LED display structure having chip-on-board-type touch recognition function, and electronic display board using same

Abstract

The present invention relates to an LED display structure having a chip-on-board-type capacitive touch function, the touch function being implemented in the LED display structure to be used in a large electronic display board, wherein a chip-type transmission / reception sensor unit integrated in a space between RGB LEDs constituting a pixel is configured such that an object located in front of a screen can be recognized on a pixel-by-pixel basis.

Description

LED display structure having chip-on-board touch recognition function and an electronic display using the same

[0001] The present invention relates to an LED display structure having a touch function and an electronic display using the same. More specifically, it relates to an LED display structure used in large electronic displays that implements a touch function by configuring a chip-type transmitting and receiving sensor unit integrated in the space between RGB LEDs forming pixels, thereby enabling the recognition of an object located on the front of the screen at the pixel level, and an electronic display using the same.

[0002] Display devices that convert electrical signals authorized from information processing devices into images are gradually becoming larger and their resolution is also increasing with technological advancements.

[0003] As a screen widely used across various fields due to its outstanding performance, LED display panels configure the image screen and resolution by using pixels—combined with light-emitting elements—as the basic unit.

[0004] Currently, commonly used display pixels consist of LEDs in the three primary colors of light: red, green, and blue. By fabricating and assembling cabinets—basic blocks made from these unit LED pixels—screens can be configured to any desired size. This structure is gaining popularity in the market as it enables high-resolution displays without bezels.

[0005] Recently, rather than unidirectional output, functions that reconstruct images through interaction with various objects, including human hands and pens, are being implemented using so-called touch screen technology. Under the name "electronic whiteboard," demand for this is steadily increasing in educational settings as well as in businesses and institutions.

[0006] There are various commercially available touch screen technologies, such as resistive, capacitive, electromagnetic induction, infrared, and ultrasonic methods. However, there is a problem in that depending on the detection method, it cannot be applied to constructing a large screen of 100 inches or more as an electronic whiteboard meeting the specifications required for the field.

[0007] In particular, existing capacitance methods include the On-cell method, in which electrode lines of a transparent conductive pattern (ITO, Metal Mesh, Silver nanowire, carbon nanotube, etc.) are patterned on a film or glass, and the In-cell method, in which patterns are patterned around RGB pixels, which are methods for measuring capacitance values.

[0008] In these on-cell and in-cell capacitance methods, the touch signal lines, the TX and RX lines, are connected via ITO pattern lines to a signal processing chip mounted outside the LCD / OLED screen. As a result, as the screen size increases, the pattern lines become longer, leading to a problem where the resistance between ITO lines increases, which clearly limits the production of touch screens in the form of large electronic displays.

[0009] In particular, as the On-cell and In-cell Tx lines and Rx lines are positioned toward the bezel located at the outer edge of the screen, a bezel is present on the film or glass, making it impossible to manufacture a large-inch touchscreen display without a bezel.

[0010] Due to these issues, the capacitive method can only be used in some high-end screens under 100 inches, and currently, commercially available large-screen products practically use only the infrared method. As a result, the screen size that can be manufactured remains limited due to limitations such as the number of multi-touches, the resulting decrease in response speed, the decrease in infrared signal reception value, and the inability to touch curved displays.

[0011] The present invention was created to solve the above-mentioned problems, and the objective of the present invention is to provide an LED display structure having a chip-on-board touch recognition function capable of recognizing an object located on the front of the screen at the pixel level by configuring a chip-type transmitting and receiving sensor unit integrated in the space between the RGB LEDs forming the pixels to implement a touch function in an LED display structure used in an electronic display board, and to provide an electronic display board using the same.

[0012] For the purpose of the above, the LED display structure having a chip-on-board touch recognition function according to the present invention is characterized in that, in an LED display structure in which LED pixel chips emitting red, green, and blue light are arranged in a set pattern on a substrate and on the front surface of the substrate, a sensor chip including a transmitter and a receiver composed of an ITO material or a conductive material is configured in the space between the LED pixel chips, and an object located on the front surface of the screen is detected through a signal processing unit that detects a reaction signal according to an approached object by applying a signal between the transmitter and the receiver.

[0013] At this time, the sensor chip is a capacitive sensor, and the signal processing unit is located on the back surface of the substrate to generate a surface electromotive force between the transmitter and the receiver, and by detecting a change in the surface electromotive force due to the approach of a conductive object, it can be configured so that there are no bezels on the top, bottom, left, or right.

[0014] In addition, the sensor chip can be configured so that there are no bezels on the top, bottom, left, or right sides, by configuring the transmitting and receiving parts as radar antennas as radar sensors and the signal processing part is located on the back of the substrate to apply a radar signal to the sensor chip.

[0015] In addition, the LED display structure having a chip-on-board touch recognition function according to the present invention is a large LED display structure in which LED pixel chips emitting red, green, and blue light are arranged in a set pattern on a substrate and on the front of the substrate to form a screen, wherein a sensor chip comprising a transmitter and a receiver composed of an ITO material or a conductive material is configured in the space between the LED pixel chips, and a display structure configured to detect an object located on the front of the screen through a signal processing unit that detects a reaction signal according to an approaching object by applying a signal between the transmitter and the receiver is continuously arranged sideways.

[0016] At this time, a controller may be provided to convert the object detection coordinate values ​​generated for each display structure into total coordinate values ​​and transmit them to the operating system.

[0017] In addition, the above display structure has a curved surface formed thereon, so that a touch function can be implemented even on a curved display.

[0018] In addition, by independently generating touch coordinates at the unit of each display structure, touch can be implemented only on selected parts when configuring the LED display.

[0019] The present invention enables the implementation of a large LED display with touch recognition capabilities through an In-cell Capacitance LED Touch Display Module capable of independent touch driving. In this case, since all touch sensor driving mechanisms are installed on a PCB circuit mounted on the rear of the LED Display Module, a bezel-less large-inch touchscreen can be manufactured at the lowest possible cost.

[0020] Furthermore, the application of a DOT-based touchscreen enables the generation of physical touch coordinates, eliminating the need for separate coordinate calculations unlike conventional infrared and capacitive methods. Additionally, since the driving and control chips are located directly behind the display module PCB, the inter-line resistance of the Tx and Rx lines is low, resulting in a high signal-to-noise ratio.

[0021] Furthermore, both Self-Capacitance and Mutual-Capacitance methods can be applied for touch recognition. Even when using the Self-Capacitance method, physical touch coordinates can be generated, enabling the creation of coordinates for multi-touch sensing. In particular, because the structure allows for independent touch sensing at the module level, infinite multi-touch support can be implemented.

[0022] In addition, a standard LED Display Module is installed for the display area out of reach of the human hand, while an LED Touch Display Module is installed for the touchable parts, allowing touchscreens to be applied only to the desired areas of a large display.

[0023] In addition, by configuring the sensor chip to have a radar antenna function and controlling the signal strength, it is possible to recognize all objects at a certain distance. Furthermore, touch functionality can be implemented without problems even on curved or angled displays.

[0024] FIG. 1 is a perspective view showing the shape of a sensor chip according to one embodiment of the present invention,

[0025] FIG. 2 is a conceptual diagram illustrating the operation and output signal of a sensor chip according to one embodiment of the present invention,

[0026] FIG. 3 is an example diagram of electric field and radar radio wave transmission and reception signals by method according to one embodiment of the present invention,

[0027] FIG. 4 is a structural diagram of an LED display module equipped with a sensor chip and a signal processing unit according to one embodiment of the present invention,

[0028] FIG. 5 is a structural diagram of a sensor chip in the form of an RGB pixel package according to a second embodiment of the present invention,

[0029] FIG. 6 is a conceptual diagram illustrating the operation and output signal of a sensor chip according to a second embodiment of the present invention.

[0030] FIG. 7 is a perspective view showing the shape of a sensor chip according to a third embodiment of the present invention,

[0031] FIG. 8 is a conceptual diagram illustrating the operation and output signal of a sensor chip according to the third embodiment of the present invention.

[0032] FIG. 9 is a perspective view showing the shape of a sensor chip according to a fourth embodiment of the present invention,

[0033] FIG. 10 is a conceptual diagram illustrating the operation and output signal of a sensor chip according to the 4th embodiment of the present invention,

[0034] FIG. 11 is a first structural diagram of an LED Touch Display Module to which the sensor chip of the present invention is applied.

[0035] FIG. 12 is a second structural diagram of an LED Touch Display Module to which the sensor chip of the present invention is applied.

[0036] FIG. 13 is a third structural diagram of an LED Touch Display Module to which the sensor chip of the present invention is applied.

[0037] FIG. 14 is a fourth structural diagram of an LED Touch Display Module to which the sensor chip of the present invention is applied.

[0038] FIG. 15 is an explanatory diagram showing the configuration of an LED Touch Display Module and a controller for touch coordinate calculation according to the present invention.

[0039] FIG. 16 is a pixel-unit touch sensor driving circuit diagram according to the present invention,

[0040] FIG. 17 is a conceptual diagram showing the application of the curved display of the present invention.

[0041] FIGS. 18 and 19 are example diagrams of various transmitting and receiving unit patterns according to the present invention.

[0042] The LED display structure having a chip-on-board touch recognition function and the LED display board using the same according to the present invention will be described in detail below with reference to the attached drawings.

[0043] The present invention is basically constructed in a form that forms a screen by arranging LED pixel chips, which emit red, green, and blue light respectively, on a substrate and on the front surface of the substrate in a set pattern, similar to a conventional LED display structure. At this time, a sensor chip operating via capacitance or radar is included in such a structure.

[0044] The above substrate is typically a PCB substrate corresponding to a unit area forming a screen in a display device, and the pixel chip has a width × height and pitch spacing ranging from a micrometer size to several millimeters depending on the type of screen. Although the present invention does not limit the size, space can be secured by aiming for a touch screen on the scale of a large-screen electronic display or electronic whiteboard that can be 100 inches or larger.

[0045] A sensor chip comprising a transmitter and a receiver made of an ITO material or a conductive material is configured in the space between the LED pixel chips. Additionally, an object located on the front of the screen is detected through a signal processing unit that detects a reaction signal according to an approached object by applying a signal between the transmitter and the receiver.

[0046] FIG. 1 is a perspective view showing the shape of a sensor chip according to one embodiment of the present invention, FIG. 2 is a conceptual diagram explaining the operation and output signal of a sensor chip according to one embodiment of the present invention, FIG. 3 is an example diagram of electric field and radar radio wave transmission and reception signals by method according to one embodiment of the present invention, and FIG. 4 is a structural diagram of an LED display module equipped with a sensor chip and a signal processing unit according to one embodiment of the present invention.

[0047] The sensor chip described above is configured such that a transmitter and a receiver, made of ITO material or a conductive material, face the front.

[0048] In one embodiment of the present invention, such a sensor chip can be used as a capacitive or radar type by changing the driving driver included in the signal processing unit in the same form.

[0049] The attached Figures 2(a), 3(a), and 4(a) illustrate a sensor chip operating in a capacitive manner, wherein the sensor chip is a capacitive sensor and the signal processing unit is located on the back surface of the substrate. Additionally, the sensor chip generates an electric field based on surface electromotive force between the transmitter and the receiver and detects changes in surface electromotive force due to the approach of a conductive object.

[0050] That is, the signal processing unit is composed of a driving driver that applies surface electromotive force through the transmitting and receiving units, and a controller that recognizes a touch signal by detecting a change in electromotive force as a conductive material, including a finger, approaches between the transmitting and receiving units.

[0051] At this time, as shown in Fig. 3(a), signal changes can be measured according to the air gap spacing, and the epoxy height can be determined by reflecting this.

[0052] The attached Figures 2(b), 3(b), and 4(b) respectively illustrate a sensor chip operating in a radar manner. The sensor chip is a radar sensor, and the transmitting and receiving parts are configured as radar antennas, and the signal processing part is located on the back of the substrate to apply a radar signal to the sensor chip.

[0053] That is, the signal processing unit is composed of a transmitter that transmits radio waves to the front, a radar chip and Tx and Rx circulators for the operation of a receiver that receives radio waves reflected from an object after transmission from the transmitter, and a controller that detects the reception of radio waves by the receiver and recognizes a touch signal. Similarly, as shown in FIG. 3(b), signal changes can be measured according to the air gap, and the epoxy height reflecting this can be determined.

[0054] In practice, radar sensors generate radio waves through strong signals, and if the signal is weak, a relatively short range of electric field is formed between the transmitter and receiver, as in the capacitive method as shown in Fig. 3(a). At this time, since a change in the electric field occurs when an object approaches, touch recognition is possible using the same principle as the capacitive method.

[0055] These sensor chips have a very simple structure and can be placed in the space between LED pixel chips, so they do not require special structures or spaces in the front, back, top, bottom, left, and right directions of the existing LED display structure. In both of the aforementioned methods, the sensor chip equipped with a transmitter and a receiver is located on the front of the substrate, and the signal processing unit is located on the back of the substrate to transmit and receive signals. Accordingly, the structure in which the On-cell and In-cell Tx lines and Rx lines move toward the bezel located at the outer edge of the screen, as in the past, inevitably results in a bezel existing on the film or glass, is improved, thereby realizing a structure that is practically bezel-less.

[0056] FIG. 5 is a structural diagram of a sensor chip in the form of an RGB pixel package according to the second embodiment of the present invention, and FIG. 6 is a conceptual diagram explaining the operation and output signal of the sensor chip according to the second embodiment of the present invention. FIG. 5(a) shows a state in which LEDs are arranged horizontally because gallium arsenide is used as the red LED, and since its properties differ significantly from those of the green and blue materials, it is sensitive to handle and difficult to stack. FIG. 5(b) shows a pixel structure in which LEDs are stacked because indium gallium nitride (InGaN) is used as the red LED, and since it is the same material as the green and blue materials, it is easy to handle.

[0057] Both structures are illustrated with sensor chips configured in the space between LED chips, allowing for the maximum area of ​​the sensor chips—specifically the transmitter and receiver sections. In this structure, ON / OFF signals are output through a signal processing chip composed of a minimum number of transistors, enabling miniaturization of both the sensor chip and the signal processing unit; furthermore, the sensing lines are minimized, resulting in very low inter-line resistance.

[0058] Furthermore, the aforementioned transmitter and receiver can utilize a transparent ITO material or be colored black to match the substrate color, thereby enabling seamless touch functionality without affecting display performance at all. In particular, by miniaturizing the sensor chip and arranging it to correspond to the pixel chip, it is also possible to detect objects located on the front of the screen at the pixel level.

[0059] FIG. 7 is a perspective view showing the shape of a sensor chip according to a third embodiment of the present invention, and FIG. 8 is a conceptual diagram explaining the operation and output signal of a sensor chip according to a third embodiment of the present invention, showing a form in which a chip for self-driving and signal processing as a signal processing unit is integrally formed with a transmitting unit and a receiving unit. The signal processing unit may be configured to detect a measured touch signal value as 1 or 0.

[0060] FIG. 9 is a perspective view showing the shape of a sensor chip according to the fourth embodiment of the present invention, and FIG. 10 is a conceptual diagram explaining the operation and output signal of a sensor chip according to the fourth embodiment of the present invention, illustrating a configuration in which the sensor chip and the signal processing unit are configured such that Rx and Tx lines are configured in a stacked manner, with an Optically Clear Adhesive configured between them. Although the transmitting unit and the receiving unit are configured in a stacked form, they can form a surface electromotive force in substantially the same form and detect a touch signal value, which is a change therein, as 1 or 0.

[0061] FIG. 11 is a first structural diagram of an LED touch display module with a sensor chip of the present invention applied, FIG. 12 is a second structural diagram of an LED touch display module with a sensor chip of the present invention applied, FIG. 13 is a third structural diagram of an LED touch display module with a sensor chip of the present invention applied, and FIG. 14 is a fourth structural diagram of an LED touch display module with a sensor chip of the present invention applied, each illustrating a configuration of various types of sensor chips in various patterns.

[0062] In FIG. 11, a sensor chip is configured in the center of each of the four pixel chips, allowing objects on the front of the screen to be detected and processed at the pixel level. Additionally, FIG. 12 illustrates a configuration in which a sensor chip is placed for each of the multiple pixel chips, thereby reducing the unit cost and adjusting the precision by controlling the number of unnecessary touch sensors according to the pixel size.

[0063] Figure 13 shows a radar-type sensor chip in which a sensor chip acting as an antenna is placed in the space between RGB pixel chips, and the sensing sensitivity is controlled by adjusting the area of ​​the sensor chip, which is the antenna area. Additionally, Figure 14 shows the size and quantity of sensor chips acting as radar antennas being adjusted according to the RGB pixel size.

[0064] FIG. 15 is an explanatory diagram showing the configuration of an LED Touch Display Module and a controller for touch coordinate calculation according to the present invention, and FIG. 16 is a pixel-unit touch sensor driving circuit diagram according to the present invention.

[0065] The display structures equipped with the aforementioned sensor chips and signal processing units are arranged continuously in the lateral directions—that is, up, down, left, and right—enabling the implementation of large-scale LED display panels. Furthermore, touch coordinates are generated for each individual LED display structure containing the sensor chips and signal processing units. These generated touch coordinate values ​​are then transmitted to a separately configured controller, which converts them into final multi-touch coordinate values ​​for the entire display panel and transmits them to the user operating system.

[0066] LED display structures widely used in the market feature a layout with 192 pixels horizontally and 108 pixels vertically, with four such LED modules grouped together to form an LED cabinet. In the case of an FHD LED display with a resolution of 1920 pixels horizontally and 1080 pixels vertically, it consists of 25 LED cabinets and a total of 100 LED modules.

[0067] A latch chip, which serves as a signal processing unit, is installed on the back of the LED display structure and is connected to a set number of sensor chips to handle signal transmission and reception for each sensor chip. Each latch chip, having processed signals from the set number of sensor chips, is connected to an STM Microprocessor that processes the overall display signals, thereby enabling touch signal processing for the entire display screen.

[0068] As previously mentioned, when a CABINET is configured by connecting four LED MODULEs, a module interface board equipped with a module connector for connecting each LED MODULE and an interface chip for signal processing are provided. Data transmission and reception and FPGA signal processing are performed with the LED CABINET control board. In the present invention, a controller for the sensor chip and signal processing unit is added to perform signal processing based on touch operations, as well as measurement and correction of coordinates based on address management and HID conversion. Additionally, through a terminal equipped with S / W for managing this, HID touch coordinate input and touch coordinate scaling settings based on screen size can be performed.

[0069] FIG. 17 is a conceptual diagram showing the application of the curved display of the present invention.

[0070] With the advancement of LED display technology, existing screens such as LCD video walls and beam projectors are being replaced. Consequently, not only are ultra-large screens without boundaries between displays being constructed, but display screens featuring convex, concave curved surfaces, or various irregular curvature structures are also being realized to match the changing trends in indoor and outdoor architecture, which are evolving into creative and innovative forms.

[0071] In the present invention, by installing a sensor chip in the space between each pixel chip, a smooth touch screen can be implemented even on a display with such a curved structure.

[0072] FIGS. 18 and 19 are exemplary diagrams of various transmitting and receiving unit patterns according to the present invention. In the present invention, since the transmitting and receiving units can be configured in the space between LED pixel chips, they can be configured in a wide variety of patterns within a range that does not interfere with the output of the LED pixel chips, and such an example is illustrated. By providing the transmitting and receiving units in such various forms, various patterns can be applied in response to the touch performance to be implemented, including the size and shape of the display, and the present invention does not impose restrictions on the shape.

Claims

1. An LED display structure comprising a substrate and LED pixel chips emitting red, green, and blue light, respectively, arranged in a set pattern on the front surface of the substrate to form a large-screen electronic display or electronic whiteboard screen, A sensor chip comprising a transmitter and a receiver, composed of a transparent ITO material or a conductive material colored black to match the color of the substrate, is configured in each space between the LED pixel chips. An LED display structure characterized by having no bezels on the top, bottom, left, and right sides, by detecting an object located on the front of the screen through a signal processing unit that is positioned on the back of the substrate and applies a signal between the transmitting and receiving parts of the sensor chip, and detects a reaction signal according to an approached object as 1 or 0 by forming a relatively short range electric field and transmitting and receiving radio waves through signal strength adjustment.

2. In an electronic display board using an LED display structure in which LED pixel chips emitting red, green, and blue light are arranged in a set pattern on a substrate and on the front surface of the substrate, respectively, to form a screen, A sensor chip comprising a transmitter and a receiver, composed of a transparent ITO material or a conductive material colored black to match the color of the substrate, is configured in each space between the LED pixel chips. An electronic display board using an LED display structure characterized by continuously arranging display structures without bezels on the top, bottom, left, and right sides in a sideways manner, by detecting an object located on the front of the screen through a signal processing unit that detects a reaction signal of 1 or 0 according to an approached object by applying a signal between a transmitting unit and a receiving unit of the sensor chip located on the back surface of the substrate, and forming a relatively short range electric field through signal strength adjustment for the transmission and reception of radio waves.

3. In Paragraph 2, An electronic display board using an LED display structure, characterized by having a controller that converts object detection coordinate values ​​generated for each display structure into total coordinate values ​​and transmits them to the operating system.

4. In Paragraph 3, An electronic display board using an LED display structure characterized by the above-mentioned display structure having a curved surface formed thereon, thereby enabling touch functionality even on a curved display.

5. In Paragraph 4, An electronic display board using an LED display structure characterized by the ability to implement touch only on selected parts when configuring an LED display by independently generating touch coordinates at each unit of the display structure.

Images