A transparent LED display

Abstract

In order to overcome the problems of low resolution and poor transparency effect of the transparent LED display screen using the LED lamp bead array arrangement in the prior art, the present application provides a transparent LED display screen, comprising a transparent substrate and a bare lamp bead; the bare lamp bead is arranged in an array on the transparent substrate; the bare lamp bead comprises a driving chip and a light-emitting wafer; the light-emitting wafer is mounted on the driving chip; the driving chip comprises two pairs of power supply pins; the power supply pins respectively comprise a first power supply pin and a second power supply pin; by using the present application, the pixel pitch can be effectively reduced, and the resolution can be effectively improved. The transparency of the transparent LED display screen can be further improved, the bare lamp beads can be connected and powered through the power supply lines using the power jumpers, and the electric energy can also be transmitted through the bare lamp beads.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of LED display, especially to the field of transparent LED display. BACKGROUND

[0002] Transparent LED display screen is gradually widely used in the market, and various product forms are developed. A transparent LED display screen technology of arraying LED lamp beads on a transparent substrate begins to appear. The existing transparent LED display screen is shown in the scheme Figure 1 、 Figure 2 , which comprises a transparent substrate 1', a printed circuit layer 3' provided on the transparent substrate 1', and LED lamp beads 2' with encapsulated driving chips arrayed on the transparent substrate 1'. Then a glue filling layer 5' is formed by filling glue on the surface of the transparent substrate 1' on which the LED lamp beads 2' are arranged. Then a protective cover plate 4' is covered on the surface of the glue filling layer 5'. The LED lamp beads 2' adopt the power supply circuit 6' shown in the figure to be directly connected to the electrode pin pad of the lamp bead welding area for power supply, wherein the power supply circuit 6' is divided into a positive power supply circuit 6a' and a negative power supply circuit 6b'. One positive power supply circuit 6a' and one negative power supply circuit 6b' are arranged on both sides of each column of LED lamp beads. And the LED lamp beads 2' are connected in series through the signal circuit 7' shown in the figure. The design of the power supply circuit 6' and the signal circuit 7' also reduces the transparency of the transparent LED display screen.

[0003] As shown in Figure 3 , the LED lamp beads 2' thereon are LED lamp beads 2' with encapsulated driving chips 21'; the LED lamp beads 2' comprise a shell 22', a driving chip 21', and red, green, and blue light emitting chips 20'; a chip mounting surface is formed on the shell 22', and a pin 23' is led out from the chip mounting surface; the driving chip 21' is mounted on the shell 22'; and the light emitting chip 20' is mounted on the driving chip 21'. The transparent LED display screen made of the LED lamp beads 2' with encapsulated driving chips 21' has high transparency, but due to the size constraint of the LED lamp beads 2', the general smaller encapsulation size is also 2.0 mm x 2.0 mm, and when the LED lamp beads 2' are arrayed and arranged with a pixel pitch of 5 mm x 5 mm or less, the size of the LED lamp beads 2' is relatively large, which obviously blocks the line of sight, and the transparent effect is not very ideal due to the dense arrangement of the power supply circuit and the signal circuit. If the resolution and the transparency are to be continuously improved, there is still a space for technical breakthrough. SUMMARY

[0004] In order to overcome the problems of low resolution and poor transparent effect of the transparent LED display screen with arrayed LED lamp beads in the prior art, the present application provides a transparent LED display screen.

[0005] The application provides a transparent LED display screen, comprising a transparent substrate and naked lamp beads; a circuit pattern is arranged on the transparent substrate; the naked lamp beads are arranged in an array on the transparent substrate; the naked lamp beads comprise driving chips and light-emitting wafers; the light-emitting wafers are mounted on the driving chips;

[0006] The circuit pattern comprises power supply pads and power supply lines; the power supply lines comprise a plurality of first power supply lines and second power supply lines with opposite polarities; the power supply pads are connected to the first power supply lines and the second power supply lines;

[0007] Each driving chip comprises two pairs of power supply pins; each pair of the power supply pins comprises a first power supply pin and a second power supply pin;

[0008] The first power supply pin on each naked lamp bead is connected to the first power supply line or the first power supply pin on an adjacent naked lamp bead through a power supply jumper; the second power supply pin on each naked lamp bead is connected to the second power supply line or the second power supply pin on an adjacent naked lamp bead through a power supply jumper; so that each naked lamp bead can directly take power from the power supply line or an adjacent naked lamp bead.

[0009] Further, the circuit pattern further comprises signal pads, and each driving chip further comprises a pair of signal pins; the signal pins comprise a first signal pin and a second signal pin;

[0010] The naked lamp beads are connected to the signal pads or adjacent naked lamp beads through signal jumpers to realize the series connection of the naked lamp beads and form a lamp bead string; so that the control signal for controlling the on-off of each naked lamp bead can be input from the signal pads through the signal jumpers and then transmitted through each series-connected naked lamp bead in turn. Further, one first power supply pin and one second power supply pin are arranged on one side edge of each driving chip; one first power supply pin and one second power supply pin are also arranged on the other side edge of each driving chip.

[0011] Further, the naked lamp beads are connected to the transparent substrate through the COG mode.

[0012] Further, the light-emitting wafers are mounted on the driving chips through the CSP or COC mode.

[0013] Further, each driving chip further comprises a pair of short-circuit pins, the pair of short-circuit pins comprising a short-circuit pin for inputting a signal and a short-circuit pin for outputting a signal; the pair of short-circuit pins are short-circuited inside the driving chip, so that the control signal is directly transmitted between the short-circuit pins without passing through the circuit inside the driving chip.

[0014] Further, each of the lamp bead strings is provided with two signal pads, respectively referred to as a first signal pad and a second signal pad;

[0015] In the lamp bead string, the signal pin of the input signal of the first bare lamp bead is connected to the first signal pad, and the short pin of the input signal of the first bare lamp bead is connected to the second signal pad;

[0016] Alternatively, the signal pin of the input signal of the first bare lamp bead is connected to the second signal pad, and the short pin of the input signal of the first bare lamp bead is connected to the first signal pad;

[0017] The signal pin of the input signal of each of the remaining bare lamp beads is connected to the short pin of the output signal of the previous bare lamp bead, and the short pin of the input signal of each of the bare lamp beads is connected to the signal pin of the output signal of the previous bare lamp bead; the signal pin of the output signal of each of the remaining bare lamp beads is connected to the short pin of the input signal of the next bare lamp bead, and the short pin of the output signal of each of the bare lamp beads is connected to the signal pin of the input signal of the next bare lamp bead.

[0018] Further, the power supply circuit includes a plurality of first power supply circuits and second power supply circuits arranged in rows or columns; a plurality of bare lamp beads are arranged between the first power supply circuits and the second power supply circuits; the first power supply circuits and the second power supply circuits are shared by the bare lamp beads.

[0019] Further, the power supply circuit is a conductive grid or an ITO conductive film or a nano-silver film.

[0020] Further, the bare lamp beads are fixed on the conductive grid by an insulating die bonding method.

[0021] Further, the transparent substrate on which the bare lamp beads are arranged is provided with a glue filling layer, and the bare lamp beads are encapsulated in the glue filling layer; the upper surface of the glue filling layer is provided with a protective cover plate.

[0022] Further, the transparent substrate is provided with a plurality of transparent unit plates; the bare lamp beads are arranged on the transparent unit plates; metal strips are arranged on both sides of each of the transparent unit plates as power supply circuits; and the bare lamp beads on each of the transparent unit plates are connected to the power supply circuits.

[0023] Further, the diameter of the power supply jumper and the signal jumper is 15 μm-70 μm.

[0024] The proposed solution removes the outer casing from existing LED beads, retaining only the driver chip. A bare LED bead, without a casing, is then placed on the driver chip and replaced with a bare LED bead array on a transparent substrate. This bare LED bead is as small as 0.5mm x 0.7mm, significantly smaller than the standard LED bead size. Therefore, it effectively reduces pixel pitch and improves resolution. It can produce transparent LED displays with a pixel pitch of less than 3mm x 3mm, maintaining over 80% transparency even at a 2mm x 2mm pitch, resulting in a very noticeable transparency. Power supply and signal transmission are achieved through jumper bonding. Using smaller diameter bonding wires, the overall obstruction of the view by conductive materials is reduced while ensuring sufficient power supply and signal transmission for the bare LED bead, further enhancing the transparency of the transparent LED display. Furthermore, the driver chip on the bare LED bead has two pairs of power pins. These pins allow each bare LED bead to draw power through a jumper bond connection, and also enable the transmission of electrical energy between the LED beads. Attached Figure Description

[0025] Figure 1 This is a cross-sectional schematic diagram of a transparent LED display screen disclosed in the prior art;

[0026] Figure 2 This is a top view schematic diagram of a transparent LED display screen disclosed in the prior art;

[0027] Figure 3 This is a three-dimensional schematic diagram of an LED lamp bead disclosed in the prior art;

[0028] Figure 4 , Figure 5 This is a partial cross-sectional view of a transparent LED display screen from different angles, provided in a specific embodiment of this application.

[0029] Figure 6 This is a three-dimensional schematic diagram of a bare LED bead provided in a specific embodiment of this application;

[0030] Figure 7 This is a top view schematic diagram of a bare LED bead provided in a specific embodiment of this application;

[0031] Figure 8 This application provides a specific embodiment of a configuration with Figure 6 , Figure 7 A top view of a transparent LED display screen with bare LED chips;

[0032] Figure 9 This is a top view schematic diagram of a further preferred bare LED bead provided in a specific embodiment of this application;

[0033] Figure 10 is a transparent LED display screen provided in the embodiment of the present application Figure 9 is a top view schematic diagram of a transparent LED display screen with bare lamp beads in the embodiment of the present application;

[0034] Figure 11 is a transparent LED display screen further extended in the embodiment of the present application Figure 8

[0035] Figure 12 is another transparent LED display screen provided in the embodiment of the present application Figure 9 is a top view schematic diagram of a transparent LED display screen with bare lamp beads in the embodiment of the present application;

[0036] Figure 13 is another transparent LED display screen provided in the embodiment of the present application Figure 9 is a top view schematic diagram of a transparent LED display screen with bare lamp beads in the embodiment of the present application;

[0037] Figure 14 is a partial sectional view schematic diagram of Figure 13

[0038] Figure 15 is a top view schematic diagram of another further improved transparent LED display screen provided in the embodiment of the present application.

[0039] In the background art, the reference signs are as follows: 1', transparent substrate; 2', LED lamp bead; 3', printed circuit layer; 4', protective cover plate; 5', glue filling layer; 6', power supply circuit; 7', signal circuit; 6a', positive power supply circuit; 6b', positive power supply circuit; 20', light-emitting wafer; 21', driving chip; 22', shell; 23', pin;

[0040] In the embodiment, the reference signs are as follows: 1, transparent substrate; 2, bare lamp bead; 3, circuit pattern; 4, protective cover plate; 5, glue filling layer; 6, transparent unit plate; 20, light-emitting wafer; 21, driving chip; 20r, red light-emitting wafer; 20g, green light-emitting wafer; 20b, blue light-emitting wafer; 211, signal pin; 212, first power supply pin; 213, second power supply pin; 214, short-circuit pin; 31, power supply circuit; 31a, first power supply circuit; 31b, second power supply circuit; 32, signal circuit; 33, signal pad; 311, power supply jumper; 321, signal jumper; 331, first signal pad; 332, second signal pad. Embodiment

[0041] ​​In order to make the technical problems, technical solutions and beneficial effects solved by the present application clearer, the present application will be further described in detail below in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0042] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "radial", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specified.

[0043] In the description of the present application, it should be noted that, unless otherwise specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0044] Embodiment

[0045] The present application will be specifically explained and described as follows. Figure 4 、 Figure 5 The transparent LED display screen disclosed in the present application comprises a transparent substrate 1 and a bare lamp bead 2; a circuit pattern 3 is arranged on the transparent substrate 1; the bare lamp bead 2 is arranged in an array on the transparent substrate 1; as shown in Figure 6 、 Figure 7 The bare lamp bead 2 comprises a driving chip 21 and a light-emitting wafer 20; the light-emitting wafer 20 is mounted on the driving chip 21; the bare lamp bead 2 in the present application cancels the packaging shell (English name: housing, Chinese name: support or base) on the basis of the traditional LED lamp bead. After mounting the light-emitting wafer 20 on the driving chip 21, it is not necessary to package again. The driving chip 21 with the light-emitting wafer 20 is directly used as a light-emitting structure to replace the traditional LED lamp bead with a shell. That is, the bare lamp bead 2 named in the present application is actually the driving chip 21 with the light-emitting wafer 20 embedded and mounted.

[0046] The size of the bare lamp bead 2 ranges from 0.5mm x 0.5mm to 0.7mm x 0.7mm. It is much smaller than the conventional LED lamp bead. Therefore, the resolution of the transparent LED display screen can be effectively improved.

[0047] Preferably, a glue-filling layer 5 is further arranged on the transparent substrate 1 with the bare lamp bead 2, which encapsulates each bare lamp bead 2 therein; the upper surface of the glue-filling layer 5 is provided with a protective cover plate 4. The design of the glue-filling layer 5 and the protective cover plate 4 is known to those skilled in the art and will not be described here.

[0048] As shown in Figure 6 , Figure 7 The driving chip 21 is known to the public, generally with a driving circuit integrated inside, and a passivation layer is arranged on the driving chip 21, which is a surface insulating layer formed when the driving chip 21 is manufactured. The driving chip 21 is provided with a plurality of pins, and the technology of mounting the light-emitting wafer 20 on the driving chip 21 is known to the public, generally fixedly mounted on the driving chip 21 by using the technology of (CSP or COC), and the pins on the driving chip 21 are electrically connected with the light-emitting wafer 20 by direct welding or through bonding wires. The bonding wires, also known as binding wires, usually include gold wires, copper wires, palladium-plated copper wires, and alloy wires, etc. No further description is given. The pins (English name: PAD) are generally arranged on the passivation layer, and the pins are the terminals inside the chip. The driving chip 21 includes a pair of signal pins 211 and two pairs of power supply pins; wherein the signal pins 211 include a first signal pin and a second signal pin; the power supply pins include a first power supply pin 212 and a second power supply pin 213, respectively; as shown in the figure, the driving chip 21 is divided into upper, lower, left and right directions; it can be seen that one pair of signal pins 211 is arranged at the right upper corner and the left lower corner of the driving chip 21; one pair of power supply pins is arranged on the upper part of the left side; the other pair of power supply pins is arranged on the lower part of the right side. In this example, as a preferred mode, the above-mentioned light-emitting wafer 20 includes three kinds of light-emitting wafers 20 of red, green and blue, respectively referred to as first, second and third light-emitting wafers; wherein the first light-emitting wafer is a red light-emitting wafer 20r, the second light-emitting wafer is a green light-emitting wafer 20g, and the third light-emitting wafer is a blue light-emitting wafer 20b. As shown in the figure, the red light-emitting wafer 20r, the green light-emitting wafer 20g and the blue light-emitting wafer 20b are sequentially mounted on the driving chip 21.

[0049] The input and output of the signal pin 211 are opposite, for example, the first signal pin is a signal input pin, and the second signal pin is a signal output pin. Conversely, the first signal pin is a signal output pin, and the second signal pin is a signal input pin. As a preferred mode, the two signal pins 211 can be switched with each other. One of the two signal pins 211 is a signal input pin, and the other is a signal output pin. As a preferred scheme, the bare lamp bead 2 is preferably a bidirectional transmission bare lamp bead. The first signal pin of the bidirectional transmission bare lamp bead is an input signal pin, and the second signal pin is an output signal pin. Conversely, the second signal pin of the bidirectional transmission bare lamp bead 2 is an input signal pin, and the first signal pin is an output signal pin. With such a bidirectional transmission bare lamp bead, bidirectional input signals of the bare lamp bead 2 can be transmitted during the series connection of the bare lamp bead 2. The bidirectional transmission scheme is the applicant's original technology, and the applicant has already patented the bidirectional transmission driving chip 21 and the lamp bead (for details, please refer to CN111341247A). In this example, the bidirectional transmission scheme can be directly quoted. No further description is given.

[0050] As shown in Figure 8 The circuit pattern 3 includes a power supply pad (not shown in the figure), a signal pad 33, and a power supply circuit 31. The power supply circuit 31 includes a plurality of first power supply circuits 31a and second power supply circuits 31b with opposite polarities. The power supply pad is connected to the first power supply circuit 31a and the second power supply circuit 31b. In this example, only one first power supply circuit 31a and one second power supply circuit 31b are shown, but the number of the above-mentioned power supply circuits 31 can be further increased. This can make several rows or columns share the first power supply circuit 31a and the second power supply circuit 31b.

[0051] The bare lamp bead 2 is connected to the signal pad 33 or the bare lamp bead 2 before or after it through a signal line 32 (specifically a signal jumper 321 in this application) to realize the series connection of the bare lamp bead 2 and form a lamp bead string. The control signal for controlling the lighting and extinguishing of each bare lamp bead 2 can be input from the signal pad 33 through the signal jumper 321 and then transmitted by each connected bare lamp bead 2 in turn.

[0052] The first power supply pin 212 on each bare lamp bead 2 is connected to the first power supply circuit 31a or the first power supply pin 212 on the adjacent bare lamp bead 2 through a power supply jumper 311. The second power supply pin 213 on each bare lamp bead 2 is connected to the second power supply circuit 31b or the second power supply pin 213 on the adjacent bare lamp bead 2 through a power supply jumper 311. This allows each bare lamp bead 2 to directly take power from the power supply circuit 31 or from the adjacent bare lamp bead 2.

[0053] In this example, the power jumper 311 and signal jumper 321 are what those skilled in the art understand as bonding wires or bonding wires; they are simply named here to distinguish the components. Using power jumpers 311 and 321 effectively improves the transparency of the transparent LED display. The power jumpers 311 and 321 are preferably 15μm-70μm in diameter and made of gold, copper, or alloy wire. Because of their small diameter, they are almost invisible to the naked eye. Therefore, while ensuring sufficient operating current for the connected bare LED chips 2, they reduce obstruction of the view and improve the product's transparency.

[0054] In this example, as Figure 6 , Figure 7 As shown, a pair of power pins (left power pins) are provided on one side (left side) of the driver chip 21: a first power pin 212 and a second power pin 213; a pair of power pins (right power pins) are also provided on the other side (right side) of the driver chip 21: a first power pin 212 and a second power pin 213. Thus, when the bare LED bead 2 is connected to the power supply line 31 or the power pins on an adjacent bare LED bead 2 using a power jumper 311, it can select the nearest power pin of the same polarity. For example, Figure 8 Taking the bare LED 2 in the first row and first column as an example, its left first power pin 212 is connected to the first power supply line 31a via a power jumper 311; its right first power pin 212 is connected to the left first power pin 212 of the bare LED 2 in the first row and second column; its right second power pin 213 is connected to the left second power pin 213 of the bare LED 2 in the first row and second column; the right first power pin 212 of the bare LED 2 in the first row and second column is connected to the left first power pin 212 of the bare LED 2 in the first row and third column; the first row... The second power pin 213 on the right side of the second row of bare LED beads 2 is connected to the second power pin 213 on the left side of the third row of bare LED beads 2; the first power pin 212 on the right side of the third row of bare LED beads 2 is connected to the first power pin 212 on the left side of the fourth row of bare LED beads 2; the second power pin 213 on the right side of the third row of bare LED beads 2 is connected to the second power pin 213 on the left side of the fourth row of bare LED beads 2; the second power pin 213 on the right side of the fourth row of bare LED beads 2 is connected to the second power supply line 31b, and so on. This method allows the LED beads in the same row to be directly or indirectly connected to the first power supply line 31a and the second power supply line 31b.

[0055] The above signal jumper 321 will be each bare lamp beads 2 in series manner is also easy to understand, for example, in the first column bare lamp beads 2 as an example, the signal input of the bare lamp beads 2 in the first row of the first column is connected to the signal pad 33 through the signal jumper 321, the signal output of the bare lamp beads 2 in the first row of the first column is connected to the signal input of the bare lamp beads 2 in the second row of the first column through the signal jumper 321; the signal output of the bare lamp beads 2 in the second row of the first column is connected to the signal input of the bare lamp beads 2 in the third row of the first column through the signal jumper 321; the signal output of the bare lamp beads 2 in the third row of the first column is connected to the signal input of the bare lamp beads 2 in the fourth row of the first column through the signal jumper 321. In this way, the transmission of the control signal in the column of bare lamp beads 2 is realized.

[0056] In the example, the bare lamp beads 2 are connected to the transparent substrate 1 by the COG (Chip On Glass) method. In the COG method, the chip is directly connected to the transparent substrate 1.

[0057] Preferably, the light-emitting wafer 20 is mounted on the driving chip 21 as a whole bare lamp bead 2, which is then mounted on the transparent substrate 1, thereby improving the process efficiency and yield.

[0058] Preferably, the light-emitting wafer 20 is mounted on the driving chip 21 by the CSP (Chip Scale Package) method. Details are not described herein as they are well known to those skilled in the art. The light-emitting wafer 20 can also be mounted on the driving chip 21 by the COC (Chip On Chip) method. Details are not described herein as they are well known to those skilled in the art.

[0059] The applicant found in the development process that, due to the signal attenuation in the signal transmission process, the number of LED lamp beads 2 in a string is limited, and the display effect will decrease if the number of LED lamp beads 2 in a string is too large. In an ideal state, the number of LED lamp beads 2 in a string is generally controlled to be less than 384. This greatly reduces the size of the LED transparent display screen.

[0060] It should be noted that the signal transmission in the example does not necessarily have to be achieved through the signal pad and the signal line and the bare lamp beads, and other implementation methods are also possible, such as transmitting signals through the power line. It is also possible to transmit signals through the power line based on the current technology. In the example, the bare lamp beads are connected in series through the signal pad and the signal jumper, which is the preferred method.

[0061] As a preferred mode, as shown in Figure 9 The driving chip 21 further comprises a pair of short-circuit pins 214, including a signal pin 214 for input signal and a signal pin 214 for output signal; the pair of short-circuit pins 214 are short-circuited inside the driving chip 21, so that the control signal is transmitted directly between the short-circuit pins 214 without passing through the circuit inside the driving chip 21.

[0062] As a preferred mode, as shown in Figure 9 , Figure 10 Each of the lamp bead strings is provided with two signal pads 33, respectively referred to as a first signal pad 331 and a second signal pad 332.

[0063] In the lamp bead string, the signal pin 211 for input signal of the first bare lamp bead 2 is connected to the first signal pad 331, and the short-circuit pin 214 for input signal of the first bare lamp bead 2 is connected to the second signal pad 332.

[0064] Alternatively, the signal pin 211 for input signal of the first bare lamp bead 2 is connected to the second signal pad 332, and the short-circuit pin 214 for input signal of the first bare lamp bead 2 is connected to the first signal pad 331.

[0065] The signal pin 211 for input signal of each of the remaining bare lamp beads 2 is connected to the short-circuit pin 214 for output signal of the previous bare lamp bead 2, and the short-circuit pin 214 for input signal of each of the bare lamp beads 2 is connected to the signal pin 211 for output signal of the previous bare lamp bead 2; the signal pin 211 for output signal of each of the remaining bare lamp beads 2 is connected to the short-circuit pin 214 for input signal of the next bare lamp bead 2, and the short-circuit pin 214 for output signal of each of the bare lamp beads 2 is connected to the signal pin 211 for input signal of the next bare lamp bead 2.

[0066] In this way, one column of lamp bead strings can be changed into two columns of lamp bead strings controlled by two control signals. For example, the odd bare lamp beads 2 in the lamp bead string transmit the control signal from the first signal pad 331, and the even bare lamp beads 2 in the lamp bead string transmit the control signal from the second signal pad 332; vice versa. Due to the above-mentioned special binding connection mode, the two signals in the first signal pad 331 and the second signal pad 332 are always transmitted in adjacent bare lamp beads 2 or are short-circuited without passing through the inside of the bare lamp beads 2.

[0067] Further described as follows, assuming that the control signal input in the first signal pad 331 is a first control signal, and the control signal input in the second signal pad 332 is a second control signal; then as shown in Figure 10As shown, taking the first row of bare LED beads 2 as an example, the first signal pad 331 is bonded to the shorting pin 214 of the input signal of the first row of bare LED beads 2; the second signal pad 332 is bonded to the signal pin 211 of the input signal of the first row of bare LED beads 2, so that the first control signal transmitted in the first signal pad 331 is shorted in the first row of bare LED beads 2 to the signal pin 211 of the input signal of the first row of bare LED beads 2, without passing through the inside of the first row of bare LED beads 2; so that the second control signal transmitted in the second signal pad 332 passes through the first row of bare LED beads 2, and the second control signal controls the lighting of the first row of bare LED beads 2, and is transmitted to the shorting pin 214 of the input signal of the first row of bare LED beads 2. Similarly, the first control signal for the bare LEDs 2 in the second row of the first column is input through the signal pin 211 of the input signal, controlling the on / off state of the bare LEDs 2 in the second row of the first column. The signal is then output from the signal pin 211 of the output signal to the shorting pin 214 of the input signal for the bare LEDs 2 in the third row of the first column. The second control signal is shorted out of the bare LEDs 2 in the second row of the first column. This process continues, with the first control signal passing through the bare LEDs 2 in even-numbered rows, controlling their on / off state, and being shorted out of the bare LEDs 2 in odd-numbered rows. The second control signal passes through the bare LEDs 2 in odd-numbered rows, controlling their on / off state, and is shorted out of the bare LEDs 2 in even-numbered rows. The reverse is also possible.

[0068] This method increases the number of bare LED chips connected in series in a row or column of LED strings. The number of bare LED chips in the string is twice that of a conventional LED string.

[0069] The power supply line 31 includes a plurality of first power supply lines 31a and second power supply lines 31b arranged in rows or columns; a plurality of rows or columns of bare LED beads 2 are provided between the first power supply lines 31a and second power supply lines 31b; the bare LED beads 2 share the first power supply lines 31a and second power supply lines 31b. For example, Figure 11 As shown, a first power supply line 31a, a second power supply line 31b, and a third power supply line 31a are spaced apart. On the left side, between the first power supply line 31a and the second power supply line 31b, there are 4 rows and 4 columns of bare LED beads 2; these 4 rows and 4 columns of bare LED beads 2 share the first power supply line 31a and the second power supply line 31b. On the right side, between the first power supply line 31a and the second power supply line 31b, there are also 4 rows and 4 columns of bare LED beads 2; these 4 rows and 4 columns of bare LED beads 2 share the first power supply line 31a and the second power supply line 31b on the right side.

[0070] In this way, several columns or several rows of bare lamp beads 2 share the same polarity power supply circuit 31, and such a circular arrangement can be made into a large-area transparent LED display screen. Sharing the power supply circuit 31 by several bare lamp beads 2 can reduce the number of power supply circuits 31, reduce the obstruction to the line of sight, and help improve the transparency of the display screen.

[0071] The power jumper 311 and the signal jumper 321 are crossed in the schematic diagram, but in the actual production process, they are wire-bonded at different heights and then fixed by glue pouring, so there is no collapse short circuit.

[0072] The present application is not limited to the implementation of the power supply circuit 31, which is not the core innovative content of the present application, and can use the implementation known to those skilled in the art. The number of first power supply circuit 31a and second power supply circuit 31b can be one or more, and the number of first power supply circuit 31a and second power supply circuit 31b can be the same or different. The specific number is determined by the power supply capacity of the power supply circuit 31 and the current demand of the bare lamp beads 2 between the first power supply circuit 31a and the second power supply circuit 31b.

[0073] The power supply circuit 31 can be straight, curved, or in the form of a snake. As a preferred way, each power supply circuit 31 is arranged in a row or column, and the implementation is not limited, as long as it can provide power. For example, it can be a metal layer etched on the transparent substrate 1, or a metal mesh, or a nano-silver coating or ITO coating, or a metal wire or metal sheet embedded in the transparent substrate 1 as described in the applicant's previous patent.

[0074] As a preferred way, as shown in Figure 12 , the power supply circuit 31 is preferably a conductive mesh. The conductive mesh can be a metal mesh or ITO, and the dots in the figure are the binding lines and the binding points (electrical connection points) of the metal mesh or ITO. The conductive capacity of the metal mesh or ITO is relatively small, so a large area is needed to meet the current demand. In the figure, the conductive mesh is arranged on both sides of the several columns of bare lamp beads 2, and the bare lamp beads 2 between the first power supply circuit 31a and the second power supply circuit 31b of the conductive mesh share the first power supply circuit 31a and the second power supply circuit 31b. At this time, it is only necessary to paste the bare lamp beads 2 thereon.

[0075] As shown in Figure 13 , Figure 14As shown, in order to enhance the conductive capacity of the conductive grid, the area of the conductive grid can also be expanded, and then the bare lamp beads 2 are installed on the conductive grid, but at this time, the bare lamp beads 2 need to be insulated from the conductive grid. That is, the bare lamp beads 2 are bound on the metal grid by an insulating die bonding method. For example, the two columns of bare lamp beads 2 on the left in the figure are arranged on the conductive grid of the first power supply line 31a, and the two columns of bare lamp beads 2 on the right in the figure are arranged on the conductive grid of the second power supply line 31b.

[0076] As for the design of the power supply line 31, there can also be other forms of modification, for example, as shown in FIG. 6, Figure 15 As shown, a plurality of transparent unit plates 6 are provided on the transparent substrate 1; the bare lamp beads 2 are arranged on the transparent unit plates 6; metal strips are provided on both sides of each transparent unit plate 6 as power supply lines 31; and the bare lamp beads 2 on each transparent unit plate 6 are connected to the power supply lines 31. The power supply lines 31 on both sides are respectively the first power supply line 31a and the second power supply line 31b. This kind of way makes the surface of the transparent substrate 1 without the power supply line 31, but embedded between the two transparent unit plates 6. The transparent unit plates 6 are mutually independent glass plates, and each transparent unit plate 6 is fixed on the lower whole transparent substrate 1.

[0077] By adopting the scheme of the present application, the shell in the existing LED lamp bead is removed, only the driving chip 21 is reserved, and the light-emitting wafer 20 is arranged on the driving chip 21 to form a bare lamp bead 2 without a shell. The bare lamp bead 2 is arranged on the transparent substrate 1 in place of the existing LED lamp bead array, and the size of the bare lamp bead 2 is as small as 0.5mm x 0.7mm, which is much smaller than the size of the LED lamp bead. Therefore, the pixel pitch can be effectively reduced, and the resolution can be effectively improved. A transparent LED display screen with a pitch smaller than 3mm x 3mm can be made, and even under the condition of a pitch of 2mm x 2mm, the transparency can be maintained at more than 80%, and the transparent effect is very obvious. The power supply and signal transmission are realized by the jumper binding method, a binding wire with a small diameter is selected, the condition of power supply and signal transmission of the bare lamp bead is just ensured, the conductive material is reduced as a whole to block the line of sight, and therefore the transparency of the transparent LED display screen can be further improved. Meanwhile, two pairs of power supply pins are arranged on the driving chip 21 of the bare lamp bead 2, and through the arrangement of the two pairs of power supply pins, each bare lamp bead 2 can be connected by the power supply jumper 311 of the power supply line 31 to take power, and the electrical energy can also be transmitted through each bare lamp bead 2.

[0078] The above only describes the preferred embodiments of the present application and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A transparent LED display, characterized by The transparent substrate and the bare lamp beads; the transparent substrate is provided with a circuit pattern; the bare lamp beads are arranged on the transparent substrate; the bare lamp beads comprise driving chips and light-emitting wafers; the light-emitting wafers are mounted on the driving chips; The circuit pattern comprises a power supply pad and a power supply circuit; the power supply circuit comprises a plurality of rows of first power supply circuits and second power supply circuits with opposite polarities and arranged alternately; a plurality of rows of bare lamp beads are arranged between the first power supply circuits and the second power supply circuits; or, the power supply circuit comprises a plurality of columns of first power supply circuits and second power supply circuits with opposite polarities and arranged alternately; a plurality of columns of bare lamp beads are arranged between the first power supply circuits and the second power supply circuits; the power supply circuit is a conductive grid, an ITO conductive film, a nano-silver thin film or a metal strip; The power supply pad is connected to the first power supply circuit and the second power supply circuit; The bare lamp beads share the first power supply circuit and the second power supply circuit; one side of the driving chip is provided with a pair of power supply pins, and the other side opposite to the one side is also provided with a pair of power supply pins; each pair of power supply pins comprises a first power supply pin and a second power supply pin; In the plurality of rows of bare lamp beads between the first power supply circuit and the second power supply circuit, the first power supply pin on one side of the first bare lamp bead is connected to the first power supply circuit through a power supply jumper, and the second power supply pin on the other side of the last bare lamp bead is connected to the second power supply circuit through a power supply jumper; The first power supply pin on one side of each of the remaining bare lamp beads is connected to the first power supply pin on the other side of the previous bare lamp bead, and the second power supply pin on one side of each of the remaining bare lamp beads is connected to the second power supply pin on the other side of the previous bare lamp bead; so that each bare lamp bead can directly take power from the power supply circuit or from the adjacent bare lamp bead; Or, in the plurality of columns of bare lamp beads between the first power supply circuit and the second power supply circuit, the first power supply pin on one side of the first bare lamp bead is connected to the first power supply circuit through a power supply jumper, and the second power supply pin on the other side of the last bare lamp bead is connected to the second power supply circuit through a power supply jumper; The first power supply pin on one side of each of the remaining bare lamp beads is connected to the first power supply pin on the other side of the previous bare lamp bead, and the second power supply pin on one side of each of the remaining bare lamp beads is connected to the second power supply pin on the other side of the previous bare lamp bead; so that each bare lamp bead can directly take power from the power supply circuit or from the adjacent bare lamp bead; The power supply jumper is a relatively small diameter binding wire or a bonding wire.

2. The transparent LED display of claim 1, wherein, The circuit pattern further comprises a signal pad, and the driving chip further comprises a pair of signal pins; the signal pins comprise a first signal pin and a second signal pin. The bare lamp beads are connected to the signal pads or the bare lamp beads before and after the signal pads through signal jumpers to realize the series connection of the bare lamp beads and form a lamp bead string.

3. The transparent LED display of claim 2, wherein, The bare lamp beads are connected to the transparent substrate through a COG mode.

4. The transparent LED display of claim 2, wherein, The light-emitting wafer is mounted on the driving chip through a CSP or COC mode.

5. The transparent LED display of claim 2, wherein, The driving chip further comprises a pair of short-circuit pins, including a short-circuit pin for input signal and a short-circuit pin for output signal; the pair of short-circuit pins are short-circuited in the driving chip, so that the control signal is transmitted directly between the short-circuit pins without passing through the circuit in the driving chip.

6. The transparent LED display of claim 5, wherein, Each lamp bead string is provided with two signal pads, respectively referred to as a first signal pad and a second signal pad. The signal pin for input signal of the first bare lamp bead in the lamp bead string is connected to the first signal pad, and the short-circuit pin for input signal of the first bare lamp bead is connected to the second signal pad. Alternatively, the signal pin for input signal of the first bare lamp bead is connected to the second signal pad, and the short-circuit pin for input signal of the first bare lamp bead is connected to the first signal pad. The signal pin for input signal of each remaining bare lamp bead is connected to the short-circuit pin for output signal of the previous bare lamp bead, and the short-circuit pin for input signal of each bare lamp bead is connected to the signal pin for output signal of the previous bare lamp bead; the signal pin for output signal of each remaining bare lamp bead is connected to the short-circuit pin for input signal of the next bare lamp bead, and the short-circuit pin for output signal of each bare lamp bead is connected to the signal pin for input signal of the next bare lamp bead.

7. The transparent LED display of claim 1, wherein, The power supply circuit is a conductive grid, and the bare lamp beads are fixed on the conductive grid through an insulating die bonding mode.

8. The transparent LED display of claim 2, wherein, The transparent substrate on which the bare lamp beads are arranged is provided with a glue filling layer, and the bare lamp beads are encapsulated in the glue filling layer. The upper surface of the glue filling layer is provided with a protective cover plate.

9. The transparent LED display of claim 8, wherein, The transparent substrate is provided with a plurality of transparent unit plates, the bare lamp beads are arranged on the transparent unit plates, metal strips are arranged on both sides of each transparent unit plate as power supply circuits, and the bare lamp beads on each transparent unit plate are connected to the power supply circuits.

10. The transparent LED display of claim 2, wherein, The diameters of the power supply jumpers and the signal jumpers are 15 μm-70 μm.

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