Passive LED drive circuit, protective shell of mobile terminal and passive LED system

Abstract

The embodiment of the utility model provides a passive LED driving circuit, a protective shell of a mobile terminal and a passive LED system. The passive LED driving circuit comprises an antenna circuit, a power supply circuit and a control circuit, the communication circuit is connected with the antenna circuit, wirelessly communicates with a mobile terminal through the antenna circuit and receives display information; the electricity taking and storing circuit is connected with the antenna circuit, converts the radio frequency energy transmitted by the mobile terminal into electric energy through the antenna circuit and stores the electric energy; the LED circuit comprises a plurality of LED lamps, the LED circuit is connected with the electricity taking and storing circuit and the communication circuit, the electricity taking and storing circuit supplies power to the LED circuit, and the communication circuit can control the display state of each LED lamp according to the display information. Patterns provided by the mobile terminal can be displayed at any time according to needs, a client can adjust the content displayed by the LED circuit at any time through the mobile terminal, customized patterns of the client are displayed, the requirements of the user are met, and only the patterns built in the LED circuit can be passively displayed.

Description

Technical Field

[0001] The present application relates to the field of electronic technology, and in particular to a passive LED driving circuit, a protective shell of a mobile terminal and a passive LED system. Background Art

[0002] With the development of science and technology, mobile terminals such as mobile phones have become indispensable devices in people's daily lives. With the increasing number of mobile terminal functions, the use scenarios of mobile terminals are also increasing, and the time of using mobile terminals is also increasing. Mobile terminals are generally equipped with protective cases to protect the mobile terminals. Some protective cases are provided with patterns to meet customer needs. At present, protective cases often only have static patterns or fixed patterns, which cannot meet customer needs. Utility Model Content

[0003] The embodiments of the present application provide a passive LED driving circuit, a protective case for a mobile terminal, and a passive LED system. Multiple LED lamps in the passive LED driving circuit can be controlled individually and form different patterns to meet user needs.

[0004] In a first aspect, an embodiment of the present application provides a passive LED driving circuit, comprising:

[0005] Antenna circuit;

[0006] A communication circuit connected to the antenna circuit and wirelessly communicating with the mobile terminal through the antenna circuit and receiving display information;

[0007] A power collection and storage circuit, connected to the antenna circuit, and converting the radio frequency energy transmitted by the mobile terminal into electrical energy through the antenna circuit and storing the electrical energy;

[0008] The LED circuit includes a plurality of LED lamps, wherein the LED circuit is connected to the power supply and storage circuit and the communication circuit, the power supply and storage circuit supplies power to the LED circuit, and the communication circuit can control the display status of each LED lamp according to the display information.

[0009] In some embodiments, the communication circuit includes an NFC chip and a microprocessor, and the microprocessor wirelessly communicates with the mobile terminal through the NFC chip and the antenna circuit. The microprocessor can control different numbers of LED lights or LED lights in different positions to light up.

[0010] In some embodiments, the NFC chip can obtain electrical energy through the antenna circuit, and the electrical energy obtained by the NFC chip is less than the electrical energy obtained by the power extraction and storage circuit.

[0011] In some embodiments, the passive LED driving circuit further includes:

[0012] A DC-DC circuit, wherein the input end of the DC-DC circuit is connected to the output end of the power extraction and storage circuit, the DC-DC circuit can change the output voltage of the power extraction and storage circuit, and the output end of the DC-DC circuit is connected to the LED circuit and supplies power to the LED circuit;

[0013] Among them, the NFC chip can power the microprocessor; the output end of the DC-DC circuit is connected to the microprocessor, the microprocessor is connected to the control end of the DC-DC circuit, and the power supply of the microprocessor can be switched from the power supply of the NFC chip to the power supply of the DC-DC circuit.

[0014] In some embodiments, the passive LED driving circuit further includes:

[0015] A memory is connected to the communication circuit, and the memory can store the display information received by the communication circuit, or the memory can replace the previously stored information with the display information received by the communication circuit for storage.

[0016] In some embodiments, the communication circuit can also obtain display information from the memory and control the display status of each of the LED lights according to the display information.

[0017] In some embodiments, the communication circuit can control at least one of the display duration, display brightness, display color and flashing frequency of each of the LED lights according to the display information.

[0018] In a second aspect, an embodiment of the present application further provides a protective case for a mobile terminal, which includes:

[0019] case;

[0020] A passive LED driving circuit is installed in the housing, and the passive LED driving circuit is the passive LED driving circuit mentioned above.

[0021] In a third aspect, the present application also provides a passive LED system, which includes:

[0022] Mobile terminals;

[0023] A protective shell is installed on the mobile terminal, and the protective shell is the protective shell mentioned above.

[0024] In some embodiments, the mobile terminal is wirelessly connected to the passive LED driving circuit of the protective shell, and controls some LED lights in the passive LED driving circuit to light up.

[0025] In the passive LED driving circuit of the embodiment of the present application, the power taking and storage circuit and the antenna circuit can cooperate to wirelessly take and store power. The power taking and storage circuit can power the LED circuit, thereby realizing passive power supply to the LED circuit. No battery is required, and the LED circuit can be applied in passive scenarios. The communication circuit can wirelessly communicate with the mobile terminal through the antenna circuit and receive display information. The communication circuit and the power taking and storage circuit are different branches and do not affect each other, which can reduce the interference between the two. The communication circuit can also control the display state of each LED lamp according to the display information, so that some of the LED lamps in the multiple LED lamps are lit to form corresponding patterns, such as different numbers, letters, texts, expressions, etc. The passive LED driving circuit can take power passively and let the LED circuit display different patterns through the mobile terminal. Compared with the LED circuit in the related art that can only display its built-in pattern, the LED circuit in this embodiment can display the pattern provided by the mobile terminal at any time as needed. The customer can adjust the content displayed by the LED circuit at any time through the mobile terminal to display the customized pattern to meet the needs of the user, instead of only being able to passively display the built-in pattern in the LED circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on these drawings without creative work.

[0027] In order to more completely understand the present application and its beneficial effects, the following description will be given in conjunction with the accompanying drawings, wherein the same figure numbers represent the same parts in the following description.

[0028] Figure 1 This is a schematic diagram of the first structure of the passive LED driving circuit provided in an embodiment of the present application.

[0029] Figure 2 for Figure 1 The specific structural schematic diagram of the power extraction and storage circuit in the passive LED driving circuit is shown.

[0030] Figure 3 A second structural schematic diagram of the passive LED driving circuit provided in an embodiment of the present application.

[0031] Figure 4 This is a third structural schematic diagram of the passive LED driving circuit provided in an embodiment of the present application.

[0032] Figure 5 This is a schematic diagram of the structure of the LED circuit in the passive LED driving circuit provided in an embodiment of the present application.

[0033] Figure 6 This is a fourth structural schematic diagram of the passive LED driving circuit provided in an embodiment of the present application.

[0034] Figure 7 A schematic diagram of the structure of a protective case for a mobile terminal provided in an embodiment of the present application.

[0035] Figure 8 A schematic diagram of the structure of a passive LED system provided in an embodiment of the present application.

[0036] Description of reference numerals:

[0037] 100, passive LED driving circuit, 110, antenna circuit, 120, communication circuit, 122, NFC chip, 124, microprocessor, 130, power supply and storage circuit, 132, matching circuit, 134, rectifier circuit, 136, energy storage circuit, 140, LED circuit, 142, LED lamp, 144, first driving circuit, 146, second driving circuit, 150, DC-DC circuit, 160, memory;

[0038] 200. Mobile Terminal

[0039] 300, protective shell, 320, shell. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0041] The present application embodiment provides a passive LED driving circuit. Figure 1 , Figure 1 The first structural diagram of the passive LED driving circuit provided in the embodiment of the present application is as follows: The passive LED driving circuit 100 includes an antenna circuit 110 , a communication circuit 120 , a power supply and storage circuit 130 and an LED circuit 140 .

[0042] The antenna circuit 110 can be wirelessly connected to a mobile terminal 200 such as a mobile phone. The antenna circuit 110 can include an NFC antenna or the like.

[0043] The communication circuit 120 is connected to the antenna circuit 110 , and wirelessly communicates with the mobile terminal through the antenna circuit 110 and receives display information.

[0044] The power collection and storage circuit 130 is connected to the antenna circuit 110 , and converts the radio frequency energy transmitted by the mobile terminal into electrical energy through the antenna circuit 110 and stores the electrical energy.

[0045] The LED circuit 140 includes a plurality of LED lamps, and the LED circuit 140 is connected to the power supply and storage circuit 130 and the communication circuit 120. The power supply and storage circuit 130 supplies power to the LED circuit 140, and the communication circuit 120 can control the display status of each LED lamp according to the display information.

[0046] The power supply and storage circuit 130 and the antenna circuit 110 can cooperate to wirelessly supply and store electricity. The power supply and storage circuit 130 can supply power to the LED circuit 140, thereby realizing passive power supply to the LED circuit 140. There is no need to set up a battery, and the LED circuit 140 can be used in passive scenarios, such as in the protective shell 300 of the mobile terminal 200. It should be noted that the power of the LED circuit 140 is relatively large. If it is powered by a battery, the battery needs to be replaced frequently, which is inconvenient to use. If a large-capacity battery is used, the overall volume is relatively large, which is not suitable for small or thin products, such as the protective shell 300 of the mobile terminal 200. Passive power supply can solve the problem that small-capacity batteries need to be replaced frequently and large-capacity batteries are large in size. When there is no mobile terminal to provide radio frequency energy, the passive LED drive circuit 100 is in a completely powerless state, achieving true zero power consumption, and the circuit is highly safe.

[0047] The communication circuit 120 can communicate with the outsourced device wirelessly through the antenna circuit 110 and receive display information. The communication circuit 120 and the power supply and storage circuit 130 are different branches and do not affect each other, which can reduce the interference between the two. The communication circuit 120 can also control the display state of each LED lamp according to the display information, so that some of the LED lamps in the multiple LED lamps are lit to form corresponding patterns, such as different numbers, letters, texts, expressions, etc. The passive LED driving circuit 100 can passively draw power and allow the LED circuit 140 to display different patterns through the mobile terminal. Compared with the LED circuit 140 in the related art that can only display its built-in pattern, the LED circuit 140 in this embodiment can display the pattern provided by the mobile terminal at any time as needed. The customer can adjust the content displayed by the LED circuit 140 at any time through the mobile terminal to display the customized pattern to meet the needs of the user, instead of only being able to passively display the built-in pattern in the LED circuit 140.

[0048] See also Figure 2 , Figure 2 for Figure 1 The specific structural diagram of the power supply and storage circuit in the passive LED driving circuit is shown in FIG. In some embodiments, the power supply and storage circuit 130 includes a matching circuit 132 , a rectifier circuit 134 and an energy storage circuit 136 .

[0049] The matching circuit 132 is connected to the antenna circuit 110 and cooperates to output electrical energy. The matching circuit 132 and the antenna circuit 110 cooperate to better obtain the RF signal of the mobile terminal. For example, the matching circuit 132 can cooperate with the antenna circuit 110 to adjust the resonant frequency of the antenna circuit 110 so as to be closer to the frequency of the RF signal. The closer the resonant frequency of the antenna circuit 110 is to the frequency of the RF signal, the more energy the antenna circuit 110 can obtain.

[0050] The rectifier circuit 134 is connected to the matching circuit 132 and rectifies the electric energy output by the antenna circuit 110 and the matching circuit 132. The rectifier circuit 134 may include different circuit structures as required, such as a rectifier bridge or a diode.

[0051] The energy storage circuit 136 is connected to the rectifier circuit 134 and stores the rectified electric energy. The energy storage circuit 136 may include one energy storage capacitor or multiple energy storage capacitors connected in parallel. The energy storage circuit 136 is connected to the LED circuit 140, and the energy storage circuit 136 supplies power to the LED circuit 140 after storing enough electric energy.

[0052] The matching circuit 132 cooperates with the antenna circuit 110 to output an oscillation wave signal, the rectifier circuit 134 rectifies the oscillation wave signal and outputs a direct current signal, and the energy storage circuit 136 stores the direct current signal.

[0053] See also Figure 3 , Figure 3 A second structural diagram of a passive LED driving circuit provided in an embodiment of the present application. In some embodiments, the communication circuit 120 includes an NFC chip 122 and a microprocessor 124. The microprocessor 124 communicates wirelessly with the mobile terminal through the NFC chip 122 and the antenna circuit 110. The microprocessor 124 can control different numbers of LED lights or LED lights at different positions to light up. After the microprocessor 124 obtains the display information through the NFC chip 122, the microprocessor 124 can control different numbers of LED lights or LED lights at different positions to light up according to the display information, so that some LED lights light up and form corresponding patterns, such as different numbers, letters, words, expressions, etc.

[0054] It should be noted that the more LED lights there are, the better the pattern effect that can be displayed, but at the same time, more power is required. In some examples, the LED circuit 140 includes 16*16 LED lights. In some other examples, the LED circuit 140 may include 15*15 LED lights, 15*20 LED lights, 20*20 LED lights, 20*25 LED lights, 25*25 LED lights, etc. The number and arrangement of the LED lights in the LED circuit 140 can be set as needed, such as the LED lights can also be arranged into regular images or irregular images, such as circles, ellipses, trapezoids, regular polygons, stars, flowers, hearts, etc.

[0055] In some embodiments, the NFC chip 122 can obtain electrical energy through the antenna circuit 110 , and the electrical energy obtained by the NFC chip 122 is less than the electrical energy obtained by the power extraction and storage circuit 130 .

[0056] The NFC chip 122 integrates an energy processing circuit to process the energy provided by the antenna circuit 110 and convert it into electrical energy, thereby powering the NFC chip 122 itself, thereby starting other functions of the NFC chip 122, such as controlling other circuits, etc. It is understandable that the electrical energy obtained by the NFC chip 122 is much less than the electrical energy obtained by the power extraction and storage circuit 130.

[0057] In some examples, the NFC chip 122 can also power the microprocessor 124 , so that the microprocessor 124 can start working before the remote power storage circuit 130 stores enough power.

[0058] See also Figure 4 , Figure 4 The third structural diagram of the passive LED driving circuit provided in the embodiment of the present application. In some embodiments, the passive LED driving circuit 100 further includes a DC-DC circuit 150, the input end of the DC-DC circuit 150 is connected to the output end of the power taking and storage circuit 130, the DC-DC circuit 150 can change the output voltage of the power taking and storage circuit 130, and the output end of the DC-DC circuit 150 is connected to the LED circuit 140 and supplies power to the LED circuit 140.

[0059] It should be noted that in order to store more electric energy, the storage voltage of the power supply and storage circuit 130 is a higher voltage. For example, the energy storage circuit 136 of the power supply and storage circuit 130 includes an energy storage capacitor, and the rated voltage of the energy storage capacitor is relatively high, which can reach more than ten V or even tens of V, such as 16V, 20V, 25V, 30V or 36V, etc. The energy storage capacitor with the highest rated voltage can store more electric energy and has a stronger driving ability. The energy storage capacitor with a higher rated voltage stores more electric energy, so that the LED circuit 140 can be driven stably and for a long time. However, the energy storage capacitor with a higher rated voltage cannot directly drive related circuits such as the LED circuit 140. Therefore, the passive LED driving circuit 100 is further provided with a DC-DC circuit 150, and the DC-DC circuit 150 is connected to the output end of the power taking and storage circuit 130, so as to provide the signal output by the power taking and storage circuit 130 to the LED circuit 140 after the voltage is reduced, such as reducing the voltage of the signal output by the power taking and storage circuit 130 to about 3V or about 5V to supply power to the LED circuit 140. The voltage value of the output signal of the DC-DC circuit 150, i.e., the voltage value after the voltage reduction, is set according to the circuit to be driven as required, such as reducing the voltage to 3V or 5V as required by the LED circuit 140.

[0060] In some embodiments, the NFC chip 122 can supply power to the microprocessor 124, such as the NFC chip 122 can provide a voltage of about 3V. The output end of the DC-DC circuit 150 is connected to the microprocessor 124, and the microprocessor 124 is connected to the control end of the DC-DC circuit 150. The power supply of the microprocessor 124 can be switched from the power supply of the NFC chip 122 to the power supply of the DC-DC circuit 150. After the power supply storage circuit 130 stores enough electric energy, it supplies power to the microprocessor 124 through the DC-DC circuit 150, which can provide more stable electric energy. The power supply storage circuit 130 supplies power to the microprocessor 124 through the DC-DC circuit 150 and can also provide higher power, so that the microprocessor 124 can start more functional modules or adopt a higher operating frequency to provide stronger processing capabilities.

[0061] In some embodiments, the communication circuit 120 is not provided with the NFC chip 122 , that is, the communication circuit 120 cannot be powered by the antenna circuit 110 , and the signal output by the DC-DC circuit 150 can also power the communication circuit 120 .

[0062] In some embodiments, see Figure 5 , Figure 5The structure diagram of the LED circuit in the passive LED driving circuit provided in the embodiment of the present application. The plurality of LED lamps 142 are arranged in a matrix, that is, the plurality of LED lamps 142 include a plurality of rows of LED lamps 142 or a plurality of columns of LED lamps 142. The LED circuit 140 also includes a first driving circuit 144 and a second driving circuit 146. The microprocessor 124 controls the first driving circuit 144 to supply power to the plurality of rows of LED lamps 142 in sequence, and controls the second driving circuit 146 to drive the LED lamps 142 in part or all of the columns in each row of LED lamps 142 to light up.

[0063] The first driving circuit 144 supplies power to the multiple rows of LED lights 142 in sequence, and the second driving circuit 146 drives some or all of the columns of LED lights 142 in each row of LED lights 142 to light up as needed, so that the multiple LED lights 142 dynamically light up the corresponding LED lights 142 row by row, and finally some of the LED lights 142 are displayed to form corresponding patterns.

[0064] It is understandable that the microprocessor 124 can dynamically drive the LED circuit 140 to display different patterns in sequence as needed, such as cyclically displaying multiple numbers, letters, words or expressions.

[0065] See also Figure 6 , Figure 6 The fourth structural diagram of the passive LED driving circuit provided in the embodiment of the present application. In some embodiments, the passive LED driving circuit 100 further includes a memory 160 , which is connected to the communication circuit 120 , and the memory 160 can store the display information received by the communication circuit 120 .

[0066] After the communication circuit 120 obtains the display information, it stores the display information in the memory 160, so that the passive LED driving circuit 100 can obtain the display information from the memory 160 and drive the LED circuit 140 according to the display information. For example, the display information may include information corresponding to multiple patterns, and the passive LED driving circuit 100 can drive the LED circuit 140 to display one or more of the multiple patterns according to the display information.

[0067] It is understandable that the communication circuit 120 can also obtain display information from the memory 160 and control the display state of each LED lamp according to the display information. Specifically, after the communication circuit 120 obtains the display information, it stores it in the memory 160, and then the microprocessor 124 obtains the display information from the memory 160, and then drives the LED circuit 140 according to the display information, that is, controls the display state of each LED lamp to display the corresponding pattern. Alternatively, after the communication circuit 120 obtains the display information, the microprocessor 124 directly drives the LED circuit 140 according to the display information, and stores the display information in the memory 160, so that the microprocessor 124 can obtain the display information next time.

[0068] Optionally, in some embodiments, the memory 160 can replace the previously stored information with the display information received by the communication circuit 120. In some examples, the memory 160 replaces the previously stored information with the new display information, and the subsequent LED circuit 140 displays the pattern corresponding to the new display content to meet the needs of the user. In some examples, the capacity of the memory 160 is small, so the previously stored information can be replaced by the display information.

[0069] In some embodiments, the communication circuit 120 can control at least one of the display duration, display brightness, display color, and flashing frequency of each LED light according to the display information. The communication circuit 120 can control at least one of the display duration, display brightness, display color, and flashing frequency of each LED light, so that the LED circuit 140 can be displayed in different ways. For example, a pattern of preset duration is displayed, a pattern of different brightness is displayed in different scenes, a pattern of different colors is displayed, a pattern can be displayed constantly, or a pattern can be displayed flashingly. In addition, the communication circuit 120 can also control the LED circuit 140 to display different patterns in sequence, that is, to display patterns of animated images, such as displaying different texts or expressions in sequence.

[0070] The microprocessor 124 in the communication circuit 120 can control the LED circuit 140 to display multiple patterns in a cycle, or to display one pattern continuously or intermittently.

[0071] In some examples, the LED circuit 140 can also display different brightness according to the ambient brightness. For example, the communication circuit 120 obtains the ambient brightness from the mobile terminal, and then adjusts the brightness of the LED lamp according to the ambient brightness. For example, the brightness of the LED lamp is positively correlated with the ambient brightness, that is, the greater the ambient brightness, the greater the brightness of the LED lamp; the smaller the ambient brightness, the smaller the brightness of the LED lamp.

[0072] The present application also provides a protective case for a mobile terminal. Figure 7 , Figure 7The protective case 300 of the mobile terminal includes a housing 320 and a passive LED driving circuit 100, wherein the passive LED driving circuit 100 is installed in the housing 320 and the passive LED driving circuit 100 is any one of the above embodiments.

[0073] The housing 320 is installed on the mobile terminal 200 and can protect the mobile terminal 200. For example, the housing 320 can be mounted on the periphery of the mobile terminal 200 to protect the mobile terminal 200.

[0074] The present application also provides a passive LED system. Figure 8 , Figure 8 The passive LED system provided in the embodiment of the present application is a schematic diagram of the structure of the passive LED system. The passive LED system includes a mobile terminal 200 and a protective shell 300, wherein the protective shell 300 is installed on the mobile terminal 200, and the protective shell 300 is the protective shell 300 in any of the above embodiments.

[0075] In some embodiments, the mobile terminal 200 is wirelessly connected to the passive LED driving circuit 100 of the protective case 300, and controls some LED lights in the passive LED driving circuit 100 to light up. The mobile terminal 200 can control the passive LED driving circuit 100 to make the LED circuit 140 in the passive LED driving circuit 100 display different patterns. Display information corresponding to the pattern can also be sent to the passive LED driving circuit 100 to make the LED circuit 140 display a new pattern to meet the needs of the user.

[0076] In some examples, the mobile terminal 200 may be a mobile phone, and the protective case 300 may be a mobile phone case.

[0077] In the above embodiments, the description of each embodiment has its own emphasis. For parts not described in detail in a certain embodiment, reference can be made to the relevant description of other embodiments. The embodiments, implementation methods and related technical features of the present application can be combined and replaced with each other without conflict.

[0078] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0079] The passive LED driving circuit, the protective case of the mobile terminal and the passive LED system provided in the embodiments of the present application are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for technical personnel in this field, according to the ideas of the present application, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A passive LED driving circuit, characterized in that: include: Antenna circuit; A communication circuit connected to the antenna circuit and wirelessly communicating with the mobile terminal through the antenna circuit and receiving display information; A power collection and storage circuit, connected to the antenna circuit, and converting the radio frequency energy transmitted by the mobile terminal into electrical energy through the antenna circuit and storing the electrical energy; The LED circuit includes a plurality of LED lamps, wherein the LED circuit is connected to the power supply and storage circuit and the communication circuit, the power supply and storage circuit supplies power to the LED circuit, and the communication circuit can control the display status of each LED lamp according to the display information.

2. The passive LED driving circuit according to claim 1, characterized in that: The communication circuit includes an NFC chip and a microprocessor. The microprocessor communicates wirelessly with a mobile terminal via the NFC chip and the antenna circuit. The microprocessor can control different numbers of LED lights or LED lights at different positions to light up.

3. The passive LED driving circuit according to claim 2, characterized in that: The NFC chip can obtain electric energy through the antenna circuit, and the electric energy obtained by the NFC chip is less than the electric energy obtained by the power extraction and storage circuit.

4. The passive LED driving circuit according to claim 3, characterized in that: The passive LED driving circuit also includes: A DC-DC circuit, wherein the input end of the DC-DC circuit is connected to the output end of the power extraction and storage circuit, the DC-DC circuit can change the output voltage of the power extraction and storage circuit, and the output end of the DC-DC circuit is connected to the LED circuit and supplies power to the LED circuit; Among them, the NFC chip can power the microprocessor; the output end of the DC-DC circuit is connected to the microprocessor, the microprocessor is connected to the control end of the DC-DC circuit, and the power supply of the microprocessor can be switched from the power supply of the NFC chip to the power supply of the DC-DC circuit.

5. The passive LED driving circuit according to claim 1, characterized in that: The passive LED driving circuit also includes: A memory is connected to the communication circuit, and the memory can store the display information received by the communication circuit, or the memory can replace the previously stored information with the display information received by the communication circuit for storage.

6. The passive LED driving circuit according to claim 5, characterized in that: The communication circuit can also obtain display information from the memory and control the display state of each LED lamp according to the display information.

7. The passive LED driving circuit according to claim 1, characterized in that: The communication circuit can control at least one of the display duration, display brightness, display color and flashing frequency of each of the LED lights according to the display information.

8. A protective case for a mobile terminal, characterized in that: include: case; A passive LED driving circuit is installed in the housing, and the passive LED driving circuit is the passive LED driving circuit according to any one of claims 1 to 7.

9. A passive LED system, characterized in that: include: Mobile terminals; A protective shell is installed on the mobile terminal, and the protective shell is the protective shell described in claim 8 above.

10. The passive LED system according to claim 9, characterized in that: The mobile terminal is wirelessly connected to the passive LED driving circuit of the protective shell, and controls some LED lamps in the passive LED driving circuit to light up.

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