TWI724640B - Scanning laser system with capability of laser dynamic compensation and method of scanning laser dynamic compensation - Google Patents

Abstract

A scanning laser system with capability of laser dynamic compensation includes a laser source device, a galvanometer scanning device, a driving voltage processing device and a current ratio controller. The laser source device generates a controllable laser beam. The galvanometer scanning device includes one or more galvanometers operating according one or more driving voltages and controls the laser beam to focus on a focal plane in form of a laser spot. The driving voltage processing device obtains moving speed information of the laser spot according to the one or more driving voltages. The driving voltage processing device generates a triggering parameter based on the moving speed information of the laser spot for determining whether to output a triggering signal. The current ratio controller outputs a pumping driving current and corrects the pumping driving current according to the moving speed information of the laser spot when receiving the triggering signal, so as to regulate power of the laser beam.

Description

Scanning laser system with laser dynamic compensation function and scanning laser dynamic compensation method

The invention relates to a scanning laser system with a laser dynamic compensation function and a scanning laser dynamic compensation method, in particular to a scanning laser system and a laser dynamic compensation method that are adjusted for laser output power.

Scanning laser processing technology is widely used in various industries, and the processing quality of this technology mainly depends on the scanning galvanometer. Generally speaking, under ideal conditions, the fiber laser is used in conjunction with the scanning galvanometer, and the scanning motor is converted to a certain angle according to a certain voltage and angle, so that the laser focus point can be scanned back and forth on the processing plane stably.

However, in practical applications, scanning laser processing systems operate at the start or end stage, or in non-straight areas (such as corner areas), and the moving speed of the laser focus point on the processing plane cannot be kept stable, and over processing is prone to occur. And lead to poor processing quality.

The present invention provides a scanning laser dynamic compensation system. By detecting the change of the driving voltage of the scanning galvanometer, the output power of the laser light is adjusted in the unsteady phase of the speed, so that the effect of laser processing is uniform, so as to avoid excessive processing. problem.

According to an embodiment of the present invention, a scanning laser system with laser dynamic compensation function is disclosed, which includes a laser source device, a galvanometer scanning device, a driving voltage processing device, and a current proportional controller. The laser source device continuously generates a controllable laser beam. The galvanometer scanning device includes one or more galvanometers. The one or more galvanometers operate according to one or more driving voltages. The galvanometer scanning device controls the laser beam to focus to form a laser spot on the focal plane. Perform scanning processing. The driving voltage processing device is connected to the galvanometer scanning device, the driving voltage processing device obtains the moving speed information of the laser spot according to the one or more driving voltages, and the driving voltage processing device is further based on the movement of the laser spot The speed information generates trigger parameters to determine whether to output a trigger signal. The current proportional controller is connected to the laser source device and the driving voltage processing device to output the pump driving current to the laser source device. The current proportional controller adjusts according to the moving speed information of the laser spot when the trigger signal is received The driving current is pumped to modulate the power of the laser beam.

According to an embodiment of the present invention, a scanning laser dynamic compensation method is disclosed, which includes: using a laser source device to continuously generate a controllable laser beam; using one or more galvanometers of the galvanometer scanning device to receive one or more A plurality of driving voltages are used to control the laser beam to focus on the laser spot of the focal plane for scanning processing; the driving voltage processing device obtains the moving speed information of the laser spot according to the one or more driving voltages; and the driving voltage is used for processing The device generates trigger parameters according to the moving speed information of the laser spot; the drive voltage processing device determines whether to output the trigger signal according to the trigger parameters; and the current proportional controller outputs the pump drive current to the laser source device, and the current When the proportional controller receives the trigger signal, it uses the moving speed information of the laser spot to adjust the pump drive current to adjust the power of the laser beam.

In summary, in the scanning laser system with laser dynamic compensation function and the scanning laser dynamic compensation method proposed in the present invention, the driving voltage of the galvanometer scanning device is monitored, and the driving voltage processing device is used to monitor the driving voltage of the galvanometer scanning device. The driving voltage is calculated and analyzed to determine the changing state of the moving speed of the laser focus point on the focal plane, and in the stage of unstable speed, the current proportional controller is used to adjust the pump driving current to control the laser source device The power of the output laser beam, thereby avoiding the problem of over-processing and achieving a uniform laser processing effect.

The above description of the disclosure and the following description of the implementation manners are used to demonstrate and explain the spirit and principle of the present invention, and to provide a further explanation of the patent application scope of the present invention.

The detailed features and advantages of the present invention will be described in detail in the following embodiments. The content is sufficient to enable anyone familiar with the relevant art to understand the technical content of the present invention and implement it accordingly, and in accordance with the content disclosed in this specification, the scope of patent application and the drawings. Anyone who is familiar with relevant skills can easily understand the purpose and advantages of the present invention. The following examples further illustrate the viewpoints of the present invention in detail, but do not limit the scope of the present invention by any viewpoint.

Please refer to FIG. 1. FIG. 1 is a functional block diagram of a scanning laser system with laser dynamic compensation function according to an embodiment of the present invention. As shown in Fig. 1, a scanning laser system 1 with laser dynamic compensation function (hereinafter referred to as "scanning laser system 1") is suitable for the focal plane P1. The scanning laser system 1 includes a laser source device 10, The galvanometer scanning device 12, the driving voltage processing device 14, and the current proportional controller 16.

The laser source device 10 can continuously generate a controllable laser beam, and output the laser beam to the galvanometer scanning device 12. The galvanometer scanning device 12 has one or more galvanometers and lenses (not shown in FIG. 1). The galvanometer mirrors rotate/swing according to the driving voltage. The galvanometer scanning device 12 can be used in combination with the galvanometer and the lens. The beam is deflected and focused on the focal plane to form a laser spot for laser scanning processing.

The driving voltage processing device 14 correspondingly generates the time variable of the output voltage signal according to the driving voltage. The time variable of the output voltage signal reflects the moving speed information of the laser spot, so the driving voltage processing device 14 can generate trigger parameters based on the moving speed information of the laser spot to determine whether to output the trigger signal. The current proportional controller 16 outputs the pump drive current to the laser source device 10. The current proportional controller 16 adjusts the pump drive current according to the speed information of the galvanometer when receiving the trigger signal, thereby regulating the laser beam Power.

In order to explain the operation of the scanning laser system 1 more clearly, please refer to FIG. 2. FIG. 2 is a detailed structure diagram of the scanning laser system 1 according to the embodiment of FIG. 1 of the present invention. As shown in FIG. 2, the laser source device 10 has a laser seed source 101, a first-stage amplifier 102, a second-stage amplifier 103, a first pump source 104, a second pump source 105 and a light collimator 106. The laser seed source 101 can be realized by a laser diode (laser diode) for generating seed laser light SD, and the first stage amplifier 102 and the second stage amplifier 103 respectively pass through the first pump source 104 And the pump light energy of the second pump source 105 to amplify the power of the seed laser light SD, and then output the laser beam LB.

The light collimator 106 is used to converge the divergent light output from the optical fiber and turn it into a collimated light beam to facilitate the transmission of the light beam to the galvanometer scanning device 12. In practice, the laser fiber is transmitted between the laser seed source 101, the first-stage amplifier 102, the second-stage amplifier 103, the first pump source 104, the second pump source 105, and the optical collimator 106. Connected, and the laser seed source 101, the first-stage amplifier 102, the second-stage amplifier 103 and other components can be individually set up with optical isolators to limit the direction of laser transmission to avoid excess laser light It is fed back to the laser seed source 101. This embodiment takes the fiber laser architecture of a two-stage master oscillator power amplifier (MOPA) as an example, where the second stage amplifier 103 is the last stage amplifier before the laser beam LB is output. Although this embodiment shows a two-stage amplifier, the invention is not limited to this. In practice, the laser source device 10 may include a multi-stage amplifier with more than two stages.

The galvanometer scanning device 12 includes a galvanometer composed of a motor 121 and a reflector 122, a fixed reflector 123 and a lens 124. In practice, the motor 121 receives a driving voltage V _a to the operating member is rotated to drive the reflector 122 at an angle to swing. When the laser beam LB is transmitted to the galvanometer scanning device 12 through the light collimator 106, the laser beam LB is reflected by the fixed reflector 123 to the reflector 122, and the laser beam LB is reflected by the reflector 122 and enters the lens 124 . The lens 124 focuses the laser beam LB to form a laser spot SPT on the focal plane P1. In practice, the lens 124 may be, for example, a flat-field laser focusing lens (F-theta lens), but the invention is not limited thereto. With the swing of the reflector 122 and the focusing function of the lens 124, the laser spot SPT can be moved back and forth on the focal plane P1 for laser scanning processing. In other words, the lens 124 (a flat-field laser focusing lens) is used to focus and converge the laser beam LB into a laser spot SPT, and the galvanometer is used to control the movement mode of the laser spot SPT.

The driving voltage processing device 14 of this embodiment includes a voltage sensor 141 and a speed calculation device 142. Voltage sensor 141 connected to the motor 121 of the scanning device 12 to detect the driving voltage V _a, and generates a corresponding output voltage signal V _1, the output voltage signal V ₁ which is proportional to the driving voltage line V _a. Speed calculating means 142 is connected and _a voltage sensor 141 generates an output voltage signal V ₁ when the variable voltage according to the output signal V.

When the output voltage signal V ₁ is a variable reflecting the moving speed of the laser light spot SPT therefore speed calculating means 142 can obtain the laser spots accordingly SPT moving speed information S _t. Speed calculating means 142 further laser spots SPT according to the obtained information of the moving speed S _t to generate acceleration information as a trigger parameter. Further, the speed calculation device 142 determines whether to output the trigger signal TR according to the acceleration information.

In an implementation aspect, as shown in FIG. 2, the speed calculation device 142 includes a speed calculation unit 1421 and an acceleration calculation unit 1422. The speed calculator 1421 is connected to the current proportional controller 16 and the voltage sensor 141. Speed computing unit 1421 is configured to output a first voltage signal V ₁ performs a differential operation on the output voltage signal is calculated when the variable V _1, to obtain the laser beam spot SPT moving speed information S _t. Acceleration computing unit 1422 connected to the speed ratio computing unit 1421 and the current controller 16, the acceleration computing unit 1422 pairs of laser spots SPT moving speed information S _t calculated by performing a second differential operation acceleration information. Hereinafter, the operation and compensation method of the scanning laser system 1 will be further explained with the parameter waveform diagram.

Please refer to FIG. 2 and FIG. 3 together. FIG. 3 is a waveform diagram of various parameters of the scanning laser system 1 in time according to an embodiment of the present invention. As shown in Figure 3, the waveform diagram of each parameter includes the position x of the laser spot, the output voltage signal V ₁ , the voltage-time variable V ₁ 'of the output voltage signal V ₁ , the speed-time variable a, and the last stage in order from top to bottom. The pump drive current I of the amplifier.

In detail, the position x of the output voltage signal waveform of the laser light spot V system ₁ is consistent in speed computing unit 1421 receives the first differential output voltage signal V after operation ₁ will first output voltage signal V1 will be is obtained when the variable output voltage signal V ₁ V ₁ 'output voltage signal wherein the voltage variable V ₁ V _1' is proportional to the moving speed of the laser beam spot SPT.

As mentioned above, since the time variable V _{1 ′ of the output voltage signal V 1} is proportional to the moving speed of the laser spot SPT, the speed calculator 1421 can obtain the moving speed information S _{t of the} laser spot SPT, and combine the laser spot SPT point moving speed information S _t acceleration computing unit 1422 is transmitted to differential operation for the second time. As shown in FIG. 3, through the second differential operation, the acceleration calculator 1422 generates the speed-time variable a, that is, acceleration information, which indicates the acceleration value associated with the movement of the laser spot SPT.

In this embodiment, in an implementation state, the acceleration information indicates that the acceleration value is non-zero, and the acceleration calculator 1422 of the speed calculation device 142 determines to output the trigger signal TR. Specifically, as shown in Fig. 3, at the stage of time t=1, 3, 5, and 7 seconds, the acceleration value (variable a at the time of velocity) is not equal to zero, which means that the laser spot SPT does not move at a constant speed. In other words, the acceleration calculator 1422 determines that the moving speed of the laser spot SPT is unstable at this time, and therefore sends the trigger signal TR to the current proportional controller 16.

When the ratio of the current controller 16 receives the trigger signal TR, the controller 16 will use the current proportional laser spots SPT moving speed information S _t to adjust the pump drive current I _o. More specifically, the current proportional controller 16 adjusts the output power of the laser beam LB in a timely manner by _{adjusting the pump driving current I o to avoid the problem of excessive processing caused by unstable scanning speed.} As shown in FIG. 3, the current proportional controller 16 appropriately reduces the laser output power at approximately time t=1, 3, 5, and 7 seconds to reduce the effect of laser power processing and avoid excessive processing.

，其中I _c係為比例調整後的泵浦驅動電流（即校正的泵浦驅動電流），S _m係為量測訊號值（對應量測到的移動速度資訊S _t），S _s係為設定訊號值（對應設定的移動速度資訊）。換言之，電流比例控制器16係依據雷射光點SPT的移動速度資訊及設定移動速度資訊計算比例參數，並且根據比例參數調整泵浦驅動電流I _o。所述比例參數為雷射光點SPT的移動速度資訊的量測訊號值與設定移動速度資訊的設定訊號值的比值（例如S _m/S _s）。如圖2所示，電流比例控制器16進一步將經過比例調整後的泵浦驅動電流I _c（即最後一級放大器的泵浦驅動電流）傳送到第二泵浦源105，藉此調降雷射光束LB的雷射輸出功率。上述的演算法僅是用於舉例說明，本發明不以此為限。 In an implementation manner, the current proportional controller 16 may perform an algorithm to perform proportional correction _{on the pump drive current I o, such as}

, Where I _c is the pump drive current after proportional adjustment (ie corrected pump drive current), S _m is the measured signal value (corresponding to the measured movement speed information S _t ), and S _s is the setting Signal value (corresponding to the set movement speed information). In other words, the current proportional controller 16 calculates the proportional parameter based on the moving speed information of the laser spot SPT and the set moving speed information, and adjusts the pump drive current I _o according to the proportional parameter. The ratio parameter is the ratio of the measured signal value of the movement speed information of the laser spot SPT to the set signal value of the set movement speed information (for example, S _m /S _s ). As shown in FIG. 2, the current proportional controller 16 further transmits the proportionally adjusted pump drive current I _c (that is, the pump drive current of the last stage amplifier) to the second pump source 105, thereby reducing the laser Laser output power of beam LB. The above algorithm is only for illustration, and the present invention is not limited to this.

FIG. 2 shows that when there is a trigger signal TR, the current proportional controller 16 outputs the adjusted pump drive current I _c . However, in another implementation state, the acceleration information indicates that the acceleration value is zero, and the acceleration calculator 1422 of the speed calculation device 142 decides not to output the trigger signal TR. Specifically, as shown in Figure 3, when the acceleration value (variable a at speed) is zero, it means that the laser spot SPT is moving at a constant speed, and the acceleration calculator 1422 determines that the moving speed of the laser spot SPT is stable at this time. Therefore, the trigger signal TR is not sent to the current proportional controller 16. When the trigger signal TR is not received, the current proportional controller 16 does not _{adjust the pump drive current I o} in any proportion, but adjusts the original pump drive current I _o (that is, the pump of the last stage amplifier). The driving current) is transmitted to the second pump source 105. At this time, the output power of the laser beam LB maintains its original size stably without any modulation. In the embodiment of FIG. 3, the driving voltage processing device 14 performs voltage and velocity/acceleration calculations in the manner of analog signals, but the present invention is not limited to this. In other embodiments, the driving voltage processing device 14 may perform voltage and speed/acceleration calculations in the form of digital signals. For example, the driving voltage processing device 14 may be implemented by a device such as a microprocessor or a microcontroller.

Please further refer to FIG. 4, which is a diagram illustrating the relationship between speed and laser power output current according to an embodiment of the present invention. Figure 4 shows the state of laser power control when the laser spot is scanned from zero to a stable constant velocity. The curve SV1 represents the speed-laser power control curve using the technology in this case, and the curve SV2 Represents the speed-laser power control curve without applying the technology in this case. It can be seen from Fig. 4 that starting from the stationary state, when the scanning speed of the laser spot SPT gradually increases from zero until the speed becomes stable, the laser power of the curve SV1 is reduced to a greater degree than that of the curve SV2. The degree to which the laser power is reduced, so it can effectively avoid the situation that the laser power is too high and lead to over-processing. For example, when processing a corner, when the laser scan enters the corner, it will decelerate. After this time, the laser power must be reduced to a certain degree, and after the laser scan comes out of the corner, it will gradually accelerate until the speed is reached. stable. In this way, the significant reduction in laser power can effectively solve the problem of over-processing that may be caused by excessive laser power during corner processing.

Please refer to FIG. 5. FIG. 5 is another detailed architecture diagram of the scanning laser system with laser dynamic compensation function according to the embodiment of FIG. 1 of the present invention. The embodiment of FIG. 5 is substantially the same as the embodiment of FIG. 2, but the difference is that the galvanometer scanning device 22 in the scanning laser system 2 shown in the embodiment of FIG. 5 includes two galvanometers. In more detail, as shown in FIG. 5, the laser source device 20 has a laser seed source 201, a first-stage amplifier 202, a second-stage amplifier 203, a first pump source 204, a second pump source 205, and a light source. Collimating lens 206. The laser seed source 201 generates seed laser light SD, and the first stage amplifier 202 and the second stage amplifier 203 respectively transmit the pump light energy of the first pump source 204 and the second pump source 205 to treat the seed laser light. The SD performs power amplification, and then outputs the laser beam LB. The light collimator 206 is used to converge the divergent light output from the optical fiber and turn it into a collimated light beam to facilitate the transmission of the light beam to the galvanometer scanning device 22. This embodiment takes the fiber laser architecture of a two-stage master oscillator power amplifier (MOPA) as an example, where the second stage amplifier 203 is the last stage amplifier before the laser beam LB is output. Although this embodiment shows a two-stage amplifier, the invention is not limited to this. In practice, the laser source device 20 may include a multi-stage amplifier with more than two stages.

The galvanometer scanning device 22 includes two galvanometers and lenses 225. One galvanometer is composed of a motor 221 and a reflector 222, and the other galvanometer is composed of a motor 223 and a reflector 224. In practice, the galvanometer motor 221 receives a driving voltage V _a to the operating member is rotated to drive the reflector 222 at an angle to control the swinging movement of the laser spots in a particular axial SPT (e.g., X-axis), The motor 223 of the galvanometer receives the driving voltage V _b to operate and rotate to drive the reflector 224 to swing at a certain angle to control the movement of the laser spot SPT on another specific axis (such as the Y axis).

When the laser beam LB is transmitted to the galvanometer scanning device 22 through the light collimator 206, the laser beam LB is reflected by the reflector 222 to the reflector 224, and the laser beam LB is reflected by the reflector 224 and enters the lens 225. The lens 225 focuses the laser beam LB to form a laser spot SPT on the focal plane P2. By using the reflectors 223 and 224 to control the movement of the laser spot SPT in different axial directions, the laser spot can be laser processed on the focal plane P2. In other words, the lens 225 (for example, a flat-field laser focusing lens) is used to focus and converge the laser beam LB into a laser spot SPT, and the two galvanometers are used to control the movement mode of the laser spot SPT.

The driving voltage processing device 24 of this embodiment includes a voltage sensor 241 and a speed calculation device 242. Voltage sensor 241 are connected to the device 22 of the scanning galvanometer 221 and the motor 223 to detect driving voltage V _a and V _b, and generating an output voltage signal V ₁ and V _2, respectively, wherein the output voltage signal V _1, V ₂ are proportional to the driving voltage line V _a, V _b. The speed computing device 242 is connected to the voltage sensor 241 and generates time variables of the _{output voltage signals V 1} and V ₂ according to the output voltage signals V ₁ and V _{2, respectively.}

The time variables of the output voltage signals V ₁ and V ₂ respectively reflect the moving speed of the laser spot SPT in different axes (such as X-axis and Y-axis), so the speed calculation device 242 can obtain the resultant vector of the laser spot SPT accordingly The moving speed information of the combined vector can be used by the current proportional controller 26 when the trigger signal TR is received to adjust the pump drive current I _{o accordingly} . In addition, the speed calculation device 242 further calculates the obtained moving speed information of the laser spot SPT in different axial directions to generate acceleration information as the trigger parameter. The speed calculation device 242 determines whether to output the trigger signal TR according to the trigger parameter.

In one embodiment, as shown in FIG. 5, the speed calculation device 242 includes a speed calculation unit 2421 and an acceleration calculation unit 2422. The speed calculator 2421 is connected to the current proportional controller 26 and the voltage sensor 241. The speed calculator 2421 performs a first differential operation on the output voltage signals V ₁ and V ₂ to calculate the time variables of the output voltage signals V ₁ and V ₂ to obtain the moving speed information of the laser spot SPT in different axes, and Obtain the moving speed information of the SPT composite vector of the laser spot by the total vector calculation. The acceleration calculator 2422 is connected to the speed calculator 2421 and the current proportional controller 26. The acceleration calculator 2422 performs a second differential operation on the moving speed information of the laser spot in different axial directions to calculate individual acceleration information.

與

。 Please further refer to FIG. 6. FIG. 6 is a circuit structure diagram of a speed computing device according to an embodiment of the present invention. As shown in FIG. 6, the speed calculator 2421 may include a differentiation circuit 2421_1, a square circuit 2421_2, an addition circuit 2421_3, and a square root circuit 2421_4. Among them, the differentiation circuit 2421_1 includes several operational amplifiers CP1, CP2, resistors R _f , R _c, and capacitor C _i to differentiate the output voltage signals V ₁ and V ₂ to output the moving speed of the laser spot in different axes Information S ₁ and S ₂ . The squaring circuit 2421_2 includes several operational amplifiers CP3, CP4, and resistor R ₂ , wherein the operational amplifiers CP3 and CP4 each have endpoints X ₁ , X ₂ , Y ₁ , Y ₂ , +V _s , -V _s , V _os , The connection relationship between OUT and Z is shown in Figure 6. The squaring circuit 2421_2 is mainly used to square the movement speed information S ₁ and S ₂ respectively.

versus

.

+

。平方根電路2421_4包括運算放大器CP6及數個電阻R3~R7。同樣地，運算放大器CP6具有端點X ₁、X ₂、Y ₁、Y ₂、+V _s、-V _s、V _os、OUT、Z，其中端點Z連接運算放大器CP5的輸出端，其餘元件連接關係如圖6所示，平方根電路2421_4用以進行平方根運算而輸出合向量的移動速度資訊S _t=

作為電流比例控制器26後續對泵浦驅動電流I _o進行比例調整的依據。 The addition circuit 2421_3 includes an operational amplifier CP5, a number of resistors R, R ₁ , R _f, and voltage sources V ₁ , V ₂ connected to the terminals OUT of the operational amplifiers CP3 and CP4. The specific connection relationship is shown in Figure 6, and the addition circuit 2421_3 uses To perform the addition operation to get

+

. The square root circuit 2421_4 includes an operational amplifier CP6 and several resistors R3~R7. Similarly, the operational amplifier CP6 has endpoints X ₁ , X ₂ , Y ₁ , Y ₂ , +V _s , -V _s , _Vos , OUT, Z, where the endpoint Z is connected to the output terminal of the operational amplifier CP5, and the remaining components The connection relationship is shown in Figure 6. The square root circuit 2421_4 is used to perform the square root operation and output the moving speed information of the resultant vector S _t =

As a basis for the current proportional controller 26 to subsequently adjust the proportional adjustment of the _{pump drive current I o.}

On the other hand, the acceleration calculator 2422 includes another differentiation circuit 2422_1, which includes several operational amplifiers CP7, CP8, a resistor R _f and a capacitor C _i , which are used to transfer the movement speed information S output by the differentiation circuit of the speed calculator 2421 ₁ and S ₂ are differentiated for the second time respectively to obtain individual acceleration information. Finally, the acceleration calculator 2422 _{performs a logical operation on the acceleration values a 1} and a ₂ respectively indicated by the acceleration information to determine whether to issue the trigger signal TR. While the circuit architecture diagram shown in FIG. 6 is only an implementation of the speed computing device, the present invention is not limited to this circuit architecture. Those skilled in the art can modify the circuit architecture diagram to achieve the same computing function.

Please refer to FIG. 5 and FIG. 7 together. FIG. 7 is a waveform diagram of various parameters of the scanning laser dynamic compensation system in time according to an embodiment of the present invention. As shown in Figure 7, the waveform diagram of each parameter includes the position of the laser spot L, the output voltage signal V, the voltage-time variable V'of the output voltage signal V, the speed-time variable a, and the pump of the last stage amplifier in order from top to bottom. Pu drive current I.

）的波形係為一致，在速度運算器2421接收到輸出電壓訊號V後先對輸出電壓訊號V進行第一次的微分運算便可得到輸出電壓訊號V的時變量V’，其中輸出電壓訊號V的電壓時變量V’與雷射光點SPT的移動速度成正比關係。 Compared with the embodiment in FIG. 3, for the convenience of description, the position L of the laser spot in the embodiment in FIG. 7 is represented by the combined vector of the position of the laser spot in the X-axis and Y-axis directions (the same direction and an included angle of 45 degrees) . The position L of the laser spot SPT expressed by the resultant vector and the output voltage signal V (ie

) Is consistent. After the speed calculator 2421 receives the output voltage signal V, the first differential operation is performed on the output voltage signal V to obtain the time variable V'of the output voltage signal V, where the output voltage signal V The voltage-time variable V'is proportional to the moving speed of the laser spot SPT.

As mentioned above, since the time variable V'of the output voltage signal V is proportional to the moving speed of the laser spot SPT, the speed calculator 2421 can obtain the moving speed information of the laser spot SPT, and move the laser spot SPT The speed information is sent to the acceleration calculator 2422 for the second differential operation. Through the second differential operation, the acceleration calculator 2422 generates acceleration information, that is, the velocity time variable a, and the acceleration information indicates the acceleration value associated with the laser spot SPT. In an implementation state, the acceleration information indicates that the acceleration value is non-zero, and the acceleration calculator 2422 of the speed calculation device 142 determines to output the trigger signal TR. Specifically, as shown in Fig. 7, at about time t=1, 3, 5, and 7 seconds, the acceleration value (velocity variable a) is not equal to zero, which means that the laser spot SPT does not move at a constant speed.

In other words, the acceleration calculator 2422 determines that the moving speed of the laser spot is in an unstable state at this time, and therefore sends the trigger signal TR to the current proportional controller 26. When the current proportional controller 26 receives the trigger signal TR, the current proportional controller 26 uses the moving speed information of the laser spot SPT to adjust the pump drive current I _o . In other words, the current proportional controller 26 adjusts the pump drive current I _o to reduce the output power of the laser beam LB in a timely manner to avoid the problem of excessive processing caused by unstable scanning speed.

，其中I _c係為比例調整後的泵浦驅動電流（即校正的泵浦驅動電流），S _m係為量測訊號值（對應量測到的移動速度資訊S _t），S _s係為設定訊號值（對應設定的移動速度資訊）。換言之，電流比例控制器26係依據雷射光點SPT的移動速度資訊及設定移動速度資訊計算比例參數，並且根據比例參數調整泵浦驅動電流I _o。所述比例參數為雷射光點SPT的移動速度資訊的量測訊號值與設定移動速度資訊的設定訊號值的比值（例如S _m/S _s）。如圖5所示，電流比例控制器26進一步將經過比例調整後的泵浦驅動電流I _c（即最後一級放大器的泵浦驅動電流）傳送到第二泵浦源205，藉此調降雷射光束的輸出功率。上述演算法僅為實施方式之一，本發明並不以此為限。 In an implementation manner, the current proportional controller 26 may perform an algorithm to perform proportional correction _{on the pump drive current I o, such as}

, Where I _c is the pump drive current after proportional adjustment (ie corrected pump drive current), S _m is the measured signal value (corresponding to the measured movement speed information S _t ), and S _s is the setting Signal value (corresponding to the set movement speed information). In other words, the current proportional controller 26 calculates the proportional parameter according to the moving speed information of the laser spot SPT and the set moving speed information, and adjusts the pump drive current I _o according to the proportional parameter. The ratio parameter is the ratio of the measured signal value of the movement speed information of the laser spot SPT to the set signal value of the set movement speed information (for example, S _m /S _s ). As shown in FIG. 5, the current proportional controller 26 further transmits the proportionally adjusted pump drive current I _c (that is, the pump drive current of the last stage amplifier) to the second pump source 205, thereby reducing the laser The output power of the beam. The above algorithm is only one of the implementation manners, and the present invention is not limited to this.

FIG. 5 shows that when there is a trigger signal TR, the current proportional controller 26 outputs the adjusted pump drive current I _c . However, in another implementation state, the acceleration information indicates that the acceleration value is zero, and the acceleration calculator 2422 of the speed calculation device 242 decides not to output the trigger signal TR. Specifically, as shown in Figure 7, when the acceleration value (variable a at speed) is zero, it means that the laser spot SPT is moving at a constant speed, and the acceleration calculator 2422 determines that the moving speed of the laser spot SPT is stable at this time. Therefore, the trigger signal TR is not sent to the current proportional controller 26. When the trigger signal TR is not received, the current proportional controller 26 does not _{adjust the pump drive current I o} in any proportion. Instead, it adjusts the original pump drive current I _o (that is, the pump of the last stage amplifier). The driving current) is transmitted to the second pump source 205. At this time, the output power of the laser beam LB maintains its original size stably without any modulation.

Please refer to FIGS. 8A and 8B together. FIG. 8A is a schematic diagram showing the results of laser scanning processing with an existing scanning laser system, and FIG. 8B is a diagram showing the laser dynamics according to an embodiment of the present invention. A schematic diagram of the results of laser scanning processing performed by a scanning laser system with compensation function. Taking FIG. 8A as an example, because the existing scanning laser system cannot dynamically adjust the laser output power in real time, the PC1 is over-processed at the corner where the laser spot speed is unstable, resulting in poor processing quality.

In contrast, taking Fig. 8B as an example, through the above-mentioned dynamic compensation method of the scanning laser system of the present invention, the PC2 can timely adjust the laser output power at the corner where the speed of the laser spot is unstable, so as to compensate for the laser spot. The over-processing problem caused by the unstable speed makes the overall laser scanning processing effect uniform and improves the processing quality.

Please refer to FIG. 9. FIG. 9 is a method flowchart of a scanning laser dynamic compensation method according to an embodiment of the present invention. This method is suitable for the laser dynamic compensation function of FIG. 1 and FIG. 2 or FIG. 5 The scanning laser system. For the convenience of description, the method in FIG. 9 will be described below in conjunction with the systems in FIG. 1 and FIG. 2. As shown in FIG. 9, in step S1, the laser source device 10 is used to continuously generate a controllable laser beam LB. In step S2, the galvanometer scanning galvanometer 12 to receive the driving voltage V _a, to control the laser beam LB is focused in the scanning laser beam spot SPT processing P1 of the focal plane.

In step S3, the voltage to drive the processing means 14 acquires the moving speed of the laser light spot SPT information according to the driving voltage V _a. In step S4, the driving voltage processing device 14 generates trigger parameters according to the moving speed information of the laser spot SPT. In step S5, the driving voltage processing device 14 determines whether to output the trigger signal TR according to the trigger parameter.

When the drive voltage processing device 14 decides to output the trigger signal TR, in step S6, the current proportional controller 16 receives the trigger signal TR and adjusts the pump drive current I _o to change the adjusted pump drive current (ie, the corrected pump drive current). The driving current I _c ) is transmitted to the laser source device 10. Conversely, when the drive voltage processing device 14 decides not to output the trigger signal TR, in step S7, the current proportional controller 16 does not adjust the pump drive current I _o and transmits the unadjusted original pump drive current I _o to the laser Source device 10. In one embodiment, the current proportional controller 16 calculates the proportional parameter according to the moving speed information of the laser spot SPT and the set moving speed information, and adjusts the pump drive current I _o according to the proportional parameter. The ratio parameter is the ratio of the measured signal value of the movement speed information of the laser spot SPT to the set signal value of the set movement speed information.

Please refer to FIG. 10. FIG. 10 is a detailed method flowchart of the scanning laser dynamic compensation method depicted in the embodiment of FIG. 9 of the present invention. The steps of the embodiment of FIG. 10 are roughly similar to those of the embodiment of FIG. 9, except that step S3 of FIG. 10 includes sub-steps S31 and S32. In sub-step S31, the driving voltage to voltage sensor 14 of the processing apparatus 141 detects the input of the scanning means 12 of the drive voltage V _a, and generating said output voltage signal V _1, wherein said output voltage signal V ₁ proportional to the drive voltage V _a.

In sub-step S32, the processing means driving voltage output speed calculating means 14 based on the voltage signal V ₁ 142 to produce the output voltage signal V ₁ is a variable time, in order to obtain laser spots according to the moving speed of SPT News.

In the method shown in FIG. 10, to one aspect of the embodiment, the driving voltage to the processing means 14 output speed calculating means 142 based on the voltage signal V ₁ to generate the output voltage signal V ₁ when the variable, Obtaining the moving speed information of the laser spot SPT includes: using the speed calculator 1421 of the speed calculating device 142 to _{perform a first differential operation on the output voltage signal V 1} to calculate the time of the output voltage signal V ₁ Variable to obtain the moving speed information of the laser spot SPT.

In the method shown in FIG. 10, in an implementation aspect, generating the trigger parameter by the driving voltage processing device 14 according to the speed information of the galvanometer includes: using the speed calculation device 142 of the driving voltage processing device 14 according to the laser light The movement speed information of the point SPT generates acceleration information as the trigger parameter.

In the above-mentioned embodiment, the speed calculation device 142 of the drive voltage processing device 14 generates acceleration information based on the movement speed information of the laser spot SPT as the trigger parameter, including: the acceleration calculator 1422 of the speed calculation device 142 responds to the laser spot The second differential operation is performed on the SPT moving speed information to calculate the acceleration information as the trigger parameter.

In the foregoing embodiment, determining whether to output the trigger signal TR by the driving voltage processing device 14 according to the trigger parameter includes: determining whether the acceleration value indicated by the acceleration information as the trigger parameter is zero by the speed calculation device 142 of the driving voltage processing device 14 . In one case, when the speed calculation device 142 determines that the acceleration value is not zero, the speed calculation device 142 determines to output the trigger signal TR. In another case, when the speed calculation device 142 determines that the acceleration value is zero, the speed calculation device 142 decides not to output the trigger signal TR.

In summary, in the scanning laser system with laser dynamic compensation function and the scanning laser dynamic compensation method proposed in the present invention, the driving voltage of the galvanometer scanning device is monitored, and the driving voltage processing device is used to monitor the driving voltage of the galvanometer scanning device. The driving voltage is calculated and analyzed to determine the changing state of the moving speed of the laser focusing point on the focal plane, and in the phase of unstable speed, the current proportional controller is used to adjust the pump driving current, according to the laser source device The last stage of the amplifier directly regulates the power of the output laser beam. Therefore, the laser output power can be dynamically adjusted in real time without turning off the laser light source or changing the laser pulse frequency, avoiding the problem of over-processing and achieving Uniform laser processing effect.

Although the present invention is disclosed in the foregoing embodiments, it is not intended to limit the present invention. All changes and modifications made without departing from the spirit and scope of the present invention fall within the scope of the patent protection of the present invention. For the scope of protection defined by the present invention, please refer to the attached scope of patent application.

1: Scanning laser system with laser dynamic compensation function 10, 20: Laser source device 101, 201: Laser seed source 102, 202: First-stage amplifier 103, 203: Second-stage amplifier 104, 204: First pump source 105, 205: Second pump source 106, 206: Optical collimator 12, 22: Galvanometer scanning device 121, 221, 223: Motor 122, 123, 222, 224: Reflector 124, 225 : Lens 14, 24: Drive voltage processing device 141, 241: Voltage sensor 142, 242: Speed calculation device 1421, 1422: Speed calculator 1422, 2422: Acceleration calculator 16, 26: Current proportional controller TR: Trigger signal I _o: pump drive current SPT: laser spots LB: laser beam V _a, V _b: the drive voltage V _1, V _2: output voltage signal SD: seed laser light P1, P2: focal plane CP1 ~ CP8: Operational amplifier R, R _c , R _f , R1~R7: resistance C _i : capacitance S _t , S ₁ , S ₂ : moving speed information SV1, SV2: curve a ₁ , a ₂ : acceleration value X1, X2, Y1 Y2, +Vs, -Vs, OUT, Z: endpoint

FIG. 1 is a functional block diagram of a scanning laser system with laser dynamic compensation function according to an embodiment of the present invention. 2 is a detailed architecture diagram of a scanning laser system with laser dynamic compensation function according to the embodiment of FIG. 1 of the present invention. FIG. 3 is a time waveform diagram of various parameters of a scanning laser system with laser dynamic compensation function according to an embodiment of the present invention. Fig. 4 is a diagram showing the relationship between laser power and speed according to an embodiment of the present invention. FIG. 5 is another detailed architecture diagram of the scanning laser system with laser dynamic compensation function according to the embodiment of FIG. 1 of the present invention. FIG. 6 is a circuit structure diagram of a speed calculation device according to an embodiment of the present invention. FIG. 7 is a time waveform diagram of various parameters of a scanning laser system with laser dynamic compensation function according to another embodiment of the present invention. FIG. 8A is a schematic diagram showing the result of laser scanning processing with an existing scanning laser system. FIG. 8B is a schematic diagram showing the result of laser scanning processing with the scanning laser system with laser dynamic compensation function proposed by the embodiment of the present invention. FIG. 9 is a method flowchart of a scanning laser dynamic compensation method according to an embodiment of the present invention. FIG. 10 is a detailed method flowchart of the scanning laser dynamic compensation method depicted in the embodiment of FIG. 9 according to the present invention.

1: Scanning laser system with laser dynamic compensation function

10: Laser source device

12: Galvanometer scanning device

14: Drive voltage processing device

16: current proportional controller

Claims (15)

A scanning laser system with laser dynamic compensation function includes: a laser source device that continuously generates a controllable laser beam; a galvanometer scanning device, including one or more galvanometers, the one Or a plurality of galvanometers operate according to one or more driving voltages, the galvanometer scanning device controls the laser beam to focus to form a laser spot on a focal plane for scanning processing; a driving voltage processing device is connected to the galvanometer Scanning device, the drive voltage processing device obtains the moving speed information of the laser spot according to the one or more drive voltages, the drive voltage processing device further generates a trigger parameter according to the moving speed information of the laser spot to determine whether to output a Trigger signal; and a current proportional controller connected to the laser source device and the drive voltage processing device to output a pumped drive current to the laser source device, the current proportional controller according to when receiving the trigger signal The moving speed information of the laser spot adjusts the pump driving current to adjust the power of the laser beam. The scanning laser system according to claim 1, wherein the driving voltage processing device includes: a voltage sensor connected to the galvanometer scanning device, and the voltage sensor is used to detect the input to the galvanometer scanning device One or more driving voltages and generating one or more output voltage signals, the one or more output voltage signals being proportional to the one or more driving voltages; and a speed computing device connected to the voltage sensor, the speed The arithmetic device generates the time variable of the one or more output voltage signals according to the one or more output voltage signals, and obtains the moving speed information of the laser spot accordingly. The scanning laser system according to claim 2, wherein the speed calculation device comprises: a speed calculator connected to the current proportional controller and the voltage sensor, and the speed calculator is used to output the one or more The voltage signal performs a first differential operation to calculate the time variable of the one or more output voltage signals to obtain the moving speed information of the laser spot. The scanning laser system according to claim 2, wherein the speed calculation device further generates acceleration information as the trigger parameter according to the moving speed information of the laser spot to determine whether to output the trigger signal. The scanning laser system according to claim 4, wherein the speed calculation device includes: an acceleration calculator connected to the current proportional controller, and the acceleration calculator is used to perform a second operation on the movement speed information of the laser spot The acceleration information is calculated by differential operation. The scanning laser system according to claim 4, wherein the acceleration information indicates that an acceleration value is non-zero, the speed calculation device determines to output the trigger signal, and the current proportional controller uses the moving speed information of the laser spot Adjust the pump drive current. The scanning laser system according to claim 1, wherein the current proportional controller calculates a proportional parameter according to the moving speed information of the laser spot and a set moving speed information, and adjusts the pump drive current according to the proportional parameter , Wherein the ratio parameter is the ratio of a measured signal value of the moving speed information of the laser spot to a set signal value of the set moving speed information. The scanning laser system according to claim 4, wherein the acceleration information indicates that an acceleration value is zero, the speed calculation device decides not to output the trigger signal, and the current proportional controller does not adjust the pump driving current. A scanning laser dynamic compensation method includes: using a laser source device to continuously generate a controllable laser beam; using one or more galvanometers of a galvanometer scanning device to receive one or more driving voltages, The laser beam is controlled to focus on a laser spot on a focal plane for scanning processing; a driving voltage processing device obtains the moving speed information of the laser spot according to the one or more driving voltages; the driving voltage processing device Generate a trigger parameter based on the moving speed information of the laser spot; use the drive voltage processing device to determine whether to output a trigger signal based on the trigger parameter; and use a current proportional controller to output a pump drive current to the laser source device And when the current proportional controller receives the trigger signal, the moving speed information of the laser spot is used to adjust the pump driving current to adjust the power of the laser beam. The scanning laser dynamic compensation method according to claim 9, wherein obtaining the moving speed information of the laser spot by the driving voltage processing device according to the one or more driving voltages includes: processing a voltage of the driving voltage The sensor detects the one or more driving voltages input to the galvanometer scanning device, and generates one or more output voltage signals, wherein the one or more output voltage signals are proportional to the one or more driving voltages; and A speed calculation device of the driving voltage processing device generates the time variable of the one or more output voltage signals according to the one or more output voltage signals, so as to obtain the moving speed information of the laser spot. The scanning laser dynamic compensation method according to claim 10, wherein the speed calculation device of the drive voltage processing device generates the time variable of the one or more output voltage signals according to the one or more output voltage signals, Obtaining the moving speed information of the laser spot includes: using a speed calculator of the speed calculating device to perform a first differential operation on the one or more output voltage signals to calculate the one or more output voltage signals Time variable to obtain the moving speed information of the laser spot. The scanning laser dynamic compensation method according to claim 9, wherein generating the trigger parameter by the driving voltage processing device according to the speed information of the laser spot includes: using a speed calculation device of the driving voltage processing device according to the laser The moving speed information of the light emitting point generates acceleration information as the trigger parameter. The scanning laser dynamic compensation method according to claim 12, wherein the speed calculation device of the driving voltage processing device generates the acceleration information as the trigger parameter according to the moving speed information of the laser spot includes: calculating at the speed An acceleration calculator of the device performs a second differential operation on the movement speed information of the laser spot to calculate the acceleration information as the trigger parameter. The scanning laser dynamic compensation method according to claim 12, wherein the driving voltage processing device determines whether to output the trigger signal according to the trigger parameter includes: The speed calculation device of the drive voltage processing device determines whether an acceleration value indicated by the acceleration information as the trigger parameter is zero; when the speed calculation device determines that the acceleration value is not zero, the speed calculation device determines to output the Trigger signal; and when the speed calculation device determines that the acceleration value is zero, the speed calculation device decides not to output the trigger signal. The scanning laser dynamic compensation method according to claim 9, wherein when the current proportional controller receives the trigger signal, using the moving speed information of the laser spot to adjust the pump drive current includes: controlling the current proportionally The device calculates a proportional parameter according to the moving speed information of the laser spot and a set moving speed information, and adjusts the pump drive current according to the proportional parameter, wherein the proportional parameter is a measurement of the moving speed information of the laser spot The ratio of the signal value to a set signal value of the set moving speed information.

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