Driving circuit

Abstract

The utility model provides a driving circuit, which is used for driving an emission laser tube and comprises a parameter receiving module and a signal transmission module which are connected in series. Wherein the parameter receiving module receives a preset parameter and transmits the preset parameter to the signal transmission module; the signal transmission module receives the preset parameters, converts the preset parameters into light intensity parameters and transmits the light intensity parameters to the laser emitting tube, and the laser emitting tube emits laser according to the light intensity parameters. The driving circuit provided by the utility model is simple to realize, low in cost and high in stability.

Description

Technical Field

[0001] The utility model belongs to the field of laser control, and in particular relates to a driving circuit. Background Art

[0002] Due to the advantages of laser such as good monochromaticity and strong directionality, laser is widely used in the high-precision and accurate measurement of the distance of the measured object. Compared with other rangefinders, laser rangefinders are light in weight, small in size, small in error and low in cost. Therefore, they are widely used in topographic surveying, satellite measurement, industrial measurement and control and other fields.

[0003] The laser rangefinder uses a laser diode as a light source, and the laser diode requires a suitable driving power supply to work properly. The working modes of the laser tube include constant current, constant voltage, and constant power. The laser diode is very sensitive to the applied current and voltage. When working, it is necessary to adjust the light intensity according to the process requirements, and ensure that the current and voltage of the device itself do not exceed the allowable range.

[0004] Chinese invention patent CN103730831A proposes a constant power laser output control method, in which the feedback signal is taken from the main optical path, and the summing and integrating amplifier is based on The reflected power is converted into voltage data, and the output voltage of the laser diode is calculated in combination with the output voltage to provide real-time feedback on the changes in the laser diode output power. However, the devices used in this solution are complex and costly, which is not conducive to the promotion of laser diode drive circuits.

[0005] Chinese utility model patent CN207638148U proposes a laser diode constant power drive circuit, which uses a differential operational amplifier to collect current, and realizes constant power drive of the laser diode by forming a constant power drive circuit through a current detection circuit and a constant current control circuit. However, the drive circuit proposed in the utility model patent does not consider the structure of protecting the laser diode. When the power of the laser diode is turned on and off, the impact of surge current on it needs to be considered, and the reverse current and reverse voltage data of the laser diode are both limited. The patent scheme also does not involve protection measures such as overcurrent protection and overvoltage protection, resulting in poor stability of the constant power drive circuit proposed in the patent.

[0006] Based on the above, this application provides a technical solution to solve the above technical problems. Utility Model Content

[0007] Aiming at the defects of the laser diode driving circuit in the prior art, such as complex implementation, high cost and general working stability, the utility model provides a driving circuit for driving the transmitting laser tube, comprising: a parameter receiving module and a signal transmission module connected in series;

[0008] Among them, the parameter receiving module receives the preset parameters and transmits the preset parameters to the signal transmission module; the signal transmission module receives the preset parameters and converts them into light intensity parameters, transmits the light intensity parameters to the emitting laser tube, and the emitting laser tube emits laser according to the light intensity parameters.

[0009] In a specific implementation of the present invention, the signal transmission module includes an amplification module and a signal control module, and the amplification module includes a first operational amplifier U1B and a second operational amplifier U1A connected in series.

[0010] In a specific embodiment of the present utility model, the signal transmission module also includes a filtering module, the filtering module includes a first filter capacitor C1 and a second filter capacitor C2, the first operational amplifier U1B is connected in parallel with the first filter capacitor C1, the second operational amplifier U1A is connected in parallel with the second filter capacitor C2, and the first filter capacitor C1 is connected in series with the second filter capacitor C2.

[0011] In a specific embodiment of the present utility model, the signal transmission module also includes a control signal receiving module, the first control signal LD_CTRL and the second control signal LD-ON are input into the control signal receiving module, the control signal receiving module is connected to the signal transmission module, the control signal receiving module transmits the first control signal LD_CTRL and the second control signal LD-ON to the signal transmission module, and jointly controls the state of the emitting laser tube through high and low levels.

[0012] In a specific embodiment of the present utility model, the first control signal LD_CTRL controls the reference level of the amplification module. When the first control signal LD_CTRL is at a high level, the output transistor Q3 is in a cut-off state, and the second operational amplifier U1A is always at a low level. At this time, the current control transistor Q1 is cut off, and the emitting laser tube does not emit light; when the first control signal LD_CTRL is at a low level, the second operational amplifier U1A is in a normal working state, and the emitting laser tube works.

[0013] In a specific embodiment of the present utility model, the signal transmission module also includes an overcurrent protection circuit, which includes a current control transistor Q1 and a pull-down resistor R5 connected in series, the emitter of the current control transistor Q1 is connected to the pull-down resistor R5, and the base of the current control transistor Q1 is provided with a current limiting resistor, so that the current control transistor Q1 is in an amplified state.

[0014] In a specific embodiment of the present utility model, the signal transmission module also includes an overvoltage protection circuit, including a voltage-controlled transistor Q2, a voltage protection module and a clamping diode D3. The voltage-controlled transistor Q2 is connected in series with the clamping diode D3 and in parallel with the voltage protection module. The positive pole of the clamping diode D3 is grounded, and the negative pole is connected to the light-emitting diode LD.

[0015] In a specific embodiment of the present utility model, the voltage protection module includes a first resistor R7 and a second resistor R9 connected in series, the second control signal LD-ON is input by one end of the second resistor R9, the other end of the second resistor R9 is connected to the first resistor R7, the other end of the first resistor R7 is connected to the pull-down resistor R5, the base of the voltage-controlled transistor Q2 is connected between the first resistor R7 and the second resistor R9, the collector is connected to the pull-down resistor R5, and the emitter is connected to the clamping diode D3.

[0016] In a specific implementation of the present invention, the signal transmission module further includes a varistor D1 , the anode of the varistor D1 is grounded, and the cathode is connected to the inverting input terminal of the first operational amplifier U1B.

[0017] In a specific embodiment of the present utility model, the parameter receiving module is a feedback receiving tube PD, the reverse input end of the first operational amplifier U1B is connected to the feedback receiving tube PD, and a protection resistor R6 is also connected between the feedback receiving tube PD and the reverse input end of the first operational amplifier U1B.

[0018] The present invention can bring at least one of the following beneficial effects: The present invention proposes a driving circuit, which is used to drive a laser diode, wherein a parameter receiving module receives preset parameters and transmits the preset parameters to a signal transmission module; the signal transmission module receives the preset parameters and converts them into light intensity parameters, and transmits the light intensity parameters to the emitting laser tube, and the emitting laser tube emits laser according to the light intensity parameters. The driving circuit proposed in the present invention has a simple implementation logic, and only ordinary low-cost devices are required to achieve stable driving of the laser diode. In addition, the driving circuit proposed in the present invention includes a protection module, which can effectively cope with the requirements of the laser diode for the working environment, prevent the influence of overvoltage, overcurrent and surge current, and ensure the stable operation of the laser diode. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The preferred implementation scheme will be described below in a clear and understandable manner with reference to the accompanying drawings to further illustrate the above-mentioned characteristics, technical features, advantages and their implementation methods.

[0020] Figure 1 A circuit logic diagram of a driving circuit proposed in an embodiment of the present invention. DETAILED DESCRIPTION

[0021] The various aspects of the utility model are further described in detail below.

[0022] Unless otherwise defined or indicated, all professional and scientific terms used herein have the same meanings as those familiar to those skilled in the art. In addition, any methods and materials similar or equivalent to those described herein may be applied to the present invention.

[0023] The following is an explanation of the terms.

[0024] Unless otherwise clearly specified and limited, the "or" mentioned in the present invention includes the relationship of "and". The "and" is equivalent to the Boolean logic operator "AND", the "or" is equivalent to the Boolean logic operator "OR", and "AND" is a subset of "OR".

[0025] It is to be understood that although the terms "first", "second", etc. may be used herein to describe different elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. Therefore, the first element may be referred to as the second element without departing from the teachings of the present invention.

[0026] In the present invention, the terms "contain", "include" or "comprise" indicate that various components can be applied together in the mixture or composition of the present invention. Therefore, the term "mainly composed of..." is included in the terms "contain", "include" or "comprise".

[0027] Unless otherwise clearly specified and limited, the terms "connected", "connected" and "connection" in the present invention should be understood in a broad sense, for example, it can be a fixed connection, or it can be connected through an intermediary medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0028] For example, if an element (or component) is referred to as being on, coupled to, or connected to another element, the element may be directly formed on, coupled to, or connected to the other element, or there may be one or more intervening elements between them. In contrast, if the expressions "directly on," "directly coupled to," and "directly connected to" are used herein, then no intervening elements are indicated. Other words used to describe the relationship between elements should be similarly interpreted, such as "between" and "directly between," "attached" and "directly attached," "adjacent" and "directly adjacent," and the like.

[0029] It should also be noted that the words "front", "rear", "left", "right", "upper" and "lower" used in the following description refer to directions in the drawings. The words "inner" and "outer" used refer to directions toward or away from the geometric center of a particular component, respectively. It can be understood that these terms are used here to describe the relationship of one element, layer or region relative to another element, layer or region as shown in the drawings. In addition to the orientations described in the drawings, these terms should also include other orientations of the device.

[0030] Other aspects of the present invention will be apparent to those skilled in the art from the disclosure herein.

[0031] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the specific implementation methods of the utility model will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings and other implementation methods can be obtained based on these drawings without creative work.

[0032] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application. The drawings only show the components related to the present application and are not drawn according to the number, shape and size of the components in actual implementation. The type, quantity and proportion of each component in actual implementation may be changed arbitrarily, and the component layout may also be more complicated. For example, the thickness of the components in the drawings may be exaggerated for the sake of clarity.

[0033] Example

[0034] In view of the defects of the laser diode driving circuit in the prior art, such as complex implementation, high cost and general working stability, see Figure 1 , the present invention proposes a driving circuit for driving a transmitting laser tube, comprising: a parameter receiving module and a signal transmission module connected in series;

[0035] Among them, the parameter receiving module receives the preset parameters and transmits the preset parameters to the signal transmission module; the signal transmission module receives the preset parameters and converts them into light intensity parameters, transmits the light intensity parameters to the emitting laser tube, and the emitting laser tube emits laser according to the light intensity parameters.

[0036] Preferably, the parameter receiving module is a feedback receiving tube PD.

[0037] In the prior art, the driving modes of laser diodes include several basic forms such as constant current, constant voltage and constant power. Preferably, the present invention uses a constant power laser diode driving mode.

[0038] In a preferred embodiment of the present invention, the signal transmission module includes an amplification module and a signal control module, and the amplification module includes a first operational amplifier U1B and a second operational amplifier U1A connected in series.

[0039] Preferably, the signal transmission module also includes a filtering module, the filtering module includes a first filter capacitor C1 and a second filter capacitor C2, the first operational amplifier U1B is connected in parallel with the first filter capacitor C1, the second operational amplifier U1A is connected in parallel with the second filter capacitor C2, and the first filter capacitor C1 is connected in series with the second filter capacitor C2.

[0040] More specifically, the first operational amplifier U1B is connected in parallel with the resistor R2 and the sliding resistor VR1, and the resistor R2 and the sliding resistor VR1 are connected in series to jointly control the amplification ratio of the first operational amplifier U1B. Similarly, the second operational amplifier U1A is connected in parallel with the resistor R4 to control the amplification ratio of the second operational amplifier U1A.

[0041] In a preferred embodiment of the present utility model, the signal transmission module also includes a control signal receiving module, the first control signal LD_CTRL and the second control signal LD-ON are input into the control signal receiving module, the control signal receiving module is connected to the signal transmission module, the control signal receiving module transmits the first control signal LD_CTRL and the second control signal LD-ON to the signal transmission module, and the state of the emitting laser tube is jointly controlled by high and low levels.

[0042] Preferably, the first control signal LD_CTRL controls the reference level of the amplification module. When the first control signal LD_CTRL is at a high level, the output transistor Q3 is in a cut-off state, and the second operational amplifier U1A is always at a low level. At this time, the current control transistor Q1 is cut off, and the emitting laser tube does not emit light; when the first control signal LD_CTRL is at a low level, the second operational amplifier U1A is in a normal working state, and the emitting laser tube works.

[0043] The present invention realizes the pulse width modulation working mode of the laser diode through the first control signal LD_CTRL and the second control signal LD-ON, which not only ensures the adjustability of the average light intensity of the emitted laser, but also allows the laser tube to have a certain emission interval to avoid continuous operation, thereby further extending the working stability and service life of the laser diode.

[0044] In a preferred embodiment of the present utility model, the signal transmission module also includes an overcurrent protection circuit, which includes a current control transistor Q1 and a pull-down resistor R5 connected in series, the emitter of the current control transistor Q1 is connected to the pull-down resistor R5, and the base of the current control transistor Q1 is provided with a current limiting resistor, so that the current control transistor Q1 is in an amplified state.

[0045] In a preferred embodiment of the present utility model, the signal transmission module also includes an overvoltage protection circuit, including a voltage-controlled transistor Q2, a voltage protection module and a clamping diode D3. The voltage-controlled transistor Q2 is connected in series with the clamping diode D3 and in parallel with the voltage protection module. The positive electrode of the clamping diode D3 is grounded, and the negative electrode is connected to the light-emitting diode LD.

[0046] In a preferred embodiment of the present utility model, the voltage protection module includes a first resistor R7 and a second resistor R9 connected in series, the second control signal LD-ON is input by one end of the second resistor R9, the other end of the second resistor R9 is connected to the first resistor R7, the other end of the first resistor R7 is connected to the pull-down resistor R5, the base of the voltage-controlled transistor Q2 is connected between the first resistor R7 and the second resistor R9, the collector is connected to the pull-down resistor R5, and the emitter is connected to the clamping diode D3.

[0047] Preferably, when the voltage-controlled transistor Q2 is normally turned on, the voltage at the emitter of the voltage-controlled transistor Q2 is approximately 0.7*r9 / r7, wherein r9 refers to the resistance value of the second resistor R9, and r7 refers to the resistance value of the first resistor R7.

[0048] In a preferred embodiment of the present invention, the signal transmission module further includes a varistor D1 , the anode of the varistor D1 is grounded, and the cathode is connected to the inverting input terminal of the first operational amplifier U1B.

[0049] Preferably, the inverting input terminal of the first operational amplifier U1B is connected to the feedback receiving tube PD, and a protection resistor R6 is further connected between the feedback receiving tube PD and the inverting input terminal of the first operational amplifier U1B.

[0050] In summary, the utility model has achieved the following effects:

[0051] The utility model proposes a driving circuit, which is used to drive a laser diode, wherein a parameter receiving module receives preset parameters and transmits the preset parameters to a signal transmission module; the signal transmission module receives the preset parameters and converts them into light intensity parameters, and transmits the light intensity parameters to the emitting laser tube, and the emitting laser tube emits laser according to the light intensity parameters. The driving circuit proposed by the present invention has a simple implementation logic, and only ordinary low-cost devices are required to achieve stable driving of the laser diode. In addition, the driving circuit proposed by the present invention includes a protection module, which can effectively respond to the requirements of the laser diode for the working environment, prevent the influence of overvoltage, overcurrent and surge current, and ensure the stable operation of the laser diode.

[0052] Based on this application, it should be understood by those skilled in the art that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspect described herein can be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device and / or practice this method.

[0053] Those skilled in the art know that, in addition to implementing the system and its various devices, modules, and units provided by the utility model in a purely computer-readable program code, it is entirely possible to implement the same functions in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, the system and its various devices, modules, and units provided by the utility model can be considered as a hardware component, and the devices, modules, and units included therein for realizing various functions can also be considered as structures within the hardware component; the devices, modules, and units for realizing various functions can also be considered as both software modules for realizing the method and structures within the hardware component.

[0054] It should be noted that the above embodiments can be freely combined as needed. The above is only a preferred implementation of the utility model. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the utility model, and these improvements and modifications should also be regarded as the protection scope of the utility model.

[0055] All documents mentioned in this utility model are cited as references in this application, just as each document is cited as reference separately. In addition, it should be understood that after reading the above content of this utility model, those skilled in the art can make various changes or modifications to this utility model, and these equivalent forms also fall within the scope defined by the claims attached to this application.

Claims

1. A driving circuit for driving a laser tube, characterized in that: include: A parameter receiving module and a signal transmission module connected in series; The parameter receiving module receives the preset parameters and transmits the preset parameters to the signal transmission module; The signal transmission module receives the preset parameters and converts them into light intensity parameters, and transmits the light intensity parameters to the emitting laser tube, and the emitting laser tube emits laser according to the light intensity parameters.

2. The driving circuit according to claim 1, characterized in that: The signal transmission module includes an amplification module and a signal control module. The amplification module includes a first operational amplifier and a second operational amplifier connected in series.

3. The driving circuit according to claim 2, characterized in that: The signal transmission module also includes a filtering module, which includes a first filtering capacitor and a second filtering capacitor. The first operational amplifier is connected in parallel with the first filtering capacitor, the second operational amplifier is connected in parallel with the second filtering capacitor, and the first filtering capacitor is connected in series with the second filtering capacitor.

4. The driving circuit according to claim 3, characterized in that: The signal transmission module also includes a control signal receiving module. The first control signal and the second control signal are input into the control signal receiving module. The control signal receiving module is connected to the signal transmission module. The control signal receiving module transmits the first control signal and the second control signal to the signal transmission module, and controls the state of the emitting laser tube through high and low levels.

5. The driving circuit according to claim 4, characterized in that: The first control signal controls the reference level of the amplification module. When the first control signal is at a high level, the output transistor is in a cut-off state, and the second operational amplifier is always at a low level. At this time, the current controls the transistor to be cut off, and the emitting laser tube does not emit light; when the first control signal is at a low level, the second operational amplifier is in a normal working state, and the emitting laser tube works.

6. The driving circuit according to claim 3, characterized in that: The signal transmission module also includes an overcurrent protection circuit, which includes a current control transistor and a pull-down resistor connected in series. The emitter of the current control transistor is connected to the pull-down resistor, and the base of the current control transistor is provided with a current limiting resistor, so that the current control transistor is in an amplified state.

7. The driving circuit according to claim 6, characterized in that: The signal transmission module also includes an overvoltage protection circuit, including a voltage-controlled transistor, a voltage protection module and a clamping diode. The voltage-controlled transistor is connected in series with the clamping diode and in parallel with the voltage protection module. The positive electrode of the clamping diode is grounded and the negative electrode is connected to a light-emitting diode.

8. The driving circuit according to claim 7, characterized in that: The voltage protection module includes a first resistor and a second resistor connected in series, a second control signal is input from one end of the second resistor, the other end of the second resistor is connected to the first resistor, the other end of the first resistor is connected to the pull-down resistor, the base of the voltage-controlled transistor is connected between the first resistor and the second resistor, the collector is connected to the pull-down resistor, and the emitter is connected to the clamping diode.

9. The driving circuit according to claim 8, characterized in that: The signal transmission module also includes a varistor, the positive electrode of the varistor is grounded, and the negative electrode is connected to the reverse input terminal of the first operational amplifier.

10. The driving circuit according to claim 9, characterized in that: The parameter receiving module is a feedback receiving tube, the reverse input end of the first operational amplifier is connected to the feedback receiving tube, and a protection resistor is further connected between the feedback receiving tube and the reverse input end of the first operational amplifier.

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