WO2020252877A1

WO2020252877A1 - Micron light-emitting diode matrix display

Info

Publication number: WO2020252877A1
Application number: PCT/CN2019/100967
Authority: WO
Inventors: 刘召军; 李伟增; 吕志坚; 范柚攸; 刘心怡; 赵晨曦; 雷雨
Original assignee: 深圳市思坦科技有限公司
Priority date: 2019-06-21
Filing date: 2019-08-16
Publication date: 2020-12-24
Also published as: CN110111729A; CN110111729B

Abstract

A micron light-emitting diode matrix display (10), comprising: a plurality of pixel circuits (100), each comprising a micron light-emitting diode (101), and the micron light-emitting diodes (101) being connected to a driving power supply (111) by means of a first switch (107) and a second switch (108); a first scanning line (102) connected to a control end of a third switch (109); a data line (103) connected to a control end of a second switch (108) by means of the third switch (109); a second scanning line (104) connected to a control end of a fourth switch (110); a third scanning line (105) connected to a control end of the first switch (107) and configured to cut off the first switch (107) at the optical communication receiving time so as to cut off the power of the driving power supply (111) to the micrometer light-emitting diode (101); and a photosensitive unit (106) connected to the data line (103) by means of the fourth switch (110) and configured to transmit a photosensitive signal to the data line when the fourth switch (110) is switched on.

Description

Micron LED matrix display

This application claims the priority of a Chinese patent application filed with the Chinese Patent Office with an application number of 201910542504.9 on June 21, 2019, and the entire content of the application is incorporated into this application by reference.

Technical field

The embodiments of the present application relate to visible light communication technology, such as a micron LED matrix display.

Background technique

With the rapid development of light-emitting diodes, light-emitting diodes are used in many occasions. Visible light communication technology relies on high-speed blinking signals from light-emitting diodes to transmit information.

At this stage, the network access technology is usually radio frequency communication. Because of the increase in the number of electronic devices, especially people's demand for video services "Anywhere, Anytime", the wireless spectrum resources are greatly consumed. The 380-780nm spectral bandwidth of visible light (equivalent to 405THZ) can be used to alleviate this problem. At this stage, visible light communication technology uses light-emitting diodes as light sources, which can realize both the lighting function and the data transmission function. And light-emitting diodes can be used not only in the field of lighting, but also in the field of display. If the display and optical communication are organically combined, visible light wireless communication (lightfidelity, LiFi) can be realized.

Summary of the invention

The embodiment of the present application discloses a micron light emitting diode matrix display, so as to realize that it can emit light signals and can also accept light signals.

In the first aspect, the embodiments of the present application disclose a micron light-emitting diode matrix display, including a plurality of pixel circuits, each pixel circuit includes: a micron light-emitting diode, a first switch, a second switch, a driving power supply, a first scan line, The third switch, the data line, the second scan line, the fourth switch, the third scan line, the photosensitive unit; the micron light emitting diode is connected to the driving power source through the first switch and the second switch; The first scan line is connected to the control terminal of the third switch, and is configured to provide a first scan voltage during the pixel scan time to turn on the third switch; the data line is connected to the third switch through the third switch The control terminal of the second switch is set to provide the pixel voltage corresponding to the pixel brightness information during the pixel scanning time to control the conduction current of the second switch; the second scan line is connected to the control terminal of the fourth switch, Is configured to provide a second scan voltage during the optical communication reception time to turn on the fourth switch; the third scan line is connected to the control terminal of the first switch, and is configured to enable the The first switch is turned off to cut off the power supply of the driving power supply to the micron light-emitting diode, and a modulation signal is provided during the optical communication transmission time to control the switching frequency of the first switch to modulate the optical signal emitted by the micron light-emitting diode; The photosensitive unit is connected to the data line through the fourth switch, and is configured to transmit a photosensitive signal to the data line when the fourth switch is turned on.

Description of the drawings

FIG. 1 is a schematic structural diagram of a micron LED matrix display provided by an embodiment of the present application;

FIG. 2 is a schematic structural diagram of another micron LED matrix display provided by an embodiment of the present application.

Detailed ways

In addition, the terms "first", "second", etc. may be used herein to describe various directions, actions, steps or elements, etc., but these directions, actions, steps or elements are not limited by these terms. These terms are only used to distinguish a first direction, action, step or element from another direction, action, step or element. For example, without departing from the scope of the present application, the first speed difference may be referred to as the second speed difference, and similarly, the second speed difference may be referred to as the first speed difference. Both the first speed difference and the second speed difference are speed differences, but they are not the same speed difference. The terms "first", "second", etc. cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of these features. In the description of this application, "multiple" and "batch" mean at least two, such as two, three, etc., unless specifically defined otherwise.

FIG. 1 is a schematic structural diagram of a micron light-emitting diode matrix display provided by an embodiment of the present application, in which a micron light-emitting diode (Micro Light Emitting Diode, micron LED) is used in a display element, and its size is only about 1-100 μm. The micron LED matrix display includes a plurality of pixel circuits. The drawings in this embodiment are only for illustration, and do not represent the actual number of pixel circuits. This embodiment is suitable for realizing a situation where both optical signals can be sent and optical signals can be received.

As shown in FIG. 1, the first embodiment provides a micron light-emitting diode matrix display 10, which includes a plurality of pixel circuits 100, wherein each pixel circuit 100 includes: a micron light-emitting diode 101, and the micron light-emitting diode 101 passes through the first The switch 107 and the second switch 108 are connected to the driving power supply 111; the first scan line 102 is connected to the control terminal G3 of the third switch 109, and is set to provide a first scan voltage during the pixel scan time to turn on the third Switch 109; data line 103, connected to the control terminal G2 of the second switch 108 through the third switch 109, set to provide pixel voltage corresponding to pixel brightness information within the pixel scan time, and control the conduction current of the second switch 108 The second scan line 104, connected to the control terminal G4 of the fourth switch 110, is set to provide a second scan voltage during the optical communication receiving time to turn on the fourth switch 110; the third scan line 105 is connected to The control terminal G1 of the first switch 107 is set to turn off the first switch 107 during the optical communication reception time to cut off the power supply of the driving power supply 111 to the micron light-emitting diode 101, and to provide a modulation signal control station during the optical communication transmission time. The switching frequency of the first switch 107 is used to modulate the light signal emitted by the micron LED 101; the photosensitive unit 106 is connected to the data line 103 through the fourth switch 110, and is set to be when the fourth switch 110 is turned on, The photosensitive signal is transmitted to the data line 103.

In one embodiment, during the pixel scan time, the first scan line 102 continuously provides a scan voltage. For example, the scan voltage can be 12V, which is not limited here. When the scan voltage provided by the first scan line 102 is received by the third switch 109 and the scan voltage provided by the first scan line 102 meets the conduction condition of the third switch 109, the third switch 109 is in the conduction state. For example, the third switch 109 can be turned on at a high level or turned on at a low level. In the case that the third switch is a low level on switch, the first scan line 102 can continuously provide a -12V scan Voltage. The conduction condition of the third switch 109 in this embodiment can be set as required, and there is no limitation here. When the third switch 109 is turned on at a high level and the scan voltage provided by the first scan line 102 is at a high level, the third switch 109 is in a conductive state. At this time, the data line 103 provides the pixel voltage corresponding to the pixel brightness information to the second switch 108 and controls the conduction degree of the second switch 108. The second switch 108 may be turned on at a high level or turned on at a low level, which can be set as required, and there is no limitation here. The third scan line 105 is connected to the control terminal G1 of the first switch 107, provides a pulse voltage, and continuously controls the on and off of the first switch 107, that is, the first switch 107 will be on and off during the duration of the pulse voltage. Turn off the two states to change back and forth. The frequency at which the first switch 107 is turned on and off is consistent with the pulse frequency provided by the third scan line 105. The first switch 107 may be turned on at a high level or turned on at a low level, which can be set as required, and there is no limitation here. The working timing of the pixel circuit includes a digital 1 state timing and a digital 0 state timing. The digital 1 state timing corresponds to the bright state of the micron LED 101, and the digital 0 state timing corresponds to the dark state of the micron LED 101. Through the turn-on and turn-off of the first switch 107, the working timing is in the digital 1 state timing and the digital 0 state timing, so that the micron light-emitting diode 101 is always in the state of flashing light and dark, and data is transmitted outward through the high-speed light and dark blinking signal . At the same time, because the flicker frequency is much higher than the frequency that the human eye can recognize, it does not affect the user's use of lighting or display functions. Among them, the micron light-emitting diodes can be white light-emitting diodes, phosphor light-emitting diodes or color light-emitting diodes. In an alternative embodiment, the degree of conduction of the first switch 107 can also be controlled to reduce the amplitude of the luminous intensity variation of the micron light-emitting diode 101 for signal modulation of the emitted light.

During the optical communication receiving time, the second scan line 104 provides a second voltage to turn on the fourth switch 110. The fourth switch 110 may be turned on at a high level or turned on at a low level, which can be set as required, and there is no limitation here. At the same time, the photosensitive unit 106 converts the received light signal into an electric signal. When the fourth switch 110 is turned on, the electrical signal converted by the optical signal will transmit data to the data line 103 through the fourth switch 110. In this embodiment, there is only one data line 103 connected to each pixel. In an embodiment, it is also possible to set multiple data lines connected to each pixel. Exemplarily, a data line can be set to transmit data to the micron light-emitting diode 101 during the scanning time, and another data line can be set to be used during the optical communication receiving time, the photosensitive unit converts the optical signal into an electrical signal for transmission The data is given to the data line, and there is no restriction here. Setting multiple data lines can make the scanning time and the optical communication receiving time not be affected by each other. Among them, the optical communication transmission time, that is, the pixel scanning time and the optical communication receiving time are interleaved. In the case of optical communication transmission time, optical communication reception cannot be carried out. Similarly, in the case of optical communication reception time, optical communication transmission cannot be carried out, so as to avoid mutual interference between the photosensitive unit and the micron LED, which can be controlled by The fourth switch 110 and the first switch 107 are turned on and off.

In this embodiment, by arranging multiple pixel circuits on the display, and arranging micron light-emitting diodes and photosensitive units in each pixel circuit, it avoids the situation that only light signals can be emitted or only light signals can be received, and it overcomes the need to transmit and receive light signals. The technical defect that the optical signals are combined can affect each other, which realizes that both the optical communication signal can be transmitted, and the optical communication signal can be converted into an electrical signal and then the data can be transmitted. In the same display, both the optical signal and the light can be received. signal.

2 is a schematic structural diagram of another micron LED matrix display provided by an embodiment of the present application. The technical solution provided in this embodiment is refined on the basis of the above technical solution, and is suitable for scenarios that also include capacitors.

As shown in FIG. 2, the micron LED matrix display 10 includes a plurality of pixel circuits 100, and each pixel circuit 100 may also include a first capacitor 112. The first terminal of the first capacitor 112 is electrically connected to the source of the second switch, the second terminal of the first capacitor 112 is electrically connected to the gate of the second switch, and the first capacitor 112 It is set to continuously turn on the second switch after the pixel scanning time.

In an embodiment, the first switch 107, the second switch 108, the third switch 109, and the fourth switch 110 may all be P-type metal oxide semiconductor (Positive channel Metal Oxide Semiconductor, PMOS) tubes or N-type metal oxide. Semiconductor (Negative channel Metal Oxide Semiconductor, NMOS) tube. The gate of the MOS tube corresponds to the control terminals of the first switch 107, the second switch 108, the third switch 109, and the fourth switch 110. The first switch 107, the second switch 108, the third switch 109, and the fourth switch 110 may be turned on by a high level or a low level. When the first switch 107, the second switch 108, the third switch 109, and the fourth switch 110 are PMOS transistors, the switches are turned on at a low level. When the first switch 107, the second switch 108, the third switch 109, and the fourth switch 110 are NMOS transistors, the switches are turned on at a high level. It can be set to use PMOS tube or NMOS tube as needed. Taking the first switch 107, the second switch 108, the third switch 109, and the fourth switch 110 as an example, during the pixel scan time, the first scan line 102 is at a low level, and the display signal of the pixel is changed by The data line 103 is incoming. According to the level of the incoming signal, the first capacitor 112 will be charged and discharged. When the incoming signal level is higher than the capacitance stored by the first capacitor 112, the first capacitor 112 will be charged; When the level is lower than the capacitance stored in the first capacitor 112, the first capacitor 112 will be discharged. After the pixel scan time, the first scan line 102 is at a high level, and the third switch 109 is in the cut-off region at this time. After the first capacitor 112 is charged and discharged, it maintains the level of the incoming display signal, so that the pixel remains on or off in the frame. The first switch 107 controls the entire circuit to send out modulated optical communication data. When the pixel is in the lighting state, the third scan line 105 controls the lighting or extinguishing of the entire pixel through the conversion of high and low levels, and then sends out modulated optical communication data. By adding a first capacitor 112, even after the pixel scanning time, the first capacitor 112 can provide pixel voltage, so that the micron LED 101 can continue to work, prolong the working time of the micron LED 101, and improve the optical communication transmission. effectiveness. That is, the optical communication emission time and the pixel scanning time at least partially overlap.

During the optical communication receiving time, the third scan line 105 is at a high level, that is, the first switch 107 is in the cut-off area, and the micron LED 101 does not emit light. At the same time, the second scan line 104 is at a low level, the fourth switch 110 is turned on, and the light signal received by the photosensitive unit 106 is transmitted to the data line 103. In this state, the reception of optical communication can be completed.

In an embodiment, as shown in FIG. 2, each pixel circuit 100 may further include a second capacitor 113. The first end of the second capacitor 113 is connected to the first end of the photosensitive unit 106, the second end of the second capacitor 113 is connected to the second end of the photosensitive unit 106, and the second capacitor 113 It is set to stabilize the voltage across the photosensitive unit 106. For example, in the case of the optical communication receiving time, the photosensitive unit 106 converts the optical signal into an electrical signal, and the second scan line 104 provides a second scan voltage to turn on the fourth switch 110. When the fourth switch 110 is turned on, the electrical signal converted by the photosensitive unit 106 is transmitted to the data line through the fourth switch 110. However, the electrical signal at this time will fluctuate and be unstable. By providing a second capacitor 113 at both ends of the photosensitive unit 106, when the electrical signal is at a low fluctuating voltage, the voltage across the photosensitive unit 106 is stabilized and output If the electrical signal is stable, the transmitted data is more stable.

In an embodiment, as shown in FIG. 2, each pixel circuit 100 may further include a first safety unit 114. Wherein, the first safety unit 114 is arranged between the first switch 107 and the micron light-emitting diode 101, and is electrically connected to the first switch 107 and the micron light-emitting diode 101, and the first safety unit 114 It is configured to protect the pixel circuit when the micron light-emitting diode 101 is short-circuited. For example, the micron light-emitting diode 101 is a light-emitting diode, which has unidirectional conductivity and cannot be turned on in the reverse direction under normal operating conditions. However, when the micron light-emitting diode 101 is in an abnormal working state, for example, when it is broken down, the micron light-emitting diode 101 will be short-circuited. If voltage continues to be supplied to the micron light-emitting diode 101 at this time, the entire pixel circuit will be short-circuited, and other components may even be affected. By arranging a first safety unit 114 between the first switch 107 and the micron light-emitting diode 101, in the case of a short-circuit failure of the micron light-emitting diode 101, the circuit is disconnected, thereby protecting the entire pixel circuit.

In an embodiment, as shown in FIG. 2, each pixel circuit 100 may further include a second safety unit 115. The second safety unit 115 is arranged between the fourth switch 110 and the photosensitive unit 106, and is electrically connected to the fourth switch 110 and the photosensitive unit 106. The second safety unit 115 is arranged in the photosensitive unit 106. In the case of a short circuit, the pixel circuit is protected. For example, the photosensitive unit may be a photodetector, and the photodetector is a photosensitive diode, which has unidirectional conductivity. Under normal working conditions, reverse conduction cannot be conducted. However, when the photosensitive unit 106 is in an abnormal working state, for example, when it is broken down, the photosensitive unit 106 will be short-circuited. If the voltage is continuously supplied to the photosensitive unit 106 at this time, the entire pixel circuit will be short-circuited, and other components may even be affected. By providing a second safety unit 115 between the fourth switch 110 and the photosensitive unit 106, in the event of a short-circuit failure of the photosensitive unit 106, the circuit is disconnected, thereby protecting the entire pixel circuit.

In this embodiment, the first capacitor is added to each pixel circuit in the display. By connecting with the source and gate of the second switch, the electric energy stored by the capacitor can also provide pixel voltage after the pixel scanning time, which extends The working time of micron light-emitting diodes improves the efficiency of optical communication transmission.

Claims

A micron light-emitting diode matrix display, including a plurality of pixel circuits, each pixel circuit includes: a micron light-emitting diode, a first switch, a second switch, a driving power supply, a first scan line, a third switch, a data line, and a second scan Line, fourth switch, third scan line, photosensitive unit;

The micron light emitting diode is connected to the driving power supply through the first switch and the second switch;

The first scan line is connected to the control terminal of the third switch, and is configured to provide a first scan voltage during the pixel scan time to turn on the third switch;

The data line is connected to the control terminal of the second switch through the third switch, and is configured to provide pixel voltage corresponding to pixel brightness information within the pixel scanning time, and control the conduction current of the second switch;

The second scan line is connected to the control terminal of the fourth switch, and is configured to provide a second scan voltage during the optical communication receiving time to turn on the fourth switch;

The third scan line is connected to the control terminal of the first switch, and is set to turn off the first switch during the optical communication receiving time, so as to cut off the power supply of the driving power supply to the micron light-emitting diode. Provide a modulation signal during the optical communication transmission time to control the switching frequency of the first switch to modulate the optical signal emitted by the micron light-emitting diode;

The photosensitive unit is connected to the data line through the fourth switch, and is configured to transmit a photosensitive signal to the data line when the fourth switch is turned on.
3. The micron LED matrix display according to claim 1, wherein the micron LED is a white light emitting diode, a phosphor light emitting diode or a color light emitting diode.
7. The micron LED matrix display of claim 1, wherein the optical communication emission time and the pixel scanning time at least partially overlap.
7. The micron LED matrix display of claim 1, wherein the pixel circuit further comprises:

The optical communication transmission time and the optical communication reception time are interleaved with each other, and the optical communication transmission time and the optical communication reception time do not overlap.
The micron LED matrix display of claim 1, wherein the first switch, the second switch, the third switch and the fourth switch are all P-type metal oxide semiconductor PMOS transistors or N Type metal oxide semiconductor NMOS tube.
7. The micron LED matrix display of claim 5, the pixel circuit further comprising:

The first capacitor, the first terminal of the first capacitor is electrically connected to the source of the second switch, the second terminal of the first capacitor is electrically connected to the gate of the second switch, the first The capacitor is set to continuously turn on the second switch after the pixel scanning time.
7. The micron LED matrix display of claim 5, the pixel circuit further comprising:

A second capacitor, the first end of the second capacitor is connected to the first end of the photosensitive unit, the second end of the second capacitor is connected to the second end of the photosensitive unit, and the second capacitor is arranged To stabilize the voltage across the photosensitive unit.
7. The micron LED matrix display of claim 1, wherein the pixel circuit further comprises:

The first safety unit, the first safety unit is arranged between the first switch and the micron light-emitting diode, and is electrically connected to the first switch and the micron light-emitting diode, and the first safety unit is arranged at When the micron light-emitting diode is short-circuited, the pixel circuit is protected.
7. The micron LED matrix display of claim 1, wherein the pixel circuit further comprises:

The second safety unit, the second safety unit is arranged between the fourth switch and the photosensitive unit, and is electrically connected to the fourth switch and the photosensitive unit, and the second safety unit is arranged at the When the photosensitive unit is short-circuited, the pixel circuit is protected.
8. The micron LED matrix display according to any one of claims 1-9, wherein at most one of the first switch and the fourth switch is in an on state.