Driving circuit of laser module and laser device

Abstract

The utility model discloses a driving circuit of a laser module and a laser device, and relates to the technical field of laser equipment, the driving circuit of the laser module comprises a first control switch, a feedback module and a comparison module; the first control switch and the feedback module are connected with the laser module; the comparison module is connected with the feedback module and the first control switch; when the feedback voltage of the feedback module exceeds the preset voltage, the comparison module is used for controlling the first control switch to be switched off according to the feedback voltage. When the feedback voltage of the feedback module exceeds the preset voltage, the comparison module can control the first control switch to be switched off according to the feedback voltage, so that the current flowing through the laser module can be limited, the electro-optical conversion efficiency of the laser module is ensured, and the service life of the laser module is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of laser equipment, in particular to a driving circuit of a laser module and a laser device. Background Art

[0002] The indicator light of medical laser equipment often uses a laser module that indicates green light.

[0003] When the temperature of the green laser module increases, the working current of the laser module will increase, the electro-optical conversion efficiency of the green laser module will decrease, and the output laser brightness will decrease. If used in this way for a long time, the service life of the laser module will be reduced.

[0004] In addition, the packaging form of the green light indicating laser module has a great influence on its high temperature resistance. The heat of the green light indicating laser module is relatively large. Therefore, it is necessary to ensure that the temperature of the laser module is controlled within its working range after thermal equilibrium. Utility Model Content

[0005] The embodiment of the utility model provides a driving circuit and a laser device of a laser module to solve the technical problem in the related art that the temperature of the existing laser module indicating green light increases during use, resulting in an increase in the current flowing through the laser module, affecting the electro-optical conversion efficiency, and long-term use will reduce the service life of the laser module.

[0006] In a first aspect, a driving circuit of a laser module is provided, comprising: a first control switch Q1, a feedback module and a comparison module;

[0007] The first control switch Q1 and the feedback module are connected to the laser module;

[0008] The comparison module is connected to the feedback module and the first control switch Q1;

[0009] When the feedback voltage of the feedback module exceeds a preset voltage, the comparison module is used to control the first control switch Q1 to be turned off according to the feedback voltage.

[0010] In some embodiments, the comparison module includes an operational amplifier U1 and a voltage divider unit;

[0011] The first end of the voltage dividing unit and the first end of the laser module are connected to a power source, and the second end of the voltage dividing unit is grounded;

[0012] The non-inverting input terminal of the operational amplifier U1 is connected to the voltage divider output terminal of the voltage divider unit, the inverting input terminal of the operational amplifier U1 is connected to the feedback module, and the output terminal of the operational amplifier U1 is connected to the first control switch Q1; wherein the voltage divider output terminal of the voltage divider unit outputs a preset voltage.

[0013] In some embodiments, the voltage dividing unit includes a first resistor R1, a second resistor R2 and a third resistor R3;

[0014] A first end of the first resistor R1, the second resistor R2 and the third resistor R3 connected in series in sequence is connected to a power supply, and a second end of the first resistor R1, the second resistor R2 and the third resistor R3 connected in series in sequence is grounded;

[0015] The common end of the second resistor R2 and the third resistor R3 is the voltage division output end of the voltage division unit and is connected to the non-inverting input end of the operational amplifier U1.

[0016] In some embodiments, the driving circuit of the laser module further includes:

[0017] A first diode D1 , wherein a first end of the first diode D1 is connected to a common end of the first resistor R1 and the second resistor R2 , and a second end of the first diode D1 is grounded.

[0018] In some embodiments, the driving circuit of the laser module further includes:

[0019] A step-down module is provided between the power supply and the laser module, and is used for stepping down the voltage of the power supply and outputting it to the laser module.

[0020] In some embodiments, the step-down module includes a second diode D2 and a third diode D3, the first end of the second diode D2 is connected to a power supply, the second end of the second diode D2 is connected to the first end of the third diode D3, and the second end of the third diode D3 is connected to the first end of the laser module.

[0021] In some embodiments, the driving circuit of the laser module further includes:

[0022] A second control switch Q2 and a PWM control module, wherein the second control switch Q2 is arranged between the power supply and the step-down module, the PWM control module is connected to the control end of the second control switch Q2, and the PWM control module is used to control the second control switch Q2 to be turned on or off with different duty cycles.

[0023] In some embodiments, the driving circuit of the laser module further includes:

[0024] The PWM control module includes a PWM generating unit, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6 and an optocoupler chip U2;

[0025] The output end of the PWM generating unit is connected to the first end of the fourth resistor R4, the second end of the fourth resistor R4 is connected to the first pin of the optocoupler chip U2, the second pin and the third pin of the optocoupler chip U2 are grounded, the fourth pin of the optocoupler chip U2 is connected to the second end of the fifth resistor R5 and the first end of the sixth resistor R6, the first end of the fifth resistor R5 is connected to the power supply, and the second end of the sixth resistor R6 is connected to the second control switch Q2.

[0026] In some embodiments, both the first control switch Q1 and the second control switch Q2 are transistors, and the feedback module is a seventh resistor R7.

[0027] In a second aspect, a laser device is provided, comprising a driving circuit of the aforementioned laser module, and further comprising:

[0028] A fin heat sink is sleeved on the outer periphery of the laser module.

[0029] The beneficial effects brought by the technical solution provided by the utility model include:

[0030] An embodiment of the utility model provides a driving circuit of a laser module and a laser device. The driving circuit of the laser module is provided with a first control switch, a feedback module and a comparison module. When the feedback voltage of the feedback module exceeds a preset voltage, the comparison module can control the first control switch to be disconnected according to the feedback voltage, thereby ensuring the electro-optical conversion efficiency of the laser module, thereby limiting the current flowing through the laser module and extending the service life of the laser module. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 A principle block diagram of a driving circuit of a laser module provided in an embodiment of the utility model;

[0033] Figure 2 A circuit diagram of a driving circuit of a laser module provided in an embodiment of the utility model;

[0034] Figure 3 A schematic diagram of the structure of a laser device provided in an embodiment of the utility model;

[0035] Figure 4 The embodiment of the utility model provides Figure 3Explosion diagram of

[0036] In the figure:

[0037] 1. Laser module;

[0038] 2. Fin radiator. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0040] The embodiment of the utility model provides a driving circuit of a laser module, which can solve the technical problem that the temperature of the existing laser module indicating green light increases during use, causing the current flowing through the laser module to increase, affecting the electro-optical conversion efficiency of the laser module, and reducing the service life of the laser module after long-term use.

[0041] See also Figure 1 and Figure 2 As shown, an embodiment of the utility model provides a driving circuit of a laser module, including: a first control switch Q1, a feedback module and a comparison module.

[0042] The first control switch Q1 and the feedback module are connected to the laser module. Specifically, the first control switch Q1, the feedback module and the laser module are connected in series and then connected to a power source and a ground to form a loop for powering the laser module. The comparison module is connected to the feedback module and the first control switch Q1. Specifically, the comparison module is connected to the feedback module and the first control switch Q1 to form a feedback loop.

[0043] When the feedback voltage of the feedback module exceeds a preset voltage, the comparison module is used to control the first control switch Q1 to be turned off according to the feedback voltage.

[0044] The driving circuit of the laser module in the implementation of the utility model is provided with a first control switch, a feedback module and a comparison module. When the feedback voltage of the feedback module exceeds a preset voltage, the comparison module can control the first control switch to be disconnected according to the feedback voltage, thereby limiting the current flowing through the laser module, ensuring the electro-optical conversion efficiency of the laser module, and extending the service life of the laser module.

[0045] As an optional implementation, in one embodiment of the utility model, the comparison module includes an operational amplifier U1 and a voltage divider unit.

[0046] A first end of the voltage divider unit and a first end of the laser module are connected to a power source, and a second end of the voltage divider unit is grounded.

[0047] The non-inverting input terminal of the operational amplifier U1 is connected to the voltage divider output terminal of the voltage divider unit, the inverting input terminal of the operational amplifier U1 is connected to the feedback module, and the output terminal of the operational amplifier U1 is connected to the first control switch Q1. The voltage divider output terminal of the voltage divider unit outputs a preset voltage.

[0048] Specifically, see Figure 2 As shown, the first control switch Q1 can be an NPN transistor, the feedback module can be a seventh resistor R7, and when the operating parameter of the load (laser module) is 3V / 300mA, the seventh resistor R7 can be selected as 1Ω. The output end of the operational amplifier U1 is connected to the gate of the first control switch Q1, and the inverting input end of the operational amplifier U1 is connected to the first end of the seventh resistor R7 and the emitter of the first control switch Q1.

[0049] The voltage divider output end of the voltage divider unit is used to provide a comparison reference voltage (i.e., a preset voltage) for the non-inverting input end of the operational amplifier U1. When the feedback voltage of the feedback module obtained by the inverting input end of the operational amplifier U1 exceeds the comparison reference voltage, the output end of the operational amplifier U1 outputs a low level to control the first control switch Q1 to be disconnected. The entire comparison module has a simple structure and high feedback control efficiency. By disconnecting the first control switch Q1, the current flowing through the laser module can be limited, thereby extending the service life of the laser module.

[0050] See also Figure 2 As shown, when the temperature of the laser module rises, the current flowing through the laser module will increase, the current passing through the collector and emitter of the first control switch Q1 will increase, the voltage at the first end of the seventh resistor R7 will increase, and the voltage at the first end of the seventh resistor R7 will be fed back to the inverting input terminal of the operational amplifier U1. When the voltage at the first end of the seventh resistor R7 exceeds the voltage at the non-inverting input terminal of the operational amplifier U1, the output of the operational amplifier U1 is low level, and the collector and emitter of the first control switch Q1 are disconnected.

[0051] Furthermore, the voltage divider unit includes a first resistor R1, a second resistor R2 and a third resistor R3. The first end of the first resistor R1, the second resistor R2 and the third resistor R3 connected in series is connected to a power supply, and the second end of the first resistor R1, the second resistor R2 and the third resistor R3 connected in series is grounded. The common end of the second resistor R2 and the third resistor R3 is the voltage divider output end of the voltage divider unit connected to the in-phase input end of the operational amplifier U1. The three resistors form a voltage divider unit with a simple structure, and can provide an accurate comparison reference voltage for the in-phase input end of the operational amplifier U1. Optionally, the third resistor R3 is a precision potentiometer, and the comparison reference voltage can be accurately set according to requirements.

[0052] As an optional implementation, in one embodiment of the utility model, the driving circuit of the laser module further includes: a first diode D1, a first end of the first diode D1 is connected to the common end of the first resistor R1 and the second resistor R2, and a second end of the first diode D1 is grounded. The first diode D1 is used to clamp the voltage of the common end of the first resistor R1 and the second resistor R2 to prevent the voltage from being too high and protect the subsequent operational amplifier U1. The model of the first diode D1 can be BAV70.

[0053] As an optional implementation, in one embodiment of the utility model, the driving circuit of the laser module further includes: a step-down module, which is arranged between the power supply and the laser module, and is used to step down the voltage of the power supply and output it to the laser module. The step-down module steps down the voltage of the power supply and outputs it, which can protect the subsequent laser module and comparison module.

[0054] Further, the step-down module includes a second diode D2 and a third diode D3, wherein the first end of the second diode D2 is connected to a power source, the second end of the second diode D2 is connected to the first end of the third diode D3, and the second end of the third diode D3 is connected to the first end of the laser module. Optionally, the second diode D2 and the third diode D3 may be of the 1N4000 series, and the second diode D2 and the third diode D3 are connected in series, and the voltage drop when the diode is turned on is used to achieve step-down, which is simple, practical, and low in cost.

[0055] As an optional implementation, in one embodiment of the utility model, the driving circuit of the laser module further includes: a second control switch Q2 and a PWM control module.

[0056] The second control switch Q2 is arranged between the power supply and the step-down module, and the PWM control module is connected to the second control switch Q2, and the PWM control module is used to control the second control switch Q2 to be turned on or off with different duty cycles. The input current of the laser module is controlled by PWM, and the duty cycle of the PWM input signal of multiple gears can be used to adjust different output laser brightness, and the control is simple and convenient. For example, four gears of adjustable brightness can be set, wherein the duty cycle of the input signal of the first gear is 25%, the duty cycle of the input signal of the second gear is 50%, the duty cycle of the input signal of the third gear is 75%, and the duty cycle of the input signal of the fourth gear is 100%, and each gear of brightness is stable. When the duty cycle of the input signal is 0, it is equivalent to turning off the laser module.

[0057] As an optional implementation, in one embodiment of the utility model, the PWM control module includes a PWM generation unit, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6 and an optocoupler chip U2.

[0058] The output end of the PWM generating unit is connected to the first end of the fourth resistor R4, the second end of the fourth resistor R4 is connected to the first pin of the optocoupler chip U2, the second pin and the third pin of the optocoupler chip U2 are grounded, the fourth pin of the optocoupler chip U2 is connected to the second end of the fifth resistor R5 and the first end of the sixth resistor R6, the first end of the fifth resistor R5 is connected to the power supply VCC (DC +5V), and the second end of the sixth resistor R6 is connected to the second control switch Q2. Specifically, the second control switch Q2 can be a PNP type transistor, that is, the second end of the sixth resistor R6 is connected to the gate of the second control switch Q2, the emitter of the second control switch Q2 is connected to the power supply, and the collector of the second control switch Q2 is connected to the first end of the second diode D2.

[0059] The PWM signal frequency output by the PWM generating unit does not exceed 3KHz, the fourth resistor R4 and the sixth resistor R6 are current limiting resistors, the fifth resistor R5 is a pull-up resistor, and the resistance value of the sixth resistor R6 determines the base current I of the second control switch Q2. b In order to make the second control switch Q2 work in the switch state, that is, the second control switch Q2 works in the deep saturation state, a suitable resistance value of the sixth resistor R6 can be selected to meet the deep saturation condition: I b >2×I c / β, where I cis the maximum collector current of the second control switch Q2 when loaded, and the β parameter is the current amplification factor of the second control switch Q2. In addition, an optocoupler chip U2 is provided between the PWM generation unit and the second control switch Q2, and the anti-interference ability of the circuit can be improved through optocoupler isolation.

[0060] As an optional implementation, in an embodiment of the utility model, the driving circuit of the laser module also includes: a fourth diode D2, the first end of the fourth diode D2 is connected to the output end of the laser module, and the second end of the fourth diode D2 is connected to the input end of the laser module. The function of the fourth diode D2 is to prevent the power supply from having a reverse voltage (negative voltage), thereby protecting the laser module.

[0061] As an optional implementation, in one embodiment of the utility model, the driving circuit of the laser module further includes: a first capacitor C1, a first end of the first capacitor C1 is connected to the power supply pin of the operational amplifier U1 and the second end of the third diode D3, and a second end of the first capacitor C1 is grounded. The first capacitor C1 is used to reduce power supply noise and interference to ensure that the power supply pin of the operational amplifier U1 is powered normally.

[0062] As an optional implementation, in a utility model embodiment, the driving circuit of the laser module further includes: a second capacitor C2 and an eighth resistor R8, wherein the first end of the second capacitor C2 is connected to the output end of the operational amplifier U1, the second end of the second capacitor C2 is grounded, the first end of the eighth resistor R8 is connected to the reference ground pin of the operational amplifier U1, and the second end of the eighth resistor R8 is grounded. The second capacitor C2 and the eighth resistor R8 are used to ensure the stability of the output signal of the output end of the operational amplifier U1.

[0063] The embodiment of the utility model provides a laser device, including the driving circuit of the laser module mentioned above. The laser device also includes: a fin heat sink 2 , and the fin heat sink 2 is sleeved on the outer periphery of the laser module 1 .

[0064] See also Figure 3 and Figure 4 As shown, the heat dissipation area of ​​the laser module 1 is limited. In order to ensure the stability of its maximum power output, the embodiment of the utility model adds a metal fin heat sink 2 on the surface of the cylindrical laser module 1. The cylindrical laser module 1 and the metal fin heat sink can conduct heat through thermal grease. In this way, the overall heat dissipation area is increased, the heat dissipation rate is fast, the overall thermal equilibrium can be quickly reached, and the temperature is relatively low after thermal equilibrium, which is beneficial to prolonging the life of the laser module.

[0065] Furthermore, an insulating (plastic) bracket may be used to fix the laser module to ensure that the input of the laser module is a separate power supply and ground, and is not interfered by other power supplies.

[0066] In the description of the present utility model, it should be noted that the terms "upper", "lower", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present utility model. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to the specific circumstances.

[0067] It should be noted that, in the present utility model, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0068] The above description is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features of the present invention.

Claims

1. A driving circuit of a laser module, characterized in that: include: A first control switch Q1, a feedback module and a comparison module; The first control switch Q1 and the feedback module are connected to the laser module; The comparison module is connected to the feedback module and the first control switch Q1; When the feedback voltage of the feedback module exceeds a preset voltage, the comparison module is used to control the first control switch Q1 to be turned off according to the feedback voltage.

2. The driving circuit of the laser module according to claim 1, characterized in that: The comparison module includes an operational amplifier U1 and a voltage divider unit; The first end of the voltage dividing unit and the first end of the laser module are connected to a power source, and the second end of the voltage dividing unit is grounded; The non-inverting input terminal of the operational amplifier U1 is connected to the voltage divider output terminal of the voltage divider unit, the inverting input terminal of the operational amplifier U1 is connected to the feedback module, and the output terminal of the operational amplifier U1 is connected to the first control switch Q1; wherein the voltage divider output terminal of the voltage divider unit outputs a preset voltage.

3. The driving circuit of the laser module according to claim 2, characterized in that: The voltage dividing unit includes a first resistor R1, a second resistor R2 and a third resistor R3; A first end of the first resistor R1, the second resistor R2 and the third resistor R3 connected in series in sequence is connected to a power supply, and a second end of the first resistor R1, the second resistor R2 and the third resistor R3 connected in series in sequence is grounded; The common end of the second resistor R2 and the third resistor R3 is the voltage-dividing output end of the voltage-dividing unit and is connected to the non-inverting input end of the operational amplifier U1 .

4. The driving circuit of the laser module according to claim 3, characterized in that: Also includes: A first diode D1 , wherein a first end of the first diode D1 is connected to a common end of the first resistor R1 and the second resistor R2 , and a second end of the first diode D1 is grounded.

5. The driving circuit of the laser module according to claim 1, characterized in that: Also includes: A step-down module is provided between the power supply and the laser module, and is used for stepping down the voltage of the power supply and outputting it to the laser module.

6. The driving circuit of the laser module according to claim 5, characterized in that: The step-down module includes a second diode D2 and a third diode D3, wherein a first end of the second diode D2 is connected to a power source, a second end of the second diode D2 is connected to a first end of the third diode D3, and a second end of the third diode D3 is connected to a first end of the laser module.

7. The driving circuit of the laser module according to claim 5, characterized in that: Also includes: A second control switch Q2 and a PWM control module, wherein the second control switch Q2 is arranged between the power supply and the step-down module, the PWM control module is connected to the second control switch Q2, and the PWM control module is used to control the second control switch Q2 to be turned on or off with different duty cycles.

8. The driving circuit of the laser module according to claim 7, characterized in that: Also includes: The PWM control module includes a PWM generating unit, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6 and an optocoupler chip U2; The output end of the PWM generating unit is connected to the first end of the fourth resistor R4, the second end of the fourth resistor R4 is connected to the first pin of the optocoupler chip U2, the second pin and the third pin of the optocoupler chip U2 are grounded, the fourth pin of the optocoupler chip U2 is connected to the second end of the fifth resistor R5 and the first end of the sixth resistor R6, the first end of the fifth resistor R5 is connected to the power supply, and the second end of the sixth resistor R6 is connected to the second control switch Q2.

9. The driving circuit of the laser module according to claim 7, characterized in that: The first control switch Q1 and the second control switch Q2 are both transistors, and the feedback module is a seventh resistor R7.

10. A laser device, characterized in that: A driving circuit comprising the laser module according to any one of claims 1 to 9, further comprising: The fin heat sink is sleeved on the outer periphery of the laser module.

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