A transparent LED display

Abstract

In order to overcome the problem of low resolution and poor transparency of the transparent LED display screen using the LED lamp bead array arrangement in the prior art, the application provides a transparent LED display screen, which comprises a transparent substrate and bare lamp beads; the bare lamp beads are 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 a pair of power supply pins; the pair of power supply pins comprises a first power supply pin and a second power supply pin; the application can effectively reduce the pixel pitch and effectively improve the resolution; the transparency of the transparent LED display screen can be further improved; and each bare lamp bead can directly take power from the power supply circuit through the power supply jumper.

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 present application provides a transparent LED display screen, comprising a transparent substrate and a naked lamp bead; 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 bead comprises a driving chip and a light-emitting wafer; the light-emitting wafer is mounted on the driving chip;

[0006] The circuit pattern comprises a power supply pad and a power supply circuit; the power supply circuit comprises a plurality of first power supply circuits and second power supply circuits with opposite polarities; the power supply pad is connected to the first power supply circuit and the second power supply circuit;

[0007] The driving chip comprises a pair of power supply pins; wherein the pair of 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 circuit or the first power supply pin on its 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 circuit or the second power supply pin on its adjacent naked lamp bead through a power supply jumper; so that each naked lamp bead can directly take power from the power supply circuit.

[0009] Further, the circuit pattern further comprises a signal pad, and the driving chip further comprises a pair of signal pins; the pair of signal pins comprises a first signal pin and a second signal pin; one of the first signal pin and the second signal pin is an input signal signal pin, and the other of the first signal pin and the second signal pin is an output signal signal pin;

[0010] Wherein, the naked lamp bead is connected to the signal pad or its front and rear naked lamp beads through a signal jumper to realize the series connection of the naked lamp beads and form a lamp bead string; so that the control signal for controlling each naked lamp bead to turn on or off can be input from the signal pad through the signal jumper and then transmitted through each series-connected naked lamp bead in turn.

[0011] Further, the naked lamp bead is connected to the transparent substrate by COG.

[0012] Further, the light-emitting wafer is mounted on the driving chip by CSP or COC.

[0013] Further, the driving chip further comprises a pair of short-circuit pins, the pair of short-circuit pins comprises an input signal short-circuit pin and an output signal short-circuit pin; the pair of short-circuit pins are short-circuited inside the driving chip, so that the control signal is directly transmitted between the pair of 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, a signal pin of the input signal of the first bare lamp bead is connected to the first signal pad, and a short pin of the input signal of the first bare lamp bead is connected to the second signal pad.

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

[0017] A signal pin of the input signal of each of the remaining bare lamp beads is connected to a short pin of the output signal of the previous bare lamp bead, and a short pin of the input signal of each of the bare lamp beads is connected to a signal pin of the output signal of the previous bare lamp bead; a signal pin of the output signal of each bare lamp bead is connected to a short pin of the input signal of the next bare lamp bead, and a short pin of the output signal of each bare lamp bead is connected to a 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 bare lamp beads between the first power supply circuits and the second power supply circuits share the first power supply circuits and the second power supply circuits.

[0019] Further, the first power supply circuit is connected to the first power pin of each bare lamp bead in the same row or column between the first power supply circuit and the second power supply circuit through a power supply jumper;

[0020] The second power supply circuit is connected to the second power pin of each bare lamp bead in the same row or column between the first power supply circuit and the second power supply circuit through a power supply jumper.

[0021] Further, the power supply circuit is a conductive grid or an ITO conductive film or a nano-silver film.

[0022] Further, the bare lamp beads are fixed on the conductive grid by an insulating die bonding method.

[0023] Further, the transparent substrate on which the bare lamp beads are arranged is provided with a glue filling layer, and each of the bare lamp beads is encapsulated in the glue filling layer; the upper surface of the glue filling layer is provided with a protective cover plate.

[0024] Further, the transparent substrate is provided with a plurality of transparent unit boards; the bare lamp beads are arranged on the transparent unit boards; the transparent unit boards are provided with metal strips on both sides as the power supply lines; and the bare lamp beads on the transparent unit boards are connected to the power supply lines.

[0025] Further, the diameters of the power jumpers and the signal jumpers are 15 μm-70 μm.

[0026] By removing the shell in the existing LED lamp bead, only retaining the driving chip, and arranging the light-emitting wafer on the driving chip to form a bare lamp bead without a shell, the bare lamp bead is arranged on the transparent substrate to replace the existing LED lamp bead array. The size of the bare lamp bead is as small as 0.5 mm x 0.7 mm, 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. The transparent LED display screen with a pitch smaller than 3 mm x 3 mm can be manufactured. Even under the condition of a pitch of 2 mm x 2 mm, the transparency of more than 80% can be maintained, and the transparent effect is very obvious. The power supply and signal transmission are realized by the jumper binding. The diameter of the binding wire is small. Under the condition of ensuring the power supply and signal transmission of the bare lamp bead, the overall resistance of the conductive material to the line of sight is reduced, so that the transparency of the transparent LED display screen can be further improved. Meanwhile, a pair of power pins are arranged on the driving chip of the bare lamp bead. The first power supply line is connected to the first power pin of each bare lamp bead through the power jumper. The second power supply line is connected to the second power pin of each bare lamp bead through the power jumper. The power of each bare lamp bead can be directly taken from the power supply line through the power jumper. The power transmission does not need to pass through the internal circuit of each bare lamp bead. When the internal circuit of the bare lamp bead fails, the normal work of other bare lamp beads is not affected. The power jumper is connected outside the bare lamp bead. The fault query and maintenance are more intuitive and convenient, and the maintenance difficulty is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a cross-sectional view of a transparent LED display screen disclosed in the prior art;

[0028] Figure 2 is a top view of a transparent LED display screen disclosed in the prior art;

[0029] Figure 3 is a three-dimensional view of an LED lamp bead disclosed in the prior art;

[0030] Figure 4 、 Figure 5 is a partial cross-sectional view of a transparent LED display screen from different angles provided in the specific embodiment of the present application;

[0031] Figure 6 is a perspective view of a bare lamp bead provided in the specific embodiment of the present application;

[0032] Figure 7 is a top view of a bare lamp bead provided in the specific embodiment of the present application;

[0033] Figure 8 is a top view of a transparent LED display screen provided with bare lamp beads in the specific embodiment of the present application; Figure 6 , Figure 7

[0034] Figure 9 is a further preferred top view of a bare lamp bead provided in the specific embodiment of the present application;

[0035] Figure 10 is a top view of a transparent LED display screen provided with bare lamp beads in the specific embodiment of the present application; Figure 9

[0036] Figure 11 is a transparent LED display screen further extended in the specific embodiment of the present application; Figure 8

[0037] Figure 12 is a top view of a transparent LED display screen provided with bare lamp beads in the specific embodiment of the present application; Figure 9

[0038] Figure 13 is a top view of a transparent LED display screen provided with bare lamp beads in the specific embodiment of the present application; Figure 9

[0039] Figure 14 is a partial cross-sectional view of the Figure 13

[0040] Figure 15 is a top view of a further improved transparent LED display screen provided in the specific embodiment of the present application.

[0041] In the background art, the following reference signs are used: 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', housing; 23', pin;

[0042] ​​​​​​Specific implementation method: 1, transparent substrate; 2, bare lamp beads; 3, circuit pattern; 4, protective cover plate; 5, glue 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 pin; 31, power supply circuit; 31a, first power supply circuit; 31b, second power supply circuit; 32, signal line; 33, signal pad; 311, power jumpers; 321, signal jumpers; 331, first signal pad; 332, second signal pad. Specific implementation

[0043] In order to make the technical problems solved by the present application, technical solutions and beneficial effects more clear, the present application will be further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application, and not to limit the present application.

[0044] In the description of the present application, it should be understood that the terms "longitudinal", "radial", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, which 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, therefore it cannot be understood as a limitation on the present application. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0045] In the description of the present application, it should be noted that, unless otherwise specified and limited, the terms "mounting", "connecting", "connecting" 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.

[0046] Examples

[0047] This example will specifically explain the transparent LED display screen disclosed in the present application, as shown in Figure 4 , Figure 5 , which includes a transparent substrate 1 and bare lamp beads 2; the transparent substrate 1 is provided with a circuit pattern 3; the bare lamp beads 2 are arrayed on the transparent substrate 1; as shown in Figure 6 , Figure 7As shown, 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 package housing (English name: housing, also named as bracket or base in Chinese) on the basis of the traditional LED lamp bead. After the light-emitting wafer 20 is mounted 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 housing. That is, the bare lamp bead 2 in the present example is essentially the driving chip 21 with the light-emitting wafer 20 embedded and mounted.

[0048] 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 traditional LED lamp bead. Therefore, the resolution of the transparent LED display screen can be effectively improved.

[0049] Preferably, a glue-filling layer 5 is further arranged on the transparent substrate 1 with the bare lamp bead 2, the glue-filling layer 5 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.

[0050] As shown in FIG. 1, the transparent substrate 1 is provided with a plurality of bare lamp beads 2 arranged in a matrix form. The bare lamp beads 2 are arranged in a matrix form on the transparent substrate 1, and the transparent substrate 1 is provided with a plurality of bare lamp beads 2 arranged in a matrix form. Figure 6 , Figure 7As shown, the driving chip 21 is known to the public, generally the driving chip 21 has driving circuit integrated inside, and has a passivation layer on the driving chip 21, the passivation layer is a surface insulation layer formed when the driving chip 21 is manufactured. The driving chip 21 has several pins, the technology of mounting the light emitting wafer 20 on the driving chip 21 is known to the public, generally adopts the technology of (CSP or COC) to be fixedly mounted on the driving chip 21, the pins on the driving chip 21 are electrically connected with the light emitting wafer 20 through direct welding or through bonding wires. The bonding wires or binding wires generally include gold wires, copper wires, palladium plated copper wires and alloy wires, etc. Not described again. The pins (English name: PAD) are generally arranged on the passivation layer, the pins are terminals inside the chip. The driving chip 21 includes a pair of signal pins 211 and a pair of power pins; wherein, the pair of signal pins 211 includes a first signal pin and a second signal pin; the pair of power pins includes a first power pin 212 and a second power pin 213; as shown in the figure, the driving chip 21 is divided into upper, lower, left and right directions; it can be seen that, the pair of signal pins 211 are arranged at the right upper corner and the left lower corner of the driving chip 21 respectively; the pair of power pins are arranged at the left upper corner and the right lower corner respectively. In this example, as a preferred mode, the above-mentioned light emitting wafer 20 includes three kinds of red, green and blue light emitting wafers 20, which are respectively called first light emitting wafer, second light emitting wafer and third light emitting wafer; 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.

[0051] In this configuration, the input and output of the aforementioned signal pins 211 are opposite. For example, if the first signal pin is the input signal pin 211, then the second signal pin is the output signal pin 211. Conversely, if the first signal pin is the output signal pin 211, then the second signal pin is the input signal pin 211. Preferably, the two signal pins 211 can be switched. One of the two signal pins 211 serves as the input signal pin 211, and the other serves as the output signal pin 211. Preferably, the bare LED 2 is a bidirectional transmission bare LED. If the first signal pin of the bidirectional transmission bare LED 2 is the input signal pin 211, then the second signal pin is the output signal pin 211; conversely, if the second signal pin of the bidirectional transmission bare LED 2 is the input signal pin 211, then the first signal pin is the output signal pin 211. Using this bidirectional transmission bare LED chip, when bare LED chips 2 are connected in series, bidirectional input signals from bare LED chips 2 can be transmitted. The bidirectional transmission scheme is the applicant's original technology, and the applicant has already obtained patent protection for the bidirectional transmission driver chip 21 and the LED chips (see CN111341247A for details). This example can directly reference its bidirectional transmission scheme; further details are omitted.

[0052] like Figure 8 As shown, circuit pattern 3 includes power pads (not shown), signal pads 33, and power supply lines 31. The power supply lines 31 include several first power supply lines 31a and second power supply lines 31b with opposite polarities. The power pads connect the first power supply lines 31a and the second power supply lines 31b. In this example, only one first power supply line 31a and one second power supply line 31b are shown, but the number of power supply lines 31 can be further increased. This allows several rows or columns to share the first power supply lines 31a and the second power supply lines 31b.

[0053] In this embodiment, the bare LED 2 is connected to the signal pad 33 or the bare LED 2 before and after it via the signal line 32 (specifically the signal jumper 321 in this application) to realize the series connection of the bare LED 2 and form a string of LEDs; so that the control signal for controlling the on and off of each bare LED 2 can be input from the signal pad 33 through the signal jumper 321 and then transmitted sequentially through each series-connected bare LED 2;

[0054] The first power pin 212 on each bare LED 2 is connected to the first power supply line 31a or the first power pin 212 on the adjacent bare LED 2 via a power jumper 311; the second power pin 213 on each bare LED 2 is connected to the second power supply line 31b or the second power pin 213 on the adjacent bare LED 2 via a power jumper 311; so that each bare LED 2 can directly draw power from the power supply line 31.

[0055] In the present application, several columns or several rows of bare lamp beads 2 share the power supply lines 31, that is, several bare lamp beads 2 between the first power supply line 31a and the second power supply line 31b share the first power supply line 31a and the second power supply line 31b.

[0056] Preferably, the first power supply line 31a is connected to the first power supply pin 212 of each bare lamp bead 2 in the same row (or column) between the first power supply line 31a and the second power supply line 31b by a power jumper 311. Using a power jumper 311 to connect bare lamp beads 2 in the same row (or column) does not need to disconnect the power jumper 311 in the middle, improves the efficiency of wiring, and can prevent the power jumpers 311 on each bare lamp bead 2 from interfering with each other, facilitating processing and installation. In addition, multiple power jumpers 311 can also be used to connect the first power supply pin 212 of each bare lamp bead 2.

[0057] Preferably, the second power supply line 31b is connected to the second power supply pin 213 of each bare lamp bead 2 in the same row (or column) between the first power supply line 31a and the second power supply line 31b by a power jumper 311. Using a power jumper 311 to connect bare lamp beads 2 in the same row (or column) does not need to disconnect the power jumper 311 in the middle, improves the efficiency of wiring, and can prevent the power jumpers 311 on each bare lamp bead 2 from interfering with each other, facilitating processing and installation. In addition, multiple power jumpers 311 can also be used to connect the second power supply pin 213 of each bare lamp bead 2.

[0058] The power jumper 311 and the signal jumper 321 in the present example are the binding wires or bonding wires understood by those skilled in the art, which are only named differently here to distinguish the devices. Using power jumpers 311 and signal jumpers 321 can effectively improve the transparency of the transparent LED display screen. The power jumper 311 and the signal jumper 321 described above are preferably 15-70 μm in diameter and made of gold wire, copper wire or alloy wire. Since the diameter is very small, it is almost invisible to the naked eye, thus reducing the obstruction to the line of sight while ensuring that the working current of the connected several bare lamp beads 2 is met, and improving the transparency of the product.

[0059] 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 signal pin 211 of the bare lamp beads 2 in the first column first row is connected to the signal pad 33 through the signal jumper 321, the signal output of the signal pin 211 of the bare lamp beads 2 in the first column first row is connected to the signal input of the signal pin 211 of the bare lamp beads 2 in the first column second row through the signal jumper 321; the signal output of the signal pin 211 of the bare lamp beads 2 in the first column second row is connected to the signal input of the signal pin 211 of the bare lamp beads 2 in the first column third row through the signal jumper 321; the signal output of the signal pin 211 of the bare lamp beads 2 in the first column third row is connected to the signal input of the signal pin 211 of the bare lamp beads 2 in the first column fourth row through the signal jumper 321. In this way, the transmission of the control signal in the column of bare lamp beads 2 is realized.

[0060] In this example, the bare lamp beads 2 are connected to the transparent substrate 1 by COG (English full name: chip on glass) method. The COG method means that the chip is directly connected to the transparent substrate 1.

[0061] 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.

[0062] Preferably, the light-emitting wafer 20 is mounted on the driving chip 21 by CSP (English full name: Chip Scale Package, Chinese full name: Chip Scale Package) method. Details are not described herein. The light-emitting wafer 20 can also be mounted on the driving chip 21 by COC (English full name: Chip On Chip, Chinese full name: Chip On Chip) method. Details are not described herein.

[0063] The applicant found in the research and development process that, at present, due to the objective fact of signal attenuation in the signal transmission process, the number of LED lamp beads connected in series in the traditional LED lamp bead is too large, and the display effect will decrease. In the ideal state, the number of LED lamp beads connected in series in a lamp string is generally controlled within 384. This greatly reduces the size of the LED transparent display screen.

[0064] It should be noted that the signal transmission in this example does not necessarily have to be achieved through the signal pad and the signal line and each bare lamp bead, 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 this example, the method of connecting each bare lamp bead in series through the signal pad and the signal jumper is the preferred method.

[0065] As a preferred mode, as shown in Figure 9 The driving chip 21 further comprises a pair of short-circuit pins 214, which comprises a short-circuit pin 214 of input signal and a short-circuit pin 214 of 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.

[0066] As a preferred mode, as shown in Figure 9 , Figure 10 Each lamp bead string is provided with two signal pads 33, which are respectively referred to as a first signal pad 331 and a second signal pad 332.

[0067] In the lamp bead string, the signal pin 211 of the input signal of the first bare lamp bead 2 is connected to the first signal pad 331, and the short-circuit pin 214 of the input signal of the first bare lamp bead 2 is connected to the second signal pad 332.

[0068] Alternatively, the signal pin 211 of the input signal of the first bare lamp bead 2 is connected to the second signal pad 332, and the short-circuit pin 214 of the input signal of the first bare lamp bead 2 is connected to the first signal pad 331.

[0069] The signal pin 211 of the input signal of each bare lamp bead 2 is connected to the short-circuit pin 214 of the output signal of the previous bare lamp bead 2, and the short-circuit pin 214 of the input signal of each bare lamp bead 2 is connected to the signal pin 211 of the output signal of the previous bare lamp bead 2; the signal pin 211 of the output signal of each bare lamp bead 2 is connected to the short-circuit pin 214 of the input signal of the next bare lamp bead 2, and the short-circuit pin 214 of the output signal of each bare lamp bead 2 is connected to the signal pin 211 of the input signal of the next bare lamp bead 2.

[0070] 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; 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.

[0071] 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, still taking the first column of bare lamp beads 2 as an example, the first signal pad 331 is bound to the shorting pin 214 of the input signal of the first column of the first row of bare lamp beads 2; the second signal pad 332 is bound to the signal pin 211 of the input signal of the first column of the first row of bare lamp beads 2, so that the first control signal transmitted in the first signal pad 331 is short-circuited to the signal pin 211 of the input signal of the first column of the second row of bare lamp beads 2 without passing through the inside of the first column of the first row of bare lamp beads 2; so that the second control signal transmitted in the second signal pad 332 passes through the first column of the first row of bare lamp beads 2, controls the on-off of the first column of the first row of bare lamp beads 2 by the second control signal, and is transmitted to the shorting pin 214 of the input signal of the first column of the second row of bare lamp beads 2. By analogy, the first control signal is input from the signal pin 211 of the input signal of the first column of the second row of bare lamp beads 2, controls the on-off of the first column of the second row of bare lamp beads 2, and is output to the shorting pin 214 of the input signal of the first column of the third row of bare lamp beads 2 from the signal pin 211 of the output signal, and the second control signal is short-circuited without passing through the inside of the first column of the second row of bare lamp beads 2. By analogy, the first control signal sequentially passes through the bare lamp beads 2 in the even rows, controls the on-off of the bare lamp beads 2 in the even rows, and is short-circuited and transmitted in the bare lamp beads 2 in the odd rows. The second control signal sequentially passes through the bare lamp beads 2 in the odd rows, controls the on-off of the bare lamp beads 2 in the odd rows, and is short-circuited and transmitted in the bare lamp beads 2 in the even rows. Of course, the opposite is also possible.

[0072] In this way, the number of bare lamp beads 2 connected in series in a row or a column of the lamp string can be increased. In this way, the number of bare lamp beads 2 in the lamp string is twice that of the LED lamp beads in a conventional lamp string.

[0073] The power supply circuit 31 includes a plurality of first power supply circuits 31a and second power supply circuits 31b arranged in rows or columns; a plurality of rows or columns of bare lamp beads 2 are arranged between the first power supply circuit 31a and the second power supply circuit 31b; the bare lamp beads 2 share the first power supply circuit 31a and the second power supply circuit 31b. For example, as shown, Figure 11 The first power supply circuit 31a, the second power supply circuit 31b and the first power supply circuit 31a are arranged in intervals; wherein the left first power supply circuit 31a and the second power supply circuit 31b are provided with 4 rows and 4 columns of bare lamp beads 2; the 4 rows and 4 columns of bare lamp beads 2 share the first power supply circuit 31a and the second power supply circuit 31b. The right first power supply circuit 31a and the second power supply circuit 31b are also provided with 4 rows and 4 columns of bare lamp beads 2; the 4 rows and 4 columns of bare lamp beads 2 share the right first power supply circuit 31a and the second power supply circuit 31b.

[0074] 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.

[0075] Although the power jumpers 311 and the signal jumpers 321 intersect each other in the schematic diagram, they are actually wire-bonded at different heights and then fixed by glue filling, so there is no risk of collapse and short circuit.

[0076] 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 circuits 31a and second power supply circuits 31b can be one each, or multiple each. The number of first power supply circuits 31a and second power supply circuits 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.

[0077] 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. 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 a metal sheet embedded in the transparent substrate 1 as described in the applicant's previous patent.

[0078] 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 this figure, the conductive mesh is arranged on both sides of 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.

[0079] As shown in Figure 13 , Figure 14As shown, in order to enhance the conductivity 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.

[0080] As for the design of the power supply line 31, there can also be other forms of variations, 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 the power supply line 31; and the bare lamp beads 2 on each transparent unit plate 6 are connected to the power supply line 31. The power supply lines 31 on both sides are the first power supply line 31a and the second power supply line 31b, respectively. This 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 independent glass plates, and each transparent unit plate 6 is fixed on the lower whole transparent substrate 1.

[0081] By removing the shell in the existing LED lamp bead, only the driving chip 21 is retained, 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 to replace 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. It can make a transparent LED display screen with a pitch less than 3mm x 3mm, and even under the condition of a pitch of 2mm x 2mm, it can maintain a transparency of more than 80%, and the transparent effect is very obvious. The power supply and signal transmission are realized by the way of jumper binding, and a smaller diameter binding wire is selected, which can reduce the obstruction of the conductive material to the line of sight under the condition of ensuring the power supply and signal transmission of the bare lamp bead, so as to further improve the transparency of the transparent LED display screen. At the same time, the driving chip 21 on the bare lamp bead 2 is provided with a pair of power supply pins, the first power supply line 31a is connected to the first power supply pin 212 of each bare lamp bead 2 through the power supply jumper 311, and the second power supply line 31b is connected to the second power supply pin 213 of each bare lamp bead 2 through the power supply jumper 311, so that each bare lamp bead 2 can directly take power from the power supply line 31 through the power supply jumper 311, and the transmission of electric energy does not need to pass through the internal circuit of each bare lamp bead 2, which avoids affecting the normal work of other bare lamp beads 2 when the internal circuit of the bare lamp bead 2 fails, and the power supply jumper 311 is connected outside the bare lamp bead 2, so the fault query and maintenance are more intuitive and convenient, and the maintenance difficulty is reduced.

[0082] The above merely provides the preferred embodiment of the present application, and not intended to limit the present application. Accordingly, any modification, equivalent replacement, and improvement made without departing from the spirit and principle of the present application shall fall in the scope of protection of the present application.

Claims

1. A transparent LED display, characterized by The transparent substrate and the bare lamp beads are included; the circuit pattern is arranged on the transparent substrate; the bare lamp beads are arranged on the transparent substrate in an array; the bare lamp beads include driving chips and light-emitting wafers; the light-emitting wafers are mounted on the driving chips; The circuit pattern includes power supply pads and power supply lines; the power supply lines include 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; The driving chips include a pair of power supply pins; the pair of power supply pins includes first power supply pins and second power supply pins; The first power supply pins on each of the bare lamp beads are connected to the first power supply lines or the first power supply pins on adjacent bare lamp beads through power supply jumpers; the second power supply pins on each of the bare lamp beads are connected to the second power supply lines or the second power supply pins on adjacent bare lamp beads through power supply jumpers; so that each bare lamp bead can directly take power from the power supply lines; The circuit pattern further includes signal pads; the bare lamp beads are connected to the signal pads or adjacent bare lamp beads through signal jumpers; so that the control signals for controlling the on-off of the bare lamp beads can be input from the signal pads and transmitted through the bare lamp beads in sequence; The driving chips further include a pair of signal pins; the driving chips further include a pair of short-circuit pins, including an input signal short-circuit pin and an output signal short-circuit pin; each lamp bead string is provided with two signal pads, namely a first signal pad and a second signal pad; the pair of short-circuit pins are short-circuited inside the driving chips; so that the control signals are directly transmitted between the pair of short-circuit pins without passing through the internal circuit of the driving chips; In the lamp bead string, the input signal signal pin of the first bare lamp bead is connected to the first signal pad, and the input signal short-circuit pin of the first bare lamp bead is connected to the second signal pad; Alternatively, the input signal signal pin of the first bare lamp bead is connected to the second signal pad, and the input signal short-circuit pin of the first bare lamp bead is connected to the first signal pad; The input signal signal pin of each of the remaining bare lamp beads is connected to the output signal short-circuit pin of the previous bare lamp bead, and the input signal short-circuit pin of each of the bare lamp beads is connected to the output signal signal pin of the previous bare lamp bead; the output signal signal pin of each bare lamp bead is connected to the input signal short-circuit pin of the next bare lamp bead, and the output signal short-circuit pin of each bare lamp bead is connected to the input signal signal pin of the next bare lamp bead; The power supply lines include a plurality of first power supply lines and second power supply lines arranged in rows or columns; a plurality of rows or columns of bare lamp beads are arranged between the first power supply lines and the second power supply lines; The first power supply line is connected to the first power supply pin of each bare lamp bead in the same row or column between the first power supply line and the second power supply line through a power supply jumper; the second power supply line is connected to the second power supply pin of each bare lamp bead in the same row or column between the first power supply line and the second power supply line through a power supply jumper; the power supply line is a conductive grid, and the bare lamp bead is fixed on the conductive grid by an insulating die bonding method.

2. The transparent LED display of claim 1, wherein, The pair of signal pins includes a first signal pin and a second signal pin; one of the first signal pin and the second signal pin is a signal pin for inputting a signal, and the other of the first signal pin and the second signal pin is a signal pin for outputting a signal.

3. The transparent LED display of claim 2, wherein, The bare lamp bead is connected to the transparent substrate by a COG method.

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

5. The transparent LED display of claim 2, wherein, The bare lamp bead between the first power supply line and the second power supply line shares the first power supply line and the second power supply line.

6. The transparent LED display of claim 2, wherein, The power supply line is a conductive grid, an ITO conductive film, or a nano-silver thin film.

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

8. The transparent LED display of claim 7, wherein, The transparent substrate is provided with a plurality of transparent unit plates; the bare lamp bead is arranged on the transparent unit plate; metal strips are arranged on both sides of each transparent unit plate as the power supply line; and the bare lamp bead on each transparent unit plate is connected to the power supply line.

9. The transparent LED display of claim 2, wherein, The diameter of the power supply jumper and the signal jumper is 15 μm-70 μm.

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