CN104793334A - Cascading coarse-fine data coupling optical scanning device - Google Patents

Abstract

The invention relates to a cascaded coarse-fine coupling optical scanning device, which is composed of a rotating double prism system and an orthogonal deflection optical flat plate system along the optical axis, and the rotating double prism system uses two rotating stepping motors to respectively drive two The wedge-shaped prism rotates around the Z axis to achieve coarse scanning; the orthogonal yaw optical flat panel system uses two rotating stepper motors to drive the two optical flat panels to swing around the Y axis and the X axis respectively, and realizes the beam shift by the displacement of the refracted beam. The displacement and translation in a local range meet the fine scanning requirements; the two sets of prism systems of the rotating double prism system are composed of a base, a rotating stepping motor, an encoder, a wedge prism, a mirror frame, a worm wheel, a worm and a mirror frame. The orthogonal yaw plate system consists of a second base, a third mirror frame, a third rotary stepper motor, a first plane mirror, a third mirror frame, a third encoder, a fourth encoder, a fourth mirror frame, and a second plane mirror 1. Composed of the fourth rotating stepping motor and the fourth mirror frame, the invention is easy to control the propagation direction of the light beam, and the control is convenient.

Description

A Cascaded Coarse and Fine Coupling Optical Scanning Device

technical field

The invention relates to an optical scanning system, in particular to a high-precision optical scanning device integrating a rotating double prism and an orthogonally deflecting optical flat plate.

Background technique

As a typical beam scanning device, the rotating biprism has the characteristics of compact structure, small moment of inertia, and good dynamic performance. It can be widely used in laser communication, microstructure processing, biomedicine, military weapons and other fields. High-precision positioning of the beam can be achieved by rotating the double prism. The prior technology (Yun Maojin and other patents, patent number: 200310108487.7) mentioned that when the rotating double prism is used in the field of laser communication, the accuracy can reach the milliradian level. Due to the installation error of the prism during installation, such as the tilt of the prism or the tilt of the bearing, the scanning tracking accuracy is affected. Therefore, during high-precision scanning, higher requirements are put forward for the manufacture of the prism in the rotating double prism system and the installation of the system.

The prior technology (Journal of Mechanical Engineering, 2009, Issue 01, Volume 45, Page 200, Li Anhu "Large Aperture Precision Beam Scanning Device") can achieve sub-micro radian scanning accuracy by using orthogonally deflected double prisms, which are mainly used for beam scanning. Pointing adjustment; the prior technology (Pan Yong and other patents, patent number: 2012101172862) proposes an orthogonal flat-panel scanning device, which can realize micron-level displacement adjustment. In the process of beam tracking and scanning, it is sometimes necessary to achieve local high-precision scanning near the target point without changing the beam pointing, which is a difficult problem in system design. For example, when processing laser micro-holes, in order to ensure the centrality of the laser holes, the laser is required to produce a small displacement while maintaining the same direction during the laser processing process.

In order to solve the problem of laser coarse-fine coupling tracking and scanning, the previous technology (Li Anhu et al. patent, patent number: 201210439061.9) mentioned a cascaded prism coarse-fine coupling scanning device, but the structure of the device is complex, and the device is used to adjust the beam Pointing, unable to meet the beam translation requirements in the local range. However, in practical applications, it is necessary to achieve fine displacement adjustment in many occasions, and the orthogonal yaw optical flat plate can meet this requirement, such as the application in laser microhole processing.

Contents of the invention

The object of the present invention is to provide a cascaded coarse-fine coupling optical scanning device, which includes two parts: a rotating double prism and an orthogonal optical plate. When the rotating double prism is used for rough scanning in the whole field area, the orthogonal optical flat plate can produce higher-precision displacement and translation near the local target point without changing the beam scanning direction, which is especially suitable for large-scale laser fine processing and other occasions.

A cascaded coarse-fine coupling optical scanning device provided by the present invention is composed of a rotating double prism system and an orthogonal deflection optical flat plate system along the optical axis. The rotating double prism system uses two rotating stepping motors to drive two A wedge-shaped prism rotates around the Z axis to achieve coarse scanning; the orthogonal yaw optical flat panel system uses two rotary stepper motors to drive the two optical flat panels to swing around the Y axis and the X axis respectively, and realizes the displacement and offset of the refracted beam. The displacement and translation of the beam in a local range meets the fine scanning requirements;

The rotating double prism system consists of a first base 1, a first rotating stepper motor 2, a first encoder 3, a first wedge prism 4, a first mirror frame 5, a first worm wheel 6, a first worm 7, a first The mirror frame 8, the second rotary stepper motor 9, the second encoder 10, the second wedge prism 11, the second mirror frame 12, the second worm wheel 13, the second worm 14 and the second mirror frame 15 are composed of the first mirror frame 8 is provided with a first mirror frame 5, the first wedge-shaped prism 4 is built in the first mirror frame 5, the first mirror frame 5 is pressed inside the first worm wheel 6, and the first worm wheel 6 is engaged with the first worm 7 to form a worm gear connection. The first rotary stepper motor 2 and the first encoder 3 are respectively located at the two ends of the worm shaft of the first worm; the second mirror frame 15 is provided with a second mirror frame 17, and the second wedge-shaped prism 11 is built in on the second mirror frame 17, The second mirror frame 12 is compressed inside the second worm wheel 13, the second worm wheel 13 engages with the second worm screw 14 to form a worm gear connection, and the second rotary stepper motor 9 and the second encoder 10 are respectively located on the worm shaft of the second worm screw 14 Both ends; the first frame 8 and the second frame 15 are respectively arranged on the first base 1, and can slide back and forth along the Z axis on the first base 1 to adjust the first wedge prism 4 and the second wedge prism 11 The distance of the first rotating stepper motor 2 is transmitted to the first mirror frame 5 through the first worm wheel 6 and the first worm 7 inside the first mirror frame 8, so that the first mirror frame 5 rotates around the Z axis, and then drives the first mirror frame 5 A wedge-shaped prism 4 rotates around the Z axis; the rotary motion of the second rotary stepper motor 9 is transmitted to the second frame 12 through the second worm wheel 13 and the second worm screw 14 inside the second frame 15, so that the second frame 12 rotates around Z axis rotation, and then drive the second wedge prism 11 to rotate around the Z axis;

The said orthogonal yaw plate system consists of a second base 16, a third mirror frame 17, a third rotary stepper motor 18, a first flat mirror 19, a third mirror frame 20, a third encoder 21, a fourth encoder 22, The fourth mirror frame 23, the second plane mirror 24, the fourth rotating stepper motor 25 and the fourth mirror frame 26 are composed of the third mirror frame 17 with a first rotation axis, and the third mirror frame 20 is fixed on the first On the rotating shaft, the third rotary stepper motor 18 and the third encoder 21 are installed at both ends of the first rotating shaft respectively, and the first plane mirror 19 is built in the third mirror frame 20; the fourth mirror frame 26 is provided with a first Two rotating shafts, the fourth mirror frame 23 is fixed on the second rotating shaft, the fourth rotary stepper motor 25 and the fourth encoder 22 are respectively installed at both ends of the second rotating shaft, and the second plane mirror 24 is built in the fourth rotating shaft. On the mirror frame 23; the third mirror frame 17 and the fourth mirror frame 26 are arranged on the second base 16 respectively, and can slide back and forth along the Z axis on the second base 16, and the rotation motion of the third rotary stepping motor 18 passes through the second base 16 A rotation axis is transmitted to the third mirror frame 20, so that the third mirror frame 20 yaws around the Y axis, and drives the first plane mirror 19 to yaw around the Y axis; the rotation of the fourth rotary stepping motor 25 passes through the second rotation axis Transfer to the fourth mirror frame 23, so that the fourth mirror frame 23 swings around the X-axis, and drives the second plane mirror 24 to swing around the X-axis;

The first rotary stepper motor 2, the second rotary stepper motor 9, the third rotary stepper motor 18 and the fourth rotary stepper motor 25 are respectively connected to a motion control system through a data communication port, and the motion control system is connected to a PC machine.

The basic principle of the cascade coarse-fine coupling optical scanning device of the present invention is:

1. In combination with attached drawings 3 and 4, explain the principle of the control system: the motion control system can convert the target trajectory point into a coordinate point . The data transmission interface connects the motion control system to the PC to realize the communication between the motion control system and the PC. Combined with Figure 3, in order to achieve rough scanning, first of all, in the case of known coarse scanning target track points, the target track points are converted into coordinates through the motion control system And transfer to PC. PC according to scan coordinates , respectively calculate the rotation angles of the first wedge prism 4 and the second wedge prism 11 And the rotation speed data, and transmitted to the motion control system through the data transmission interface, the motion control system according to the received and rotation speed information to control the rotation of the first rotary stepper motor 2 and the second rotary stepper motor 9 to realize rough scanning. During fine scanning, in conjunction with accompanying drawing 4, firstly, in the case of known fine scanning target trajectory points, the target trajectory points are converted into coordinates by the motion control system And transfer to PC. PC according to scan coordinates Calculate the displacement offset required by the beam , and then calculate the deflection angles of the first plane mirror 19 and the second plane mirror 24 according to the relationship between the deflection angle of the orthogonal deflection double plate and the translation of the refracted beam And the yaw speed data, and transmit to the motion control system through the data transmission interface, the motion control system according to the received and the yaw speed information to control the rotation of the third rotary stepper motor 18 and the fourth rotary stepper motor 25 to realize the micro-displacement translation of the light beam.

2. In rough scanning, according to the vector refraction theorem, when the beam is incident from the center of the rotating double prism, the direction of the outgoing light after the beam passes through the rotating double prism can be deduced. When the rotation angle of the two wedge prisms is adjusted, the direction of the outgoing light can be changed. direction. In this device, the first wedge-shaped prism 4 is driven to rotate around the Z axis by the first rotary stepping motor 2, and the second rotary stepping motor 9 drives the second wedge-shaped prism 11 to rotate around the Z axis, and the rotation angles are respectively , , so as to achieve a rough scan in a certain area.

3. During fine scanning, as shown in Figure 2, when the light beam passes through the plane mirror, the propagation direction will not change, but the light beam will shift. (a) The figure shows that when the first plane mirror 19 deflects around the Y axis , after the incident beam passes through the first plane mirror 19, the propagation direction of the outgoing beam remains unchanged, and there will be a certain offset in the X-axis direction ; Similarly, (b) figure shows that when the second plane mirror 24 deflects around the Y axis , after the incident beam passes through the second plane mirror 24, the propagation direction of the outgoing beam remains unchanged, and there will be a certain offset in the Y-axis direction . In this device, the first flat mirror 19 is driven to swing around the Y axis by the third rotary stepping motor 18 , the light beam is displaced along the X axis after passing through the first plane mirror 19 ; The fourth rotary stepper motor 25 drives the second plane mirror 24 to swing around the X axis , the light beam is displaced along the Y axis after passing through the second plane mirror 21 . Realize fine scanning in a small area.

The beneficial effects of the present invention are:

1. The present invention can realize coarse and fine scanning. The rotating double prism system can realize coarse scanning, and the orthogonal yaw optical flat plate can realize fine scanning. The two parts can work simultaneously or independently to meet different rough and fine scanning precision requirements.

2. The present invention is easy to control the beam propagation direction. Without changing the propagation direction of the beam, the slight displacement of the beam along the X-axis and Y-axis direction can be realized by changing the deflection angle of the double plates and .

3. The present invention is convenient to control. The device adopts an independent control mode, which can separately control the rough scanning mechanism and the fine scanning mechanism. At the same time, it adopts an open-loop control mode, which is convenient to control and the control process is simple.

Description of drawings

Fig. 1 is a schematic diagram of a cascaded coarse-fine coupling scanning device according to the present invention, the former part is a rotating double prism, and the latter part is an orthogonal deflection plate. , is the rotation angle of the prism, , is the deflection angle of the plate.

Figure 2 shows the corresponding offset when the beam passes through the deflected plate and schematic diagram of the principle.

Fig. 3 is a flow chart of the control part of the cascaded coarse-fine coupling scanning device according to the present invention. The control method of this device is briefly described.

Fig. 4 is a flow chart of the control part of the cascaded coarse-fine coupling scanning device according to the present invention. The control method of this device is briefly described.

Labels in the figure: 1-the first base; 2-the first rotary stepping motor; 3-the first encoder; 4-the first wedge-shaped prism; 5-the first mirror frame; 6-the first worm wheel; 7-the first worm ; 8-the first mirror frame; 9-the second rotary stepping motor; 10-the second encoder; -the second frame; 16-the second base; 17-the third frame; 18-the third rotary stepping motor; 19-the first plane mirror; 20-the third frame; 21-the third encoder; 22-the fourth Encoder; 23-the fourth mirror frame; 24-the second plane mirror; 25-the fourth rotary stepper motor; 26-the fourth mirror frame.

Detailed ways

The composition of the cascaded coarse-fine coupling optical scanning device and the process of realizing the coarse-fine scanning in the present invention will be further described in detail through the accompanying drawings, but the protection scope of the present invention is not limited thereto.

The cascaded coarse-fine coupling optical scanning device shown in FIG. 1 mainly includes two parts, the first part is a rotating double prism system, and the second part is an orthogonal deflection flat plate system.

The rotating double prism system consists of a first base 1, a first rotating stepper motor 2, a first encoder 3, a first wedge prism 4, a first mirror frame 5, a first worm wheel 6, a first worm 7, a first The mirror frame 8, the second rotary stepper motor 9, the second encoder 10, the second wedge prism 11, the second mirror frame 12, the second worm wheel 13, the second worm 14 and the second mirror frame 15 are composed. The first frame 8 and the second frame 15 are arranged on the first base 1 and can slide on the first base 1 to adjust the distance between the first wedge prism 4 and the second wedge prism 11 . The first rotary stepping motor 2 and the first encoder 3 are installed on the worm shaft of the first worm 7, the first worm wheel 6 is engaged with the first worm 7 to form a worm-wheel connection, and the first mirror frame 5 is pressed against the first worm wheel 6 Inside, the first wedge prism 4 is built into the first mirror frame 5 . The rotary motion of the first rotary stepper motor 2 is transmitted to the first mirror frame 5 through the first worm wheel 6 and the first worm screw 7 inside the first mirror frame 8, so that the first mirror frame 5 rotates around the Z axis and drives the first wedge prism 4 Rotate around the Z axis. The second rotary stepper motor 9 and the second encoder 10 are installed on the worm shaft of the second worm 14, the second worm wheel 13 is engaged with the second worm wheel 14 to form a worm wheel connection, and the second mirror frame 12 is pressed against the second worm wheel 14 Inside, the second wedge prism 11 is built on the second mirror frame 12 . The rotary motion of the second rotary stepper motor 9 is transmitted to the second mirror frame 12 through the second worm wheel 13 and the second worm screw 14 inside the second mirror frame 15, so that the second mirror frame 12 rotates around the Z axis and drives the second wedge prism 11 Rotate around the Z axis.

The described orthogonal yaw plate system consists of a second base 16, a third mirror frame 17, a third rotary stepper motor 18, a first plane mirror 19, a third mirror frame 20, a third encoder 21, and a fourth encoder 22 , the fourth mirror frame 23, the second plane mirror 24, the fourth rotary stepper motor 25 and the fourth mirror frame 26. The third mirror frame 17 and the fourth mirror frame 26 are arranged on the second base 16 and can slide on the second base 16 to adjust the distance between the first plane mirror 19 and the second plane mirror 24 . The third rotary stepping motor 18 and the third encoder 21 are installed on the rotating shaft, the third mirror frame 20 is fixed on the rotating shaft, and the first plane mirror 19 is built in the third mirror frame 20 . The rotary motion of the third rotary stepping motor 18 is transmitted to the third mirror frame 20 through the rotating shaft, so that the third mirror frame 20 swings around the Y axis, and drives the first plane mirror 19 to swing around the Y axis. The fourth rotary stepping motor 25 and the fourth encoder 22 are installed on the rotating shaft, the fourth mirror frame 23 is fixed on the rotating shaft, and the second plane mirror 24 is built in the fourth mirror frame 23 . The rotary motion of the fourth rotary stepping motor 25 is transmitted to the fourth mirror frame 23 through the rotating shaft, so that the fourth mirror frame 23 is swung around the X axis, and the second plane mirror 24 is driven to swing around the X axis.

The working principle of the cascaded coarse-fine coupling optical scanning device is as follows:

The controller collects point data to be scanned, and sends control signals to the rotating double prism system and the orthogonal deflection flat plate system to control the rotation of the first rotating stepping motor 2 and the second rotating stepping motor 9 to realize rough scanning. At the same time, the controller controls the rotation of the third rotary stepper motor 18 and the fourth rotary stepper motor 25 to realize fine scanning and achieve the purpose of coarse-fine coupling optical scanning.

Coarse-fine coupling optical scanning is performed according to the following steps:

1. According to the rough scanning target trajectory point, the motion control system will position coordinates It is transmitted to the PC through the data transmission interface, and the PC according to the coordinates , calculate the angle of rotation of the first wedge prism 4 and the second wedge prism 11 And the rotation speed data are transmitted to the motion control system through the data transmission interface. Then according to the fine scanning target trajectory point, the target trajectory point is converted into coordinates through the motion control system And transfer to PC. PC according to scan coordinates , to calculate the displacement offset required by the beam , and then calculate the deflection angles of the first plane mirror 19 and the second plane mirror 24 according to the relationship between the deflection angle of the orthogonal deflection double plate and the beam translation And the yaw speed data, which are transmitted to the motion control system through the data transmission interface.

2. The first rotary stepper motor 2 and the second rotary stepper motor 9 are transmitted according to the motion system And the rotation speed information drives the rotation of the first wedge prism 4 and the second wedge prism 11 respectively, so that the light beam moves in the coarse scanning area to realize the coarse scanning process.

3. Determine whether the scanning beam is in the fine scanning area, if it is in the fine scanning area, then execute step 4, if it is not in the fine scanning area, then execute step 2.

4. The third rotation stepping motor 18 and the fourth rotation stepping motor 25 transmit the power according to the motion system And the rotation speed information, respectively drive the first plane mirror 19 to yaw around the Y axis and the second plane mirror 24 to yaw around the X axis, so that the beam shifts in the local fine scanning domain , to realize the fine scanning process.

The cascaded coarse-fine coupling optical scanning device can perform high-precision scanning in a local small area without changing the propagation direction of the light beam while satisfying large-scale scanning.

The above description is only an example of the application of the present invention in scanning, and for those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (1)

1. the thick smart coupling optical scanister of cascade, it is characterized in that described rotation prism arrangement adopts two rotating stepper motors to drive two prism wedges to rotate around Z axis respectively and realizes coarse scanning along optical axis direction by rotating prism arrangement and orthogonal beat optical flat system forms; Orthogonal beat optical flat system adopts two rotating stepper motors to drive two optical flats around Y-axis with around X-axis beat respectively, realizes the displacement translation of light beam in subrange, meet meticulous scanning requirement by the displacement bias of deflecting light beams;

Described rotation prism arrangement is by the first base (1), first rotating stepper motor (2), first scrambler (3), first prism wedge (4), first picture frame (5), first worm gear (6), first worm screw (7), first mirror holder (8), second rotating stepper motor (9), second scrambler (10), second prism wedge (11), second picture frame (12), second worm gear (13), second worm screw (14) and the second mirror holder (15) composition, first mirror holder (8) is provided with the first picture frame (5), first prism wedge (4) is built on the first picture frame (5), it is inner that first picture frame (5) is pressed in the first worm gear (6), first worm gear (6) and the first worm screw (7) engage and form worm and gear and be connected, first rotating stepper motor (2) and the first scrambler (3) lay respectively at the worm shaft two ends of the first worm screw, second mirror holder (15) is provided with the second picture frame (17), second prism wedge (11) is built on the second picture frame (17), it is inner that second picture frame (12) is pressed in the second worm gear (13), second worm gear (13) and the second worm screw (14) engage and form worm and gear and be connected, and the second rotating stepper motor (9) and the second scrambler (10) lay respectively at the worm shaft two ends of the second worm screw (14), first mirror holder (8) and the second mirror holder (15) are arranged on the first base (1) respectively, and can slide on the first base (1), to regulate the distance of the first prism wedge (4) and the second prism wedge (11), inner the first worm gear (6) of the first mirror holder (8) is passed through in the rotary motion of the first rotating stepper motor (2) and the first worm screw (7) is delivered to the first picture frame (5), first picture frame (5) is rotated around Z axis, and then drives the first prism wedge (4) to rotate around Z axis, inner the second worm gear (13) of the second mirror holder (15) is passed through in the rotary motion of the second rotating stepper motor (9) and the second worm screw (14) is delivered to the second picture frame (12), second picture frame (12) is rotated around Z axis, and then drives the second prism wedge (11) to rotate around Z axis,

Described orthogonal beat flat-panel systems is by the second base (16), 3rd mirror holder (17), 3rd rotating stepper motor (18), first level crossing (19), 3rd picture frame (20), 3rd scrambler (21), 4th scrambler (22), 4th picture frame (23), second level crossing (24), 4th rotating stepper motor (25) and the 4th mirror holder (26) composition, described 3rd mirror holder (17) is provided with the first turning axle, 3rd picture frame (20) is fixed on described first turning axle, 3rd rotating stepper motor (18) and the 3rd scrambler (21) are installed on the first rotating shaft terminal respectively, first level crossing (19) is built on the 3rd picture frame (20), described 4th mirror holder (26) is provided with the second turning axle, 4th picture frame (23) fixedly lies on described second turning axle, 4th rotating stepper motor (25) and the 4th scrambler (22) are installed on the second rotating shaft terminal respectively, and the second level crossing (24) is built on the 4th picture frame (23), 3rd mirror holder (17) and the 4th mirror holder (26) are arranged on the second base (16) respectively, and can slide on the second base (16), the rotary motion of the 3rd rotating stepper motor (18) is delivered on the 3rd picture frame (20) by the first turning axle, make the 3rd picture frame (20) around Y-axis beat, drive the first level crossing (19) around Y-axis beat, the rotary motion of the 4th rotating stepper motor (25) is delivered on the 4th picture frame (23) by the second turning axle, makes the 4th picture frame (23) around X-axis beat, drives the second level crossing (24) around X-axis beat,

Described first rotating stepper motor (2), the second rotating stepper motor (9), the 3rd rotating stepper motor (18) are connected kinetic control system with the 4th rotating stepper motor (25) respectively by data communication mouth, and described kinetic control system connects PC.