CN110149746B

CN110149746B - LED light source circuit, equipment with light source and brightness control method of equipment

Info

Publication number: CN110149746B
Application number: CN201910335866.0A
Authority: CN
Inventors: 庞凤颖
Original assignee: Goertek Optical Technology Co Ltd
Current assignee: Goertek Optical Technology Co Ltd
Priority date: 2019-04-24
Filing date: 2019-04-24
Publication date: 2021-08-31
Anticipated expiration: 2039-04-24
Also published as: CN110149746A

Abstract

The invention provides an LED light source circuit, a device with a light source and a brightness control method of the device, wherein the LED light source circuit comprises: the LED basic circuit comprises a controller, an LED lamp and an electronic switch, the LED lamp and the electronic switch are connected in series on the first power supply loop, and the output end of the controller, which is used for outputting a control signal, is connected with the control end of the electronic switch; the brightness compensation circuit comprises a brightness compensation lamp bead which is connected to the second power supply circuit; and the compensation control circuit comprises a switch circuit used for outputting a switch signal according to the switch operation, and the compensation control circuit is arranged for controlling the on-off state of the second power supply loop according to the control signal and the switch signal so that the second power supply loop has the same on-off state as the first power supply loop under the condition that the switch signal represents that the brightness compensation is started.

Description

LED light source circuit, equipment with light source and brightness control method of equipment

Technical Field

The invention relates to the technical field of illumination, in particular to an LED light source circuit, equipment with a light source and a brightness control method of the equipment.

Background

Compared with a micro-projection product of a laser light source, the micro-projection product of the LED light source is safer and more efficient, so that the micro-projection product of the LED light source is more and more widely used.

At present, the micro-production of the LED light source generally consists of three light sources of red, green and blue. However, as the demand of users increases, the brightness that can be achieved by three light sources has gradually failed to meet the market demand. And then, the effect of increasing the overall brightness of the micro-projection product of the LED light source by adding four light sources of one light source to the existing three light sources is achieved. However, the prior art techniques have poor performance in the synchronous adjustment of the added light sources.

Disclosure of Invention

The invention aims to provide a novel scheme of an LED light source circuit.

According to a first aspect of the present invention, there is provided an LED light source circuit comprising:

the LED basic circuit comprises a controller, an LED lamp and an electronic switch, wherein the LED lamp and the electronic switch are connected in series on a first power supply loop, and the output end of the controller for outputting a control signal is connected with the control end of the electronic switch;

the brightness compensation circuit comprises a brightness compensation lamp bead which is connected to the second power supply loop; and the number of the first and second groups,

a compensation control circuit comprising a switching circuit for outputting a switching signal in dependence on a switching operation, the compensation control circuit being arranged to control the on-off state of the second supply loop in dependence on the control signal and the switching signal such that the second supply loop has the same on-off state as the first supply loop in the event that the switching signal represents a switch on of the brightness compensation.

Optionally, the second power supply loop is provided by a DC-DC switching power supply.

Optionally, the compensation control circuit further includes a logic circuit, a first input end of the logic circuit is connected to the output end of the switching signal of the switching circuit, a second input end of the logic circuit is connected to the output end of the switching control signal of the controller, and an output end of the logic circuit is connected to the control end of the second power supply loop.

Optionally, the brightness compensation lamp bead has the same color as the LED lamp.

Optionally, the first power supply loop is provided by the controller, and the controller is configured to provide currents of a plurality of different gears to the first power supply loop.

Optionally, the LED basic circuit further includes a detection resistor connected in series with the LED lamp on the first power supply circuit, and the controller is configured to provide the currents of the plurality of different gears by changing a resistance value of the detection resistor.

Optionally, the control signal is a PWM wave.

According to a second aspect of the present invention, there is provided a device having a light source comprising at least one LED light source circuit as described in any one of the first aspects.

Optionally, the apparatus is a projector, the apparatus includes one LED light source circuit, and a color of an LED lamp of the LED light source circuit is green; the device also comprises another two LED basic circuits, wherein the colors of the LED lamps of the other two LED basic circuits are respectively red and blue; all the LED basic circuits share one controller.

According to a third aspect of the present invention, there is provided a luminance control method of an apparatus as set forth in the second aspect, the luminance control method comprising:

acquiring input target brightness;

according to the input target brightness, obtaining a target gear of current required to be provided for the LED basic circuit and a target state of a required switch signal;

under the condition that the target state is brightness compensation starting, prompting of closing a switch circuit is carried out;

and supplying current to the LED basic circuit according to the target gear.

Optionally, the obtaining of the target gear of the current required to be provided for the LED basic circuit and the target state of the required switching signal includes:

acquiring prestored brightness control data, wherein the brightness control data reflects the mapping relation between each set target brightness and the target gear and the target state;

and obtaining the target gear corresponding to the input target brightness and the target state corresponding to the input target brightness according to the brightness control data.

Optionally, the method further includes:

under the condition that the target state is brightness compensation closing, detecting whether a switching signal currently output by the switching circuit represents that the brightness compensation is opened;

when the brightness compensation is turned on, the switching circuit is turned off.

In the LED light source circuit provided in this embodiment of the present invention, because the LED lamp is connected in series to the first power supply loop, the brightness compensation lamp bead is connected to the second power supply loop, and the compensation control circuit can make the second power supply loop have the same on-off state as the first power supply loop when the switching signal represents that the brightness compensation is turned on, on the one hand, the LED light source circuit provided in the embodiment of the present invention can perform the brightness compensation on the LED basic circuit, and on the other hand, when the switching signal represents that the brightness compensation is turned on, the on-off states of the LED lamp and the brightness compensation lamp bead are the same, that is, the LED lamp and the brightness compensation lamp bead can perform stable synchronous adjustment. Meanwhile, the LED light source circuit provided by the embodiment of the invention has a simple circuit structure and a small circuit volume.

Other features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the embodiments will be briefly described below. It is appreciated that the following drawings depict only certain embodiments of the invention and are therefore not to be considered limiting of its scope. For a person skilled in the art, it is possible to derive other relevant figures from these figures without inventive effort.

Fig. 1 is a schematic circuit structure diagram of an LED light source circuit according to an embodiment of the present invention;

fig. 2 is a schematic circuit diagram of another LED light source circuit according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a light source circuit included in an apparatus having a light source according to an embodiment of the present invention;

FIG. 4 is a flow chart of a method for controlling brightness of an apparatus according to an embodiment of the present invention;

fig. 5 is a flowchart illustrating a pre-debugging process of brightness control data according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of a luminance control apparatus of a device according to an embodiment of the present invention.

Detailed Description

Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.

In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values.

< LED light Source Circuit >

Referring to fig. 1, a circuit structure of an LED light source circuit according to an embodiment of the present invention is described:

the LED light source circuit includes: the LED backlight module comprises an LED basic circuit, a brightness compensation circuit and a compensation control circuit. Wherein:

the LED basic circuit comprises a controller, an LED lamp and an electronic switch, wherein the LED lamp and the electronic switch are connected in series on a first power supply loop, and the output end of the controller, which is used for outputting a control signal, is connected with the control end of the electronic switch.

In one example, the controller includes at least one output terminal for outputting a control signal for controlling the electronic switch to be turned on/off, and a ground terminal. The controller may be a driving chip of the LED. For example, the controller may be a driving chip DLP3005 of the LED. Further, the control signal may be a PWM wave set according to an empirical value.

In one example, the first power supply loop is provided by a controller arranged to provide different levels of current to the first power supply loop.

In one example, in one way of implementing that the controller is configured to provide currents of different gears to the first power supply circuit, the LED basic circuit further comprises a detection resistor, the detection resistor and the LED lamp are connected in series on the first power supply circuit, and the controller is configured to provide the currents of the plurality of different gears by changing the resistance value of the detection resistor. Wherein the detection resistor may be integrated in the controller.

In another example, the first power supply circuit may be provided by another current source capable of providing current for a different gear.

In one example, the LED lamp may be one of a red LED or the like, a green LED lamp, and a blue LED lamp. Meanwhile, the electronic switch may be: NMOS transistor or NPN transistor. When the electronic switch is an NPN transistor, the base stage of the NPN transistor serves as the control terminal of the electronic switch. When the electronic switch is an NMOS transistor, as shown in fig. 2, the gate of the NMOS transistor serves as the control terminal of the electronic switch.

In one example, to ensure stable operation of the LED basic circuit, a voltage dividing resistor R1 is usually connected in series in the first power supply loop.

In one example, the operation principle of the LED basic circuit is as follows: the controller is configured to supply a current to the first power supply loop, and an output terminal of the controller outputs a control signal for controlling the electronic switch to be turned on/off. When the output end of the controller outputs a control signal for controlling the electronic switch to be switched on, the first power supply loop is switched on, and the LED lamp is lightened. When the other output end of the controller outputs a control signal for controlling the electronic switch to be switched off, the first power supply loop is switched off, and the LED lamp is turned off.

The luminance compensation circuit includes: and the brightness compensation lamp bead is connected to the second power supply loop.

In this embodiment, the brightness compensation lamp bead is used for supplementing the brightness of the LED basic circuit, and the brightness compensation lamp bead is an LED lamp. In one example, the brightness compensation lamp bead is the same color as the LED lamp in the LED basic circuit. For example, the color of the brightness compensation lamp bead and the color of the LED lamp in the LED basic circuit are the same as green.

In one example, as shown in fig. 2, the second supply loop is provided by a DC-DC switching power supply. In another example, the second supply loop may also be provided by another constant current source. It should be noted that the magnitude of the current provided by the DC-DC switching power supply or other constant current source to the second power supply loop is the same as the maximum current that can be provided by the controller or other current source to the first power supply loop. For example, the controller or other current source can provide a maximum current of 25A to the first power supply loop, and correspondingly, the DC-DC switching power supply or other constant current source can provide a current of 25A to the second power supply loop.

In one example, to ensure stable operation of the luminance compensation circuit, a voltage dividing resistor R2 is usually connected in series in the second power supply loop, as shown in fig. 2.

In this embodiment, the operation principle of the brightness compensation circuit is as follows: when the second power supply loop is switched on, the brightness compensation lamp beads are lightened, and brightness compensation can be carried out on the LED basic circuit. When the second power supply loop is disconnected, the brightness compensation lamp bead is extinguished.

The compensation control circuit includes: and the compensation control circuit is arranged to control the on-off state of the second power supply loop according to the control signal and the switching signal, so that the second power supply loop has the same on-off state as the first power supply loop under the condition that the switching signal represents that the brightness compensation is started.

In one example, the switching circuit has a circuit configuration as shown in fig. 2. The switch circuit comprises a third power supply loop provided by a +5V voltage source, a resistor R3 and a key switch are connected in series on the third power supply loop, and a terminal is led out between the resistor R3 and the key switch and is connected to the compensation control circuit. Based on this, the switch operation in the embodiment of the present invention is an operation in which a user triggers the key switch, and the switch signal is used to represent a state in which the key switch is turned on or off.

In one example, as shown in fig. 2, when the key switch is disposed at the voltage source side of the third power supply loop, the switch circuit is configured to indicate that the brightness compensation needs to be turned on when the switch signal output by the switch circuit indicates that the key switch is turned on, i.e., the third power supply loop is turned on. Correspondingly, when the switch signal output by the switch circuit represents that the key switch is switched on, namely the third power supply circuit is switched off, the representation does not need to carry out brightness compensation.

In another example, when the resistor R3 is disposed on the voltage source side of the third power supply loop, the switch circuit may be further configured to represent that the brightness compensation is not required to be turned on when the switch signal output by the switch circuit indicates that the keyswitch is turned on, i.e., the third power supply loop is turned on. Correspondingly, when the switch signal output by the switch circuit represents that the key switch is switched on, namely the third power supply circuit is switched off, the representation needs to be subjected to brightness compensation.

Further, the compensation control circuit is further configured to control the on-off state of the second power supply circuit according to the control signal and the switching signal, so that the second power supply circuit maintains the off state under the condition that the switching signal represents that the brightness compensation is turned off.

In one example, in one manner of implementing the functionality of the compensation control circuit described above, the compensation control circuit further includes a logic circuit. Specifically, a first input end of the logic circuit is connected with an output end of a switching signal of the switching circuit, a second input end of the logic circuit is connected with an output end of a switching control signal of the controller, and an output end of the logic circuit is connected with a control end of the second power supply loop. Further, as shown in fig. 2, the logic circuit may be an and circuit or a circuit having the same function as the and circuit.

In this embodiment, the operation principle of the compensation control circuit is as follows: when the output of the switch circuit represents the condition of starting brightness compensation and the first power supply loop is conducted, the second power supply loop is conducted, and the brightness compensation lamp bead is lightened at the moment to compensate brightness for the LED basic circuit. When the output of the switch circuit represents the condition of starting the brightness compensation and the first power supply circuit is disconnected, the second power supply circuit is disconnected, and the brightness compensation lamp bead is turned off at the moment. Further, under the condition that the output of the switch circuit represents that the brightness compensation is turned off, the second power supply loop is disconnected, and the brightness compensation lamp bead is turned off at the moment.

< apparatus with light Source >

The embodiment of the invention also provides equipment with the light source, which comprises any one of the LED light source circuits in the embodiment.

In one example, the apparatus with a light source may comprise an LED light source circuit according to any of the embodiments described above. In another example, the device may also comprise at least two of the LED light source circuits of any of the embodiments described above. In this other example, multiple LED light source circuits may share a single controller. In this other example, a plurality of LED light source circuits may share a single sensing resistor.

In one example, the device having the light source may be a projector, a lighting device, or the like.

In one example, when the apparatus having the light source is a projector, the apparatus having the light source includes an LED light source circuit, and the LED lamp of the LED light source circuit is green in color. The equipment with the light source also comprises another two LED basic circuits, wherein the colors of the LED lamps of the other two LED basic circuits are respectively red and blue; all the LED basic circuits share one controller. On the basis of the LED light source circuit described above, the apparatus having a light source provided in this example may include a light source circuit as shown in fig. 3.

In the above example, the current provided by the controller to the first power supply loop of the two other LED basic circuits can be obtained empirically.

The controller in this embodiment may be implemented by, for example, a chip DLP 3005. Since the chip DLP3005 may provide three outputs for respectively providing a current source to the corresponding first power supply circuit in each LED basic circuit, and three outputs for respectively outputting a control signal for controlling on/off of the corresponding electronic switch in each LED basic circuit. Therefore, when the apparatus having the light source includes three LED basic circuits, the controller in the three LED basic circuits may be implemented by one chip DLP 3005.

< method for controlling luminance of device >

The embodiment of the invention also provides a brightness control method of the equipment, wherein the equipment is any one of the equipment provided in the above embodiments. As shown in fig. 4, the method includes the steps of:

s401, acquiring the input target brightness.

In the present embodiment, the target luminance is the required luminance of the user.

S402, obtaining a target gear of current required to be provided for the LED basic circuit and a target state of a required switch signal according to the input target brightness.

In one example, the above S402 is implemented as the following steps S4021 and S4022:

s4021, acquiring pre-stored brightness control data, wherein the brightness control data reflect the mapping relation between each set target brightness and the target gear and the target state.

S4022, obtaining a target gear corresponding to the input target brightness and a target state corresponding to the input target brightness according to the brightness control data.

In this embodiment, the specific implementation of S4022 is to search for a set target luminance in the luminance control data, where a difference value between the set target luminance and the target luminance is within a preset range, and use a current tap position corresponding to the searched set target luminance and a state of the required switching signal as a target tap position of the current and a target state of the required switching signal.

In this embodiment, the brightness control data is pre-adjusted based on any one of the LED light source circuits in the above embodiments. Taking the LED light source circuit shown in fig. 3 as an example, the pre-debugging process of the brightness control data is shown in fig. 5:

s1, manually confirming that the key switch is turned off;

s2, inputting current of an initial gear into a first power supply loop corresponding to the three LED basic circuits by a controller respectively, and inputting PWM waves obtained according to empirical values into control ends of electronic switches of the three LED basic circuits respectively;

s3, determining whether the brightness of the LED light source circuit meets the set brightness;

in this step, when the key switch is turned off, the controller determines the brightness of the LED light source circuit according to the currents input into the first power supply circuits corresponding to the three LED basic circuits, respectively. When the key switch is closed, the controller determines the brightness of the LED light source circuit according to the current input into the first power supply loop and the input current into the second power supply loop corresponding to the three LED basic circuits. It should be noted that, the controller determines the brightness of the LED light source circuit according to the current input into the first power supply loop corresponding to the three LED basic circuits, and the input current in the second power supply loop, which are well known to those skilled in the art, and are not described herein again.

S4, if yes, the current I _ G _ LED flowing through the G _ LED lamp in the first power supply loop and the on/off state of the key switch provided by the controller and the set brightness are used as a group of brightness control data;

in this step, the on/off state of the key switch is taken as the state of the switch signal. Specifically, when the key switch is in the on state, the state of the switch signal represents that the brightness compensation needs to be turned on. When the key switch is in an off state, the state of the switch signal represents that the brightness compensation needs to be turned off.

S5, if not, determining whether the I _ G _ LED is the maximum value;

s6, if not, increasing the current of one gear for the G _ LED, and returning to the S3;

s7, if yes, detecting whether the key switch is disconnected;

s8, if not, outputting a first prompt message indicating that the set brightness is greater than the adjustable brightness of the LED light source;

s9, if not, prompting a debugging person to close the key switch;

s10, re-detecting whether the case switch is disconnected;

s11, if yes, outputting a prompt message II which represents that the key switch is turned off and the brightness cannot be adjusted temporarily;

s12, set I _ G _ LED to 0, and return to S3.

N sets of brightness control data are obtained by setting the set brightness to the set first brightness, the set second brightness, and the set N brightness of … …, and executing the above steps S1-S12.

It should be noted that, when the maximum current that the controller can provide to the first power supply circuit is 25A, and correspondingly, the current that the DC-DC switching power supply or other constant current source provides to the second power supply circuit is also 25A of the constant current, based on the above-mentioned S1-S12, the adjustment range of the I _ G _ LED in the LED light source circuit provided in this embodiment is 0 to 50A.

And S403, under the condition that the target state is the state of opening the brightness compensation, prompting of closing the switch circuit is performed.

In one example, in the case that the target state is to turn off the brightness compensation, detecting whether the switching signal currently output by the switching circuit represents that the brightness compensation is turned on; when the brightness compensation is turned on, the switching circuit is turned off.

And S404, providing current to the LED basic circuit according to the target gear.

The brightness control method of the equipment can control the brightness of the equipment to the target brightness meeting the requirements of users.

< luminance control device of device >

As shown in fig. 6, the brightness control device 60 of an apparatus provided in this embodiment includes: a memory 61 and a processor 62. Wherein the content of the first and second substances,

a memory 61 for storing executable instructions.

And a processor 62, configured to operate the brightness control device 60 of the apparatus according to the control of the executable instructions, and execute the brightness control method of the apparatus provided in any of the above embodiments.

In the present embodiment, the luminance control device 60 of the apparatus may have various physical forms. The brightness control means 60 of the device may be, for example, a projector or be a part provided in a projector.

It will be appreciated by those skilled in the art that the brightness control means 60 of the above described apparatus may be implemented in various ways. For example, the brightness control means 60 of the device may be implemented by an instruction configuration processor. For example, instructions may be stored in ROM and read from ROM into a programmable device when the device is started up to implement brightness control means 60 of the device.

< computer storage Medium >

The present embodiment provides a computer storage medium, which stores computer instructions, and when the computer instructions in the storage medium are executed by a processor, the method for controlling the brightness of the device provided in any one of the above embodiments is implemented.

The computer readable storage medium may be a tangible device that can hold and store the instructions for use by the instruction execution device. The computer readable storage medium may be, for example, but not limited to, an electronic memory device, a magnetic memory device, an optical memory device, an electromagnetic memory device, a semiconductor memory device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a Static Random Access Memory (SRAM), a portable compact disc read-only memory (CD-ROM), a Digital Versatile Disc (DVD), a memory stick, a floppy disk, a mechanical coding device, such as punch cards or in-groove projection structures having instructions stored thereon, and any suitable combination of the foregoing. Computer-readable storage media as used herein is not to be construed as transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission medium (e.g., optical pulses through a fiber optic cable), or electrical signals transmitted through electrical wires.

The present invention may be a computer program product. The computer program product may include a computer-readable storage medium having computer-readable program instructions embodied therewith for causing a processor to implement various aspects of the present invention.

The computer readable storage medium may be a tangible device that can hold and store the instructions for use by the instruction execution device. The computer readable storage medium may be, for example, but not limited to, an electronic memory device, a magnetic memory device, an optical memory device, an electromagnetic memory device, a semiconductor memory device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer-readable storage medium include a portable computer diskette, a hard disk, a random access memory (RAM, a read-only memory (ROM, an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM, a portable compact disc read-only memory (CD-ROM), a digital versatile disc (DVD, a memory stick, a floppy disk, a mechanical coding device, a punch card or an in-groove protrusion structure having instructions stored thereon, for example, and any suitable combination of the foregoing.

The computer-readable program instructions described herein may be downloaded from a computer-readable storage medium to a respective computing/processing device, or to an external computer or external storage device via a network, such as the internet, a local area network, a wide area network, and/or a wireless network. The network may include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers and/or edge servers. The network adapter card or network interface in each computing/processing device receives computer-readable program instructions from the network and forwards the computer-readable program instructions for storage in a computer-readable storage medium in the respective computing/processing device.

The computer program instructions for carrying out operations of the present invention may be assembler instructions, instruction set architecture (ISA instructions, machine-related instructions, microcode, firmware instructions, state setting data, or source or object code written in any combination of one or more programming languages, including an object oriented programming language such as Smalltalk, C + + or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages In some embodiments, the various aspects of the present invention are implemented by personalizing electronic circuitry, such as programmable logic circuits, field programmable gate arrays (FPGAs, or Programmable Logic Arrays (PLAs), that execute computer-readable program instructions, with state information of the computer-readable program instructions.

It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer readable program instructions.

These computer-readable program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer-readable program instructions may also be stored in a computer-readable storage medium that can direct a computer, programmable data processing apparatus, and/or other devices to function in a particular manner, such that the computer-readable medium storing the instructions comprises an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks.

The computer readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer, other programmable apparatus or other devices implement the functions/acts specified in the flowchart and/or block diagram block or blocks.

The flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions. It is well known to those skilled in the art that implementation by hardware, by software, and by a combination of software and hardware are equivalent.

Having described embodiments of the present invention, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen in order to best explain the principles of the embodiments, the practical application, or improvements made to the technology in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein. The scope of the invention is defined by the appended claims.

Claims

1. An LED light source circuit, comprising:

2. The LED light source circuit of claim 1, wherein the second power supply loop is provided by a DC-DC switching power supply.

3. The LED light source circuit of claim 2, wherein the compensation control circuit further comprises a logic circuit, a first input terminal of the logic circuit is connected to the output terminal of the switching signal of the switching circuit, a second input terminal of the logic circuit is connected to the output terminal of the control signal of the controller, and an output terminal of the logic circuit is connected to the control terminal of the second power supply loop.

4. The LED light source circuit as claimed in any one of claims 1 to 3, wherein the brightness compensation lamp bead is the same color as the LED lamp.

5. The LED light source circuit of any of claims 1 to 3, wherein the first power supply loop is provided by the controller, the controller being arranged to provide a plurality of different levels of current to the first power supply loop.

6. The LED light source circuit of claim 5, wherein the LED base circuit further comprises a sensing resistor connected in series with the LED lamp on the first power supply loop, and wherein the controller is configured to provide the plurality of different tap positions by changing a resistance of the sensing resistor.

7. The LED light source circuit according to any one of claims 1 to 3, wherein the control signal is a PWM wave.

8. An apparatus having a light source, characterized in that the light source comprises at least one LED light source circuit as claimed in any one of claims 1 to 7.

9. The apparatus of claim 8, wherein the apparatus is a projector, the apparatus includes one of the LED light source circuits, and a color of an LED lamp of the LED light source circuit is green; the device also comprises another two LED basic circuits, wherein the colors of the LED lamps of the other two LED basic circuits are respectively red and blue; all the LED basic circuits share one controller.

10. A brightness control method of a device, characterized in that the device is the device of claim 8 or 9, the brightness control method comprising:

acquiring input target brightness;

and supplying current to the LED basic circuit according to the target gear.

11. The method of claim 10, wherein obtaining the target gear of the current required to be provided to the LED base circuit and the target state of the required switching signal comprises:

12. The method of claim 10, further comprising: