than the driving voltage and driving time of the first frame.

[0012] The above target brightness may be the average of the first brightness and the second brightness.

[0013] The sensor unit includes an input sensor and a sensor driving circuit electrically connected to the input sensor, and the sensor driving circuit is synchronized with the display unit to detect the proximity signal through the input sensor.

[0014] The sensor unit can detect the proximity signal in the second frame.

[0015] When the above proximity sensing mode is executed, the display unit can gradually reduce the brightness to the target brightness.

[0016] A first region and a second region adjacent to the first region are defined on a plane, and

[0017] The above display unit can lower the brightness of the display panel of the first area to the target brightness.

[0018] The sensor unit can detect the proximity signal in the first area.

[0019] The sensor portion may be positioned on the display portion so as to overlap with the display portion in the thickness direction of the display portion.

[0020] Among the embodiments, a proximity sensing method using an input sensor comprises the steps of: when a control unit receives a start signal generated according to user input, the input sensor executes a proximity sensing mode in which it detects a proximity signal instead of a touch signal; when the proximity sensing mode is executed, a display unit reduces the brightness of a display panel to a target brightness; and a sensor unit synchronized with the display unit detects the proximity signal.

[0021] The above display panel includes a first frame and a second frame that alternate with each other, and the first brightness of the display panel in the first frame may be higher than the second brightness of the display panel in the second frame.

[0022] The above display unit includes a display driving circuit, and the display driving circuit can make the driving voltage in the second frame lower than the driving voltage in the first frame.

[0023] The sensor unit includes a sensor driving circuit, and the sensor driving circuit can detect the proximity signal in the second frame. Effects of the invention

[0024] A proximity signal sensing method using a display device and an input sensor according to one embodiment of the present invention can reduce noise caused by a display panel during the process of detecting a proximity signal through an input sensor.

[0025] A proximity signal sensing method using a display device and an input sensor according to one embodiment of the present invention can reduce the brightness of the display panel while the input sensor detects a proximity signal, thereby reducing noise caused by the display panel and improving proximity signal detection performance. Brief explanation of the drawing

[0026] FIG. 1 is a perspective view of a display device according to one embodiment of the present invention. FIG. 2 is an exploded perspective view of a display device according to one embodiment of the present invention. FIG. 3 is a block diagram of a display device according to one embodiment of the present invention. FIGS. 4a and FIGS. 4b are cross-sectional views of a display module according to an embodiment of the present invention. FIG. 5 is an enlarged cross-sectional view of a display module according to one embodiment of the present invention. FIGS. 6a and FIGS. 6b are block diagrams of a display device according to an embodiment of the present invention. FIGS. 7a and FIGS. 7b are flowcharts illustrating a proximity signal sensing method using an input sensor according to an embodiment of the present invention. FIG. 8 is a graph showing the reduction in brightness of a display panel according to one embodiment of the present invention. FIGS. 9a to 9c are graphs showing a method for lowering the brightness of a display panel according to an embodiment of the present invention. FIG. 10 is a plan view of a display module according to one embodiment of the present invention. Specific details for implementing the invention

[0027] In this specification, where a component (or region, layer, part, etc.) is described as being “on,” “connected,” or “joined” another component, it means that it may be directly placed / connected / joined on the other component, or that a third component may be placed between them.

[0028] Identical reference numerals denote identical components. Additionally, in the drawings, the thicknesses, proportions, and dimensions of components are exaggerated for the effective illustration of the technical content. “And / or” includes all one or more combinations that the associated components may define.

[0029] Terms such as "first," "second," etc., may be used to describe various components, but said components should not be limited by said terms. These terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component. A singular expression includes a plural expression unless the context clearly indicates otherwise.

[0030] Additionally, terms such as “below,” “lower,” “above,” and “upper” are used to describe the relationships between the components depicted in the drawings. These terms are relative concepts and are described based on the directions indicated in the drawings.

[0031] Terms such as "include" or "have" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0032] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Additionally, 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 are explicitly defined herein unless interpreted in an ideal or overly formal sense.

[0033] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0034] FIG. 1 is a perspective view of a display device according to one embodiment of the present invention, and FIG. 2 is an exploded perspective view of a display device according to one embodiment of the present invention.

[0035] Referring to FIGS. 1 and 2, the display device (DD) may be a device that is activated according to an electrical signal. The display device (DD) may include various embodiments. For example, the display device (DD) may be used in large display devices such as televisions, monitors, or external billboards, as well as small and medium-sized display devices such as personal computers, laptop computers, personal digital terminals, car navigation units, game consoles, portable electronic devices, and cameras. Furthermore, these are presented merely as embodiments, and it is understood that they may be adopted in other display devices without departing from the concept of the present invention. In this embodiment, the display device (DD) is illustrated as a smartphone.

[0036] The display device (DD) can display an image (IM) toward the third direction (DR3) on a display surface (FS) parallel to each of the first direction (DR1) and the second direction (DR2). The display surface (FS) on which the image (IM) is displayed may correspond to the front surface of the display device (DD) and may correspond to the front surface (FS) of the window (100). The same reference numerals may be used for the display surface, the front surface of the display device (DD), and the front surface of the window (100). The image (IM) may include a still image as well as a dynamic image. In FIG. 1, a clock window and application icons are shown as examples of the image (IM).

[0037] In this embodiment, the front (or top) and back (or bottom) surfaces of each member may be defined based on the direction in which the image (IM) is displayed. The front and back surfaces face each other in a third direction (DR3), and the normal direction of each of the front and back surfaces may be parallel to the third direction (DR3). The third direction (DR3) may be a direction that intersects the first direction (DR1) and the second direction (DR2). The first direction (DR1), the second direction (DR2), and the third direction (DR3) may be orthogonal to each other.

[0038] In this specification, the plane defined by the first direction (DR1) and the second direction (DR2) is defined as a plane, and “viewed on the plane” can be defined as viewed from the third direction (DR3).

[0039] The display device (DD) may include a window (100), a display module (200), a driving circuit unit (300), a housing (400), and an electronic module (500). In this embodiment, the window (100) and the housing (400) may be combined to form the exterior of the display device (DD).

[0040] The window (100) may include an optically transparent insulating material. For example, the window (100) may include glass or plastic. The window (100) may have a multilayer structure or a single layer structure. For example, the window (100) may include a plurality of plastic films bonded with an adhesive, or a glass substrate and a plastic film bonded with an adhesive.

[0041] In a planar view, the window (100) can be divided into a transparent area (TA) and a bezel area (BZA). The transparent area (TA) may be an optically transparent area. The bezel area (BZA) may be an area with a relatively lower light transmittance compared to the transparent area (TA). The bezel area (BZA) may define the shape of the transparent area (TA). The bezel area (BZA) is adjacent to the transparent area (TA) and may surround the transparent area (TA).

[0042] The bezel area (BZA) may have a predetermined color. The bezel area (BZA) may cover the surrounding area (NAA) of the display module (200) to block the surrounding area (NAA) from being visible from the outside. Meanwhile, this is illustrated as an example, and in a window (100) according to one embodiment of the present invention, the bezel area (BZA) may be omitted.

[0043] In one embodiment of the present invention, the module area (MA) may overlap with the electronic module (500). The display device (DD) may receive an external signal required by the electronic module (500) through the module area (MA) or provide a signal output from the electronic module (500) to the outside. According to the present invention, the module area (MA) may be defined by overlapping with the transmission area (TA). Accordingly, a separate area provided to provide the module area (MA) in an area other than the transmission area (TA) may be omitted. Accordingly, the area of ​​the bezel area (BZA) may be reduced.

[0044] A display module (200) may be placed below a window (100). The display module (200) may display an image (IM). The display module (200) may include a front surface (IS) comprising an active area (AA) and a peripheral area (NAA). The active area (AA) may be an area that is activated according to an electrical signal. The active area (AA) may be defined as a first area, and the peripheral area (NAA) may be defined as a second area.

[0045] In this embodiment, the active area (AA) may be an area where an image (IM) is displayed. The transparent area (TA) may overlap with the active area (AA). For example, the transparent area (TA) may overlap with the front of or at least a part of the active area (AA). Accordingly, the user can view the image (IM) through the transparent area (TA).

[0046] The peripheral area (NAA) may be an area covered by the bezel area (BZA). The peripheral area (NAA) may be adjacent to the active area (AA). The peripheral area (NAA) may surround the active area (AA). Driving circuits or driving wiring for driving the active area (AA) may be placed in the peripheral area (NAA).

[0047] In this embodiment, the display module (200) is assembled in a flat state where the active area (AA) and the peripheral area (NAA) face the window (100). However, this is illustrated as an example, and a portion of the peripheral area (NAA) may be curved. In this case, a portion of the peripheral area (NAA) may face the back of the display device (DD), thereby reducing the area of ​​the bezel area (BZA) on the front of the display device (DD). Alternatively, the display module (200) may be assembled with a portion of the active area (AA) curved. Alternatively, in the display module (200) according to one embodiment of the present invention, the peripheral area (NAA) may be omitted.

[0048] The driving circuit section (300) can be electrically connected to the display module (200). The driving circuit section (300) may include a display driving circuit (DC), a main circuit board (MB), a sensor driving circuit (TC), and a flexible film (CF).

[0049] The display driving circuit (DC) may be positioned adjacent to the flexible film (CF) on the peripheral area (NAA) of the display module (200), and the sensor driving circuit (TC) may be positioned on the main circuit board (MB), but is not necessarily limited thereto. For example, the display driving circuit (DC) may be positioned on the main circuit board (MB) like the sensor driving circuit (TC).

[0050] The flexible film (CF) can be electrically connected to the display module (200). The flexible film (CF) can be connected to pads of the display module (200) placed in the peripheral area (NAA). The flexible film (CF) can provide an electrical signal to the display module (200) to drive the display module (200). The electrical signal may be generated from the flexible film (CF) or from the main circuit board (MB). The main circuit board (MB) may include various driving circuits for driving the display module (200) or connectors for power supply. In this embodiment, the main circuit board (MB) may include a sensor driving circuit (TC).

[0051] In one embodiment of the present invention, a region of the display module (200) corresponding to the module region (MA) may have a relatively high transmittance compared to an active region (AA) that does not overlap with the module region (MA). For example, at least some of the components of the display module (200) may be removed. Thus, the electronic module (500) can easily transmit and / or receive a signal through the module region (MA).

[0052] The electronic module (500) may be placed below the display module (200). Specifically, the electronic module (500) may be placed below the display panel. On a plane, the electronic module (500) may overlap with the module area (MA). The electronic module (500) may receive external input transmitted through the module area (MA) or provide output through the module area (MA). The electronic module (500) may include a speaker module, a camera module, and related electronic components. In this embodiment, the electronic module (500) may include a speaker module that outputs the other party's voice during a call. The electronic module (500) may be adjacent to the user's ear while the user is making a call.

[0053] The housing (400) can be combined with the window (100). The housing (400) can be combined with the window (100) to provide an internal space. The display module (200) and the electronic module (500) can be accommodated in the internal space.

[0054] The housing (400) may include a material having relatively high rigidity. For example, the housing (400) may include glass, plastic, or metal, or may include a plurality of frames and / or plates composed of a combination thereof. The housing (400) can reliably protect the components of the display device (DD) housed in the internal space from external impact.

[0055] FIG. 3 is a block diagram of a display device according to one embodiment of the present invention.

[0056] Referring to FIG. 3, the display device (DD) may include a display module (200), a power supply module (PM), a first electronic module (EM1), and a second electronic module (EM2). The display module (200), the power supply module (PM), the first electronic module (EM1), and the second electronic module (EM2) may be electrically connected to each other.

[0057] The display module (200) may include a display panel (210) and an input sensor (220).

[0058] The display panel (210) may be a configuration that substantially generates an image (IM). The image (IM) generated by the display panel (210) is displayed on the front (IS) and is visible to the user from the outside through the transparent area (TA).

[0059] The input sensor (220) detects an external input (EIP) applied from the outside. For example, the input sensor (220) can detect an external input (EIP) provided to the window (100). The external input (EIP) may be user input. User input includes various forms of external inputs such as a part of the user's body, light, heat, a pen, or pressure. In FIG. 1, the external input (EIP) is a touch signal and is illustrated as a user's hand applied to the front (FS). However, this is illustrated as an example, and as described above, the external input (EIP) may be provided in various forms, and depending on the structure of the display device (DD), the external input (EIP) applied to the side or back of the display device (DD) may also be detected, and is not limited to any one embodiment. In this embodiment, if the external input (EIP) is a proximity signal, it may correspond to an ear or cheek, which is a part of the user's body.

[0060] The power supply module (PM) supplies power necessary for the overall operation of the display device (DD). The power supply module (PM) may include a conventional battery module.

[0061] The first electronic module (EM1) and the second electronic module (EM2) may include various functional modules for operating the display device (DD).

[0062] The first electronic module (EM1) may be directly mounted on a motherboard electrically connected to the display module (200) or mounted on a separate board and electrically connected to the motherboard through a connector (not shown), etc.

[0063] The first electronic module (EM1) may include a control module (CM), a wireless communication module (TM), an image input module (IIM), an audio input module (AIM), a memory (MM), and an external interface (IF). Some of the modules may not be mounted on the motherboard but may be electrically connected to the motherboard via a flexible circuit board.

[0064] The control module (CM) controls the overall operation of the display device (DD). The control module (CM) may be a microprocessor. For example, the control module (CM) enables or disables the display module (200). The control module (CM) may control other modules, such as the light-emitting module (LLM), the image input module (IIM), or the sound input module (AIM), based on the touch signal received from the display module (200).

[0065] The control module (CM) may be a microprocessor connected to the electronic module (500) to control the operation of the electronic module (500). In one embodiment, the control module (CM) may control the overall operation of the electronic module (500). The control module (CM) may include a processor that controls the electronic module (500).

[0066] In this embodiment, the control module (CM) is electrically connected to the display panel (210) and the input sensor (220) to control the operation of the display panel (210) and the input sensor (220). The control module (CM) can control a display driving circuit (DC, see FIG. 2) that drives the display panel (210). The control module (CM) can control a sensor driving circuit (TC, see FIG. 2) that drives the input sensor (220). The control module (CM) can provide various signals according to user input to the display driving circuit (DC) and the sensor driving circuit (TC).

[0067] In one embodiment, the control module (CM) can control synchronization between the display panel (210) and the input sensor (220). For example, the control module (CM) can issue a command to the input sensor (220) to synchronize with the display panel (210) by transmitting it when a call mode is executed according to user input.

[0068] The wireless communication module (TM) can transmit and receive wireless signals with another terminal using a Bluetooth or Wi-Fi line. The wireless communication module (TM) can transmit and receive voice signals using a general communication line. The wireless communication module (TM) may include a transmitting unit (TM1) that modulates and transmits a signal to be transmitted, and a receiving unit (TM2) that demodulates a received signal.

[0069] The video input module (IIM) processes the video signal and converts it into video data that can be displayed on the display module (200). The audio input module (AIM) receives an external audio signal via a microphone in recording mode, voice recognition mode, etc., and converts it into electrical audio data.

[0070] The external interface (IF) can serve as an interface connected to an external charger, wired / wireless data port, card socket (e.g., memory card, SIM / UIM card), etc.

[0071] The second electronic module (EM2) may include an acoustic output module (AOM), a light-emitting module (LMM), a light-receiving module (LRM), and an electronic module (500) according to one embodiment of the present invention. The above components may be directly mounted on a motherboard or mounted on a separate substrate and electrically connected to a display module (200) or electrically connected to a first electronic module (EM1) through a connector (not shown), etc.

[0072] The audio output module (AOM) converts audio data received from the wireless communication module (TM) or audio data stored in memory (MM) and outputs it externally.

[0073] The light-emitting module (LMM) generates and outputs light. The light-emitting module (LMM) can output infrared light. The light-emitting module (LMM) may include LED elements. The light-receiving module (LRM) can detect infrared light. The light-receiving module (LRM) may be activated when infrared light above a predetermined level is detected. The light-receiving module (LRM) may include a CMOS sensor. After the infrared light generated by the light-emitting module (LMM) is output, it is reflected by an external object (e.g., a user's finger or face), and the reflected infrared light may be incident on the light-receiving module (LRM). The electronic module (500) can capture an external image.

[0074] An electronic module (500) according to one embodiment of the present invention may be included in at least one of a first electronic module (EM1) and a second electronic module (EM2). For example, the electronic module (500) may be included as one of the second electronic modules (EM2) together with an acoustic output module (AOM), a light-emitting module (LMM), and a light-receiving module (LRM). The electronic module (500) may detect an external subject received through a module area (MA) or provide sound signals such as voice, or light such as infrared light, to the outside through the module area (MA). The electronic module (500) may include a camera module and an actuator, etc., to photograph an external subject.

[0075] FIGS. 4a and FIGS. 4b are cross-sectional views of a display module according to an embodiment of the present invention.

[0076] FIG. 4a is a cross-sectional view of a display module according to an embodiment of the present invention. Referring to FIG. 4a, the display module (200) may include a display panel (210) and an input sensor (220). The display panel (210) may include a base layer (BL), a circuit element layer (ML), a light-emitting element layer (EML), and an encapsulation layer (TFE). The input sensor (220) may include an encapsulation layer (TFE) and a sensing circuit layer (ML-T).

[0077] According to one embodiment of the present invention, the display panel (210) and the input sensor (220) can be formed in a continuous process. That is, the sensing circuit layer (ML-T) can be formed directly on the encapsulation layer (TFE). The input sensor (220) is placed directly on the display panel (210) and is affected by noise originating from the display driving circuit when the screen of the display panel (210) is output. For example, the input sensor (220) may be affected by noise generated during screen switching of the display panel (210) when detecting input signals.

[0078] The base layer (BL) may be a laminated structure comprising a silicon substrate, a plastic substrate, a glass substrate, an insulating film, or a plurality of insulating layers.

[0079] A circuit element layer (ML) may be disposed on a base layer (BL). The circuit element layer (ML) may include a plurality of insulating layers, a plurality of conductive layers, and a semiconductor layer. The plurality of conductive layers of the circuit element layer (ML) may form signal wiring or control circuits of pixels.

[0080] A light-emitting element layer (EML) may be disposed on a circuit element layer (ML). The light-emitting element layer (EML) may include a light-emitting layer that generates light. For example, the light-emitting layer of an organic light-emitting display panel may include an organic light-emitting material. The light-emitting layer of a quantum dot light-emitting display panel may include at least one of quantum dots and quantum rods.

[0081] The sensing circuit layer (ML-T) may be disposed on the encapsulation layer (TFE). The sensing circuit layer (ML-T) may include a plurality of insulating layers and a plurality of conductive layers. The plurality of conductive layers may form a sensing electrode that detects an external input, a sensing wire connected to the sensing electrode, and a sensing pad connected to the sensing wire.

[0082] FIG. 4b is a cross-sectional view of a display module according to an embodiment of the present invention. In describing FIG. 4b, the same reference numerals are used for components described through FIG. 4a, and descriptions thereof are omitted.

[0083] Referring to FIG. 4b, the display module (200-1) may include a display panel (210-1) and an input detection unit (220-1). The display panel (210-1) may include a base layer (BL), a circuit element layer (ML), and a light-emitting element layer (EML). The input detection unit (220-1) may include a cover substrate (CBL) and a detection circuit layer (ML-T).

[0084] A cover substrate (CBL) may be disposed on a light-emitting element layer (EML). Each cover substrate (CBL) may be a laminated structure comprising a silicon substrate, a plastic substrate, a glass substrate, an insulating film, or a plurality of insulating layers. A predetermined space may be defined between the cover substrate (CBL) and the light-emitting element layer (EML). The space may be filled with air or an inert gas. Additionally, in one embodiment of the present invention, the space may be filled with a filler such as a silicon-based polymer, an epoxy-based resin, or an acrylic resin.

[0085] A bonding member (SLM) may be disposed between the base layer (BL) and the cover substrate (CBL). The bonding member (SLM) may bond the base layer (BL) and the cover substrate (CBL). The bonding member (SLM) may include an organic material such as a photocurable resin or a photoplastic resin, or an inorganic material such as a frit seal, and is not limited to any one embodiment.

[0086] FIG. 5 is an enlarged cross-sectional view of a display module according to one embodiment of the present invention.

[0087] Referring to FIG. 5, the display module (200) may include a display panel (210) and an input sensor (220) placed directly on the display panel (210). The display panel (210) may include a base layer (BL), a circuit element layer (ML), a light-emitting element layer (EML), and an encapsulation layer (TFE).

[0088] The base layer (BL) can provide a base surface on which the circuit element layer (ML) is placed. The base layer (BL) may be a glass substrate, a metal substrate, or a polymer substrate, etc. However, the embodiments are not limited thereto, and the base layer (BL) may be an inorganic layer, an organic layer, or a composite material layer.

[0089] The base layer (BL) may have a multilayer structure. For example, the base layer (BL) may have a three-layer structure consisting of a synthetic resin layer, an adhesive layer, and a synthetic resin layer. In particular, the synthetic resin layer may include a polyimide-based resin. Additionally, the synthetic resin layer may include at least one of an acrylate-based resin, a methacrylate-based resin, a polyisoprene-based resin, a vinyl-based resin, an epoxy-based resin, a urethane-based resin, a cellulose-based resin, a siloxane-based resin, a polyamide-based resin, and a perylene-based resin.

[0090] A circuit element layer (ML) can be disposed on a base layer (BL). The circuit element layer (ML) may include an insulating layer, a semiconductor pattern, a conductive pattern, and a signal line, etc. An insulating layer, a semiconductor layer, and a conductive layer are formed on the base layer (BL) by means such as coating or deposition, and subsequently, the insulating layer, the semiconductor layer, and the conductive layer can be selectively patterned through multiple photolithography processes. Subsequently, the semiconductor pattern, the conductive pattern, and the signal line included in the circuit element layer (ML) can be formed.

[0091] At least one inorganic layer is formed on the upper surface of the base layer (BL). The inorganic layer may include at least one of aluminum oxide, titanium oxide, silicon oxide, silicon oxynitride, zirconium oxide, and hafnium oxide. The inorganic layer may be formed in multiple layers. The multiple inorganic layers may constitute a barrier layer and / or a buffer layer. In this embodiment, the display panel (210) is shown to include a buffer layer (BFL).

[0092] The buffer layer (BFL) can improve the bonding strength between the base layer (BL) and the semiconductor pattern. The buffer layer (BFL) may include a silicon oxide layer and a silicon nitride layer, and the silicon oxide layer and the silicon nitride layer may be stacked alternately.

[0093] A semiconductor pattern may be placed on a buffer layer (BFL). The semiconductor pattern may include polysilicon. However, it is not limited thereto, and the semiconductor pattern may include amorphous silicon or metal oxide.

[0094] FIG. 5 illustrates only a portion of the semiconductor pattern, and additional semiconductor patterns may be placed in other areas. The semiconductor pattern may be arranged according to a specific rule across the pixels. The electrical properties of the semiconductor pattern may differ depending on whether it is doped. The semiconductor pattern may include a doped region and a non-doped region. The doped region may be doped with an N-type dopant or a P-type dopant. A PMOS transistor may include a doped region doped with a P-type dopant, and an NMOS transistor may include a doped region doped with an N-type dopant.

[0095] The doped region has greater conductivity than the non-doped region and can effectively function as an electrode or signal line. The non-doped region can effectively correspond to the active region (or channel region) of the transistor. In other words, a part of the semiconductor pattern may be the active region of the transistor, while another part may be the source or drain region.

[0096] Each pixel may have an equivalent circuit including seven transistors, one capacitor, and a light-emitting element, and the equivalent circuit diagram of the pixel may be modified in various forms. In FIG. 5, one transistor (TR) and a light-emitting element (EMD) included in the pixel are illustrated as examples.

[0097] The source region (SR), active region (CHR), and drain region (DR) of the transistor (TR) can be formed from the semiconductor pattern. The source region (SR) and the drain region (DR) can be provided in opposite directions from the active region (CHR) in cross-section. FIG. 5 shows a portion of a signal line (SCL) placed on the same layer as the semiconductor pattern. Although not separately illustrated, the signal line (SCL) can be electrically connected to the transistor (TR) in a planar manner.

[0098] The first insulating layer (IL1) may be placed on the buffer layer (BFL). The first insulating layer (IL1) overlaps commonly across a plurality of pixels and may cover a semiconductor pattern. The first insulating layer (IL1) may be an inorganic layer and / or an organic layer and may have a single-layer or multi-layer structure. The first insulating layer (IL1) may include at least one of aluminum oxide, titanium oxide, silicon oxide, silicon oxynitride, zirconium oxide, and hafnium oxide. In this embodiment, the first insulating layer (IL1) may be a single-layer silicon oxide layer. In addition to the first insulating layer (IL1), the insulating layer of the circuit element layer (ML) described below may be an inorganic layer and / or an organic layer and may have a single-layer or multi-layer structure. The inorganic layer may include at least one of the materials described above, but is not limited thereto.

[0099] The gate (GR) of the transistor (TR) is placed on the first insulating layer (IL1). The gate (GR) may be part of a metal pattern. The gate (GR) overlaps the active region (CHR). In the process of doping the semiconductor pattern, the gate (GR) can function as a mask.

[0100] The second insulating layer (IL2) is placed on the first insulating layer (IL1) and can cover the gate (GR). The second insulating layer (IL2) can overlap the pixels in common. The second insulating layer (IL2) may be an inorganic layer and / or an organic layer and may have a single-layer or multi-layer structure. In this embodiment, the second insulating layer (IL2) may be a single-layer silicon oxide layer.

[0101] The third insulating layer (IL3) may be placed on the second insulating layer (IL2), and in this embodiment, the third insulating layer (IL3) may be a single layer of silicon oxide.

[0102] The first connecting electrode (CNE1) can be placed on the third insulating layer (IL3). The first connecting electrode (CNE1) can be connected to a signal line (SCL) through a contact hole (CNT1) that penetrates the first, second, and third insulating layers (IL1, IL2, IL3).

[0103] The fourth insulating layer (IL4) may be placed on the third insulating layer (IL3). The fourth insulating layer (IL4) may be a single layer of silicon oxide. The fifth insulating layer (IL5) may be placed on the fourth insulating layer (IL4). The fifth insulating layer (IL5) may be an organic layer.

[0104] The second connecting electrode (CNE2) can be placed on the fifth insulating layer (IL5). The second connecting electrode (CNE2) can be connected to the first connecting electrode (CNE1) through a contact hole (CNT2) that penetrates the fourth insulating layer (IL4) and the fifth insulating layer (IL5).

[0105] The sixth insulating layer (IL6) is disposed on the fifth insulating layer (IL5) and can cover the second connecting electrode (CNE2). The sixth insulating layer (IL6) may be an organic layer. The light-emitting element layer (EML) may be disposed on the circuit element layer (ML). The light-emitting element layer (EML) may include a light-emitting element (EMD). For example, the light-emitting element layer (EML) may include an organic light-emitting material, a quantum dot, a quantum rod, a micro LED, or a nano LED. The light-emitting element (EMD) may include a first electrode (AE), a light-emitting layer (EL), and a second electrode (CE).

[0106] The first electrode (AE) can be placed on the sixth insulating layer (IL6). The first electrode (AE) can be connected to the second connecting electrode (CNE2) through a contact hole (CNT3) penetrating the sixth insulating layer (IL6).

[0107] A pixel defining film (IL7) is placed on the sixth insulating layer (IL6) and can cover a portion of the first electrode (AE). An opening (OP) is defined in the pixel defining film (IL7). The opening (OP) of the pixel defining film (IL7) exposes at least a portion of the first electrode (AE). In this embodiment, a light-emitting region (PXA) is defined to correspond to a portion of the first electrode (AE) exposed by the opening (OP). A non-light-emitting region (NPXA) may surround the light-emitting region (PXA).

[0108] The light-emitting layer (EL) may be placed on the first electrode (AE). The light-emitting layer (EL) may be placed in the aperture (OP). That is, the light-emitting layer (EL) may be formed separately on each pixel. When the light-emitting layer (EL) is formed separately on each pixel, each of the light-emitting layers (EL) may emit light of at least one color among blue, red, and green. However, it is not limited thereto, and the light-emitting layer (EL) may be connected to the pixels and provided in common. In this case, the light-emitting layer (EL) may provide blue light or white light.

[0109] The second electrode (CE) can be placed on the light-emitting layer (EL). The second electrode (CE) has a single shape and can be placed commonly across a plurality of pixels. A common voltage can be provided to the second electrode (CE), and the second electrode (CE) can be referred to as a common electrode.

[0110] Although not shown, a hole control layer may be disposed between the first electrode (AE) and the light-emitting layer (EL). The hole control layer may be disposed in common in the light-emitting region (PXA) and the non-light-emitting region (NPXA). The hole control layer includes a hole transport layer and may further include a hole injection layer. An electronic control layer may be disposed between the light-emitting layer (EL) and the second electrode (CE). The electronic control layer includes an electron transport layer and may further include an electron injection layer. The hole control layer and the electronic control layer may be formed in common in a plurality of pixels using an open mask. An encapsulation layer (TFE) may be disposed on the light-emitting element layer (EML). The encapsulation layer (TFE) may include sequentially stacked inorganic layers, organic layers, and inorganic layers, but the layers constituting the encapsulation layer (TFE) are not limited thereto.

[0111] Inorganic layers can protect the light-emitting diode layer (EML) from moisture and oxygen, and organic layers can protect the light-emitting diode layer (EML) from foreign substances such as dust particles. Inorganic layers may include silicon nitride layers, silicon oxynitride layers, silicon oxide layers, titanium oxide layers, or aluminum oxide layers. Organic layers may include, but are not limited to, acrylic-based organic layers.

[0112] The input sensor (220) can be formed on the display panel (210) through a continuous process. The input sensor (220) may include a base layer (IIL1), a first conductive layer (ICL1), a sensing insulating layer (IIL2), a second conductive layer (CIL1), and a cover insulating layer (IIL3).

[0113] The base layer (IIL1) may be an inorganic layer comprising any one of silicon nitride, silicon oxynitride, and silicon oxide. Alternatively, the base layer (IIL1) may be an organic layer comprising epoxy resin, acrylic resin, or imide-based resin. The base layer (IIL1) may have a single-layer structure or a multilayer structure stacked along a third direction (DR3).

[0114] Each of the first conductive layer (ICL1) and the second conductive layer (ICL2) may have a single-layer structure or a multilayer structure stacked along the third direction (DR3). The single-layer conductive layer may include a metal layer or a transparent conductive layer. The metal layer may include molybdenum, silver, titanium, copper, aluminum, or an alloy thereof. The transparent conductive layer may include a transparent conductive oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), or indium zinc tin oxide (IZTO). Additionally, the transparent conductive layer may include a conductive polymer such as PEDOT, metal nanowires, graphene, etc.

[0115] The conductive layer of the multilayer structure may include metal layers. The metal layers may have a three-layer structure, for example, titanium / aluminum / titanium. The conductive layer of the multilayer structure may include at least one metal layer and at least one transparent conductive layer.

[0116] At least one of the sensing insulating layer (IIL2) and the cover insulating layer (IIL3) may include an inorganic film. The inorganic film may include at least one of aluminum oxide, titanium oxide, silicon oxide, silicon oxynitride, zirconium oxide, and hafnium oxide.

[0117] At least one of the sensing insulating layer (IIL2) and the cover insulating layer (IIL3) may include an organic film. The organic film may include at least one of an acrylic resin, a methacrylic resin, a polyisoprene, a vinyl resin, an epoxy resin, a urethane resin, a cellulose resin, a siloxane resin, a polyimide resin, a polyamide resin, and a perylene resin.

[0118] FIGS. 6a and FIGS. 6b are block diagrams of a display device according to an embodiment of the present invention.

[0119] Referring to FIG. 6a, the display device includes a control unit (10), a display unit (20), and a sensor unit (30).

[0120] The control unit (10) can control signal transmission and operation between the display unit (20) and the sensor unit (30). The control unit (10) may include a control module (CM, FIG. 3). The control unit (10) can transmit commands corresponding to the display unit (20) and the sensor unit (30) based on user input received through an input sensor.

[0121] In one embodiment, the control unit (10) can activate a call mode when the user touches the call button (CAL, see FIG. 1). When the call mode is activated, the control unit (10) can activate a proximity sensing mode. The proximity sensing mode may correspond to a mode in which the input sensor (220) detects a proximity signal instead of a touch signal. Here, the touch signal corresponds to a signal applied to the display device when a part of the user's body (e.g., a finger) directly touches the display surface (FS, see FIG. 1) of the display device (DD, see FIG. 1), and the proximity signal corresponds to a signal applied to the display device when a part of the user's body (e.g., an ear) comes into close contact with the display surface (FS).

[0122] Referring to FIGS. 6a and FIGS. 6b, the display unit (20) includes a display panel (210) and a display driving circuit (DC).

[0123] When the proximity sensing mode is executed, the display unit (20) can reduce the brightness of the display panel (210) to a target brightness by means of a display driving circuit (DC). Here, the target brightness corresponds to the optimal brightness of the display panel (210) required for the input sensor (220) to detect a proximity signal in the proximity sensing mode. In the case of a proximity signal, the signal strength is lower than that of a touch signal. Therefore, the display panel (210) is susceptible to noise. A display driving circuit (DC) according to an embodiment of the present invention can reduce noise generated from the display panel (210) by reducing the brightness of the display panel (210) to a target brightness in the proximity sensing mode.

[0124] The target brightness may correspond to a value pre-set by the user. Alternatively, the target brightness may correspond to a brightness value that is automatically set by the display driving circuit (DC) in proximity sensing mode based on noise generated from the display panel (210).

[0125] The sensor unit (30) may include an input sensor (220) and a sensor driving circuit (TC). The input sensor (220) is placed on a display panel (210). The input sensor (220) may overlap with the display panel (210) in the thickness direction of the display panel (210). The sensor driving circuit (TC) drives the input sensor (220). The sensor driving circuit (TC) may be integrated with or configured separately from the display driving circuit (DC). The sensor driving circuit (TC) may be placed on a main circuit board (MB, see FIG. 2).

[0126] In proximity sensing mode, the sensor unit (30) can operate in synchronization with the display unit (20). That is, the sensor unit (30) can detect a proximity signal through the input sensor (220) when the display panel (210) has a target brightness.

[0127] More specifically, the sensor driving circuit (TC) can be synchronized with the display driving circuit (DC) in a proximity sensing mode. The sensor driving circuit (TC) receives brightness information of the display panel (210) from the display driving circuit (DC) and detects a proximity signal through the input sensor (220) when the brightness of the display panel (210) corresponds to a target brightness.

[0128] FIGS. 7a and FIGS. 7b are flowcharts illustrating a proximity signal sensing method using an input sensor according to an embodiment of the present invention.

[0129] Figure 7a is a flowchart schematically showing a proximity signal sensing method using an input sensor.

[0130] In FIG. 7a, a proximity sensing method using an input sensor can be initiated by executing a proximity sensing mode when a user presses a call button (step S710).

[0131] If the call button is not pressed by the user, the display device operates in normal touch mode without the proximity sensing mode being activated.

[0132] When the proximity sensing mode is executed, the display driving circuit can perform an adjustment to reduce the brightness of the display panel to a target brightness (step S720). This adjustment method of the display driving circuit is described in detail in FIG. 7b and FIG. 9a through 9c.

[0133] When the display panel is driven at the target brightness, the sensor driving circuit causes the input sensor to detect a proximity signal (step S730). In one embodiment, the display panel is driven at the target brightness to reduce noise generation, and the proximity signal detection performance of the input sensor can be improved according to the low noise of the display panel.

[0134] FIG. 7b is a flowchart specifically illustrating a proximity signal sensing method using an input sensor according to an embodiment of the present invention. FIG. 7b illustrates a method for reducing the brightness of a display panel to a target brightness.

[0135] In FIG. 7b, the display driving circuit can adjust the driving voltage of the display panel in the second frame to be lower than the driving voltage in the first frame (step S721). That is, the display driving circuit can apply different driving voltages for each alternating frame during the driving of the display panel. The target brightness may correspond to the brightness at the average driving voltage of the driving voltage of the first frame and the driving voltage of the second frame.

[0136] In another embodiment, the display driving circuit can adjust the driving time of the display panel in the second frame to be smaller than the driving time in the first frame (step S722). That is, the display driving circuit can make the driving time different for each alternating frame. The target brightness may correspond to the brightness of the display panel at the average driving time of the driving time of the first frame and the driving time of the second frame.

[0137] In one embodiment, either step S721 or step S722 may be omitted.

[0138] A sensor driving circuit synchronized with a display driving circuit can detect a proximity signal in a second frame. The sensor driving circuit detects the proximity signal only in a second frame where the driving voltage and / or driving time is low. That is, the sensor driving circuit can detect the proximity signal only in frames where the brightness of the display panel is low. Since the noise applied from the display panel to the input sensor is small at low brightness, the input sensor can effectively detect the proximity signal. This will be explained further with reference to FIGS. 9a through 9c.

[0139] FIG. 8 is a graph showing the reduction in brightness of a display panel according to one embodiment of the present invention.

[0140] In FIG. 8, when the proximity sensing mode (PSM) is executed, the display driving circuit can gradually decrease the brightness from the current brightness (OLM) of the display panel to the target brightness (TLM). When the target brightness (TLM) is reached during the proximity sensing mode (PSM), the display driving circuit can maintain the brightness at a constant level.

[0141] FIGS. 9a to 9c are graphs showing a method for lowering the brightness of a display panel according to an embodiment of the present invention.

[0142] FIG. 9a illustrates a method of lowering brightness by adjusting the driving voltage of a display panel. FIG. 9b illustrates a method of lowering brightness by adjusting the driving time of a display panel. FIG. 9c illustrates a method of lowering brightness by adjusting the driving voltage and driving time of a display panel.

[0143] Referring to FIGS. 9a through 9c, the display unit may include a first frame (FR1) and a second frame (FR2). The first frame (FR1) and the second frame (FR2) appear alternately. The second frame (FR2) follows the first frame (FR1).

[0144] In FIG. 9a, the display driving circuit can drive the second brightness (LM2) in the second frame (FR2) to be lower than the first brightness (LM1) of the display panel in the first frame (FR1). The target brightness (TLM) may correspond to the average brightness of the first brightness (LM1) and the second brightness (LM2). That is, the display driving circuit can determine the target brightness (TLM) through the average driving voltage by increasing the driving voltage of the first frame (FR1) and decreasing the driving voltage of the second frame (FR2).

[0145] The sensor driving circuit can detect a proximity signal detected in a second frame (FR2) having low brightness due to a low driving voltage. The second brightness (LM2) of the second frame (FR2) is lower than the target brightness (TLM). The target brightness (TLM) can be determined as an appropriate brightness level at which the user can perceive the screen. The second brightness (LM2) is determined as a small brightness to reduce noise in the display panel. One embodiment of the present invention sets the first brightness (LM1) and the second brightness (LM2) to alternate and drives the circuit to detect a proximity signal at the second brightness (LM2), thereby enabling the user to perceive the screen during a call while simultaneously improving the proximity signal detection performance.

[0146] In FIG. 9b, the display driving circuit can adjust the brightness of the display panel by making the second driving time (DT2) of the second frame (FR2) smaller than the first driving time (DT1) of the first frame (FR1). The brightness of the second driving time (DT2) is smaller than the brightness of the first driving time (DT1).

[0147] In this embodiment, the driving voltage of the first frame (FR1) and the second frame (FR2) is the same. The average driving time is the average value of the first driving time (DT1) and the second driving time (DT2). The target brightness (TLM) can be determined according to the average driving time.

[0148] A sensor driving circuit synchronized with a display driving circuit can drive an input sensor to detect a proximity signal during a second driving time (DT2) of a second frame (FR2) with low brightness.

[0149] In FIG. 9c, the display driving circuit can adjust both the driving voltage and the driving time to lower the brightness of the display panel to a target brightness.

[0150] The display driving circuit can increase the driving voltage and driving time in the first frame (FR1) and decrease the driving voltage and driving time in the second frame (FR2). Accordingly, the display driving circuit can drive the display panel at the target brightness (TLM).

[0151] The sensor driving circuit can detect a proximity signal detected in the second frame (FR2), which has a smaller driving voltage and driving time among the alternating first frame (FR1) and second frame (FR2). The brightness of the display panel is lowest in the second frame (FR2). Therefore, the noise on the display panel is low, allowing the proximity signal to be detected effectively.

[0152] FIG. 10 is a plan view of a display module according to one embodiment of the present invention.

[0153] In one embodiment, a first area (PSA) and a second area (NSA) may be defined in the display panel (210) of the display device (DD). The first area (PSA) and the second area (NSA) may be defined in the active area (AA). The first area (PSA) and the second area (NSA) are defined adjacently. In one embodiment, the first area (PSA) may be positioned adjacent to the speaker module (SPK). That is, during a call, the first area (PSA) may be located closer to the user's ear than the second area (NSA).

[0154] In one embodiment, the display driving circuit can lower the brightness of a first area (PSA) of the display panel to a target brightness in a proximity sensing mode. That is, the display driving circuit can adjust only the brightness of the first area (PSA) close to the user's ear while keeping the brightness of the second area (NSA) unchanged.

[0155] The sensor driving circuit can detect a proximity signal input to the first area (PSA). That is, the sensor driving circuit can reduce the noise impact on the display panel by detecting a proximity signal in the first area (PSA) driven at the target brightness.

[0156] Referring to FIGS. 9a to 9c, the display driving circuit can adjust the driving voltage and / or driving time frame by frame to reduce the brightness of the display panel in the first area (PSA) to a target brightness. That is, when driving the pixels of the first area (PSA) of the display panel, the display driving circuit can adjust the driving voltage and / or driving time of alternating first frames (FR1) and second frames (FR2).

[0157] The display driving circuit can lower the brightness of the second frame (FR2) compared to the first frame (FR1) in the first area (PSA). The sensor driving circuit can detect a proximity signal in the second frame (FR2). That is, a display device according to one embodiment adjusts the brightness of the first frame (FR1) and the second frame (FR2) of the display panel only in the first area (PSA), and detects a proximity signal detected through an input sensor in the second frame (FR2) with low brightness. Refer to FIGS. 9a to 9c for redundant descriptions.

[0158] As described above, embodiments have been disclosed in the drawings and specification. Specific terms have been used herein, but they are used only for the purpose of describing the invention and are not intended to limit the meaning or the scope of the invention as described in the claims. Therefore, those skilled in the art will understand that various modifications and equivalent alternative embodiments are possible therefrom. Accordingly, the true technical scope of protection of the invention should be determined by the technical spirit of the appended claims. Explanation of the symbols

[0159] DD: Display device 210: Display panel 220: Input sensor 10: Control unit 20: Display section 30: Sensor section DC: Indicator driving circuit TC: Sensor driving circuit TLM: Target Luminance

Claims

Claim 1 A display device comprising: a control unit that executes a proximity sensing mode that detects a proximity signal instead of a touch signal when a start signal is received according to user input; a display unit that reduces the brightness of the entire display panel to a target brightness when the proximity sensing mode is executed; and a sensor unit that is synchronized with the display unit and detects the proximity signal, wherein detection of the proximity signal is not performed before reducing the brightness of the entire display panel to the target brightness, the display unit comprises the display panel and a display driving circuit electrically connected to the display panel, the display driving circuit reduces the brightness of the entire display panel to the target brightness, the display unit comprises a first frame and a second frame that alternate with each other, wherein the first brightness of the entire display panel in the first frame is greater than the second brightness of the entire display panel in the second frame, and the driving voltage applied to the entire display panel from the display driving circuit in the second frame is smaller than the driving voltage applied to the entire display panel in the first frame. Claim 2 In paragraph 1, the initiation signal is a display device that is a call mode entry signal according to the user's call button input. Claim 3 delete Claim 4 delete Claim 5 delete Claim 6 A display device according to claim 1, characterized in that the second driving time of the second frame is smaller than the first driving time of the first frame. Claim 7 delete Claim 8 A display device according to claim 1, wherein the target brightness is the average of the first brightness and the second brightness. Claim 9 In claim 1, the sensor unit comprises an input sensor and a sensor driving circuit electrically connected to the input sensor, and the sensor driving circuit is synchronized with the display unit to detect the proximity signal detected at the target brightness. Claim 10 A display device according to claim 1, wherein the sensor unit detects the proximity signal in the second frame. Claim 11 delete Claim 12 delete Claim 13 A display device according to claim 1, characterized in that when the proximity sensing mode is executed, the display unit gradually reduces the brightness to the target brightness. Claim 14 delete Claim 15 delete Claim 16 In claim 1, the sensor part is a display device disposed on the display part so as to overlap with the display part in the thickness direction of the display part. Claim 17 A proximity sensing method using an input sensor, comprising: a step of executing a proximity sensing mode in which an input sensor detects a proximity signal instead of a touch signal when a control unit receives a start signal generated according to user input; a step of, when the proximity sensing mode is executed, a step of, in which a display unit reduces the brightness of the entire display panel to a target brightness; and a step of, in which a sensor unit synchronized with the display unit detects the proximity signal, wherein detection of the proximity signal is not performed before reducing the brightness of the entire display panel to the target brightness, and the display unit includes the display panel and a display driving circuit electrically connected to the display panel, wherein the display driving circuit reduces the brightness of the entire display panel to the target brightness, and the display unit includes a first frame and a second frame that alternate with each other, wherein the first brightness of the entire display panel in the first frame is greater than the second brightness of the entire display panel in the second frame, and the driving voltage applied to the entire display panel from the display driving circuit in the second frame is smaller than the driving voltage applied to the entire display panel in the first frame. Claim 18 delete Claim 19 delete Claim 20 A proximity sensing method using an input sensor according to claim 17, wherein the sensor unit includes a sensor driving circuit, and the sensor driving circuit detects the proximity signal detected in the second frame.

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