A naked lamp bead and LED display screen

Abstract

In order to overcome the problem that the size of the LED display screen cannot be made large due to the receiving limit of the LED lamp bead string formed by stringing the LED lamp beads in the prior art, the application provides a bare lamp bead and an LED display screen. The bare lamp bead comprises a driving chip and a light-emitting wafer; the light-emitting wafer is mounted on the driving chip; a pair of power supply pins, a pair of signal pins and a pair of short-circuit pins are arranged on the driving chip; the short-circuit pins comprise a first short-circuit pin and a second short-circuit pin; the first short-circuit pin and the second short-circuit pin are short-circuited; a control signal for controlling the light-emitting wafer to turn on or off does not pass through the internal circuit of the driving chip and is transmitted to the next bare lamp bead. The bare lamp bead provided by the application adopts a shell-free structure, so that the size of the bare lamp bead can be reduced. In this way, the length of the lamp bead string can be effectively lengthened, so that when the lamp bead string is applied to the LED display screen, the size of the LED display screen can be increased.

Description

TECHNICAL FIELD

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

[0002] LED display screen is gradually widely used in the market, and various product forms are developed. The existing LED display screen generally includes a substrate and LED lamp beads arranged in an array on the substrate, as shown in the drawing, the existing LED lamp bead 2' generally includes a shell 22' and a driving chip 21' and a light-emitting wafer 20' formed in the shell 22'; generally, a pin 23' is led out on the shell 22', and the pin 23' is used for mounting on the substrate. Figure 1

[0003] As shown in the drawing, the existing LED display screen is generally formed by a plurality of LED lamp beads 2' (such as one row or one column, or a plurality of rows or a plurality of columns) connected in series end to end to form a lamp bead string, and the LED display screen is composed of a plurality of lamp bead strings. 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 display effect of the traditional LED lamp bead 2' will decrease when the number of connection is too large. In the ideal state, the number of LED lamp beads 2' connected in a lamp bead string is generally controlled within a certain range. This way controls and limits the size of the LED display screen, and the size of the LED display screen cannot be made larger. Figure 2 SUMMARY

[0004] In order to overcome the problem that the size of the LED display screen cannot be made larger due to the limitation of the LED lamp bead string formed by the LED lamp bead in the prior art, the present application provides a bare lamp bead and an LED display screen.

[0005] One aspect of the present application provides a bare lamp bead, which comprises a driving chip and a light-emitting wafer; the light-emitting wafer is mounted on the driving chip;

[0006] A pair of power pins, a pair of signal pins and a pair of short-circuit pins are arranged on the driving chip;

[0007] The signal pins include a first signal pin and a second signal pin, and the control signal for controlling the light-emitting wafer to turn on or off passes through the internal circuit of the driving chip between the first signal pin and the second signal pin, and is transmitted to the next bare lamp bead;

[0008] The short-circuit pins include a first short-circuit pin and a second short-circuit pin; the first short-circuit pin and the second short-circuit pin are short-circuited, and the control signal for controlling the light-emitting wafer to turn on or off does not pass through the internal circuit of the driving chip, and is transmitted to the next bare lamp bead. ​​

[0009] The bare lamp bead provided by the application adopts a shell-free structure, so that the size of the bare lamp bead can be reduced. A pair of signal pins and a pair of short-circuit pins are arranged directly on the driving chip, so that the bare lamp bead can receive two groups of control signals. When one group of control signals is input and output from the signal pins, the control signals will pass through the internal circuit of the driving chip to control the on-off of the light-emitting wafer and be transmitted to the next bare lamp bead. When the other group of control signals is input and output from the short-circuit pins, the control signals will not pass through the internal circuit of the driving chip, but will be directly transmitted to the next bare lamp bead. When the bare lamp bead is connected in series to form a lamp bead string, the two groups of control signals are spaced in the lamp bead string and are transmitted in the bare lamp bead string. In this way, the length of the lamp bead string can be effectively lengthened, so that the size of the LED display screen can be increased when the lamp bead string is applied to the LED display screen.

[0010] Further, the bare lamp bead is provided with color pins, which are electrically connected with the light-emitting wafer respectively.

[0011] Further, the light-emitting wafer is mounted on the driving chip in a CSP or COC mode.

[0012] The application further provides an LED display screen, which comprises a substrate and bare lamp beads.

[0013] The circuit pattern comprises power supply pads, signal 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 with the first power supply lines and the second power supply lines.

[0014] The bare lamp bead comprises a driving chip and a light-emitting wafer. The light-emitting wafer is mounted on the driving chip.

[0015] The driving chip is provided with a pair of power supply pins, a pair of signal pins and a pair of short-circuit pins.

[0016] The power supply pins comprise first power supply pins and second power supply pins. The first power supply pins are directly or indirectly connected with the first power supply lines, and the second power supply pins are directly or indirectly connected with the second power supply lines.

[0017] The signal pins comprise first signal pins and second signal pins. The first signal pins and the second signal pins pass through the internal circuit of the driving chip. Control signals for controlling the on-off of the light-emitting wafer pass through the internal circuit of the driving chip and are transmitted to the next bare lamp bead.

[0018] The shorting pin includes a first shorting pin and a second shorting pin; the first shorting pin and the second shorting pin are shorted; a control signal for controlling the light-emitting chip to turn on or off does not pass through the internal circuit of the driving chip and is transmitted to the next bare lamp bead;

[0019] The bare lamp beads are connected in series to form a lamp bead string, and each lamp bead string is provided with two signal pads, namely a first signal pad and a second signal pad;

[0020] 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 shorting pin of the input signal of the first bare lamp bead is connected to the second signal pad; or the signal pin of the input signal of the first bare lamp bead is connected to the second signal pad, and the shorting pin of the input signal of the first bare lamp bead is connected to the first signal pad;

[0021] The signal pin of the input signal of each remaining bare lamp bead is connected to the shorting pin of the output signal of the previous bare lamp bead, and the shorting pin of the input signal of each bare lamp bead 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 bare lamp bead is connected to the shorting pin of the input signal of the next bare lamp bead, and the shorting pin of the output signal of each bare lamp bead is connected to the signal pin of the input signal of the next bare lamp bead.

[0022] The LED display screen disclosed in the present application can reduce the size of the bare lamp bead due to the array arrangement of the bare lamp bead without a shell structure. A pair of signal pins and a pair of shorting pins are directly arranged on the driving chip, so that the bare lamp bead can receive two groups of control signals. When one group of control signals is input and output from the signal pin, the control signal will pass through the internal circuit of the driving chip to control the light-emitting chip to turn on or off and be transmitted to the next bare lamp bead. When the other group of control signals is input and output from the shorting pin, the control signal will not pass through the internal circuit of the driving chip but be directly transmitted to the next bare lamp bead. Each bare lamp bead not only receives the control signal output by the second bare lamp bead upstream and works, but also is a signal transmission medium of the previous bare lamp bead, which directly transmits the control signal of the previous bare lamp bead to the next bare lamp bead without passing through the bare lamp bead. When the bare lamp beads are connected to form a lamp bead string, the two groups of control signals are spaced in the lamp bead string and are transmitted in the bare lamp bead string. This method can effectively lengthen the length of the lamp bead string, so that the size of the LED display screen can be increased when the LED display screen is applied to the LED display screen.

[0023] Further, the substrate is a transparent substrate. At this time, the LED display screen is a transparent LED display screen.

[0024] Further, the bare lamp bead is connected to the transparent substrate by a COG method.

[0025] Further, the transparent substrate with the bare lamp beads is provided with a glue filling layer, and the bare lamp beads are packaged in the glue filling layer; and the upper surface of the glue filling layer is provided with a protective cover plate.

[0026] Further, the bare lamp beads are connected with the signal pads, or the short-circuit pads, or the bare lamp beads in front of and behind the bare lamp beads through signal jumpers.

[0027] Further, the first power supply pins on the bare lamp beads are connected to the first power supply lines, or the first power supply pins on the adjacent bare lamp beads through power jumpers; and the second power supply pins on the bare lamp beads are connected to the second power supply lines, or the second power supply pins on the adjacent bare lamp beads through power jumpers; so that the bare lamp beads can directly take power from the power supply lines, or from the adjacent bare lamp beads.

[0028] Further, the diameters of the power jumpers and the signal jumpers are 15 μm-70 μm. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a schematic view of a LED lamp bead in the prior art;

[0030] Figure 2 is a schematic view of a LED lamp bead string in the prior art;

[0031] Figure 3 is a schematic view of a bare lamp bead in the embodiment of the present application;

[0032] Figure 4 is a schematic view of a bare lamp bead in the embodiment of the present application;

[0033] Figure 5 is a schematic view of a transparent LED display screen provided with bare lamp beads in the embodiment of the present application; Figure 3 , Figure 4 is a schematic view of a transparent LED display screen provided with bare lamp beads in the embodiment of the present application;

[0034] Figure 6 is a schematic view of a transparent LED display screen provided with bare lamp beads in the embodiment of the present application; Figure 3 , Figure 4 is a schematic view of a transparent LED display screen provided with bare lamp beads in the embodiment of the present application;

[0035] Figure 7 is a schematic view of another transparent LED display screen in the embodiment of the present application.

[0036] In the background art, the reference signs are as follows: 2', LED lamp bead; 20', light emitting chip; 21', driving chip; 22', shell; 23', pin;

[0037] Specific embodiments of the drawings: 1, transparent substrate; 2, bare lamp beads; 3, circuit pattern; 4, protective cover plate; 5, glue layer; 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 pin; 213, second power 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 jumper; 321, signal jumper; 331, first signal pad; 332, second signal pad. Specific embodiments

[0038] 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. 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.

[0039] 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 therefore cannot be understood as indicating or implying 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 limiting the present application. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0040] 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.

[0041] Example 1

[0042] This example will specifically explain the bare lamp beads 2 disclosed in the present application. As shown in Figure 3 , Figure 4 The bare lamp beads 2 disclosed in this example include a driving chip 21 and a light emitting wafer 20; the light emitting wafer 20 is mounted on the driving chip 21;

[0043] The driving chip 21 is provided with a pair of power supply pins, a pair of signal pins 211 and a pair of short-circuit pins 214;

[0044] The signal pins 211 include a first signal pin and a second signal pin, and the first signal pin 211 and the second signal pin pass through the internal circuit of the driving chip 21; the control signal for controlling the on-off of the light-emitting wafer 20 passes through the internal circuit of the driving chip 21 and is transmitted to the next bare lamp bead 2;

[0045] The short-circuit pins 214 include a first short-circuit pin and a second short-circuit pin, and the first short-circuit pin and the second short-circuit pin are short-circuited; the control signal for controlling the on-off of the light-emitting wafer 20 does not pass through the internal circuit of the driving chip 21 and is transmitted to the next bare lamp bead 2.

[0046] The bare lamp bead 2 in the present application is based on the traditional LED lamp bead, and the housing (English name) is cancelled. The light-emitting wafer 20 is installed on the driving chip 21 without encapsulation. 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 embedded with the light-emitting wafer 20.

[0047] The size of the bare lamp bead 2 is 0.5mm x 0.5mm to 0.7mm x 0.7mm, which is much smaller than the traditional LED lamp bead. Therefore, the resolution of the transparent LED display screen can be effectively improved.

[0048] Generally, the driving chip 21 has a driving circuit integrated inside, and a passivation layer is provided on the driving chip 21. The passivation layer is a surface insulating layer formed when the driving chip 21 is manufactured. The driving chip 21 is provided with a plurality of pins. The technology of mounting the light-emitting wafer 20 on the driving chip 21 is known to the public. Generally, the technology of (CSP or COC) is used to fix and mount on the driving chip 21. The pins on the driving chip 21 are electrically connected to the light-emitting wafer 20 through direct welding or through bonding wires. The bonding wire, also known as the binding wire, usually includes gold wire, copper wire, palladium-plated copper wire, and alloy wire, etc. It will not be described again. The pin (English name: PAD) is generally provided on the passivation layer, and the pin is a terminal inside the chip. The driving chip 21 includes a pair of signal pins 211 and power pins and a pair of short pins 214; wherein the signal pins 211 include a first signal pin and a second signal pin; the power pins include a first power pin 212 and a second power pin 213213; 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 respectively arranged at the right upper corner and the left lower corner of the driving chip 21; one pair of power pins is arranged on the upper part of the left side; the other pair of power 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 red, green and blue light-emitting wafers 20, which are 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] Among them, the input and output of the above-mentioned 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 serves as a signal input pin, and the other serves as 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. By using such a bidirectional transmission bare lamp bead, bidirectional input signals of the bare lamp bead 2 can be realized and transmitted when the bare lamp bead 2 is connected in series. The bidirectional transmission scheme is the original technology of the applicant, and the applicant has already patented the driving chip 21 and the lamp bead for bidirectional transmission (for details, please refer to CN111341247A). In this example, the bidirectional transmission scheme can be directly quoted. It will not be described again.

[0050] The pair of short-circuiting pins 214 includes a short-circuiting pin 214 for input signal and a short-circuiting pin 214 for output signal; the pair of short-circuiting pins 214 are short-circuited inside the driving chip 21, so that the control signal is transmitted directly between the short-circuiting pins 214 without passing through the circuit inside the driving chip 21. For example, the first short-circuiting pin is the short-circuiting pin 214 for input signal, and the second short-circuiting pin is the short-circuiting pin 214 for output signal, or vice versa; the second short-circuiting pin is the short-circuiting pin 214 for input signal, and the first short-circuiting pin is the short-circuiting pin 214 for output signal.

[0051] 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. 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.

[0052] Preferably, the light-emitting wafer 20 is mounted on the driving chip 21, and then the bare lamp bead 2 is mounted on the transparent substrate 1 as a whole, which is beneficial to improve the process efficiency and yield.

[0053] Preferably, the bare lamp bead 2 is provided with color pins, and the color pins are electrically connected with the light-emitting wafer 20 respectively. For example, the color pins include red pin, green pin and blue pin, the red pin is electrically connected with the red light-emitting wafer 20r, the green pin is electrically connected with the green light-emitting wafer 20g, and the blue pin is electrically connected with the blue light-emitting wafer 20b; the on-off of each light-emitting wafer is controlled through the color pins.

[0054] The bare lamp bead 2 provided by the present application adopts a shell-free structure, so that the size of the bare lamp bead 2 can be reduced. A pair of signal pins 211 and a pair of short-circuiting pins 214 are arranged on the driving chip 21, so that the bare lamp bead 2 can receive two groups of control signals. When one group of control signals is input and output from the signal pins 211, the control signals will pass through the internal circuit of the driving chip 21 to control the on-off of the light-emitting wafer 20 and be transmitted to the next bare lamp bead 2; when the other group of control signals is input and output from the short-circuiting pins 214, the control signals will not pass through the internal circuit of the driving chip 21, but be directly transmitted to the next bare lamp bead 2. When the bare lamp bead 2 is connected in series to form a lamp bead string, the two groups of control signals are spaced in the lamp bead string and are transmitted in the bare lamp bead 2. In this way, the length of the lamp bead string can be effectively lengthened, so that the size of the LED display screen can be increased when the bare lamp bead 2 is applied to the LED display screen.

[0055] Embodiment 2

[0056] The present example will be explained in detail for the LED display screen disclosed in the present application. As shown in Figure 5 , Figure 6 The LED display screen disclosed in the present example comprises a substrate and bare lamp beads 2. A circuit pattern 3 is arranged on the substrate. The bare lamp beads 2 are arranged in an array on the substrate. The bare lamp beads 2 are the bare lamp beads 2 shown in Embodiment 1.

[0057] The circuit pattern 3 comprises a power supply pad (not shown in the figure), a signal pad 33 and a power supply circuit 31. The power supply circuit 31 comprises 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.

[0058] The first power supply pin 212 is directly or indirectly connected to the first power supply circuit 31a, and the second power supply pin 213 is directly or indirectly connected to the second power supply circuit 31b.

[0059] A plurality of bare lamp beads 2 are connected in series to form a lamp bead string. 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.

[0060] 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 pin 214 of the input signal of the first bare lamp bead 2 is connected to the second signal pad 332; or, 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 pin 214 of the input signal of the first bare lamp bead 2 is connected to the first signal pad 331.

[0061] The signal pin 211 of the input signal of each of the remaining bare lamp beads 2 is connected to the short pin 214 of the output signal of the previous bare lamp bead 2, and the short pin 214 of the input signal of each of the bare lamp beads 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 pin 214 of the input signal of the next bare lamp bead 2, and the short 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.

[0062] As for the connection mode between the bare lamp beads 2, a signal line 32 known to those skilled in the art can be used to connect the signal pads and the bare lamp beads 2. As a preferred mode, which is not known, the bare lamp beads 2 are connected to the signal pads, or the short pads, or the bare lamp beads before and after them through signal jumpers 321.

[0063] In this way, a single LED string can be transformed into two LED strings controlled by two control signals. For example, the odd-numbered bare LEDs 2 in the LED string transmit control signals from the first signal pad 331; the even-numbered bare LEDs 2 in the LED string transmit control signals from the second signal pad 332; and vice versa. Due to this special bonding connection method, the two signals from the first signal pad 331 and the second signal pad 332 are always transmitted in adjacent bare LEDs 2 or short-circuited so that they do not pass through the interior of those bare LEDs 2.

[0064] Further description is as follows: Let the control signal input to the first signal pad 331 be the first control signal, and the control signal input to the second signal pad 332 be the second control signal; then... Figure 6 As 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.

[0065] This method increases the number of bare LED chips (2) connected in a row or column of LED strings. The number of bare LED chips in a string using this method is twice that of a conventional LED string.

[0066] The substrate can be any substrate well known to those skilled in the art, such as an opaque substrate or a transparent substrate 1. In this example, a transparent substrate 1 is preferred. In this case, the LED display screen is a transparent LED display screen.

[0067] The bare LED chip 2 is bonded to the transparent substrate 1 via COG (chip-on-glass) bonding. COG means the chip is directly bonded to the transparent substrate 1. This is well known to those skilled in the art.

[0068] In this example, a potting layer 5 is provided on the transparent substrate 1 on which the bare LED beads 2 are arranged, and the potting layer 5 encapsulates each of the bare LED beads 2 therein; a protective cover plate 4 is provided on the upper surface of the potting layer 5. The design of the potting layer 5 and the protective cover plate 4 is well known to those skilled in the art and will not be described in detail here.

[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 7 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] By using the above method, several columns or rows of bare LED beads 2 can share the same polarity power supply line 31. By arranging them in this cyclical manner, a large-area transparent LED display screen can be made. Sharing the power supply line 31 with several bare LED beads 2 can reduce the number of power supply lines 31, reduce obstruction of the view, and help improve the transparency of the display screen.

[0071] This application is not limited to the implementation of power supply line 31, which is not the core innovation of this application. It can be implemented in a manner known to those skilled in the art. The number of first power supply lines 31a and second power supply lines 31b can be only one or multiple. The number of first power supply lines 31a and second power supply lines 31b can be the same or different. The specific number depends on the power supply capacity of power supply line 31 and the current demand of bare LED beads 2 between first power supply lines 31a and second power supply lines 31b.

[0072] The power supply line 31 can be in the form of a straight line, or can be arranged in a curved line, or can be arranged in a serpentine line segment, etc. As a preferred mode, each power supply line 31 is generally arranged in a row or column, and the implementation mode is not limited, as long as it can provide power supply power. For example, it can be a metal layer etched on the transparent substrate 1, or a metal mesh, or a nano-silver plating film or an ITO plating film, or a metal wire or a metal sheet embedded in the transparent substrate 1, etc. as arranged in the patent previously applied by the applicant.

[0073] The first power supply pin 212 on each of the bare lamp beads 2 is connected to the first power supply line or the first power supply pin 212 on the adjacent bare lamp bead 2 through the power supply jumper 311; the second power supply pin 213 on each of the bare lamp beads 2 is connected to the second power supply line or the second power supply pin 213 on the adjacent 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 or from the adjacent bare lamp bead 2.

[0074] The power supply jumper 311 and the signal jumper 321 in this 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. By using the power supply jumper 311 and the signal jumper 321, the transparency of the transparent LED display screen can be effectively improved. The power supply jumper 311 and the signal jumper 321 described above are preferably 15-70 μm in diameter, and are made of gold wire, copper wire or alloy wire. Since the diameter is very small, it is almost invisible to the naked eye, so while ensuring that the working current of the connected several bare lamp beads 2 is met, the blockage to the line of sight is reduced, and the transparency of the product is improved.

[0075] Although the power supply jumper 311 and the signal jumper 321 are crossed with each other in the schematic diagram, they are actually wire-bonded at different heights, and then fixed by pouring glue, so they will not be short-circuited by collapsing.

[0076] The LED display screen disclosed in the application can reduce the size of the bare lamp bead 2 due to the shell-free structure of the arrayed bare lamp bead 2. A pair of signal pins and a pair of short-circuit pins 214 are arranged directly on the driving chip 21, so that the bare lamp bead 2 can receive two groups of control signals. When one group of control signals is input and output from the signal pins, the control signals will pass through the internal circuit of the driving chip 21 to control the light-emitting wafer 20 to turn on and off and be transmitted to the next bare lamp bead 2. Another group of control signals will not pass through the internal circuit of the driving chip 21, but be directly transmitted to the next bare lamp bead 2 when input and output from the short-circuit pins 214. Each bare lamp bead 2 not only receives the control signals output by the second upstream bare lamp bead 2 and works, but also is the signal transmission medium of the previous bare lamp bead 2, so that the control signals of the previous bare lamp bead 2 are directly transmitted to the next bare lamp bead 2 without passing through the bare lamp bead 2. When the bare lamp beads 2 are connected in series to form a lamp bead string, the two groups of control signals are spaced in the lamp bead string and are transmitted in the bare lamp bead 2 string. In this way, the length of the lamp bead string can be effectively lengthened, so that the size of the LED display screen can be increased when the LED display screen is applied.

[0077] The above only describes the preferred embodiments of the application and is not used to limit the application. Any modification, equivalent replacement and improvement within the spirit and principle of the application should be included in the protection scope of the application.

Claims

1. A bare LED bead, characterized in that, The bare LED bead includes a driver chip and a light-emitting chip; the light-emitting chip is mounted on the driver chip. The driver chip has a pair of power pins, a pair of signal pins, and a pair of shorting pins; The signal pins include a first signal pin and a second signal pin. The first signal pin and the second signal pin are connected through the internal circuit of the driver chip. The control signal for controlling the light-emitting chip to turn on and off passes through the internal circuit of the driver chip and is transmitted to the next bare LED. The shorting pin includes a first shorting pin and a second shorting pin; the first shorting pin and the second shorting pin are shorted together, so that the control signal for controlling the light-emitting chip to turn on or off does not pass through the internal circuit of the driver chip, but is transmitted to the next bare LED. A string of bare LEDs is formed by connecting several bare LEDs in series. Each LED string has two signal pads, referred to as the first signal pad and the second signal pad, respectively. In the LED string, the signal pin of the input signal of the first bare LED is connected to the first signal pad, and the shorting pin of the input signal of the first bare LED is connected to the second signal pad; or, the signal pin of the input signal of the first bare LED is connected to the second signal pad, and the shorting pin of the input signal of the first bare LED is connected to the first signal pad. The input signal pins of the remaining bare LEDs are connected to the shorting pins of the output signal of the previous bare LED, and the shorting pins of the input signals of each bare LED are connected to the signal pins of the output signal of the previous bare LED; the output signal pins of each bare LED are connected to the shorting pins of the input signal of the next bare LED, and the shorting pins of the output signal of each bare LED are connected to the signal pins of the input signal of the next bare LED.

2. The bare LED bead according to claim 1, wherein the bare LED bead is provided with color pins, and the color pins are electrically connected to the light-emitting chip respectively.

3. The bare LED bead according to claim 1, characterized in that, The light-emitting chip is mounted on the driver chip via CSP or COC.

4. An LED display screen, characterized in that, It includes a substrate and bare LED beads; the substrate has a circuit pattern; the bare LED bead array is arranged on the substrate; The circuit pattern includes power pads, signal pads, and power supply lines; the power supply lines include several first power supply lines and second power supply lines with opposite polarities; the power pads connect the first power supply lines and the second power supply lines. The bare LED bead includes a driver chip and a light-emitting chip; the driver chip has a passivation layer; the light-emitting chip is mounted on the driver chip; the driver chip has one or more power pins, one pair of signal pins, and one pair of shorting pins; The power pin includes a first power pin and a second power pin; the first power pin is directly or indirectly connected to the first power supply line, and the second power pin is directly or indirectly connected to the second power supply line. The signal pins include a first signal pin and a second signal pin, and the first signal pin and the second signal pin are connected through the internal circuit of the driver chip; the control signal for controlling the light-emitting chip to turn on or off passes through the internal circuit of the driver chip and is transmitted to the next bare LED. The shorting pin includes a first shorting pin and a second shorting pin; the first shorting pin and the second shorting pin are shorted together; the control signal that controls the on / off state of the light-emitting chip does not pass through the internal circuit of the driver chip, but is transmitted to the next bare LED bead; A string of bare LEDs is formed by connecting several bare LEDs in series. Each LED string is provided with two signal pads, which are referred to as the first signal pad and the second signal pad, respectively. In the LED string, the signal pin of the input signal of the first bare LED is connected to the first signal pad, and the shorting pin of the input signal of the first bare LED is connected to the second signal pad; or, the signal pin of the input signal of the first bare LED is connected to the second signal pad, and the shorting pin of the input signal of the first bare LED is connected to the first signal pad. The input signal pins of the remaining bare LEDs are connected to the shorting pins of the output signal of the previous bare LED, and the shorting pins of the input signals of each bare LED are connected to the signal pins of the output signal of the previous bare LED; the output signal pins of each bare LED are connected to the shorting pins of the input signal of the next bare LED, and the shorting pins of the output signal of each bare LED are connected to the signal pins of the input signal of the next bare LED.

5. The LED display screen according to claim 4, characterized in that, The substrate is a transparent substrate.

6. The LED display screen according to claim 5, characterized in that, The bare LED beads are bonded to the transparent substrate using a COG method.

7. The LED display screen according to claim 5, characterized in that, A potting layer is provided on a transparent substrate on which the bare LED beads are arranged, and the potting layer encapsulates each of the bare LED beads therein; The upper surface of the potting layer is provided with a protective cover plate.

8. The LED display screen according to claim 5, characterized in that, The bare LEDs are connected to signal pads, shorting pads, or bare LEDs before and after them via signal jumpers.

9. The LED display screen according to claim 5, characterized in that, The first power pin on each of the bare LEDs is connected to the first power supply line or the first power pin on a neighboring bare LED via a power jumper; the second power pin on each of the bare LEDs is connected to the second power supply line or the second power pin on a neighboring bare LED via a power jumper; so that each bare LED can draw power directly from the power supply line or from a neighboring bare LED.

10. The LED display screen according to claim 8, characterized in that, The diameter of the signal jumper is 15μm-70μm.

11. The LED display screen according to claim 9, characterized in that, The diameter of the power jumper is 15μm-70μm.

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