An optical axis calibration device based on laser collimation

Abstract

The present application provides an optical axis calibration device based on laser collimation, the optical axis calibration device 100 comprises an adapter component 10, a collimation component 20, a support locking component 30 and a photoelectric detection device 40, wherein: the adapter component 10 is a barrel-shaped structure, and the collimation component 20 is arranged in the adapter component 10; the collimation component 20 comprises a phase plate fixing ring 21, a phase plate 22, a collimation tube 23 and a bubble level 24; the phase plate fixing ring 21 is a ring structure, the phase plate 22 is a circular structure, and the phase plate The shape of 22 matches the phase plate fixing ring 21; the collimating cylinder 23 is a barrel-shaped structure, the upper end face and the lower end face of the collimating cylinder 23 are parallel, the upper end face of the collimating cylinder 23 is provided with a circular groove 25, the shape of the groove 25 matches the phase plate 22; the lower end face of the collimating cylinder 23 is provided with a rectangular hole 26, the groove 25 and the rectangular hole 26 are coaxially arranged, the contact surface of the fixed phase plate 22 is parallel to the upper end face and the lower end face of the collimating cylinder 23, and the center of the rectangular hole 26 should coincide with the axis of the collimating cylinder 23.

Description

Technical Field

[0001] The invention belongs to the technical field of optical system debugging, and in particular to an optical axis calibration device based on laser collimation. Background Art

[0002] During the debugging of laser processing equipment, whether the light beam is incident vertically at the center of the light entrance of the processing system has an important impact on the processing quality and accuracy of the processing system, especially for laser scanning processing devices based on galvanometers and field lenses. If the light beam deviates from the axis of the optical system, the outgoing light beam will not be able to achieve accurate scanning processing.

[0003] In practical applications, laser processing equipment is mostly composed of a laser optical system and a three-axis, five-axis or other multi-axis CNC platform. During the equipment integration process, on the basis of ensuring the relative position relationship between the optical elements of the optical system and the laser beam (such as the angle of incidence, the point of incidence), it is also necessary to ensure the position relationship between the laser beam and the CNC platform, such as the parallel relationship with the main axis. At present, the method of coordinating the movement of the platform with detection equipment such as beam quality analyzers and CCD is mostly used, and the changes in the shape and position of the laser spot during the movement of the platform are used for debugging and calibration, but the calibration efficiency and accuracy are low. Therefore, in order to ensure the above-mentioned position relationship and improve the efficiency and accuracy of the integrated debugging of the equipment, an efficient and accurate calibration device is required.

[0004] It can be seen that the existing methods that rely on vision, beam quality analyzer, CCD and other detection means in conjunction with platform movement have low debugging efficiency and can only characterize the relative position relationship between the outgoing light beam and the platform main axis, but cannot ensure that the light beam is transmitted through the center position of each component of the optical system. Summary of the invention

[0005] The purpose of the present invention is to provide a device for calibrating the optical axis of a laser optical system, which is used to ensure that the laser beam is vertically incident on the center position of each element of the optical system, as well as the relative position relationship between the output beam and the platform main axis, thereby improving the efficiency and accuracy of the optical axis calibration.

[0006] Technical solution: An optical axis calibration device based on laser collimation, the optical axis calibration device 100 includes a transfer component 10, a collimation component 20, a support and locking component 30 and a photoelectric detection device 40, wherein:

[0007] The adapter component 10 is a barrel-shaped structure, and a collimating component 20 is arranged in the adapter component 10; the collimating component 20 includes a phase plate fixing ring 21, a phase plate 22, a collimating tube 23 and a bubble level 24; the phase plate fixing ring 21 is an annular structure, the phase plate 22 is a circular structure, and the shape of the phase plate 22 matches the phase plate fixing ring 21; the collimating tube 23 is a barrel-shaped structure, the upper end face and the lower end face of the collimating tube 23 are parallel, and the upper end face of the collimating tube 23 is provided with a circular groove 25, and the shape of the groove 25 matches the phase plate 22; the lower end face of the collimating tube 23 is provided with a rectangular hole 26, and the groove 25 is coaxially arranged with the rectangular hole 26, and the contact surface of the fixed phase plate 22 is parallel to the upper end face and the lower end face of the collimating tube 23, and the rectangular hole The center of collimator 26 should coincide with the axis of collimator 23; the upper end face of collimator 23 fixes phase plate 22 in groove 25 through phase plate fixing ring 21; bubble level 24 is installed on the lower end face of collimator 23 and away from rectangular hole 26, and the direction of bubble level 24 is toward the outside of collimator 23; threaded holes 27 are arranged on both sides of collimator 23, and collimator 23 is connected with adapter component 10 through supporting locking component 30, and can swing around supporting locking component 30 when supporting locking component 30 is not locked; the photoelectric detection device 40 is placed at a preset distance behind rectangular hole 26, and is used to receive the light beam emitted through rectangular hole 26; adapter component 10 of optical axis calibration device 100 is arranged at the light outlet of laser equipment.

[0008] Furthermore, the support rod of the adapter component 10 can pass through the two circular through holes at the lower end of the adapter component 10. The support rod of the support locking component 30 is engraved with a mark. The locking screw is tightened to the mark to achieve locking and ensure that the lengths of the left and right support rods are symmetrical. Before the locking screw 301 is tightened, the collimation component 20 can rotate around the support locking component by a certain angle. After the collimation component 20 is rotated into place, it is locked by the locking screw 301 to achieve the fixation of the relative position of the collimation component 20 and the adapter component 10.

[0009] Furthermore, an internal thread is provided on the upper end of the adapter component 10 for connection and fixation with the light outlet. The aperture of the adapter component 10 is consistent with the aperture of the light outlet of the laser device, and the adapter component 10 is coaxially fixed to the light outlet through the internal thread.

[0010] Furthermore, the support locking component 30 is connected to the collimation cylinder 23 through a thread, and the collimation cylinder 23 is swung by rotating the support shaft 302. When the bubble level 24 shows that the end surface of the collimation cylinder 23 is horizontal, the collimation cylinder can be locked and fixed by the support locking component 30.

[0011] Furthermore, the photoelectric detection device 40 includes a four-quadrant photoelectric detection device, and the laser beam spot is irradiated on the center position of the photoelectric detection device.

[0012] Furthermore, the diameter of the phase plate 22 is larger than the diameter of the laser beam of the laser device.

[0013] Furthermore, the phase plate 22 includes four sector-shaped coatings with the same angle, and the optical path difference between adjacent coatings is half the wavelength of the laser, and the optical path difference is half the wavelength, and the phase is π.

[0014] Furthermore, the diameter of the rectangular hole 26 ranges from 0.1 to 3 mm.

[0015] In summary, the present invention provides an optical axis calibration device, which overcomes the defect that the prior art can only ensure that the emission direction of the laser beam is parallel to the main axis of the platform, but cannot ensure that the laser beam is transmitted along the center position of each element of the optical system. Especially when integrating and debugging laser processing equipment that uses a galvanometer and a field lens to achieve scanning, it helps to avoid aberrations caused by optical axis offset and facilitates the best optical performance of the galvanometer and the field lens. The present invention is based on the diffraction principle of lasers and has good anti-interference performance. Through photoelectric detection devices, it can intuitively reflect the deviation state of the light beam, which can multiply the efficiency and accuracy of optical system debugging. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of an optical axis calibration device based on laser collimation provided in the present application;

[0017] Figure 2 A schematic diagram of a collimation component provided in the present application;

[0018] Figure 3 A schematic diagram of a phase plate provided in this application;

[0019] Figure 4 A schematic diagram of a switching component and a photoelectric detection device provided in this application;

[0020] Among them: 100-optical axis calibration device, 10-adapter component, 20-collimation component, 30-support locking component, 21-phase plate fixing ring, 22-phase plate, 23-collimation cylinder, 24-bubble level, 25-groove, 26-rectangular hole, 27-threaded hole, 301-locking screw, 302-support shaft, 40-photoelectric detection device. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] like Figure 1-Figure 2 As shown, the present application provides an optical axis calibration device 100 based on laser collimation, comprising a transfer component 10, a collimation component 20, a support and locking component 30 and a photoelectric detection device 40, wherein:

[0023] The adapter component 10 is a barrel-shaped structure, and a collimating component 20 is arranged in the adapter component 10; the collimating component 20 includes a phase plate fixing ring 21, a phase plate 22, a collimating tube 23 and a bubble level 24; the phase plate fixing ring 21 is an annular structure, the phase plate 22 is a circular structure, and the shape of the phase plate 22 matches the phase plate fixing ring 21; the collimating tube 23 is a barrel-shaped structure, the upper end face and the lower end face of the collimating tube 23 are parallel, and the upper end face of the collimating tube 23 is provided with a circular groove 25, and the shape of the groove 25 matches the phase plate 22; the lower end face of the collimating tube 23 is provided with a rectangular hole 26, and the groove 25 is coaxially arranged with the rectangular hole 26, and the contact surface of the fixed phase plate 22 is parallel to the upper end face and the lower end face of the collimating tube 23, and the rectangular hole The center of collimator 26 should coincide with the axis of collimator 23; the upper end face of collimator 23 fixes phase plate 22 in groove 25 through phase plate fixing ring 21; bubble level 24 is installed on the lower end face of collimator 23 and away from rectangular hole 26, and the direction of bubble level 24 is toward the outside of collimator 23; threaded holes 27 are arranged on both sides of collimator 23, and collimator 23 is connected with adapter component 10 through supporting locking component 30, and can swing around supporting locking component 30 when supporting locking component 30 is not locked; the photoelectric detection device 40 is placed at a preset distance behind rectangular hole 26, and is used to receive the light beam emitted through rectangular hole 26; adapter component 10 of optical axis calibration device 100 is arranged at the light outlet of laser equipment.

[0024] Preferably, the opening size of the rectangular hole 26 is set according to the laser wavelength and the spot size, and the diameter of the rectangular hole 26 ranges from 0.1 to 3 mm.

[0025] Preferably, the rectangular hole 26 can be replaced with other shapes, such as a circle, which also falls within the protection scope of the present invention.

[0026] Preferably, the support rod of the adapter component 10 can pass through the two circular through holes at the lower end of the adapter component 10. The support rod of the support locking component 30 is engraved with a mark. The locking screw is tightened to the mark to achieve locking and ensure that the lengths of the left and right support rods are symmetrical. Before the locking screw 301 is tightened, the collimation component 20 can rotate around the support locking component by a certain angle. After the collimation component 20 is rotated into place, it is locked by the locking screw 301 to achieve the relative position fixation of the collimation component 20 and the adapter component 10.

[0027] Preferably, an internal thread is provided on the upper end of the adapter component 10 for connection and fixation with the light outlet. The aperture of the adapter component 10 is consistent with the aperture of the light outlet of the laser device, and can be coaxially fixed to the light outlet through the internal thread of the adapter component 10.

[0028] It should be noted that different caliber connecting components can be provided to match light outlets with different calibers.

[0029] Preferably, the support locking component 30 is connected to the collimation cylinder 23 via a thread, and the collimation cylinder 23 is swung by rotating the support shaft 302 . When the bubble level 24 shows that the end surface of the collimation cylinder 23 is horizontal, the collimation cylinder can be locked and fixed by the support locking component 30 .

[0030] Preferably, the photoelectric detection device 40 includes a four-quadrant photoelectric detection device, and the laser beam spot is irradiated on the center position of the photoelectric detection device.

[0031] like Figure 3 As shown, the diameter of the phase plate 22 is larger than the diameter of the laser beam of the laser device. The phase plate includes four fan-shaped coatings with the same angle. The optical path difference between adjacent coatings is half the wavelength of the laser, with a half-wavelength optical path difference and a phase of π.

[0032] It should be noted that replacing the phase plate 22 with a phase plate that can achieve other diffraction patterns also falls within the protection scope of the present invention.

[0033] The present invention provides an optical axis calibration device. When a laser beam is incident on a phase plate in a collimator, it diffracts a dark cross stripe through the phase plate, and then is emitted through a rectangular aperture and received by a photoelectric detection device. The diffraction image is four rectangular light spots separated by the cross stripes. Only when the laser beam is incident vertically along the axis of the collimator, the intensity of the four rectangular light spots is symmetrical about the cross stripes. According to the reading of the photoelectric detector, the degree of deviation of the beam from the optical axis of the collimator can be judged, thereby achieving the purpose of calibrating the optical axis.

[0034] It should be noted that the present application provides an optical axis calibration device based on laser collimation. Based on the diffraction principle of laser, the optical axis calibration is realized by using the diffraction image of the phase plate, which has good anti-interference performance. The coaxiality of the phase plate and the rectangular aperture is utilized to ensure the coaxiality of the laser beam and the axis of the collimation tube. The horizontality of the collimation tube itself is utilized to ensure the verticality of the laser beam, and then the parallelism of the laser beam and the main axis of the platform is ensured. The coaxiality of the adapter and the light outlet is utilized to ensure that the laser beam is transmitted along the center position of each element of the optical system.

[0035] like Figure 4As shown, when in use, the components of the optical axis calibration device 100 provided are assembled, and the internal thread on the upper end of the adapter component 10 is used to connect and fix it to the light outlet of the laser processing equipment. The platform spindle is adjusted to vertical, the collimation component 20 is adjusted to horizontal using the bubble level 24, and the collimation component 20 is locked using the support locking part 30. The photoelectric detection device 40 is placed behind the optical axis calibration device 100 to receive the outgoing light. In this example, a four-quadrant photoelectric detector is used, and the light beam offset distance can be fed back by the strength of the signal received by the detector.

[0036] Specifically, when the laser beam is incident vertically at the center of the phase plate 22 , dark cross stripes appear on any cross section of the beam behind the phase plate, and then after diffraction by the rectangular hole 26 , four evenly distributed light spots appear in the photodetector 40 .

[0037] Specifically, when the laser beam deviates from the center of the phase plate 22 and is incident vertically, when the deviation distance is small, four light spots still appear on the photodetector, but the energy distribution of the four light spots is no longer uniform. The four-quadrant photodetector can be used to reversely calculate the beam deviation distance. Adjust the laser beam incident distance until the energy of the four light spots is evenly distributed. When the beam deviates from the distance by a large amount, the diffraction light spot cannot be seen, and the beam incident position needs to be greatly adjusted until the diffraction pattern appears.

[0038] Specifically, when the laser beam is incident on the phase plate 22 at a certain angle, when the incident angle is small, four non-uniformly distributed light spots will appear on the rear photodetector, and the incident direction of the laser beam is adjusted until the energy of the four light spots is evenly distributed. When the incident angle of the beam is too large, the diffraction light spot cannot be seen due to the obstruction of the rectangular hole, and the incident angle of the beam needs to be greatly adjusted until the diffraction pattern appears.

[0039] In the above example, the coaxiality of the phase plate and the rectangular aperture can ensure the coaxiality of the laser beam and the axis of the collimator. The horizontality of the collimator itself can ensure the verticality of the laser beam, and then ensure the parallelism of the laser beam and the main axis of the platform. The coaxiality of the adapter and the light outlet can ensure that the laser beam is transmitted along the center position of each element of the optical system.

[0040] Specifically, when the laser beam spot diameter is too small, the diffraction pattern is difficult to observe or the diffraction pattern cannot be formed. A beam expander can be installed in front of the device described in the above example, and the optical axis can be calibrated using the device in the above example after the beam passes through the beam expander.

[0041] Compared with the prior art, the optical axis calibration device 100 has a compact structure and strong anti-interference performance. It overcomes the defect of the prior art that the laser beam can only be emitted in a direction parallel to the main axis of the platform, but cannot be transmitted along the center position of each element of the optical system. It improves the debugging efficiency and accuracy of the optical system of the prior art.

[0042] In summary, the present invention is used for calibrating the optical axis during the integrated debugging of laser processing equipment. During the integrated debugging of laser processing equipment, it is ensured that the laser beam is vertically incident on the center position of each component of the optical system, and the outgoing beam maintains a parallel or vertical relative position relationship with the platform main axis. The problem of low debugging efficiency and accuracy in the prior art, and the inability to ensure that the light beam is transmitted through the center position of each component of the optical system, is solved.

Claims

1. An optical axis calibration device based on laser collimation, characterized in that: The optical axis calibration device (100) comprises a transfer component (10), a collimation component (20), a support locking component (30) and a photoelectric detection device (40), wherein: The adapter component (10) is a barrel-shaped structure, and a collimating component (20) is arranged inside the adapter component (10); the collimating component (20) comprises a phase plate fixing ring (21), a phase plate (22), a collimating cylinder (23) and a bubble level (24); the phase plate fixing ring (21) is a ring-shaped structure, the phase plate (22) is a circular structure, and the shape of the phase plate (22) matches the phase plate fixing ring (21); the collimating cylinder (23) is a barrel-shaped structure, the upper end face and the lower end face of the collimating cylinder (23) are parallel, and the upper end face of the collimating cylinder (23) is provided with a circular groove (25), and the shape of the groove (25) matches the shape of the phase plate (2 2) match; the lower end surface of the collimating cylinder (23) is provided with a rectangular hole (26), the groove (25) and the rectangular hole (26) are coaxially arranged, the contact surface of the fixed phase plate (22) is parallel to the upper end surface and the lower end surface of the collimating cylinder (23), and the center of the rectangular hole (26) should coincide with the axis of the collimating cylinder (23); the upper end surface of the collimating cylinder (23) fixes the phase plate (22) in the groove (25) through the phase plate fixing ring (21); the bubble level (24) is installed on the lower end surface of the collimating cylinder (23) and away from the rectangular hole (26), and the direction of the bubble level (24) is toward the outside of the collimating cylinder (23); the collimating cylinder (23) is provided with a rectangular hole (26), and the direction of the bubble level (24) is toward the outside of the collimating cylinder (23); Threaded holes (27) are arranged on both sides of the straight cylinder (23); the collimating cylinder (23) is connected to the adapter component (10) through a support locking component (30); when the support locking component (30) is not locked, the collimating cylinder (23) can swing around the support locking component (30); the photoelectric detection device (40) is arranged at a preset distance behind the rectangular hole (26) and is used to receive the light beam emitted through the rectangular hole (26); the adapter component (10) of the optical axis calibration device (100) is arranged at the light outlet of the laser device; the support rod of the adapter component (10) can pass through the two circular through holes at the lower end of the adapter component (10); the support locking component (30) ) The support rod is engraved with a mark, and the locking screw is tightened to the mark to achieve locking and ensure that the lengths of the left and right support rods are symmetrical. Before the locking screw (301) is tightened, the collimating component (20) can rotate around the supporting locking component at a certain angle. After the collimating component (20) is rotated into place, it is locked by the locking screw (301) to achieve the fixation of the relative position of the collimating component (20) and the adapter component (10); an internal thread is provided at the upper end of the adapter component (10) for connecting and fixing with the light outlet. The caliber of the adapter component (10) is consistent with the aperture of the light outlet of the laser device, and is coaxially fixed to the light outlet through the internal thread of the adapter component (10).

2. The optical axis calibration device according to claim 1, characterized in that: The support locking component (30) is connected to the collimating cylinder (23) via a thread, and the collimating cylinder (23) is swung by rotating the support shaft (302). When the bubble level (24) shows that the end surface of the collimating cylinder (23) is horizontal, the collimating cylinder can be locked and fixed by the support locking component (30).

3. The optical axis calibration device according to claim 1, characterized in that: The photoelectric detection device (40) comprises a four-quadrant photoelectric detection device, and the laser beam spot is irradiated on the center position of the photoelectric detection device.

4. The optical axis calibration device according to claim 1, characterized in that: The diameter of the phase plate (22) is larger than the diameter of the laser beam of the laser device.

5. The optical axis calibration device according to claim 1, characterized in that: The phase plate (22) comprises four fan-shaped coatings with the same angle, the optical path difference between adjacent coatings is half the wavelength of the laser, and the optical path difference is half the wavelength, and the phase is π.

6. The optical axis calibration device according to claim 1, characterized in that: The diameter of the rectangular hole (26) ranges from 0.1 to 3 mm.

Images