Dimming circuit and laser digital driving board

Abstract

The utility model relates to the technical field of laser equipment, and discloses a dimming circuit and a laser digital driver board, the dimming circuit comprises a power supply conversion unit, a light closing unit, a current modulation unit and a voltage modulation unit, the first output end of the power conversion unit is connected with the power supply end of the voltage modulation unit, and the second output end of the power conversion unit is connected with the power supply end of the light closing unit and the power supply end of the current modulation unit; the input end of the light closing unit and the first input end of the current modulation unit input dimming signals, and the output end of the light closing unit is connected with the second input end of the current modulation unit; the output end of the current modulation unit is connected with the output end of the voltage modulation unit and the power supply end of the LD, and the output end of the current modulation unit is also connected with the power supply of the LD. The device can adjust the light emitting effect of the laser in real time, can be matched with LDs with different powers, and is wide in application range.

Description

TECHNICAL FIELD

[0001] The utility model relates to laser equipment technical field, concretely relates to a light adjusting circuit and laser digital drive board. BACKGROUND

[0002] The laser drive board is an electronic board connecting the laser and the power supply in the laser system, which mainly provides power supply and drive current control, controls the opening and closing of the laser, and realizes the functions such as light power regulation. Since different power laser diodes (LD) need to be matched with different drive boards, the traditional laser drive board does not have a modulation function when designed, or uses TTL modulation or analog drive, which has the disadvantages of poor anti-interference ability, limited precision, high power consumption, etc. SUMMARY

[0003] Therefore, the utility model provides a light adjusting circuit and laser digital drive board to solve the problem of low light adjusting precision.

[0004] In a first aspect, the utility model provides a light adjusting circuit applied to a laser, which comprises a power conversion unit, a light-off unit, a current modulation unit and a voltage modulation unit. The input end of the power conversion unit is connected with an external power supply, the first output end of the power conversion unit is connected with the power supply end of the voltage modulation unit, the second output end of the power conversion unit is connected with the power supply end of the light-off unit and the power supply end of the current modulation unit, and the power conversion unit is used to convert the level of the external power supply voltage. The input end of the light-off unit and the first input end of the current modulation unit input a light adjusting signal, the output end of the light-off unit is connected with the second input end of the current modulation unit, the light-off unit is used to output a light-off signal based on the size of the light adjusting signal and the internal reference voltage, the output end of the current modulation unit is connected with the output end of the voltage modulation unit and the power supply end of the laser LD, the current modulation unit is used to output a voltage modulation signal based on the resistance value adjustment of the light adjusting signal or the light-off signal, and the voltage modulation unit is used to output a voltage modulation signal based on the resistance value of the internal resistance. The voltage modulation signal is used to adjust the voltage of the power supply end of the LD, so as to adjust the brightness of the LD.

[0005] The light adjusting circuit provided by the utility model can output a current modulation signal according to the size of the light adjusting signal, can adjust the size of the current modulation signal by adjusting the resistance value of the internal resistance of the current modulation unit, and can output a voltage modulation signal to adjust the brightness of the LD. In addition, the size of the voltage modulation signal can be adjusted by adjusting the resistance value of the internal resistance of the voltage modulation unit, and the brightness of the LD can be directly adjusted. The light output effect of the laser can be adjusted, different power LDs can be matched, and the utility scope is wide.

[0006] In an alternative embodiment, the power conversion unit comprises: a first power conversion circuit and a second power conversion circuit, wherein the input terminal of the first power conversion circuit is connected with the external power supply, the first output terminal of the first power conversion circuit is connected with the input terminal of the second power conversion circuit, and the second output terminal of the first power conversion circuit is connected with the power supply terminal of the voltage modulation unit; and the output terminal of the second power conversion circuit is connected with the power supply terminal of the light-off unit and the power supply terminal of the current modulation unit.

[0007] In an alternative embodiment, the light-off unit comprises: at least one light-off circuit, wherein the power supply terminal of each light-off circuit is connected with the second output terminal of the power conversion unit, the input terminal of each light-off circuit inputs the dimming signal corresponding to one color component, and the output terminal of each light-off circuit is connected with the second input terminal of the current modulation unit and outputs the light-off signal of the corresponding color component.

[0008] In an alternative embodiment, the light-off circuit comprises: a filter circuit, a comparison circuit and a switch circuit, wherein the input terminal of the filter circuit inputs the dimming signal corresponding to one color component, the output terminal of the filter circuit is connected with the first input terminal of the comparison circuit, the second input terminal of the comparison circuit inputs the reference voltage, the output terminal of the comparison circuit is connected with the control terminal of the switch circuit, and the output terminal of the switch circuit outputs the light-off signal of the corresponding color component.

[0009] In an alternative embodiment, the current modulation unit comprises: at least one current modulation circuit, wherein the power supply terminal of each current modulation circuit is connected with the second output terminal of the power conversion unit, the first input terminal of each current modulation circuit inputs the dimming signal corresponding to one color component, the second input terminal of each current modulation circuit inputs the current modulation signal of the corresponding color component, and the output terminal of each current modulation circuit is connected with the power supply terminal of the LD and outputs the voltage modulation signal of the corresponding color component.

[0010] In an alternative embodiment, the current modulation circuit comprises: an adjustable resistance circuit and an output circuit, wherein the first terminal of the adjustable resistance circuit inputs the dimming signal corresponding to one color component, the second terminal of the adjustable resistance circuit is connected with the first terminal of the output circuit and the output terminal of the light-off circuit corresponding to the color component, the third terminal of the adjustable resistance circuit is connected with the second terminal of the output circuit, and the output terminal of the output circuit is connected with the power supply terminal of the LD and outputs the voltage modulation signal of the corresponding color component.

[0011] In an alternative embodiment, the adjustable resistance circuit comprises: a first adjustable unit and a second adjustable unit, wherein the first terminal of the first adjustable unit inputs the dimming signal corresponding to one color component, the second terminal of the first adjustable unit is connected with the first terminal of the second adjustable unit and the first terminal of the output circuit, and the second terminal of the second adjustable unit is connected with the second terminal of the output circuit.

[0012] In an alternative embodiment, the voltage modulation unit comprises at least one voltage modulation circuit, wherein the power supply end of each voltage modulation circuit is connected with the first output end of the power conversion unit, and the output end of each voltage modulation circuit is connected with the power supply end of the LD and respectively outputs a voltage modulation signal of a color component.

[0013] In a second aspect, the utility model provides a kind of laser driver board, comprising: circuit board and the dimming circuit of the first aspect or any of its corresponding implementation mode, wherein, dimming circuit is integrated on circuit board;The power supply interface of circuit board is connected with external power supply, and the analog signal input interface of circuit board receives external analog signal, and the signal output interface of circuit board is connected with the power supply end of LD. BRIEF DESCRIPTION OF DRAWINGS

[0014] In order to more clearly illustrate the specific embodiments of the utility model or the technical solutions in the prior art, the drawings needed in the specific embodiments or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are some embodiments of the utility model, and for those skilled in the art, other drawings can be obtained without creative labor based on these drawings.

[0015] Figure 1 is a component diagram of the dimming circuit according to the embodiment of the utility model;

[0016] Figure 2 is a specific circuit diagram of the power conversion unit according to the embodiment of the utility model;

[0017] Figure 3 is a specific circuit diagram of the light-off circuit according to the embodiment of the utility model;

[0018] Figure 4 is a specific circuit diagram of the current modulation circuit according to the embodiment of the utility model;

[0019] Figure 5 is a specific circuit diagram of the control unit according to the embodiment of the utility model;

[0020] Figure 6 is a specific circuit diagram of the voltage modulation circuit according to the embodiment of the utility model;

[0021] Figure 7 is a component diagram of the laser digital driver board according to the embodiment of the utility model. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in combination with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the person skilled in the art without creative labor belong to the protection scope of the utility model.

[0023] In the description of the utility model, it needs to be explained that the orientation or position relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like is the orientation or position relationship shown based on the drawings, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, therefore, it cannot be understood as a limitation on the utility model. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0024] In the description of the utility model, it needs to be explained that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or the communication between two elements inside, it can be wireless connection, or wired connection. For the person skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0025] In addition, the technical features involved in the different embodiments of the utility model described below can be combined with each other as long as there is no conflict between them.

[0026] The embodiment provides a dimming circuit, which is applied to a laser, such as Figure 1 As shown in the figure, the dimming circuit comprises a power conversion unit 1, a light-off unit 2, a current modulation unit 3 and a voltage modulation unit 4.

[0027] Figure 1 In the embodiment, the input end of the power conversion unit 1 is connected with an external power supply, the first output end (i.e. one end of output VDC) of the power conversion unit 1 is connected with the power supply end of the voltage modulation unit 4, and the second output end (i.e. one end of output VDD) of the power conversion unit 1 is connected with the power supply end of the light-off unit 2 and the power supply end of the current modulation unit 3.

[0028] Specifically, Figure 1In the embodiment, the power conversion unit 1 is configured to convert the external power supply voltage into different levels of voltage to supply power to the light-off unit 2, the current modulation unit 3 and the voltage modulation unit 4 respectively.

[0029] Figure 1 In the embodiment, the input end of the light-off unit and the first input end of the current modulation unit are both configured to input the dimming signal, and the output end of the light-off unit is connected to the second input end of the current modulation unit. The light-off unit is configured to output the light-off signal based on the magnitude of the dimming signal and the internal reference voltage.

[0030] Specifically, Figure 1 In the embodiment, the light-off unit 2 is configured to preset a reference voltage and compare the magnitude of the dimming signal with the reference voltage. When it is determined that the voltage of the dimming signal is greater than the reference voltage, the light-off unit 2 switches the state of the switch and outputs the low-level light-off signal.

[0031] Figure 1 In the embodiment, the output end of the current modulation unit 3 is connected to the output end of the voltage modulation unit 4 and the power supply end of the laser LD. The current modulation unit 3 is configured to output the voltage modulation signal based on the resistance of the internal resistor to adjust the dimming signal, or output the voltage modulation signal based on the light-off signal. The voltage modulation unit 4 is configured to output the voltage modulation signal based on the resistance of the internal resistor.

[0032] Specifically, Figure 1 In the embodiment, the current modulation unit 3 includes an adjustable resistor circuit. A user can adjust the resistance of the resistor in the current modulation unit 3 according to the required light emission effect, so as to adjust the voltage division of the dimming signal by the current modulation unit 3, adjust the upper limit and lower limit of the current of the power supply end of the LD, and further adjust the magnitude of the output voltage modulation signal. The voltage modulation signal is used to adjust the voltage of the power supply end of the LD, so as to adjust the brightness of the LD. The voltage modulation unit 4 also includes an adjustable resistor circuit. A user can adjust the resistance of the resistor in the voltage modulation unit 4 according to the required light emission effect, so as to adjust the voltage division of the voltage of the power supply end of the LD by the voltage modulation unit 4, and thus adjust the brightness of the LD.

[0033] Specifically, Figure 1 In the embodiment, the current modulation unit 3 outputs the voltage modulation signal based on the received light-off signal, so that the voltage of the power supply end of the LD is 0V to turn off the LD.

[0034] Optionally, the LD in the embodiment can be a RGB three-color light source. Correspondingly, the light-off unit, the current modulation unit and the voltage modulation unit can respectively modulate the brightness of red light, green light and blue light, and change the light emission effect of the laser.

[0035] The dimming circuit provided by the embodiment can output a current modulation signal according to the size of the dimming signal, and the size of the current modulation signal can be adjusted by adjusting the resistance value of the resistor in the current modulation unit, so that the output voltage modulation signal adjusts the brightness of the LD. In addition, the size of the voltage modulation signal can also be adjusted by adjusting the resistance value of the resistor in the voltage modulation unit, and the brightness of the LD is directly adjusted. The laser light output effect can be adjusted, and different power LDs can be matched, so the application range is wide. In addition, the embodiment uses digital drive modulation and digital signal control, has strong anti-interference performance, natural brightness change, flexible control, low power consumption and controllability.

[0036] In some optional embodiments, as shown in Figure 2 The power conversion unit 1 includes a first power conversion circuit 11 and a second power conversion circuit 12. The input end of the first power conversion circuit 11 is connected with an external power supply (i.e. 24V). The first output end (i.e. VIN) of the first power conversion circuit 11 is connected with the input end of the second power conversion circuit 12. The second output end (i.e. VDC) of the first power conversion circuit 11 is connected with the power supply end of the voltage modulation unit 4. The output end (i.e. VDD) of the second power conversion circuit 12 is connected with the power supply end of the light-off unit 2 and the power supply end of the current modulation unit 3.

[0037] Specifically, Figure 2 The first power conversion circuit 11 includes multiple voltage stabilizing tubes for stabilizing voltage and multiple transient voltage suppression diodes for suppressing transient voltage.

[0038] Optionally, the person skilled in the art can set the voltage level and the number of output ends of the power conversion unit according to actual needs.

[0039] In some optional embodiments, referring to Figure 1 The light-off unit 2 includes at least one light-off circuit. The power supply end of each light-off circuit is connected with the second output end of the power conversion unit 1. The input end of each light-off circuit inputs a dimming signal corresponding to one color component. The output end of each light-off circuit is connected with the second input end of the current modulation unit 3 and outputs a light-off signal corresponding to the color component.

[0040] Specifically, when the LD is a multi-color light source, in order to control the brightness of each color component in the light source respectively, one light-off circuit should be set for each color, and each light-off circuit is used to output a light-off signal of the color according to the size of the dimming signal corresponding to one color component and the internal reference voltage, so as to turn off the color component in the LD.

[0041] Specifically, in the embodiment, the LD is taken as an example of RGB three-color light source. In order to control the brightness of red light, green light and blue light in the LD respectively, the light-off unit 2 includes three light-off circuits, i.e., a red light-off circuit, a green light-off circuit and a blue light-off circuit. Figure 3 Taking the red light-off circuit as an example, the red light-off circuit includes a filter circuit 211, a comparison circuit 212 and a switch circuit 213. The input end of the filter circuit 211 inputs a dimming signal corresponding to a red component, and the output end of the filter circuit 211 is connected with the first input end of the comparison circuit 212. The second input end of the comparison circuit 212 inputs a reference voltage, and the output end of the comparison circuit 212 is connected with the control end of the switch circuit. The output end of the switch circuit 213 outputs a light-off signal of the red component.

[0042] Specifically, Figure 3 In the embodiment, the dimming signal MOD_R corresponding to the red component is input into the comparison circuit 212 after filtering out interference signals by the filter circuit 211 composed of the capacitors C19 and C22 and the resistor R23. The comparison chip U5 in the comparison circuit 212 compares the reference voltage VREF with the dimming signal MOD_R corresponding to the red component. When the U5 determines that MOD_R is greater than VREF, a low-level signal is output to control the switch circuit 213 to be disconnected. The drain of the switch Q3 in the switch circuit 213 outputs a high-level light-off signal DIS_R of the red component. When the U5 determines that MOD_R is less than or equal to VREF, a high-level signal is output to control the switch circuit 213 to be connected, so that the drain of the switch Q3 is pulled down to the ground and no signal is output.

[0043] It should be noted that the specific circuit structure and principle of the green light-off circuit and the blue light-off circuit are the same as those of the red light-off circuit, and thus will not be described herein again. Figure 3

[0044] In some optional embodiments, referring to Figure 1 The current modulation unit 3 includes at least one current modulation circuit. The power supply end of each current modulation circuit is connected with the second output end of the power supply conversion unit 1. The first input end of each current modulation circuit inputs a dimming signal corresponding to a color component. The second input end of each current modulation circuit inputs a current modulation signal corresponding to the color component. The output end of each current modulation circuit is connected with the power supply end of the LD and outputs a voltage modulation signal corresponding to the color component.

[0045] ​Specifically, when the LD is a multi-color light source, the LD is provided with one power supply end for each color. In order to control the brightness of each color component in the light source respectively, a current modulation circuit should be provided for each color respectively, and the output end of the current modulation circuit of each color is connected with one power supply end of the LD. By adjusting the resistance value of any current modulation circuit, the voltage division degree of the dimming signal of the corresponding color component by the current modulation circuit is adjusted, the voltage modulation signal corresponding to the color component is output to the corresponding power supply end of the LD, and the voltage of the corresponding power supply end of the color component is adjusted, so as to adjust the brightness of the color component in the LD. Each current modulation circuit can also adjust the power supply voltage of the corresponding power supply end of the LD to 0 according to the off light signal of the corresponding color, so as to directly turn off the color component in the LD.

[0046] Specifically, in the embodiment, the LD is taken as an RGB three-color light source as an example. In order to control the brightness of the red light, green light and blue light in the LD respectively, the current modulation unit 3 includes three current modulation circuits: a red light current modulation circuit, a green light current modulation circuit and a blue light current modulation circuit. Figure 4 The red light current modulation circuit includes an adjustable resistance circuit 311 and an output circuit 312. The first end of the adjustable resistance circuit 311 inputs the dimming signal MOD_R corresponding to the red component, the second end of the adjustable resistance circuit 311 is connected with the first end of the output circuit 312 (i.e. one end of the input DIS_R) and the output end of the off light circuit corresponding to the red component, and the third end of the adjustable resistance circuit 311 is connected with the second end of the output circuit 312. The output end of the output circuit 312 is connected with the power supply end of the LD and outputs the voltage modulation signal V_R of the red component.

[0047] Specifically, Figure 4 The adjustable resistance circuit 311 includes a first adjustable unit 3111 and a second adjustable unit 3112. The first end of the first adjustable unit 3111 inputs the dimming signal MOD_R corresponding to the red component, and the second end of the first adjustable unit 3111 is connected with the first end of the second adjustable unit 3112 and the first end of the output circuit 312. The second end of the second adjustable unit 3112 is connected with the second end of the output circuit 312.

[0048] Specifically, Figure 4In the embodiment, the first adjustable unit 3111 includes a first adjustable resistor RM1 for adjusting the upper limit of the current of the LD red light power supply end, and the second adjustable unit 3112 includes a second adjustable resistor RB1 for adjusting the lower limit of the current of the LD red light power supply end. When the slider of the first adjustable resistor RM1 moves to the 3 end, the resistance value of the first adjustable resistor RM1 in series with the resistor R20 decreases, so that the current input to the first end of the output circuit 312 increases, the output circuit 312 increases the voltage modulation signal V_R of the output red component, thereby increasing the upper limit of the current of the LD red light power supply end; when the slider of the first adjustable resistor RM1 moves to the 1 end, the resistance value of the first adjustable resistor RM1 in series with the resistor R20 increases, so that the current input to the first end of the output circuit 312 decreases, the output circuit 312 decreases the voltage modulation signal V_R of the output red component, thereby decreasing the upper limit of the current of the LD red light power supply end.

[0049] Optionally, as shown in Figure 5 , the dimming circuit further includes a control unit U1, an output end (i.e. one end of the output S_EN) of the control unit U1 is connected with the enable end of each current modulation circuit, which is used for delaying for a preset time after power-on, and then outputting an enable signal S_EN so that the corresponding current modulation circuit starts to work.

[0050] It should be noted that the specific circuit structure and principle of the green light current modulation circuit and the blue light current modulation circuit are consistent with those of the red light current modulation circuit, and will not be described here. Figure 4

[0051] In some optional embodiments, referring to Figure 1 , the voltage modulation unit 4 includes at least one voltage modulation circuit, wherein the power supply end of each voltage modulation circuit is connected with the first output end of the power supply conversion unit 1, and the output end of each voltage modulation circuit is connected with the power supply end of the LD and respectively outputs a voltage modulation signal of a color component.

[0052] Specifically, when the LD is a multi-color light source, the LD is provided with one power supply end for each color, in order to control the brightness of each color component in the light source respectively, a voltage modulation circuit should be set for each color respectively, and the output end of the voltage modulation circuit of each color is connected with one power supply end of the LD respectively. By adjusting the resistance value of any voltage modulation circuit, the voltage division degree of the voltage modulation circuit to the voltage of the corresponding power supply end of the LD is adjusted, and the voltage of the corresponding power supply end of the color component is adjusted.

[0053] Specifically, in the embodiment, the LD is taken as an RGB three-color light source, in order to control the brightness of the red light, the green light and the blue light in the LD respectively, the voltage modulation unit 4 includes three current modulation circuits: a red light voltage modulation circuit, a green light voltage modulation circuit and a blue light voltage modulation circuit, Figure 6 ​Taking the red light voltage modulation circuit as an example, by adjusting the moving direction of the slider of the third adjustable resistor RA1, the resistance value of RA1 after being connected in series with resistors R28 and R26 is adjusted, thereby adjusting the magnitude of the voltage modulation signal V_R of the red component to power the light source of the red component in the LD.

[0054] It should be noted that the specific circuit structure and principle of the green light voltage modulation circuit and the blue light voltage modulation circuit are different from those of the green light voltage modulation circuit and the blue light voltage modulation circuit. Figure 6 The agreement is consistent and will not be elaborated upon here.

[0055] This embodiment provides a laser digital driver board, such as Figure 7 As shown, it includes: a circuit board and a dimming circuit of the above embodiment or any corresponding embodiment, wherein the dimming circuit is integrated on the circuit board; the power supply interface of the circuit board is connected to an external power supply, the analog signal input interface of the circuit board receives external analog signals, and the signal output interface of the circuit board is connected to the power supply terminal of the LD.

[0056] Specifically, Figure 7 In the middle, the driver board is equipped with multiple adjustment knobs, each of which is connected to an adjustable resistor slider. For example, the red light upper limit current adjustment knob IR1 is connected to... Figure 4 The slider of RM1 is connected to the red lower limit current adjustment knob IR2. Figure 4 The slider of RB1 is connected; the red light power supply voltage adjustment knob VR1 is connected to... Figure 6 The slider of RA1 is connected. When it is necessary to adjust the upper and lower limits of the red light power supply current in the LD, the user can flexibly adjust it by rotating the upper limit current adjustment knob IR1 or the lower limit current adjustment knob IR2. When it is necessary to adjust the voltage of the red light power supply in the LD, the user can flexibly adjust the brightness of the red light in the LD by rotating the red light power supply voltage adjustment knob VR1.

[0057] For example, when manufacturing the driver board, it is necessary to perform pre-shipment debugging according to the different power LDs connected. The debugging method is as follows:

[0058] (1) Before powering on the driver board, adjust the RGB voltage and current to the initial state by rotating the knob, that is, adjust the upper limit of voltage and current to the minimum value.

[0059] (2) Connect to 24V voltage, connect the negative terminal of the multimeter to the negative terminal of the power supply, and connect the positive terminal of the multimeter to the positive terminal of the RGB signal output interface. Adjust the RGB voltage to the laser voltage +1.8V respectively.

[0060] (3) Connect the RGB signal output terminal to the LD and connect the analog signal input interface to the adjustable power supply. Use a power meter to monitor the power of the LD output spot.

[0061] (4)Adjustable power supply current limiting 20mA, adjust the knob so that the RGB power supply voltage from 0V slowly increases, until the laser LD just out of light, at this power supply voltage modulation lower limit current, observe the LD output spot power reaches the minimum target, that is, the modulation of the lower limit current is completed.

[0062] (5)The adjustable power supply voltage is adjusted to 5V, and the upper limit current is modulated at this voltage, and the LD output spot power reaches the maximum target, that is, the modulation of the upper limit current is completed.

[0063] (6) After the modulation is completed, the RGB signal output interface of the drive board is connected with the LD.

[0064] Optionally, the laser drive board can be integrated in the laser lamp, and the drive board can filter and modulate the input laser color signal, so that the power of the LD changes with the signal in the set interval, and the voltage of the drive board is adjustable, so that the laser works at a suitable voltage and current parameter. The adjustable voltage of the drive board realizes the adaptation of lasers with different powers, and the adjustable current of the drive board realizes the adjustable brightness of the LD. The proportion of RGB three colors is adjusted by adjusting the current, and the brightness variation range of the LD is controlled by adjusting the upper and lower limits of the current, so that the brightness and color of the LD with different powers are consistent under the same control signal of the laser, and the color difference is reduced.

[0065] Optionally, when the LD power of the laser is different, the voltage modulation can adapt to lasers with different powers, and provide a rated output voltage for the laser. On the basis of the rated output voltage, the brightness range of the LD can be controlled by current modulation, the light output effect of the laser is adjusted, the current and voltage of the LD can be controlled more finely, the higher level and higher resolution laser is adapted, and the flexibility of the laser is improved, so that the laser works in the best state, and the application range is improved.

[0066] Although the embodiments of the present application are described in conjunction with the drawings, various modifications and variations can be made by those skilled in the art without departing from the spirit and scope of the present application, and such modifications and variations fall within the scope defined by the appended claims.

Claims

1. A dimming circuit, characterized in that, The application is applied to a laser, and the light adjusting circuit comprises a power conversion unit, a light-off unit, a current modulation unit and a voltage modulation unit, wherein The input end of the power conversion unit is connected with an external power supply, the first output end of the power conversion unit is connected with the power supply end of the voltage modulation unit, the second output end of the power conversion unit is connected with the power supply end of the light-off unit and the power supply end of the current modulation unit, and the power conversion unit is used for converting the level of the external power supply voltage. The input end of the light-off unit and the first input end of the current modulation unit input a light adjusting signal, the output end of the light-off unit is connected with the second input end of the current modulation unit, and the light-off unit is used for outputting a light-off signal based on the size of the light adjusting signal and an internal reference voltage. The output end of the current modulation unit is connected with the output end of the voltage modulation unit and the power supply end of a laser LD, the current modulation unit is used for outputting a voltage modulation signal based on the resistance value of an internal resistor after adjusting the light adjusting signal, or outputting a voltage modulation signal based on the light-off signal. The voltage modulation unit is used for outputting a voltage modulation signal based on the resistance value of an internal resistor. The voltage modulation signal is used for adjusting the voltage of the power supply end of the LD, so as to adjust the brightness of the LD.

2. The dimming circuit of claim 1, wherein, The power conversion unit comprises a first power conversion circuit and a second power conversion circuit, wherein The input end of the first power conversion circuit is connected with an external power supply, the first output end of the first power conversion circuit is connected with the input end of the second power conversion circuit, and the second output end of the first power conversion circuit is connected with the power supply end of the voltage modulation unit. The output end of the second power conversion circuit is connected with the power supply end of the light-off unit and the power supply end of the current modulation unit.

3. The dimming circuit of claim 1, wherein, The light-off unit comprises at least one light-off circuit, wherein The power supply end of each light-off circuit is connected with the second output end of the power conversion unit, the input end of each light-off circuit inputs a light adjusting signal corresponding to a color component, and the output end of each light-off circuit is connected with the second input end of the current modulation unit and outputs a light-off signal corresponding to the color component.

4. The dimming circuit of claim 3, wherein, The light-off circuit comprises a filter circuit, a comparison circuit and a switch circuit, wherein The input end of the filter circuit inputs a light adjusting signal corresponding to a color component, and the output end of the filter circuit is connected with the first input end of the comparison circuit. The second input end of the comparison circuit inputs a reference voltage, and the output end of the comparison circuit is connected with the control end of the switch circuit. The output end of the switch circuit outputs a light-off signal corresponding to the color component.

5. The dimming circuit of claim 3, wherein, The current modulation unit comprises at least one current modulation circuit, wherein The power supply end of each current modulation circuit is connected with the second output end of the power supply conversion unit, the first input end of each current modulation circuit inputs a dimming signal corresponding to a color component, the second input end of each current modulation circuit inputs a current modulation signal corresponding to the color component, and the output end of each current modulation circuit is connected with the power supply end of the LD and outputs a voltage modulation signal corresponding to the color component.

6. The dimming circuit of claim 5, wherein, The current modulation circuit comprises an adjustable resistance circuit and an output circuit, wherein, The first end of the adjustable resistance circuit inputs a dimming signal corresponding to a color component, the second end of the adjustable resistance circuit is connected with the first end of the output circuit and the output end of a dimming-off circuit corresponding to the color component, and the third end of the adjustable resistance circuit is connected with the second end of the output circuit. The output end of the output circuit is connected with the power supply end of the LD and outputs a voltage modulation signal corresponding to the color component.

7. The dimming circuit of claim 6, wherein, The adjustable resistance circuit comprises a first adjustable unit and a second adjustable unit, wherein, The first end of the first adjustable unit inputs a dimming signal corresponding to a color component, and the second end of the first adjustable unit is connected with the first end of the second adjustable unit and the first end of the output circuit. The second end of the second adjustable unit is connected with the second end of the output circuit.

8. The dimming circuit of claim 3, wherein, The voltage modulation unit comprises at least one voltage modulation circuit, wherein, The power supply end of each voltage modulation circuit is connected with the first output end of the power supply conversion unit, and the output end of each voltage modulation circuit is connected with the power supply end of the LD and outputs a voltage modulation signal of a color component.

9. A laser digital driver board, characterized by, It comprises: A circuit board and the dimming circuit according to any one of claims 1 to 8, wherein, The dimming circuit is integrated on the circuit board; The power supply interface of the circuit board is connected with an external power supply, the analog signal input interface of the circuit board receives an external analog signal, and the signal output interface of the circuit board is connected with the power supply end of the LD.

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