Display device and method for manufacturing same

Abstract

A display device, according to embodiments of the present disclosure, may comprise: a display panel for displaying an image; and a display driver IC for controlling the display panel. The display panel may comprise: a lower substrate including at least one light-emitting element; and an upper substrate including a color filter layer and a color conversion layer. The color conversion layer of the upper substrate may comprise at least one color conversion part having a rod shape. The at least one color conversion part may convert a wavelength of light by including at least one color conversion particle that is regularly arranged, and may be continuously formed at predetermined intervals on the upper substrate.

Description

Display device and manufacturing method thereof

[0001] Various embodiments of the present disclosure relate to a display device including a color filter and a color conversion unit and a method of manufacturing the same.

[0002] A display device is a device that processes image signals and image data input from the outside or stored internally through various processes and displays them as images on a display panel or screen. Depending on the method, the device can be implemented in various ways, such as a TV, monitor, or portable media player.

[0003] Recently, a display device has been proposed that includes a lower substrate including a light-emitting element and an upper substrate including a color filter and a color conversion unit. For example, the color conversion unit can convert the wavelength of light provided from the lower substrate. Therefore, the display device including the color conversion unit can emit light having a different color from the incident light. For example, the color conversion unit can include color conversion particles such as quantum materials. Such color conversion particles can be utilized as a light-emitting material of the display device, thereby contributing to improved display quality.

[0004] Various embodiments of the present disclosure can provide a display device and a manufacturing method thereof in which color conversion particles are regularly arranged inside a color conversion layer by forming a color conversion layer using electrohydraulic printing.

[0005] A display device according to embodiments of the present disclosure may include a display panel for displaying an image, and a display driver IC for controlling the display panel. The display panel may include a lower substrate including at least one light-emitting element, and an upper substrate including a color filter layer and a color conversion layer. The color conversion layer of the upper substrate may include at least one color conversion unit having a rod shape. The at least one color conversion unit may include at least one color conversion particle that is regularly arranged to convert a wavelength of light, and may be continuously formed at regular intervals on the upper substrate.

[0006] In one embodiment, the at least one color conversion unit may be arranged sequentially with respect to an adjacent homogeneous color conversion unit at a first interval and with respect to an adjacent heterogeneous color conversion unit at a second interval by spraying a color conversion ink containing the at least one color conversion particle onto the upper substrate using electrohydrodynamic printing (EHD printing).

[0007] In one embodiment, the at least one color conversion particle may comprise a cylindrical quantum rod.

[0008] In one embodiment, the color conversion layer may include at least one color conversion unit formed in a rod shape between the partition walls based on the upper substrate moving in a predetermined direction along an imaginary center line when the color conversion ink is sprayed.

[0009] In one embodiment, the quantum rod can be aligned parallel to the discharge direction of the color conversion ink within the color conversion layer by receiving a first force based on shear stress within a Taylor cone formed as the color conversion ink is ejected from the nozzle.

[0010] In one embodiment, the quantum rod can be aligned parallel to the discharge direction of the color conversion ink within the color conversion layer by the dipole moment inside the quantum rod being acted upon by a second force based on an electric field.

[0011] In one embodiment, the quantum rod may have a long axis of the cylindrical shape of 20 nm to 200 nm in length, and a diameter of the cylindrical shape of 3 nm to 7 nm in length.

[0012] In one embodiment, the display panel may further include a low-reflection layer formed over the upper substrate and including a linear polarizer and a quarterwave plate.

[0013] In one embodiment, the linear polarizing plate can transmit light polarized in a first direction and block light polarized in a second direction perpendicular to the first direction. The quantum rods can be aligned in a direction parallel to the first direction within the color conversion layer.

[0014] In one embodiment, the upper substrate may be manufactured in a process independent of the lower substrate. The upper substrate and the lower substrate may be bonded using an optical bonding material that transmits light.

[0015] A method for manufacturing a display device according to embodiments of the present disclosure may include an operation of forming a lower substrate including at least one light-emitting element, and an operation of forming an upper substrate including a color filter layer and a color conversion layer. The color conversion layer of the upper substrate may include at least one color conversion unit having a rod shape. The at least one color conversion unit may include at least one color conversion particle that is regularly arranged to convert a wavelength of light, and may be continuously formed at regular intervals on the upper substrate.

[0016] In one embodiment, the at least one color conversion unit may be arranged sequentially with respect to an adjacent homogeneous color conversion unit at a first interval and with respect to an adjacent heterogeneous color conversion unit at a second interval by spraying a color conversion ink containing the at least one color conversion particle onto the upper substrate using electrohydrodynamic printing (EHD printing).

[0017] In one embodiment, the at least one color conversion particle may comprise a cylindrical quantum rod.

[0018] In one embodiment, the color conversion layer may include at least one color conversion unit formed in a rod shape between the partition walls based on the upper substrate moving in a predetermined direction along an imaginary center line when the color conversion ink is sprayed.

[0019] In one embodiment, the operation of forming the upper substrate may align the quantum rods parallel to the discharge direction of the color conversion ink within the color conversion layer by using a first force based on shear stress within a Taylor cone formed as the color conversion ink is ejected from a nozzle.

[0020] In one embodiment, the act of forming the upper substrate may align the quantum rod parallel to the discharge direction of the color conversion ink within the color conversion layer by using a second force based on an electric field acting on a dipole moment within the quantum rod.

[0021] In one embodiment, the quantum rod may have a long axis of the cylindrical shape of 20 nm to 200 nm in length, and a diameter of the cylindrical shape of 3 nm to 7 nm in length.

[0022] In one embodiment, the method for manufacturing a display device may further include forming a low-reflection layer formed on the upper substrate. The low-reflection layer may include a linear polarizer and a quarterwave plate.

[0023] In one embodiment, the linear polarizing plate can transmit light polarized in a first direction and block light polarized in a second direction perpendicular to the first direction. The operation of forming the upper substrate can align the quantum rods in a direction parallel to the first direction within the color conversion layer.

[0024] In one embodiment, the operation of forming the lower substrate and the operation of forming the upper substrate may be performed independently of each other. The method of manufacturing a display device may further include an operation of bonding the upper substrate and the lower substrate using an optical bonding material that transmits light.

[0025] According to various embodiments of the present disclosure, the display device of the present disclosure and the manufacturing method thereof can form a color conversion layer using electrohydraulic printing, thereby allowing color conversion particles to be regularly arranged inside the color conversion layer.

[0026] In addition, the display device of the present disclosure and its manufacturing method include cylindrical quantum rods as color conversion particles, thereby maximizing the light-emitting area and minimizing light reflected after emission.

[0027] Therefore, the display device of the present disclosure and its manufacturing method can increase the light emission efficiency of the color conversion layer and improve display quality.

[0028] The effects that can be obtained from the exemplary embodiments of the present disclosure are not limited to the effects mentioned above, and other effects not mentioned can be clearly derived and understood by those skilled in the art to which the exemplary embodiments of the present disclosure pertain from the following description. In other words, unintended effects resulting from implementing the exemplary embodiments of the present disclosure can also be derived by those skilled in the art from the exemplary embodiments of the present disclosure.

[0029] FIG. 1 illustrates a block configuration of an electronic device within a network environment according to one embodiment.

[0030] FIG. 2 illustrates a block configuration of a display module according to one embodiment.

[0031] FIG. 3 illustrates a laminated structure of a display panel according to one embodiment.

[0032] FIG. 4 illustrates a method for forming a color conversion layer and a transparent layer according to one embodiment.

[0033] FIG. 5 illustrates the structure of a color conversion particle according to one embodiment.

[0034] Figure 6 illustrates the force acting during the process of forming a color conversion layer and a transparent layer according to one embodiment.

[0035] FIG. 7 illustrates a color conversion layer and a transparent layer formed on an upper substrate according to one embodiment.

[0036] Fig. 8 illustrates a laminated structure of a display panel according to another embodiment.

[0037] FIG. 9 illustrates changes in light emitted from a display panel according to one embodiment.

[0038] FIG. 10 illustrates a light-emitting area for each color conversion particle according to one embodiment.

[0039] Figure 11 illustrates the luminous efficiency according to the critical angle for each color conversion particle according to one embodiment.

[0040] Fig. 12 illustrates a laminated structure of a display panel according to another embodiment.

[0041] Figures 13a and 13b illustrate a method of forming a color conversion layer and a transparent layer according to another embodiment.

[0042] FIG. 14 illustrates a method for manufacturing a display device according to one embodiment.

[0043] Figure 15 illustrates a sequence of operations for manufacturing a color conversion layer of an upper substrate according to one embodiment.

[0044] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings so that those skilled in the art can easily implement the present disclosure. However, the present disclosure may be implemented in various different forms and is not limited to the embodiments described herein. In connection with the description of the drawings, the same or similar reference numerals may be used for identical or similar components. Furthermore, in the drawings and related descriptions, descriptions of well-known functions and configurations may be omitted for clarity and conciseness.

[0045] FIG. 1 illustrates a block configuration of an electronic device (101) within a network environment (100) according to one embodiment.

[0046] Referring to FIG. 1, in a network environment (100), an electronic device (101) may communicate with an electronic device (102) via a first network (198) (e.g., a short-range wireless communication network), or may communicate with at least one of an electronic device (104) or a server (108) via a second network (199) (e.g., a long-range wireless communication network). According to one embodiment, the electronic device (101) may communicate with the electronic device (104) via the server (108). According to one embodiment, the electronic device (101) may include a processor (120), a memory (130), an input module (150), an audio output module (155), a display module (160), an audio module (170), a sensor module (176), an interface (177), a connection terminal (178), a haptic module (179), a camera module (180), a power management module (188), a battery (189), a communication module (190), a subscriber identification module (196), or an antenna module (197). In some embodiments, the electronic device (101) may omit at least one of these components (e.g., the connection terminal (178)), or may have one or more other components added. In some embodiments, some of these components (e.g., the sensor module (176), the camera module (180), or the antenna module (197)) may be integrated into one component (e.g., the display module (160)).

[0047] The processor (120) may, for example, execute software (e.g., a program (140)) to control at least one other component (e.g., a hardware or software component) of the electronic device (101) connected to the processor (120) and perform various data processing or calculations. According to one embodiment, as at least a part of the data processing or calculations, the processor (120) may store commands or data received from other components (e.g., a sensor module (176) or a communication module (190)) in a volatile memory (132), process the commands or data stored in the volatile memory (132), and store result data in a non-volatile memory (134). According to one embodiment, the processor (120) may include a main processor (121) (e.g., a central processing unit or an application processor) or a secondary processor (123) (e.g., a graphics processing unit, a neural processing unit (NPU), an image signal processor, a sensor hub processor, or a communication processor)) that can operate independently or together therewith. For example, if the electronic device (101) includes a main processor (121) and a secondary processor (123), the secondary processor (123) may be configured to use less power than the main processor (121) or to be specialized for a specified function. The secondary processor (123) may be implemented separately from the main processor (121) or as a part thereof.

[0048] The auxiliary processor (123) may control at least a portion of functions or states associated with at least one component (e.g., a display module (160), a sensor module (176), or a communication module (190)) of the electronic device (101), for example, on behalf of the main processor (121) while the main processor (121) is in an inactive (e.g., sleep) state, or together with the main processor (121) while the main processor (121) is in an active (e.g., application execution) state. In one embodiment, the auxiliary processor (123) (e.g., an image signal processor or a communication processor) may be implemented as a part of another functionally related component (e.g., a camera module (180) or a communication module (190)). In one embodiment, the auxiliary processor (123) (e.g., a neural network processing unit) may include a hardware structure specialized for processing artificial intelligence models. The artificial intelligence models may be generated through machine learning. This learning can be performed, for example, on the electronic device (101) itself where the artificial intelligence model is executed, or can be performed through a separate server (e.g., server (108)). The learning algorithm can include, for example, supervised learning, unsupervised learning, semi-supervised learning, or reinforcement learning, but is not limited to the examples described above. The artificial intelligence model can include multiple artificial neural network layers.The artificial neural network may be one of a deep neural network (DNN), a convolutional neural network (CNN), a recurrent neural network (RNN), a restricted Boltzmann machine (RBM), a deep belief network (DBN), a bidirectional recurrent deep neural network (BRDNN), a deep Q-network, or a combination of two or more of the above, but is not limited to the examples described above. In addition to, or alternatively to, a hardware structure, an artificial intelligence model may include a software structure.

[0049] The memory (130) can store various data used by at least one component (e.g., processor (120) or sensor module (176)) of the electronic device (101). The data can include, for example, software (e.g., program (140)) and input data or output data for commands related thereto. The memory (130) can include volatile memory (132) or non-volatile memory (134).

[0050] The program (140) may be stored as software in the memory (130) and may include, for example, an operating system (142), middleware (144), or an application (146).

[0051] The input module (150) can receive commands or data to be used in a component of the electronic device (101) (e.g., a processor (120)) from an external source (e.g., a user) of the electronic device (101). The input module (150) can include, for example, a microphone, a mouse, a keyboard, a key (e.g., a button), or a digital pen (e.g., a stylus pen).

[0052] The audio output module (155) can output audio signals to the outside of the electronic device (101). The audio output module (155) can include, for example, a speaker or a receiver. The speaker can be used for general purposes, such as multimedia playback or recording playback. The receiver can be used to receive incoming calls. In one embodiment, the receiver can be implemented separately from the speaker or as part of the speaker.

[0053] The display module (160) can visually provide information to an external party (e.g., a user) of the electronic device (101). The display module (160) may include, for example, a display, a holographic device, or a projector and a control circuit for controlling the device. In one embodiment, the display module (160) may include a touch sensor configured to detect a touch, or a pressure sensor configured to measure the intensity of a force generated by the touch.

[0054] The audio module (170) can convert sound into an electrical signal, or vice versa, convert an electrical signal into sound. According to one embodiment, the audio module (170) can acquire sound through the input module (150), output sound through the sound output module (155), or an external electronic device (e.g., electronic device (102)) (e.g., speaker or headphone) directly or wirelessly connected to the electronic device (101).

[0055] The sensor module (176) can detect the operating status (e.g., power or temperature) of the electronic device (101) or the external environmental status (e.g., user status) and generate an electrical signal or data value corresponding to the detected status. According to one embodiment, the sensor module (176) can include, for example, a gesture sensor, a gyro sensor, a barometric pressure sensor, a magnetic sensor, an acceleration sensor, a grip sensor, a proximity sensor, a color sensor, an IR (infrared) sensor, a biometric sensor, a temperature sensor, a humidity sensor, or an illuminance sensor.

[0056] The interface (177) may support one or more designated protocols that may be used to directly or wirelessly connect the electronic device (101) with an external electronic device (e.g., the electronic device (102)). In one embodiment, the interface (177) may include, for example, a high definition multimedia interface (HDMI), a universal serial bus (USB) interface, an SD card interface, or an audio interface.

[0057] The connection terminal (178) may include a connector through which the electronic device (101) may be physically connected to an external electronic device (e.g., electronic device (102)). According to one embodiment, the connection terminal (178) may include, for example, an HDMI connector, a USB connector, an SD card connector, or an audio connector (e.g., a headphone connector).

[0058] A haptic module (179) can convert electrical signals into mechanical stimuli (e.g., vibration or movement) or electrical stimuli that a user can perceive through tactile or kinesthetic sensations. In one embodiment, the haptic module (179) can include, for example, a motor, a piezoelectric element, or an electrical stimulation device.

[0059] The camera module (180) can capture still images and videos. According to one embodiment, the camera module (180) may include one or more lenses, image sensors, image signal processors, or flashes.

[0060] The power management module (188) can manage power supplied to the electronic device (101). According to one embodiment, the power management module (188) can be implemented, for example, as at least a part of a power management integrated circuit (PMIC).

[0061] A battery (189) may power at least one component of the electronic device (101). In one embodiment, the battery (189) may include, for example, a non-rechargeable primary battery, a rechargeable secondary battery, or a fuel cell.

[0062] The communication module (190) may support the establishment of a direct (e.g., wired) communication channel or a wireless communication channel between the electronic device (101) and an external electronic device (e.g., electronic device (102), electronic device (104), or server (108)), and the performance of communication through the established communication channel. The communication module (190) may operate independently from the processor (120) (e.g., application processor) and may include one or more communication processors that support direct (e.g., wired) communication or wireless communication. According to one embodiment, the communication module (190) may include a wireless communication module (192) (e.g., a cellular communication module, a short-range wireless communication module, or a global navigation satellite system (GNSS) communication module) or a wired communication module (194) (e.g., a local area network (LAN) communication module, or a power line communication module). Among these communication modules, the corresponding communication module can communicate with an external electronic device (104) via a first network (198) (e.g., a short-range communication network such as Bluetooth, wireless fidelity (WiFi) direct, or infrared data association (IrDA)) or a second network (199) (e.g., a long-range communication network such as a legacy cellular network, a 5G network, a next-generation communication network, the Internet, or a computer network (e.g., a LAN or WAN)). These various types of communication modules can be integrated into a single component (e.g., a single chip) or implemented as multiple separate components (e.g., multiple chips). The wireless communication module (192) can verify or authenticate the electronic device (101) within a communication network such as the first network (198) or the second network (199) by using subscriber information (e.g., an international mobile subscriber identity (IMSI)) stored in the subscriber identification module (196).

[0063] The wireless communication module (192) can support 5G networks and next-generation communication technologies following the 4G network, such as NR access technology (new radio access technology). The NR access technology can support high-speed transmission of high-capacity data (eMBB (enhanced mobile broadband)), minimization of terminal power and connection of multiple terminals (mMTC (massive machine type communications)), or high reliability and low latency (URLLC (ultra-reliable and low-latency communications)). The wireless communication module (192) can support, for example, a high-frequency band (e.g., mmWave band) to achieve a high data transmission rate. The wireless communication module (192) can support various technologies for securing performance in a high-frequency band, such as beamforming, massive multiple-input and multiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, analog beam-forming, or large scale antenna. The wireless communication module (192) can support various requirements specified in the electronic device (101), an external electronic device (e.g., the electronic device (104)), or a network system (e.g., the second network (199)). According to one embodiment, the wireless communication module (192) can support a peak data rate (e.g., 20 Gbps or more) for eMBB realization, a loss coverage (e.g., 164 dB or less) for mMTC realization, or a U-plane latency (e.g., 0.5 ms or less for downlink (DL) and uplink (UL), or 1 ms or less for round trip) for URLLC realization.

[0064] The antenna module (197) can transmit or receive signals or power to or from an external device (e.g., an external electronic device). In one embodiment, the antenna module (197) may include an antenna including a radiator formed of a conductor or a conductive pattern formed on a substrate (e.g., a PCB). In one embodiment, the antenna module (197) may include a plurality of antennas (e.g., an array antenna). In this case, at least one antenna suitable for a communication method used in a communication network, such as the first network (198) or the second network (199), may be selected from the plurality of antennas by, for example, the communication module (190). A signal or power may be transmitted or received between the communication module (190) and an external electronic device through the selected at least one antenna. In some embodiments, in addition to the radiator, another component (e.g., a radio frequency integrated circuit (RFIC)) may be additionally formed as a part of the antenna module (197).

[0065] According to various embodiments, the antenna module (197) may form a mmWave antenna module. According to one embodiment, the mmWave antenna module may include a printed circuit board, an RFIC disposed on or adjacent a first side (e.g., a bottom side) of the printed circuit board and capable of supporting a designated high-frequency band (e.g., a mmWave band), and a plurality of antennas (e.g., an array antenna) disposed on or adjacent a second side (e.g., a top side or a side side) of the printed circuit board and capable of transmitting or receiving signals in the designated high-frequency band.

[0066] At least some of the above components can be interconnected and exchange signals (e.g., commands or data) with each other via a communication method between peripheral devices (e.g., a bus, GPIO (general purpose input and output), SPI (serial peripheral interface), or MIPI (mobile industry processor interface)).

[0067] According to one embodiment, commands or data may be transmitted or received between the electronic device (101) and an external electronic device (104) via a server (108) connected to a second network (199). Each of the external electronic devices (102 or 104) may be the same or a different type of device as the electronic device (101). According to one embodiment, all or part of the operations executed in the electronic device (101) may be executed in one or more of the external electronic devices (102, 104, or 108). For example, when the electronic device (101) is to perform a certain function or service automatically or in response to a request from a user or another device, the electronic device (101) may, instead of or in addition to executing the function or service itself, request one or more external electronic devices to perform the function or at least a part of the service. One or more external electronic devices that receive the request may execute at least a portion of the requested function or service, or an additional function or service related to the request, and transmit the result of the execution to the electronic device (101). The electronic device (101) may process the result as is or additionally and provide it as at least a portion of a response to the request. For this purpose, cloud computing, distributed computing, mobile edge computing (MEC), or client-server computing technology may be used, for example. The electronic device (101) may provide an ultra-low latency service by using distributed computing or mobile edge computing, for example. In another embodiment, the external electronic device (104) may include an Internet of Things (IoT) device. The server (108) may be an intelligent server utilizing machine learning and / or a neural network. According to one embodiment, the external electronic device (104) or the server (108) may be included in the second network (199).The electronic device (101) can be applied to intelligent services (e.g., smart home, smart city, smart car, or healthcare) based on 5G communication technology and IoT-related technology.

[0068] FIG. 2 illustrates a block configuration (200) of a display module (160) according to one embodiment.

[0069] Referring to FIG. 2, the display module (160) may include a display panel (210) and a display driver IC (DDI) (230) for controlling the same. The DDI (230) may include an interface module (231), a memory (233) (e.g., a buffer memory), an image processing module (235), or a mapping module (237). The DDI (230) may receive, for example, image data or image control signals corresponding to commands for controlling the image data, from other components of the electronic device (101) through the interface module (231). For example, according to one embodiment, image information may be received from a processor (120) (e.g., a main processor (121) (e.g., an application processor) or an auxiliary processor (123) (e.g., a graphics processing unit) that operates independently of the function of the main processor (121). The DDI (230) may communicate with a touch circuit (250) or a sensor module (176) through the interface module (231). In addition, the DDI (230) may store at least a part of the received image information in the memory (233), for example, in units of frames. The image processing module (235) may, for example, perform preprocessing or postprocessing (e.g., resolution, brightness, or size adjustment) on at least a part of the image data based on at least a characteristic of the image data or a characteristic of the display panel (210). The mapping module (237) may generate a voltage value or a current value corresponding to the image data that has been preprocessed or postprocessed through the image processing module (135). According to one embodiment, the voltage value or the current value Generation may be performed, for example, at least in part based on the properties of the pixels of the display panel (210), such as the arrangement of the pixels (RGB stripe or pentile structure), or the size of each sub-pixel.At least some pixels of the display panel (210) may be driven based at least in part on, for example, the voltage value or current value, so that visual information (e.g., text, an image, or an icon) corresponding to the image data may be displayed through the display panel (210).

[0070] According to one embodiment, the display module (160) may further include a touch circuit (250). The touch circuit (250) may include a touch sensor (251) and a touch sensor IC (253) for controlling the same. The touch sensor IC (253) may control the touch sensor (251) to detect, for example, a touch input or a hovering input for a specific location of the display panel (210). For example, the touch sensor IC (253) may detect a touch input or a hovering input by measuring a change in a signal (e.g., voltage, light quantity, resistance, or charge quantity) for a specific location of the display panel (210). The touch sensor IC (253) may provide information (e.g., location, area, pressure, or time) regarding the detected touch input or hovering input to the processor (120). According to one embodiment, at least a portion of the touch circuit (250) (e.g., touch sensor IC (253)) may be included as part of the display driver IC (230), or as part of the display panel (210), or as part of another component (e.g., auxiliary processor (123)) disposed externally to the display module (160).

[0071] According to one embodiment, the display module (160) may further include at least one sensor (e.g., a fingerprint sensor, an iris sensor, a pressure sensor, or an illuminance sensor) of the sensor module (176), or a control circuit therefor. In this case, the at least one sensor or the control circuit therefor may be embedded in a part of the display module (160) (e.g., the display panel (210) or the DDI (230)) or a part of the touch circuit (250). For example, when the sensor module (176) embedded in the display module (160) includes a biometric sensor (e.g., a fingerprint sensor), the biometric sensor may obtain biometric information (e.g., a fingerprint image) associated with a touch input through a part of the display panel (210). As another example, when the sensor module (176) embedded in the display module (160) includes a pressure sensor, the pressure sensor may obtain pressure information associated with a touch input through a part or the entire part of the display panel (210). According to one embodiment, the touch sensor (251) or sensor module (176) may be positioned between pixels of a pixel layer of the display panel (210), or above or below the pixel layer.

[0072] The display (201) according to various embodiments may be included in electronic devices such as bar type, foldable type, rollable type, sliding type, wearable type, tablet PC, and / or notebook PC. The display (201) according to various embodiments of the present invention may be included in various electronic devices as well as the examples described above.

[0073] FIG. 3 illustrates a laminated structure of a display panel (300) according to one embodiment.

[0074] Referring to FIG. 3, the display panel (300) (e.g., the display panel (210) of FIG. 2) may include a plurality of pixels (PXL), which are one unit for displaying an image. For convenience, only one pixel (PXL) is illustrated in FIG. 3 as an example. The pixel (PXL) may include a plurality of sub-pixels (SP1, SP2, SP3) that emit different colors. For example, each of the plurality of pixels (PXL) may include a first sub-pixel (SP1) that emits red, a second sub-pixel (SP2) that emits green, and a third sub-pixel (SP3) that emits blue. As another example, each of the plurality of pixels (PXL) may include first to third sub-pixels (SP1, SP2, SP3) and a fourth sub-pixel that emits white. The display panel (300) may display an image by controlling the amount of light emitted from each of the sub-pixels (SP1, SP2, SP3).

[0075] The display panel (300) may include a lower substrate (320) and an upper substrate (310) facing the lower substrate (320). Although the lower substrate (320) and the upper substrate (310) illustrated in FIG. 3 are depicted as being spaced apart from each other, the lower substrate (320) and the upper substrate (310) may be bonded together using an adhesive. For example, the lower substrate (320) and the upper substrate (310) may be bonded together using an optical bonding material that transmits light.

[0076] The lower substrate (320) may be a substrate that generates and emits light necessary for displaying an image. The lower substrate (320) may include a rear substrate (321), a light emitting element (322), and a pixel circuit that drives the light emitting element (322).

[0077] The rear substrate (321) may be a plastic substrate or a glass substrate. The rear substrate (321) may have flexible characteristics. A light-emitting element (322) and a pixel circuit may be arranged on the rear substrate (321). The light-emitting element (322) may be arranged to overlap with color filters (315) arranged on the front substrate (311), and at least a portion of the pixel circuit may be arranged to overlap with a black matrix (312) arranged on the front substrate (311).

[0078] The light-emitting element (322) may include at least one of an organic light-emitting diode, a quantum dot light-emitting diode, an inorganic-based micro light-emitting diode (Micro LED), and an inorganic-based nano light-emitting diode (nano LED). For example, the light-emitting element (322) may be a micro light-emitting diode.

[0079] The pixel circuit may be composed of a plurality of transistors. For example, the pixel circuit may be composed of a CMOS circuit composed of a combination of at least one N-type transistor and at least one P-type transistor.

[0080] The upper substrate (310) may include a front substrate (311), a black matrix (312), a color filter layer (313), a partition wall (314), a color conversion layer (315), and a transparent layer (316).

[0081] The front substrate (311) may be formed of a material having light-transmitting properties. The front substrate (311) may be formed of a plastic substrate or a glass substrate. The front substrate (311) may have flexible characteristics. A black matrix (312), a color filter layer (313), a partition wall (314), a color conversion layer (315), and a transparent layer (316) may be laminated on one surface of the front substrate (311) (e.g., a surface facing in the D2 direction). As light passing through the color filter layer (313) is emitted to the outside through the other surface of the front substrate (311) (e.g., a surface facing in the D1 direction), an image may be provided to a viewer looking at the display. In one embodiment, the display panel (300) may further include a low-reflection layer formed on the other surface of the front substrate (311) (e.g., a surface facing in the D1 direction).

[0082] The color filter layer (313) may include a first color filter (CF1), a second color filter (CF2), and a third color filter (CF3). The first color filter (CF1) may implement the same color as the light emitted from the first color conversion unit (CC1). For example, the first color filter (CF1) may be a red color filter. The first color filter (CF1) may transmit red light and absorb other color light other than the red light. The first color filter (CF1) may increase the color purity of the red light incident through the first color conversion unit (CC1). The second color filter (CF2) may implement the same color as the light emitted from the second color conversion unit (CC2). For example, the second color filter (CF2) may be a green color filter. The second color filter (CF2) may transmit green light and absorb other color light other than the green light. The second color filter (CF2) can increase the color purity of green light incident through the second color conversion unit (CC2). The third color filter (CF3) can implement the same color as the light emitted from the light emitting element (322). For example, the third color filter (CF3) can be a blue color filter. The third color filter (CF3) can transmit blue light and absorb other color lights other than blue light. The third color filter (CF3) can increase the color purity of blue light incident through the transparent layer (316).

[0083] The black matrix (312) may be placed between the first color filter (CF1), the second color filter (CF2), and the third color filter (CF3). Since the black matrix (312) divides the area of ​​each sub-pixel (SP1, SP2, SP3), it may overlap with the partition wall (314). The black matrix (312) may be formed of a material such as metal, synthetic resin, synthetic rubber, or a carbon-based organic material. For example, the black matrix (312) may be composed of chromium (Cr), a chromium oxide film (CrOx), carbon black, or a double film including these.

[0084] The color conversion layer (315) may include a first color conversion unit (CC1) and a second color conversion unit (CC2). The color conversion units (e.g., CC1, CC2) may include at least one color conversion particle. For example, the color conversion unit may convert the wavelength of light (e.g., blue light) by including at least one color conversion particle that is regularly arranged.

[0085] The first color conversion unit (CC1) may be formed to overlap with the first color filter (CF1). The first color conversion unit (CC1) may be positioned between the light emitting element (322) and the first color filter (CF1). The first color conversion unit (CC1) may convert light emitted from the light emitting element (322) into first color light using first color conversion particles. For example, the first color conversion unit (CC1) may convert blue light emitted from the light emitting element (322) into red light.

[0086] The second color conversion unit (CC2) may be formed to overlap with the second color filter (CF2). The second color conversion unit (CC2) may be positioned between the light emitting element (322) and the second color filter (CF2). The second color conversion unit (CC2) may convert light emitted from the light emitting element (322) into second color light using second color conversion particles. For example, the second color conversion unit (CC2) may convert blue light emitted from the light emitting element (322) into green light.

[0087] The transparent layer (316) may be formed to overlap with the third color filter (CF3). The transparent layer (316) may be positioned between the light-emitting element (322) and the third color filter (CF3). The transparent layer (316) may transmit light (e.g., blue light) emitted from the light-emitting element (322) without color conversion. The transparent layer (316) may be hollow so that incident light passes through as is, or may be made of a transparent resin such as ABS (Acryl-nitrile butadiene styrene), PMMA (Poly methyl methacrylate), or PC (Poly carbonate).

[0088] The partition wall (314) can block the movement of light between sub-pixels (SP1, SP2, SP3) that implement different colors. The partition wall (314) can be formed of a black color that absorbs light. The partition wall (314) can be formed of a material such as a metal, a synthetic resin, a synthetic rubber, or an organic material of the carbon family. For example, the partition wall (314) can be composed of chromium (Cr), a chromium oxide film (CrOx), carbon black, or a double film including these.

[0089] According to one embodiment, one surface of the partition wall (314) (e.g., the surface facing the second direction (D2)) and the side surface of the partition wall (314) (e.g., the surface in contact with the color conversion layer (315)) and one surface of the color filter layer (313) (e.g., the surface in contact with the color conversion member (330)) may be surface-treated. The side surface of the partition wall (314) and the one surface of the color filter layer (313) may be hydrophilic-treated to form an attractive force with ink, which is the material of each of the color conversion layer (315) and the transparent layer. One surface of the partition wall (314) may be hydrophobic-treated to form a repulsive force with ink. Since the color conversion layer (315) and the transparent layer (316) are not formed on one side of the partition wall (314), defects caused by the color conversion layer (315) and the transparent layer (316) during the bonding process of the lower substrate (320) and the upper substrate (310) can be prevented by the color conversion layer (315) and the transparent layer (316). A hole or space in which the color conversion layer (315) and the transparent layer (316) are formed can be provided between at least two partition walls (314). The hole or the space can correspond to the size and shape of the color conversion layer (315) and the transparent layer (316). For example, the color conversion layer (315) and the transparent layer (316) can be formed between at least two partition walls (314) by filling the hole or the space with color conversion ink. The hole or the space can include a rod shape and can be continuously provided at regular intervals. For example, the quantum rods inside the color conversion layer (315) described later may be arranged such that their long axes are parallel to the rod shape of the hole or space.

[0090] In one embodiment, the upper substrate (310) can be completed by sequentially forming a black matrix (312), a color filter layer (313), and a partition wall (314), and then forming a color conversion layer (315) and a transparent layer (316) through electrohydrodynamic (EHD) printing. Electrohydrodynamic (EHD) printing can form continuous ink lines by using a constant air pressure and electric field applied to a nozzle instead of the intermittent ink ejection of an inkjet process. Electrohydrodynamic printing can form a color conversion layer with excellent precision by forming a pattern printed with a color conversion ink with a constant width and height. In addition, since electrohydrodynamic printing can use high-viscosity ink, it is possible to increase the quantum dot content or add functional materials that can improve color conversion characteristics, thereby achieving a high color conversion ratio.

[0091] FIG. 4 illustrates a method of forming a color conversion layer (315) and a transparent layer (316) according to one embodiment.

[0092] Referring to FIG. 4, a color conversion layer (e.g., color conversion layer (315) of FIG. 3) and a transparent layer (e.g., transparent layer (316) of FIG. 3) can be formed using electrohydrodynamic (EHD) printing. For example, the color conversion layer and the transparent layer can be manufactured through an operation of manufacturing a color conversion ink including at least one color conversion particle, an operation of spraying the color conversion ink using electrohydrodynamic printing (EHD printing), and an operation of aligning the at least one color conversion particle in a uniform direction based on a first force and a second force according to the electrohydrodynamic printing.

[0093] Specifically, the upper substrate (310) on which the front substrate (311), the black matrix (e.g., the black matrix (312) of FIG. 3), the color filter layer (e.g., the color filter layer (313) of FIG. 3), and the partition wall (314) are formed can be mounted on the stage (411). The nozzle (412) can be aligned to coincide with the virtual center line of each sub-pixel (SP1, SP2, SP3). The nozzle (412) can move vertically to the ground along the virtual center line. Simultaneously with the application of a constant pressure to the aligned nozzle (412), an electric field can be formed between the nozzle (412) and the stage (411). For example, a negative voltage (e.g., a ground voltage) can be applied to the stage (411), and a positive voltage (e.g., a voltage higher than the ground voltage) can be applied to the nozzle (412). The air pressure and electric field are controlled to have constant values, thereby maintaining the flow rate of the color conversion ink (402) uniform. The color conversion ink (402) may be an ink used as a material for a color conversion member (e.g., the color conversion layer (315) and the transparent layer (316) of FIG. 3). The color conversion ink (402) may include color conversion particles (e.g., quantum rods (QR)).

[0094] In one embodiment, the color conversion ink (402) ejected from the nozzle (412) may gather together to form a Taylor cone whose liquid surface is in the shape of an inverted triangle. The color conversion ink (402) gathered in the shape of a Taylor cone may be ejected in the form of a continuous ink stream. As the color conversion ink (402) is ejected from the nozzle (412) in a predetermined ejection direction (e.g., ink ejection direction), a color conversion layer (315) and a transparent layer (316) may be sequentially formed on the upper substrate (310). For example, when the nozzle (412) ejects the color conversion ink (402) in a direction perpendicular to the ground, the upper substrate (310) may move along an imaginary center line on the stage (411). In this case, as the color conversion ink (402) is applied onto the upper substrate (310) according to the movement of the upper substrate (310), a color conversion layer (315) and a transparent layer (316) can be formed on the upper substrate (310). For example, the nozzle (412) can move (or scan) in a direction parallel to the ground along an imaginary center line. In this case, as the color conversion ink (402) is applied onto the upper substrate (310) according to the movement of the nozzle (412), a color conversion layer (315) and a transparent layer (316) can be formed on the upper substrate (310). For example, the color conversion parts (CC1, CC2) and the transparent layer (316) can be formed in a rod shape. The rod-shaped color conversion parts (CC1, CC2) and the transparent layer (316) can be continuously formed at regular intervals on the upper substrate (310). For example, the color conversion unit (CC1, CC2) and the transparent layer (316) can be continuously formed at regular intervals on the upper substrate (310) by spraying color conversion ink containing at least one color conversion particle onto the upper substrate (310) using electrohydrodynamic printing (EHD printing).For example, the first color conversion unit (CC1) may be arranged continuously with respect to an adjacent first color conversion unit (CC1) of the same type at a first interval. For example, the second color conversion unit (CC1) may be arranged continuously with respect to an adjacent first color conversion unit (CC2) of a different type at a second interval.

[0095] In one embodiment, when the color conversion layer (315) and the transparent layer (316) are formed, an electric field may be formed between the two ends of the upper substrate (310). For example, a negative voltage (e.g., a ground voltage) may be applied to one end of the upper substrate (310), and a positive voltage (e.g., a voltage higher than the ground voltage) may be applied to the other end of the upper substrate (310). As an electric field is formed between the two ends of the upper substrate (310), the arrangement of the color conversion particles (e.g., quantum rods (QR)) may be maintained constant during the formation of the color conversion layer (315) and the transparent layer (316).

[0096] FIG. 5 illustrates the structure of a color conversion particle according to one embodiment.

[0097] Referring to FIGS. 4 and 5, the color conversion layer (315) may include luminescent color conversion particles that convert the wavelength of light provided from the lower substrate (320). For example, the color conversion layer (315) may include at least one color conversion particle arranged parallel to each other by the action of at least one of a first force based on shear stress and a second force based on an electric field (E-field). The color conversion particle may exhibit quantum confinement or exciton confinement.

[0098] In one embodiment, the color conversion particle may comprise a cylindrical quantum rod (QR). For example, the quantum rod (QR) may have a cylindrical shape with a long axis (L) of a predetermined length and a diameter (D) of a predetermined length. For example, the quantum rod (QR) may have a cylindrical long axis (L) of a cylindrical shape of 20 nm to 200 nm in length. For example, the quantum rod (QR) may have a cylindrical diameter (D) of a cylindrical shape of 3 nm to 7 nm in length.

[0099] In one embodiment, a cylindrical quantum rod (QR) may have a dipole moment (μ). For example, the quantum rod (QR) may include cadmium selenide (CdSe). The quantum rod (QR) may have a dipole moment (μ) of a predetermined size based on the structural properties of cadmium selenide (CdSe). For example, the quantum rod (QR) may have a dipole moment (μ) of 10 Debye to 1000 Debye.

[0100] For example, the quantum rod (QR) of the present disclosure has a cylindrical shape with a long axis (L) of 20 nm to 200 nm and a diameter (D) of 3 nm to 7 nm, and has a dipole moment (μ) of 10 Debye to 1000 Debye, thereby maximizing the light emission efficiency of the color conversion layer (315).

[0101] FIG. 6 illustrates a force acting during the process of forming a color conversion layer (315) and a transparent layer (316) according to one embodiment, and FIG. 7 illustrates a color conversion layer (315) and a transparent layer (316) formed on an upper substrate (310) according to one embodiment.

[0102] Referring to FIGS. 6 and 7, when the color conversion layer (315) is formed, the color conversion ink may be sprayed onto the upper substrate (310) based on electrohydrodynamic printing (EHD printing). As the color conversion layer (315) is formed by EHD printing, the quantum rods (QR) may be aligned in a uniform direction within the color conversion layer (315). For example, when the color conversion layer (315) is formed, the color conversion ink may be subjected to a first force based on shear stress and a second force based on an electric field (E-field).

[0103] As shown in Fig. 6, the color conversion ink may be subjected to the first force based on the shear stress inside a Taylor cone formed as the color conversion ink is ejected from a nozzle. For example, the first force may be applied to a quantum rod (QR) included in the color conversion ink in the ejection direction of the color conversion ink based on the shear stress inside the Taylor cone. The quantum rod (QR) may be aligned parallel to the ejection direction (e.g., ink ejection direction) of the color conversion ink within the color conversion layer (315) according to the action of the first force based on the shear stress.

[0104] As shown in Fig. 6, the dipole moment inside the quantum rod (QR) can be acted upon by the second force based on the electric field. For example, depending on the electric field, the second force can act on the quantum rod (QR) to direct one end in the same direction as the jetting direction of the color conversion ink and to direct the other end in the opposite direction to the jetting direction of the color conversion ink. Depending on the second force acting on the dipole moment by the electric field, the quantum rod (QR) can be aligned parallel to the ejection direction (e.g., ink ejection direction) of the color conversion ink inside the color conversion layer (315).

[0105] As shown in Fig. 7, the quantum rods (QR) can be regularly arranged in a uniform direction within the color conversion layer (315). For example, the quantum rods (QR) can be aligned with the long axes of the cylinders in one direction (e.g., the D4 direction) within the color conversion layer (315). For example, the quantum rods (QR) can be arranged parallel to each other within the color conversion layer (315). The quantum rods (QR) can emit light in a direction perpendicular to the long axes of the cylinders. For example, the quantum rods (QR) within the color conversion layer (315) can emit light that is linearly polarized in a direction parallel to the long axes of the cylinders in a direction perpendicular to the long axes.

[0106] In this way, the display panel of the present disclosure can include color conversion particles regularly arranged within the color conversion layer (315) by forming the color conversion layer (315) using electrohydraulic printing. Accordingly, the display panel of the present disclosure can increase the light emission efficiency of the color conversion layer (315) and improve display quality.

[0107] FIG. 8 illustrates a laminated structure of a display panel according to another embodiment, and FIG. 9 illustrates changes in light emitted from a display panel according to one embodiment.

[0108] Referring to FIG. 8, the display panel (300) may include a lower substrate (320), an upper substrate (310) facing the lower substrate (320), and a low-reflection layer (330) facing the upper substrate (310). Although the lower substrate (320) and the upper substrate (310) illustrated in FIG. 8 are depicted as being spaced apart from each other, the lower substrate (320) and the upper substrate (310) may be bonded together using an adhesive. Similarly, although the low-reflection layer (330) and the upper substrate (310) illustrated in FIG. 8 are depicted as being spaced apart from each other, the low-reflection layer (330) and the upper substrate (310) may be bonded together using an adhesive.

[0109] The lower substrate (320) may be a substrate that generates and emits light necessary for displaying an image. The lower substrate (320) may include a rear substrate (321), a light emitting element (322), and a pixel circuit that drives the light emitting element (322).

[0110] The upper substrate (310) may be formed on one side (e.g., the side facing the D1 direction) of the lower substrate (320). The upper substrate (310) may include a front substrate (311), a black matrix (312), a color filter layer (313), a partition wall (314), a color conversion layer (315), and a transparent layer (316). The upper substrate (310) may convert the wavelength of light incident from the lower substrate (320) and output it upward.

[0111] The low-reflection layer (330) may be formed on one surface of the upper substrate (310) (e.g., the surface facing the D1 direction). The low-reflection layer (330) may include a linear polarizer (331) and a quarterwave plate (332). The low-reflection layer (330) may improve the visibility of the display panel by minimizing external light reflection. The linear polarizer (331) may transmit only a specific polarization direction of input light and may block polarization in a direction perpendicular to the specific polarization direction. For example, when light polarized in a vertical direction is incident on the linear polarizer (331) that transmits light polarized in a horizontal direction, the light polarized in the vertical direction may be blocked. The quarterwave plate (332) may adjust the phase of the light to differ by 1 / 4 wavelength for two orthogonal polarization directions. The quarter-wave plate (332) can change linearly polarized light into circularly or elliptically polarized light. For example, when the quarter-wave plate (332) is placed behind the linear polarizing plate (331), polarized light coming from the linear polarizing plate (331) can be converted into circularly polarized light.

[0112] In one embodiment, the quantum rods inside the color conversion layer (315) can minimize light reflected from the low-reflection layer (330) by being regularly arranged inside the color conversion layer (315). For example, the linear polarizing plate (331) can transmit light polarized in a first direction and block light polarized in a second direction perpendicular to the first direction. In this case, as shown in (a) of FIG. 9, light emitted from the upper substrate (310) (e.g., light emitted from quantum dots (QDs)) may be reflected from the linear polarizing plate (331) of the low-reflection layer (330), thereby reducing light output efficiency. The quantum rods of the present disclosure can be aligned in a direction parallel to the first direction inside the color conversion layer (315). For example, the quantum rods can be aligned in a direction parallel to the first direction and output light polarized in the first direction. Accordingly, as shown in (b) of Fig. 9, light emitted from the quantum rod of the upper substrate (310) is not reflected by the linear polarizing plate (331) of the low-reflection layer (330) and can be output to the outside. Therefore, the color conversion layer (315) including the quantum rod can prevent a decrease in the amount of light emitted by the linear polarizing plate (331) of the low-reflection layer (330).

[0113] FIG. 10 illustrates a light-emitting area for each color conversion particle according to one embodiment, and FIG. 11 illustrates light-emitting efficiency according to a critical angle for each color conversion particle according to one embodiment.

[0114] Referring to FIGS. 10 and 11, a cylindrical quantum rod (QR) included in the color conversion layer (315) of the present disclosure may include a wider light-emitting area than a spherical quantum dot (QD) based on the same volume. For example, as shown in (a) of FIG. 10, a spherical quantum dot (QD) may include a predetermined light-emitting area depending on the surface area ratio of the spherical shape. For example, as shown in (b) of FIG. 10, a cylindrical quantum rod (QR) may include a predetermined light-emitting area depending on the surface area ratio. Comparing FIGS. 10 (a) and (b), since a cylindrical shape has a wider surface area for emitting light than a spherical shape based on the same volume, a quantum rod (QR) may include a wider light-emitting area than a quantum dot (QD).

[0115] For example, as shown in Fig. 11, since the light-emitting area of ​​a quantum rod (QR) is wider than that of a quantum dot (QD), the outcoupling efficiency of a quantum rod (QR) can be 1.5 to 3 times higher than that of a quantum dot (QD) in the critical angle range of 20° to 60°. In particular, referring to Fig. 11, at a critical angle of 42° between air and glass, it can be confirmed that the outcoupling efficiency of a quantum rod (QR) is more than twice higher than that of a quantum dot (QD).

[0116] In this way, the display panel of the present disclosure can maximize the light-emitting area and increase the light-emitting efficiency of the color conversion layer (315) by including cylindrical quantum rods (QRs) as color conversion particles.

[0117] FIG. 12 illustrates a laminated structure of a display panel according to another embodiment, and FIGS. 13a and 13b illustrate a method of forming a color conversion layer and a transparent layer according to another embodiment.

[0118] Referring to FIG. 12, the display panel (300) may include a lower substrate (320) and an upper substrate (310) facing the lower substrate (320). Although the lower substrate (320) and the upper substrate (310) illustrated in FIG. 12 are depicted as being spaced apart from each other, the lower substrate (320) and the upper substrate (310) may be bonded together using an adhesive.

[0119] The lower substrate (320) may be a substrate that generates and emits light necessary for displaying an image. The lower substrate (320) may include a rear substrate (321), a light emitting element (322), and a pixel circuit that drives the light emitting element (322).

[0120] The upper substrate (310) may be formed on one side (e.g., the side facing the D1 direction) of the lower substrate (320). The upper substrate (310) may include a front substrate (311), a black matrix (312), a color filter layer (313), a partition wall (314), a color conversion layer (315), and a transparent layer (316). The upper substrate (310) may convert the wavelength of light incident from the lower substrate (320) and output it upward.

[0121] The color conversion layer (315) may include a first color conversion unit (CC1) and a second color conversion unit (CC2). The color conversion units (e.g., CC1, CC2) may include at least one color conversion particle. For example, the color conversion unit may convert the wavelength of light (e.g., blue light) by including at least one color conversion particle that is regularly arranged.

[0122] The first color conversion unit (CC1) may be formed to overlap with the first color filter (CF1). The first color conversion unit (CC1) may be positioned between the light emitting element (322) and the first color filter (CF1). The first color conversion unit (CC1) may convert light emitted from the light emitting element (322) into first color light using first color conversion particles. For example, the first color conversion unit (CC1) may convert blue light emitted from the light emitting element (322) into red light.

[0123] The second color conversion unit (CC2) may be formed to overlap with the second color filter (CF2). The second color conversion unit (CC2) may be positioned between the light emitting element (322) and the second color filter (CF2). The second color conversion unit (CC2) may convert light emitted from the light emitting element (322) into second color light using second color conversion particles. For example, the second color conversion unit (CC2) may convert blue light emitted from the light emitting element (322) into green light.

[0124] The transparent layer (316) may be formed to overlap with the third color filter (CF3). The transparent layer (316) may be positioned between the light-emitting element (322) and the third color filter (CF3). The transparent layer (316) may transmit light (e.g., blue light) emitted from the light-emitting element (322) without color conversion. The transparent layer (316) may be hollow so that incident light passes through as is, or may be made of a transparent resin such as ABS (Acryl-nitrile butadiene styrene), PMMA (Poly methyl methacrylate), or PC (Poly carbonate).

[0125] In one embodiment, at least one of the first color conversion unit (CC1), the second color conversion unit (CC2), and the transparent layer (316) may include a color conversion particle layer (CL) including color conversion particles and a scattering layer (SL) including a scattering material. For example, the color conversion particle layer (CL) may include quantum rods (QR) as the color conversion particles. For example, the scattering layer (SL) may include TiO2 as the scattering material. The color conversion particle layer (CL) and the scattering layer (SL) may be formed through independent processes, thereby forming separate layers. For example, the scattering layer (SL) may be formed under the color conversion particle layer (CL). For example, the process of forming the scattering layer (SL) may be performed after the process of forming the color conversion particle layer (CL).

[0126] Referring to FIGS. 13a and 13b, a color conversion layer (e.g., color conversion layer (315) of FIG. 12) and a transparent layer (e.g., transparent layer (316) of FIG. 12) can be formed using electrohydrodynamic (EHD) printing. For example, the color conversion layer and the transparent layer can be manufactured through an operation of manufacturing a color conversion ink including at least one color conversion particle, an operation of spraying the color conversion ink using electrohydrodynamic printing (EHD printing), and an operation of aligning the at least one color conversion particle in a uniform direction based on a first force and a second force according to the EHD printing.

[0127] Specifically, the upper substrate (310) on which the front substrate (311), the black matrix (e.g., the black matrix (312) of FIG. 12), the color filter layer (e.g., the color filter layer (313) of FIG. 12), and the partition wall (314) are formed can be mounted on the stage (411). The nozzle (412) can be aligned to coincide with the virtual center line of each sub-pixel (SP1, SP2, SP3). The nozzle (412) can move vertically to the ground along the virtual center line. Simultaneously with the application of a constant pressure to the aligned nozzle (412), an electric field can be formed between the nozzle (412) and the stage (411). For example, a negative voltage (e.g., a ground voltage) can be applied to the stage (411), and a positive voltage (e.g., a voltage higher than the ground voltage) can be applied to the nozzle (412). The air pressure and electric field are controlled to have constant values, thereby maintaining the flow rate of the color conversion ink (402) uniform. The color conversion ink (402) may be an ink used as a material for a color conversion member (e.g., the color conversion layer (315) and the transparent layer (316) of FIG. 12). For example, the color conversion ink (402) may include quantum rod ink (402a) and scattering material ink (402b).

[0128] As shown in Fig. 13a, the quantum rod ink (402a) ejected from the nozzle (412) can gather together to form a Taylor cone whose liquid surface is in the shape of an inverted triangle. The quantum rod ink (402a) gathered in the shape of a Taylor cone can be ejected in the form of a continuous ink line (ink stream). As the quantum rod ink (402a) is ejected from the nozzle (412) in a predetermined ejection direction (e.g., ink ejection direction), a color conversion particle layer (CL) can be sequentially formed on the upper substrate (310). For example, the color conversion particle layer (CL) can be continuously formed at regular intervals on the upper substrate (310) by ejecting the quantum rod ink (402a) including the quantum rod (QR) onto the upper substrate (310) using electrohydrodynamic printing (EHD printing).

[0129] As shown in Fig. 13b, the scattering material ink (402b) ejected from the nozzle (412) can gather together to form a Taylor cone whose liquid surface is in the shape of an inverted triangle. The scattering material ink (402b) gathered in the shape of a Taylor cone can be ejected in the form of a continuous ink stream. As the scattering material ink (402b) is ejected from the nozzle (412) in a predetermined ejection direction (e.g., ink ejection direction), a scattering layer (SL) can be sequentially formed on the color conversion particle layer (CL) formed in the process of Fig. 13a. For example, the scattering layer (SL) can be continuously formed at regular intervals on the upper substrate (310) by ejecting the scattering material ink (402b) including the scattering material (SM) onto the color conversion particle layer (CL) using electrohydrodynamic printing (EHD printing).

[0130] In this way, the color conversion layer (315) of the display panel of the present disclosure may be arranged such that the scattering layer (SL) is disposed under the color conversion particle layer (CL) in a separate process from the color conversion particle layer (CL). According to the structure of the color conversion layer (315), the scattering layer (SL) scatters light (e.g., blue light) emitted from the light emitting element (322), thereby increasing the light absorbed by the quantum rod (QR) of the color conversion particle layer (CL), while simultaneously preventing scattering of the conversion light emitted upward from the quantum rod (QR). Therefore, the display panel of the present disclosure can maximize the light emission efficiency by the color conversion layer (315).

[0131] FIG. 14 illustrates a method for manufacturing a display device according to one embodiment, and FIG. 15 illustrates a sequence of operations for manufacturing a color conversion layer of an upper substrate according to one embodiment.

[0132] Referring to FIG. 14, a method for manufacturing a display device of the present disclosure may include forming a lower substrate including at least one light-emitting element (operation 1410) and forming an upper substrate including a color filter layer and a color conversion layer (operation 1420). For example, a method for manufacturing a display panel may include forming a lower substrate, forming an upper substrate, and bonding the lower substrate and the upper substrate using an optical bonding material that transmits light.

[0133] For example, in operation 1410, a method for manufacturing a display device may form a lower substrate that generates and emits light necessary for displaying an image. For example, the method for manufacturing a display device may form a rear substrate, form a light-emitting element on the rear substrate, and form a pixel circuit for driving the light-emitting element on the rear substrate.

[0134] For example, in operation 1420, a method for manufacturing a display device may form an upper substrate that outputs light incident from a lower substrate to the outside. For example, a method for manufacturing a display device may form a front substrate, form a black matrix on the front substrate, form a color filter layer on the front substrate, form a partition wall on the front substrate, and form a color conversion layer and a transparent layer on the front substrate.

[0135] Referring to FIG. 15, a method of manufacturing a display panel of the present disclosure may include, when forming a color conversion layer of an upper substrate, manufacturing (1510) a color conversion ink including at least one color conversion particle, spraying (1520) the color conversion ink using electrohydrodynamic printing (EHD printing), and aligning (1530) the at least one color conversion particle in a uniform direction based on a first force based on a shear stress according to the electrohydrodynamic printing and a second force based on an electric field. In one embodiment, the at least one color conversion particle may include a cylindrical quantum rod. For example, the quantum rod may have a cylindrical shape with a major axis of a predetermined length and a diameter of a predetermined length. For example, the cylindrical quantum rod may have a dipole moment based on its structural characteristics.

[0136] For example, the upper substrate can be completed by sequentially forming a black matrix, a color filter layer, and a barrier rib, and then forming a color conversion layer and a transparent layer through electrohydrodynamic printing. Electrohydrodynamic (EHD) printing can form continuous ink lines by using a constant air pressure and electric field applied to the nozzle, instead of the intermittent ink ejection of the inkjet process. Electrohydrodynamic printing can form the color conversion layer with excellent precision by forming the width and height of the pattern printed with the color conversion ink consistently. In addition, since electrohydrodynamic printing can use high-viscosity ink, it is possible to increase the quantum dot content or add functional materials that can improve the color conversion characteristics, thereby achieving a high color conversion ratio.

[0137] In this way, the method for manufacturing a display device of the present disclosure can regularly arrange color conversion particles within the color conversion layer by forming a color conversion layer using electrohydraulic printing. In addition, the method for manufacturing a display device of the present disclosure can maximize the light-emitting area and minimize light reflected after emission by including cylindrical quantum rods as the color conversion particles.

[0138] Therefore, the manufacturing method of the display device of the present disclosure can increase the light output efficiency of the color conversion layer and improve display quality. However, since this has been described above, a redundant description thereof will be omitted.

[0139] The display devices according to the various embodiments disclosed in this document may take various forms. The display devices may include, for example, portable communication devices (e.g., smartphones), computer devices, portable multimedia devices, portable medical devices, cameras, wearable devices, or home appliances. The display devices according to the embodiments of this document are not limited to the aforementioned devices.

[0140] The various embodiments of this document and the terminology used herein are not intended to limit the technical features described in this document to specific embodiments, but should be understood to include various modifications, equivalents, or substitutes of the embodiments. For example, a component expressed in the singular should be understood to include plural components unless the context clearly indicates only the singular. It should be understood that the term "and / or" used herein encompasses any and all possible combinations of one or more of the listed items. The terms "comprise," "have," "consist of," and the like used herein are intended to specify that a feature, component, part, or combination thereof described in this disclosure exists, and the use of such terms does not exclude the possibility of the presence or addition of one or more other features, components, parts, or combinations thereof. In this document, phrases such as "A or B", "at least one of A and B", "at least one of A or B", "A, B, or C", "at least one of A, B, and C", and "at least one of A, B, or C" can each include any one of the items listed together in that phrase, or all possible combinations thereof. Terms such as "first", "second", or "first" or "second" may be used merely to distinguish the corresponding component from other corresponding components and do not limit the corresponding components in any other respect (e.g., importance or order).

[0141] The term "part" or "module" used in various embodiments of this document may include a unit implemented in hardware, software, or firmware, and may be used interchangeably with terms such as logic, logic block, component, or circuit, for example. The "part" or "module" may be an integrally configured component or a minimum unit or part of the component that performs one or more functions. For example, according to one embodiment, the "part" or "module" may be implemented in the form of an application-specific integrated circuit (ASIC).

[0142] The term “if” as used in various embodiments of this document may be interpreted to mean “when”, “when”, “in response to determining”, or “in response to detecting”, depending on the context. Similarly, “if it is determined that” or “if ~ is detected” may be interpreted to mean “upon determining”, “in response to determining”, or “upon detecting”, or “in response to detecting”, depending on the context.

[0143] The program executed by the electronic device described in this document may be implemented as hardware components, software components, and / or a combination of hardware components and software components. The program may be executed by any system capable of executing computer-readable instructions.

[0144] Software may include a computer program, code, instructions, or a combination of one or more of these, and may configure a processing device to perform a desired operation or command the processing device, independently or collectively. The software may be implemented as a computer program including instructions stored on a computer-readable storage medium. Examples of the computer-readable storage medium include magnetic storage media (e.g., read-only memory (ROM), random-access memory (RAM), floppy disks, hard disks, etc.) and optical reading media (e.g., CD-ROMs, digital versatile discs (DVDs)). The computer-readable storage medium may be distributed across network-connected computer systems so that the computer-readable code is stored and executed in a distributed manner. The computer program may be stored on an application store (e.g., Play Store). TM ) or directly between two user devices (e.g., smart phones), online distribution (e.g., downloading or uploading). In the case of online distribution, at least a portion of the computer program product may be at least temporarily stored or temporarily created in a machine-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or an intermediary server.

[0145] According to various embodiments, each component (e.g., a module or a program) of the above-described components may include one or more entities, and some of the entities may be separated and placed in other components. According to various embodiments, one or more components or operations of the aforementioned components may be omitted, or one or more other components or operations may be added. Alternatively or additionally, a plurality of components (e.g., a module or a program) may be integrated into a single component. In such a case, the integrated component may perform one or more functions of each of the plurality of components identically or similarly to those performed by the corresponding component among the plurality of components prior to the integration. According to various embodiments, the operations performed by a module, program, or other component may be executed sequentially, in parallel, iteratively, or heuristically, or one or more of the operations may be executed in a different order, omitted, or one or more other operations may be added.

Claims

1. In a display device including color conversion particles, a display panel for displaying images; and It includes a display driver IC (integrated circuit) that controls the above display panel, The above display panel, a lower substrate comprising at least one light-emitting element; and Comprising an upper substrate including a color filter layer and a color conversion layer, The color conversion layer of the upper substrate is, comprising at least one color converter having a rod shape, At least one color conversion unit, Converting the wavelength of light by including at least one color conversion particle arranged regularly, and continuously formed at regular intervals on the upper substrate, Display device.

2. In paragraph 1, At least one color conversion unit, By using electrohydrodynamic printing (EHD (electrohydrodynamic) printing), color conversion ink including at least one color conversion particle is sprayed onto the upper substrate, so that adjacent homogeneous color conversion units are arranged sequentially at a first interval and adjacent heterogeneous color conversion units are arranged sequentially at a second interval. Display device.

3. In paragraph 1 or 2, At least one color conversion particle, Containing a cylindrical quantum rod, Display device.

4. In paragraph 3, The above color conversion layer, When the color conversion ink is sprayed, the upper substrate moves in a predetermined direction along an imaginary center line, and includes at least one color conversion part formed in a rod shape between the partition walls. Display device.

5. In paragraph 3, The above quantum load is, By receiving the first force based on the shear stress inside the Taylor cone formed as the color conversion ink is ejected from the nozzle, the color conversion layer is aligned parallel to the discharge direction of the color conversion ink. Display device.

6. In paragraph 3, The above quantum load is, The dipole moment inside the quantum rod is aligned parallel to the discharge direction of the color conversion ink inside the color conversion layer by being subject to the action of a second force based on an electric field. Display device.

7. In paragraph 3, The above quantum load is, The length of the major axis of the above cylindrical shape is 20 nm to 200 nm, and the length of the diameter of the above cylindrical shape is 3 nm to 7 nm. Display device.

8. In paragraph 3, Further comprising a low-reflection layer formed on the upper substrate and including a linear polarizer and a quarterwave plate. Display device.

9. In paragraph 8, The above linear polarizing plate passes light polarized in a first direction and blocks light polarized in a second direction perpendicular to the first direction. The above quantum load is, Aligned in a direction parallel to the first direction within the color conversion layer, Display device.

10. In any one of paragraphs 1 to 9, The above upper substrate, It is manufactured through a process independent of the above lower substrate, The upper substrate and the lower substrate are bonded using an optical bonding material that transmits light. Display device.

11. A method for manufacturing a display device including color conversion particles, An operation of forming a lower substrate including at least one light-emitting element; and Comprising an operation of forming an upper substrate including a color filter layer and a color conversion layer, The color conversion layer of the upper substrate is, comprising at least one color converter having a rod shape, At least one color conversion unit, Converting the wavelength of light by including at least one color conversion particle arranged regularly, and continuously formed at regular intervals on the upper substrate, A method for manufacturing a display device.

12. In paragraph 11, At least one color conversion unit, Using electrohydrodynamic printing (EHD printing), a color conversion ink including at least one color conversion particle is sprayed onto the upper substrate, so that adjacent homogeneous color conversion units are arranged sequentially at a first interval and adjacent heterogeneous color conversion units are arranged sequentially at a second interval. A method for manufacturing a display device.

13. In paragraph 11 or 12, At least one color conversion particle, Containing a cylindrical quantum rod, A method for manufacturing a display device.

14. In paragraph 13, The above color conversion layer, When the color conversion ink is sprayed, the upper substrate moves in a predetermined direction along an imaginary center line, and includes at least one color conversion part formed in a rod shape between the partition walls. A method for manufacturing a display device.

15. In paragraph 13, The operation of forming the upper substrate is as follows: By using a first force based on the shear stress inside a Taylor cone formed as the color conversion ink is ejected from the nozzle, the quantum rod is aligned parallel to the ejection direction of the color conversion ink inside the color conversion layer. A method for manufacturing a display device.

Images