Light-emitting device

Abstract

The application provides a light-emitting device, comprising: a drive module comprising a power supply output positive terminal and a power supply output negative terminal, it being configured to output a power supply voltage through the power supply output positive terminal and the power supply output negative terminal; and multiple light source modules, each comprising a light source string, a first input positive terminal being electrically connected to the power supply output positive terminal and a first input negative terminal being electrically connected to the power supply output negative terminal, wherein at least one of the light source modules comprises a step-down circuit; the step-down circuit is electrically connected between the first input positive terminal and a power supply positive terminal of the light source string, and the step-down circuit is configured to step down a received input voltage to a normal operating voltage required by the light source string.

Description

Light-emitting device

[0001] The present application relates to the technical field of lighting, in particular to a light-emitting device.

[0002] In the technical field of lighting, various lighting or signalling devices are known for providing light for lighting or signalling. For example, vehicle lamps are used in motor vehicles to provide lighting or signalling functions, in order to ensure safe travel or provide an ornamental function.

[0003] Interior trim lamps in motor vehicles generally comprise multiple lamp modules, which are generally spaced far apart; when supplying power to multiple lamp modules, multiple drive circuits are generally needed, each drive circuit supplying power to one corresponding lamp module, and this undoubtedly increases costs. If only one drive circuit is used to supply power to multiple lamp modules simultaneously, the drive voltage provided by the drive circuit is unable to simultaneously satisfy the voltages required by all of the lamp modules, due to the fact that the multiple lamp modules are spaced far apart.

[0004] Thus, there is really an urgent need at present to propose a novel light-emitting device to overcome the shortcoming mentioned above.Summary of the Invention

[0005] An objective of the present application is to overcome at least one of the problems and shortcomings in the prior art.

[0006] A first aspect of the present application provides a light-emitting device, comprising:

[0007] a drive module, comprising a power supply output positive terminal and a power supply output negative terminal, the drive module being configured to output a power supply voltage through the power supply output positive terminal and the power supply output negative terminal; and

[0008] multiple light source modules, the light source module comprising a light source string, a first input positive terminal and a first input negative terminal, the first input positive terminal being electrically connected to the power supply output positive terminal, and the first input negative terminal being electrically connected to the power supply output negative terminal,

[0009] wherein at least one of the light source modules comprises a step-down circuit; within the light source module that comprises the step-down circuit, the step-down circuit is electrically connected between the first input positive terminal and a power supply positive terminal of the light source string, and the step-down circuit is configured to step down a received input voltage to a normal operating voltage required by the light source string.

[0010] In some embodiments, the light source module comprises a signal converter; a power supply positive terminal of the signal converter is electrically connected to the power supply positive terminal of the light source string, and a power supply negative terminal of the signal converter is electrically connected to a power supply negative terminal of the light source string;

[0011] within the light source module that comprises the step-down circuit, the power supply positive terminal of the signal converter is electrically connected to the first input positive terminal via the step-down circuit, and the step-down circuit is configured to step down the received input voltage to a normal operating voltage required by the signal converter.

[0012] In some embodiments, the light source module comprises a first output positive terminal and a first output negative terminal, the first output positive terminal being electrically connected to the first input positive terminal via a positive pole lead, and the first output negative terminal being electrically connected to the first input negative terminal via a negative pole lead;

[0013] the multiple light source modules are connected sequentially in a cascaded manner, the first input positive terminal of the light source module in a first stage being electrically connected to the power supply output positive terminal via a connecting line, and the first input negative terminal of the light source module in the first stage being electrically connected to the power supply output negative terminal via a connecting line;

[0014] the first input positive terminal of the light source module located in a later stage is electrically connected to the first output positive terminal of the light source module in the previous stage via a connecting line, and is indirectly electrically connected to the power supply output positive terminal via a positive pole lead of the light source module in an earlier stage; the first input negative terminal of the light source module located in a later stage is electrically connected to the first output negative terminal of the light source module in the previous stage via a connecting line, and is indirectly electrically connected to the power supply output negative terminal via a negative pole lead of the light source module in an earlier stage.

[0015] In some embodiments, within the light source module comprising the step-down circuit, the step-down circuit comprises one diode or multiple series-connected diodes; the anode of the diode is electrically connected to the first input positive terminal, and the cathode of the diode is electrically connected to the power supply positive terminal of the light source string.

[0016] In some embodiments, the light source string comprises multiple light sources, and power supply negative terminals of the multiple light sources are electrically connected to the first input negative terminal of the light source module;

[0017] within the light source module comprising a step-down circuit, power supply positive terminals of the multiple light sources are electrically connected to the first input positive terminal of the light source module via the step-down circuit;

[0018] within the light source module that does not comprise a step-down circuit, the power supply positive terminals of the multiple light sources are electrically connected to the first input positive terminal of the light source module directly via an electrically conductive lead.

[0019] In some embodiments, the light source is a smart LED, the light source is an RGB LED, and the light source is configured to emit required light according to a received control signal.

[0020] In some embodiments, an input voltage received by the light source module in an earlier stage is greater than an input voltage received by the light source module in a later stage.

[0021] In some embodiments, light sources in the light source string have the same normal operating voltages, power terminals of the light sources in the light source string are connected in parallel, and signal terminals are connected in series;

[0022] the light source module in a first stage comprises a step-down circuit, and steps down a received input voltage to a normal operating voltage required by the light source string;

[0023] the light source module in a final stage does not comprise a step-down circuit, and an input voltage received by the light source module in the final stage is equal to the normal operating voltage required by the light source string.

[0024] In some embodiments, positive pole leads of the multiple light source modules are electrically connected in sequence via a connecting line, the positive pole leads and the connecting line electrically connected thereto are formed overall as a power supply bypass line, and the power supply voltage is transmitted sequentially downstream via the power supply bypass line;

[0025] the positive pole lead is an electrically conductive lead on a circuit board, and the connecting line comprises a conductive wire and / or a connector.

[0026] In some embodiments, each of the light source modules is formed as a separate light panel, each light panel being used to illuminate a corresponding region.

[0027] In some embodiments, the drive module comprises a control circuit and a voltage regulator circuit, the voltage regulator circuit being electrically connected to the control circuit, the power supply output positive terminal and the power supply output negative terminal;

[0028] the voltage regulator circuit is configured to convert a received external voltage to the power supply voltage according to a power supply control signal of the control circuit.

[0029] In some embodiments, the drive module comprises a signal conversion circuit and a signal output terminal; the signal conversion circuit is electrically connected between the control circuit and the signal output terminal, and the signal conversion circuit is configured to convert a light source control signal in a first format outputted by the control circuit to a light source control signal in a second format, and output the light source control signal in the second format through the signal output terminal;

[0030] a signal converter in the light source module comprises a first signal transceiver and a second signal transceiver, and the first transceiver, the light source string and the second transceiver are electrically connected in sequence;

[0031] the first transceiver of the light source module in a first stage is electrically connected to the signal output terminal, and the first signal transceiver of the light source module located in a later stage is electrically connected to the second signal transceiver of the light source module in the previous stage; and based on the light source control signal, the light source string realizes corresponding switch-on and switch-off.

[0032] In some embodiments, the signal conversion circuit, the first transceiver and the second transceiver comprise CAN transceivers;

[0033] within the light source module comprising the step-down circuit, power supply positive terminals of the first transceiver and the second transceiver are electrically connected to the first input positive terminal via the step-down circuit.

[0034] In some embodiments, multiple light sources in the light source string each comprise a signal terminal, and are cascaded in sequence via the signal terminals.

[0035] In some embodiments, the light-emitting device is used as an interior trim lamp of a motor vehicle, the interior trim lamp comprising one or more of a driver's seat console ambient lamp, a centre console ambient lamp, a passenger seat ambient lamp, an armrest lamp, a charging lamp, an air conditioning outlet lamp and a door panel lamp.Brief Description of the Drawings

[0036] is a schematic diagram of the circuit structure of a light-emitting device provided in an embodiment of the present application;

[0037] is a schematic diagram of the circuit structure of a light source string provided in an embodiment of the present application.Detailed Description of the Invention

[0038] Embodiments of the present application will be described in detail below with reference to the drawings. It should be understood that these embodiments of the present application are mainly possible embodiments intended to illustrate the technical solution of the present application, and should not be interpreted as limitations of the technical solution of the present application. In this Description, identical or similar components are indicated with identical or similar reference numerals.

[0039] is a schematic diagram of the circuit structure of a light-emitting device 10 provided in an embodiment of the present application;is a schematic diagram of the circuit structure of a light source string 210 provided in an embodiment of the present application.

[0040] As shown in Figs. 1 - 2, embodiments of the present application provide a light-emitting device 10; the light-emitting device 10 may be used as an interior trim lamp of a motor vehicle, also known as an in-vehicle ambient lamp. The interior trim lamp comprises one or more of a driver's seat console ambient lamp, a centre console ambient lamp, a passenger seat ambient lamp, an armrest lamp, a charging lamp, an air conditioning outlet lamp and a door panel lamp. In addition to being used as an interior trim lamp, the light-emitting device may also be used as a signalling lamp on the outside of a vehicle; individual examples are not listed here. The light-emitting device 10 comprises a drive module 100 and multiple light source modules 200; the drive module 100 can drive the multiple light source modules 200 to operate, so as to realize multiple desired optical functions. In this embodiment, the number of light source modules 200 is 3; from a position closest to the drive module 100 to a position furthest from the drive module 100, the 3 light source modules 200 are, in sequence, a first-stage light source module 200, a second-stage light source module 200 and a third-stage light source module 200. However, in other embodiments, the number of light source modules 200 may also be 2, 4 or more.

[0041] The drive module 100 comprises a power supply output positive terminal Vs+ and a power supply output negative terminal Vs-, the drive module 100 being configured to output a power supply voltage Vs through the power supply output positive terminal Vs+ and the power supply output negative terminal Vs-. The light source module 200 comprises a light source string 210, a first input positive terminal Vin+ and a first input negative terminal Vin-; the first input positive terminal Vin+ is electrically connected to the power supply output positive terminal Vs+, and the first input negative terminal Vin- is electrically connected to the power supply output negative terminal Vs-. At least one of the light source modules 200 comprises a step-down circuit 220; within the light source module 200 that comprises the step-down circuit 220, the step-down circuit 220 is electrically connected between the first input positive terminal Vin+ and a power supply positive terminal VL+ of the light source string 210, and the step-down circuit 220 is configured to step down a received input voltage Vin1, Vin2 to a normal operating voltage VL required by the light source string 210. It should be explained that the electrical connections in embodiments of the present application refer to electrical coupling, i.e. may refer to direct connection between two components, or may refer to indirect connection between two components via conductive wires, connectors and / or other electronic elements.

[0042] In this embodiment, only one drive module 100 is used to supply power to the multiple light source modules 200, and this significantly reduces costs. Since there will often be line losses in a connecting line 300 between the first-stage light source module 200 and the drive module 100, and in connecting lines 300 between the multiple light source modules 200, the actual input voltage received by each light source module 200 will be less than the power supply voltage Vs outputted by the drive module 100, and the input voltage received by the light source module 200 in an earlier stage will be greater than the input voltage received by the light source module 200 in a later stage; for example, the magnitudes of the input voltage Vin1 of the first-stage light source module 200, the input voltage Vin2 of the second-stage light source module 200 and the input voltage Vin3 of the third-stage light source module 200 are related as follows: Vin1 > Vin2 > Vin3. Thus, in this embodiment, the power supply voltage Vs outputted by the drive module 100 can be suitably increased, and the power supply voltage Vs is greater than the normal operating voltage VL of a light source 211. Consequently, even if there are line losses, it can be ensured that the input voltages Vin1, Vin2 and Vin3 of the light source modules 200 are greater than or equal to the normal operating voltage VL. When light sources 211 of the same model number are used to form the light source string 210, the normal operating voltages VL required by the light sources 211 in the light source string 210 are the same. In a light source module 200 whose input voltage is greater than the normal operating voltage, a step-down circuit 220 is provided so that the larger input voltage is stepped down to the smaller normal operating voltage VL, to ensure that the light source 211 in this light source module 200 is able to operate normally; in a light source module 200 whose input voltage is equal to the normal operating voltage, there is no need for a step-down circuit 220, and the input voltage is used directly as a drive voltage for the light source string 210. This enables all of the multiple light source modules 200 to be supplied with power that meets requirements, and only one drive module 100 is used, i.e. effective illumination of a long string of light sources is achieved at a low cost. It should be explained here that the normal operating voltage of the light source 211 is generally a voltage range, e.g. 4.3 V - 5.5 V. When the number of light source modules 200 in the light-emitting device 10 is large and they are separated by large distances, failure to adopt a solution whereby the power supply output voltage Vs is increased and a step-down circuit 220 is added as appropriate might result in a situation where the input voltage of a light source module 200 in an earlier stage is equal to the normal operating voltage VL, but the input voltage of a light source module 200 in a later stage is less than the normal operating voltage VL due to line losses, and the light source module 200 in the later stage is unable to operate normally; in particular, the light source module 200 in the final stage is more likely to suffer from the issue of a poor illumination effect due to low input voltage. Alternatively, to ensure that the input voltage of a light source module 200 in a later stage is equal to the normal operating voltage VL, the input voltage of a light source module 200 in an earlier stage must generally be set larger, and can very easily be larger than the normal operating voltage; in this case, the light source module 200 in the earlier stage is also unable to operate normally. Alternatively, multiple drive modules 100 may be provided to drive the light source modules 200 separately; this obviously increases costs, and also increases the volume of the light-emitting device 10 as a whole. The solution of this embodiment can effectively solve these technical problems, by providing the step-down circuit 220 to ensure that the multiple light source modules 200 are supplied with power normally. In this embodiment, a light source module 200 in an earlier stage is closer to the drive module 100 than a light source module 200 in a later stage is; the light source module 200 in the later stage is indirectly electrically connected to the drive module 100 via the light source module 200 in the earlier stage.

[0043] In this embodiment, the light source module 200 further comprises a first output positive terminal Vo+ and a first output negative terminal Vo-; the first output positive terminal Vo+ is directly electrically connected to the first input positive terminal Vin+ of the same light source module 200 via a separate positive pole lead 205, and the first output negative terminal Vo- is electrically connected to the first input negative terminal Vin- of the same light source module 200 via a negative pole lead 206. In the light source module 200 comprising the step-down circuit 220, the positive pole lead 205 is electrically connected between a positive pole of the step-down circuit 220 and the first output positive terminal Vo+, and the positive pole lead 205 can directly bypass the voltage to the light source module 200 in the next stage. In this embodiment, the power supply output negative terminal Vs-, the first input negative terminal Vin-, the first output negative terminal Vo- and the negative pole lead 206 are all electrically connected to ground GND.

[0044] The multiple light source modules 200 are connected sequentially in a cascaded manner as a whole; the positive pole leads 205 of the multiple light source modules 200 are electrically connected in sequence via connecting lines 300, the positive pole leads 205 and the connecting lines 300 electrically connected thereto are formed overall as a power supply bypass line, and the power supply voltage Vs is transmitted sequentially downstream via this power supply bypass line. The positive pole lead 205 may be an electrically conductive lead on a circuit board, and the connecting line 300 may comprise a conductive wire and / or a connector; from a light source module 200 in an earlier stage to a light source module 200 in a later stage, both the positive pole lead 205 and the connecting line 300 will introduce a line loss voltage (voltage drop). Specifically, the first input positive terminal Vin+ of the first-stage light source module 200 is electrically connected to the power supply output positive terminal Vo+ of the drive module 100 via a connecting line 300, the first input negative terminal Vin- of the first-stage light source module 200 is electrically connected to the power supply output negative terminal of the drive module 100 via a connecting line 300, and the first output negative terminal Vo- is electrically connected to Vin- of the same light source module 200 via the negative pole lead 206. The first input positive terminal Vin+ of the light source module 200 located at a later stage is electrically connected to the first output positive terminal Vo+ of the light source module 200 in the previous stage via a connecting line 300, and is indirectly electrically connected to the power supply output positive terminal Vo+ of the drive module 100 via the positive pole lead 205 of the light source module 200 in an earlier stage; the first input negative terminal Vin- of the light source module 200 located at a later stage is electrically connected to the first output negative terminal Vo- of the light source module 200 in the previous stage via a connecting line 300, and is indirectly electrically connected to the power supply output negative terminal Vs- of the drive module 100 via the negative pole lead 206 of the light source module 200 in an earlier stage.

[0045] In this embodiment, each of the light source modules 200 may be formed as a separate light panel, each light panel being used to illuminate a corresponding region, and different light panels being used to realize different optical functions. The light panels are electrically connected to each other via connecting lines 300 formed by connectors and wiring harnesses.

[0046] The specific form of the step-down circuit 220 is described in detail below. The step-down circuit 220 may be realized using a simple diode; for example, within the light source module 200 comprising the step-down circuit 220, the step-down circuit 220 may comprise one diode or multiple series-connected diodes; the anode of the diode is electrically connected to the first input positive terminal Vin+ of the same light source module 200, and the cathode of the diode is electrically connected to the power supply positive terminal VL+ of the light source string 210.

[0047] In, the first-stage light source module 200 and the second-stage light source module 200 are shown as each comprising one diode; the final-stage light source module 200, i.e. the third-stage light source module 200, does not comprise a step-down circuit 220. The first-stage light source module 200 steps down the received input voltage Vin1 to the normal operating voltage VL required by the light source string 210; the second-stage light source module 200 steps down the received input voltage Vin2 to the normal operating voltage VL required by the light source string 210; and the input voltage Vin3 received by the final-stage light source module 200 is equal to the normal operating voltage VL required by the light source string 210. In other embodiments, the following configuration is also possible: the first-stage light source module 200 comprises 2 series-connected diodes, the second-stage light source module 200 comprises one diode, and the third-stage light source module 200 does not comprise a diode used as a step-down circuit 220. Alternatively, when the number of light source modules 200 is greater, for example, the light-emitting device 10 comprises a total of 8 light source modules 200, 1 light source module 200 is used as a driver's seat console ambient lamp, 1 light source module 200 is used as a centre console ambient lamp, 1 light source module 200 is used as a passenger seat ambient lamp, 1 light source module 200 is used as an air conditioning outlet lamp, and the remaining 4 light source modules 200 are used as 4 door panel lamps (front and rear, left and right). In this case, a configuration may be adopted whereby a light source module 200 in an early stage or stages comprises multiple series-connected diodes, a light source module 200 in a middle stage or stages comprises one diode, and a light source module 200 in a later stage or stages does not comprise a diode. The drive module 100 outputs a large power supply voltage Vs, and the input voltages of the light source modules 200 of the various stages have different magnitudes due to different line losses, but as a result of providing different step-down circuits so that the voltages of the power supply positive terminals VL+ of the light source strings 210 in the light source modules 200 of the various stages are all equal to the normal operating voltage VL, the light source strings 210 in all of the stages are able to emit light normally.

[0048] Diodes are generally quite low-priced; by using diodes, the illumination effect of the light-emitting device 10 can be improved at a low cost, with good stability. However, diodes generally have a fixed voltage drop value, e.g. 0.6 V - 0.8 V; in order to control the step-down value of the step-down circuit 220 more precisely and intelligently, in some variant embodiments, it is possible to use a switching transistor instead of a diode to achieve precise and controllable step-down. Examples of step-down circuits 220 realized by switching transistors include linear step-down circuits, BUCK circuits, etc., and are not listed individually here. They are only required to be capable of reducing voltage to the required normal operating voltage VL.

[0049] As shown in, the light source string 210 comprises multiple light sources 211; for example, the number of light sources 211 in the light source string 210 may be greater than 10, or even greater than 20 or greater than 50. The number of light sources 211 in each light source string 210 may be the same or different. The number of light sources 211 in the entire light-emitting device 10 is greater than 100. Theoretically, the greater the number of light sources 211, the greater the impact of line loss voltage on the illumination effect of the light sources 211. The light sources 211 may comprise smart LEDs; when the light-emitting device 10 is used as an interior trim lamp, the LEDs may be RGB LEDs, power terminals of the light sources 211 in the light source string 210 are connected in parallel, signal terminals are connected in series, and the light sources 211 are configured to emit light of various required colours according to received control signals. Specifically, power supply positive terminals VDD, VLED of the LED are electrically connected to the power supply positive terminal VL+ of the light source 211, power supply negative terminals GND1+2, GND3+4 of the LED are electrically connected to the power supply negative terminal VL- of the light source 211, the power supply positive terminals VL+ of the respective light sources 211 are electrically connected to each other, and the power supply negative terminals VL- of the respective light sources 211 are electrically connected to each other.

[0050] Furthermore, in each light source module 200, the power supply negative terminals VL- of the multiple light sources 211 are electrically connected to the first input negative terminal Vin- of the same light source module 200. In the light source module 200 comprising the step-down circuit 220, the power supply positive terminals VL+ of the multiple light sources 211 are electrically connected to the first input positive terminal Vin+ of the light source module 200 via the step-down circuit 220. In the light source module 200 that does not comprise a step-down circuit 220, the power supply positive terminals VL+ of the multiple light sources 211 are electrically connected to the first input positive terminal Vin+ of the light source module directly via an electrically conductive lead. This electrically conductive lead may be a conductive wire on a circuit board.

[0051] The drive module 100 specifically comprises a control circuit 110 and a voltage regulator circuit 120, the voltage regulator circuit 120 being electrically connected to the control circuit 110, the power supply output positive terminal Vs+ and the power supply output negative terminal Vs-. The voltage regulator circuit 120 is configured to convert a received external voltage Vb to the power supply voltage Vs according to a power supply control signal Cp of the control circuit 110. In some embodiments, the control circuit 110 may comprise an MCU, the voltage regulator circuit 120 may comprise a filter circuit and a Buck circuit, and the external voltage Vb may be a vehicle body voltage; the voltage regulator circuit filters and steps down the external voltage Vb and then outputs same as the power supply voltage Vs.

[0052] In addition, the drive module 100 may further comprise a signal conversion circuit 130 and signal output terminals Sig+, Sig-; the signal conversion circuit 130 is electrically connected between the control circuit 110 and the signal output terminals Sig+, Sig-, and the signal conversion circuit 130 is configured to convert a light source control signal in a first format outputted by the control circuit 110 to a light source control signal Sig in a second format, and output the light source control signal Sig in the second format through the signal output terminals. For example, the signal conversion circuit 130 comprises a format conversion circuit 131 and a CAN transceiver 132; the format conversion circuit 131 can convert a data signal outputted by an SPI port of the MCU to a Manchester signal for input to the CAN transceiver 132. The format conversion circuit 131 and the CAN transceiver 132 are circuit components that are separate from one another and electrically connected to each other. In other embodiments, a one-piece signal conversion circuit 130 may be used to realize signal conversion, without sub-division into the format conversion circuit 131 and the CAN transceiver 132.

[0053] Correspondingly, the light source module 200 may comprise a signal converter; a power supply positive terminal Vc+ of the signal converter is electrically connected to the power supply positive terminal VL+ of the light source string 210, and a power supply negative terminal of the signal converter is electrically connected to a power supply negative terminal of the light source string 210, i.e. the power supply negative terminal of the signal converter and the power supply negative terminal of the light source string 210 are both electrically connected to ground GND. The signal converter specifically comprises a first signal transceiver 230 and a second signal transceiver 240; the first transceiver 230 and the second transceiver 240 are for example both CAN transceivers; and the first transceiver 230, the light source string 210 and the second transceiver 240 are electrically connected in sequence. The first transceiver 230 of the first-stage light source module 200 is electrically connected to the signal output terminals Sig+, Sig- of the drive module 100, and the first signal transceiver 230 of the light source module 200 located in a later stage is electrically connected to the second signal transceiver 240 of the light source module 200 in the previous stage; based on the light source control signal Sig, the light source string 210 realizes corresponding switch-on and switch-off. The multiple light sources 211 in the light source string 210 each comprise signal terminals, and the multiple light sources 211 in the light source string 210 are cascaded in sequence via the signal terminals. Specifically, the light source 211 comprises signal input terminals SIO1+, SIO1- and signal output terminals SIO2+, SIO2-; the signal input terminals SIO1+, SIO1- of the light source 211 located in a later stage are electrically connected to the signal output terminals SIO2+, SIO2- of the light source 211 in an earlier stage; the light source 211 in an earlier stage is closer to the first transceiver 230 than the light source 211 in a later stage; the signal input terminals SIO1+, SIO1- of the light source 211 located in the first stage are electrically connected to the corresponding first transceiver 230; and the signal output terminals of the light source 211 located in the final stage are electrically connected to the corresponding second transceiver 240.

[0054] It should be explained that, within the light source module 200 comprising the step-down circuit 220, power supply positive terminals of the first transceiver 230 and the second transceiver 240 are also electrically connected to a first input positive terminal Vin+ of the same light source module 200 via the step-down circuit 220. The step-down circuit 220 may also step down the received input voltage Vin to the normal operating voltage required by the first transceiver 230 and the second transceiver 240. The normal operating voltage of the transceivers may also be a voltage range, e.g. 4.75 - 5.25 V. This range is smaller than the normal operating voltage range (4.3 - 5.5 V) of the light sources 211; therefore, when the connecting line 300 is long, the first transceiver 230 and the second transceiver 240 might be more susceptible to line loss voltage than the light source string 210. By providing the step-down circuit 220, it can be ensured that the first transceiver 230 and the second transceiver 240 transmit signals reliably.

[0055] Although the present application has been explained with reference to the drawings, the embodiments disclosed in the drawings are intended to provide an exemplary explanation of preferred implementations of the present application, and must not be construed as limiting the present application. The dimensional proportions in the drawings are merely schematic, and must not be construed as limiting the present application.

[0056] Although some embodiments of the general concept of the present application have been shown and described, those skilled in the art will understand that the present application may include other equivalent embodiments without departing from the general inventive concept of the present application, and the scope of protection of the present application is defined by the claims.

Claims

Light-emitting device (10), characterized by comprising:a drive module (100), comprising a power supply output positive terminal and a power supply output negative terminal, the drive module being configured to output a power supply voltage through the power supply output positive terminal and the power supply output negative terminal; andmultiple light source modules (200), the light source module comprising a light source string (210), a first input positive terminal and a first input negative terminal, the first input positive terminal being electrically connected to the power supply output positive terminal, and the first input negative terminal being electrically connected to the power supply output negative terminal,wherein at least one of the light source modules comprises a step-down circuit (220); within the light source module that comprises the step-down circuit, the step-down circuit is electrically connected between the first input positive terminal and a power supply positive terminal of the light source string, and the step-down circuit is configured to step down a received input voltage to a normal operating voltage required by the light source string.Light-emitting device according to Claim 1, wherein the light source module comprises a signal converter; a power supply positive terminal of the signal converter is electrically connected to the power supply positive terminal of the light source string, and a power supply negative terminal of the signal converter is electrically connected to a power supply negative terminal of the light source string;within the light source module that comprises the step-down circuit, the power supply positive terminal of the signal converter is electrically connected to the first input positive terminal via the step-down circuit, and the step-down circuit is configured to step down the received input voltage to a normal operating voltage required by the signal converter.Light-emitting device according to Claim 2, wherein the light source module comprises a first output positive terminal and a first output negative terminal, the first output positive terminal being electrically connected to the first input positive terminal via a positive pole lead (205), and the first output negative terminal being electrically connected to the first input negative terminal via a negative pole lead (206);the multiple light source modules are connected sequentially in a cascaded manner, the first input positive terminal of the light source module in a first stage being electrically connected to the power supply output positive terminal via a connecting line (300), and the first input negative terminal of the light source module in the first stage being electrically connected to the power supply output negative terminal via a connecting line;the first input positive terminal of the light source module located in a later stage is electrically connected to the first output positive terminal of the light source module in the previous stage via a connecting line, and is indirectly electrically connected to the power supply output positive terminal via a positive pole lead of the light source module in an earlier stage; the first input negative terminal of the light source module located in a later stage is electrically connected to the first output negative terminal of the light source module in the previous stage via a connecting line, and is indirectly electrically connected to the power supply output negative terminal via a negative pole lead of the light source module in an earlier stage.Light-emitting device according to Claim 1, wherein, within the light source module comprising the step-down circuit, the step-down circuit (220) comprises one diode or multiple series-connected diodes; the anode of the diode is electrically connected to the first input positive terminal, and the cathode of the diode is electrically connected to the power supply positive terminal of the light source string.Light-emitting device according to Claim 1, wherein the light source string comprises multiple light sources (211), and power supply negative terminals of the multiple light sources are electrically connected to the first input negative terminal of the light source module;within the light source module comprising a step-down circuit, power supply positive terminals of the multiple light sources are electrically connected to the first input positive terminal of the light source module via the step-down circuit;within the light source module that does not comprise a step-down circuit, the power supply positive terminals of the multiple light sources are electrically connected to the first input positive terminal of the light source module directly via an electrically conductive lead.Light-emitting device according to Claim 5, wherein the light source is a smart LED, the light source is an RGB LED, and the light source is configured to emit required light according to a received control signal.Light-emitting device according to any one of Claims 1 - 6, wherein an input voltage received by the light source module in an earlier stage is greater than an input voltage received by the light source module in a later stage.Light-emitting device according to any one of Claims 1 - 6, wherein light sources in the light source string have the same normal operating voltages, power terminals of the light sources in the light source string are connected in parallel, and signal terminals are connected in series;the light source module in a first stage comprises a step-down circuit, and steps down a received input voltage to a normal operating voltage required by the light source string;the light source module in a final stage does not comprise a step-down circuit, and an input voltage received by the light source module in the final stage is equal to the normal operating voltage required by the light source string.Light-emitting device according to any one of Claims 1 - 6, wherein positive pole leads (205) of the multiple light source modules are electrically connected in sequence via a connecting line (300), the positive pole leads and the connecting line electrically connected thereto are formed overall as a power supply bypass line, and the power supply voltage is transmitted sequentially downstream via the power supply bypass line;the positive pole lead is an electrically conductive lead on a circuit board, and the connecting line comprises a conductive wire and / or a connector.Light-emitting device according to any one of Claims 1 - 6, wherein each of the light source modules is formed as a separate light panel, each light panel being used to illuminate a corresponding region.Light-emitting device according to any one of Claims 1 - 6, wherein the drive module (100) comprises a control circuit (110) and a voltage regulator circuit (120), the voltage regulator circuit being electrically connected to the control circuit, the power supply output positive terminal and the power supply output negative terminal;the voltage regulator circuit is configured to convert a received external voltage to the power supply voltage according to a power supply control signal of the control circuit.Light-emitting device according to Claim 11, wherein the drive module comprises a signal conversion circuit (130) and a signal output terminal; the signal conversion circuit is electrically connected between the control circuit and the signal output terminal, and the signal conversion circuit is configured to convert a light source control signal in a first format outputted by the control circuit to a light source control signal in a second format, and output the light source control signal in the second format through the signal output terminal;a signal converter in the light source module (200) comprises a first signal transceiver (230) and a second signal transceiver (240), and the first transceiver, the light source string and the second transceiver are electrically connected in sequence;the first transceiver of the light source module in a first stage is electrically connected to the signal output terminal, and the first signal transceiver of the light source module located in a later stage is electrically connected to the second signal transceiver of the light source module in the previous stage; and based on the light source control signal, the light source string realizes corresponding switch-on and switch-off.Light-emitting device according to Claim 12, wherein the signal conversion circuit, the first transceiver and the second transceiver comprise CAN transceivers;within the light source module comprising the step-down circuit, power supply positive terminals of the first transceiver and the second transceiver are electrically connected to the first input positive terminal via the step-down circuit.Light-emitting device according to Claim 12, wherein multiple light sources in the light source string each comprise a signal terminal, and are cascaded in sequence via the signal terminals.Light-emitting device according to any one of Claims 1 - 6, wherein the light-emitting device is used as an interior trim lamp of a motor vehicle, the interior trim lamp comprising one or more of a driver's seat console ambient lamp, a centre console ambient lamp, a passenger seat ambient lamp, an armrest lamp, a charging lamp, an air conditioning outlet lamp and a door panel lamp.

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