JP2005055610A - Scanner and laser beam machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scanner and a laser beam machine that quickly attenuate falling vibration of a mirror and that improves positioning accuracy of light. <P>SOLUTION: A holding member 5 for holding a vibration attenuation member 6 is fixed on the housing 1 of the scanner S so that a part of the vibration attenuation member 6 comes into contact with a mirror 4. In this case, it is more effective if the vibration attenuation member 6 is brought into close contact with the rotary axis line of the shaft 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a scanner device and a laser processing machine used for positioning light such as a laser.

  In laser processing machines such as laser processing machines and laser markers that process holes in printed circuit boards, an electromagnetic force driven galvano scanner (hereinafter referred to as “scanner device”) is used to control the positioning of the mirror for laser reflection, and the laser Is processed at a desired position.

  The scanner device includes a shaft, a bearing, a coil, an angle sensor, a permanent magnet, and the like, and is controlled by a dedicated control system. The coil is integrally formed with the shaft and is supported by a bearing. The permanent magnet is arranged so as to surround the coil and creates a magnetic field around the coil. The angle sensor detects the rotation angle of the shaft. As the angle sensor, a capacitive sensor having a simple structure, high response, and high accuracy is often used. The mirror is fixed to the end of the shaft and swings integrally with the shaft.

  When the angle target value signal is input to the controller of the scanner device, the controller supplies a current having a magnitude corresponding to the signal to the coil. When a current is supplied to the coil, the shaft rotates as a result of a torque proportional to the current value acting on the coil due to the electromagnetic interaction between the current flowing in the coil and the permanent magnet. The rotation angle of the shaft is detected by an angle sensor, and this angle signal is fed back to the controller to position the shaft, that is, the mirror with high accuracy (see, for example, Patent Document 1). In the case of such a scanner device, a rotation operation of 360 degrees is not normally required, and it is only necessary to perform a swing operation within a rotation angle of ± 10 degrees.

  By the way, in a laser processing machine or a laser marker for a printed circuit board, since processing by laser irradiation is performed after positioning a mirror, the time from the start of movement to settling is required to be around 1 ms.

  If there is an unbalance of the mass of the shaft or coil, or an unbalance of the electromagnetic force that drives the coil, the inertia force or the unbalance of the electromagnetic force excites the bending vibration of the shaft. When this vibration component is divided into the in-plane direction component and the out-of-plane direction component, the in-plane vibration of the mirror does not affect the positioning of the laser, but the out-of-plane vibration of the mirror (hereinafter referred to as “falling vibration”). ") Changes the position of the laser.

  When the mirror tilts and generates vibration, a positioning error occurs in a direction orthogonal to the rotation direction, which is the original positioning direction. As response speed increases or the size of the mirror attached to the scanner device increases, the mechanical load on the scanner device increases compared to the past, and the structure of the scanner device that was previously within the allowable range. There have been cases where vibrations have exceeded acceptable levels.

  In order to prevent the mirror from falling down, a scanner device including a rotation support mechanism that rotatably supports a mirror holder provided at the tip of the mirror is disclosed (for example, see Patent Document 2).

When a bearing is used as the rotation support mechanism, the centering must be precisely performed. Therefore, Patent Document 2 discloses a method for avoiding the centering by supporting the mirror by bringing the rotating pin into contact with the end face of the mirror tip. It is shown. In this way, since the rigidity of the mirror in the tilting direction can be improved, the mirror falling vibration can be reduced.
JP 7-55500 A JP 2002-296533 A

  However, in order to give sufficient rigidity to the support portion of the mirror end surface, it is necessary to apply a preload to the contact point to ensure a frictional force, and the preload may cause the mirror to be deformed. Further, since the rotating pin and the mirror are in direct contact, the mirror may be worn.

  Patent Document 2 discloses a configuration that absorbs misalignment by using a coupling or a spring. However, if the effect of absorbing misalignment is increased, the support rigidity of the mirror tip decreases and vibration is reduced. The effect is reduced. In addition, if a coupling or spring with rigidity that is comparable to the bearing is used to provide sufficient rigidity to the support part at the mirror tip, the effect of absorbing misalignment is reduced, and the mass of attachments attached to the mirror tip There is also concern about the increase.

  As described above, the rotation support mechanism is limited to the mirror tip, and the rotation center of the mirror tip must be supported with high rigidity, so only an accessory is required at the mirror tip. There is no need for precise settings such as alignment. In addition, there are concerns about mirror deformation and wear. In Patent Document 2, consideration is given to prevention of mirror falling vibration, but further improvements have been desired in these respects.

  An object of the present invention is to provide a scanner device and a laser processing machine that can solve the above-described problems in the prior art, can quickly attenuate the tilting vibration of a mirror, and can improve the positioning accuracy of light.

  6A and 6B are diagrams showing a vibration model of a one-degree-of-freedom system and its impulse response. FIG. 6A shows a reference model, FIG. 6B shows a case where the spring constant in FIG. % Vibration damping member is provided. Further, (d) is a diagram showing the response of each model to the same impulse load normalized by the amplitude of the reference model.

  When the values of mass m and spring constant k are determined so that the natural frequency of the reference model is 1 kHz, the impulse response is curve (a) in (d). When the spring constant is K (where K = 4k), the impulse response is the curve (b) in (d). When a vibration damping member having a damping ratio of 20% is provided, the impulse response is the curve (c) in (d).

  As is apparent from FIG. 4D, when the stiffness of the spring is quadrupled, the vibration amplitude is halved, but quadrupling the spring stiffness is equivalent to doubling the natural frequency. . That is, in order to halve the vibration amplitude, it is necessary to double the natural frequency, which is a difficult problem even if the mirror tip is supported by a bearing. In order to further reduce the vibration amplitude, not only the natural frequency must be further improved, but also the residual vibration cannot be ignored.

  On the other hand, when a vibration damping material is provided, some vibration remains immediately after the impulse is applied, but the vibration is attenuated to the extent that it cannot be confirmed after three cycles.

  Immediately after the impulse load, the movement starts, and in an actual scanner, it is sufficient to sufficiently attenuate until settling. Therefore, it is more important to reduce the residual vibration than the vibration immediately after the impulse. Therefore, it is effective to be able to suppress the residual vibration by providing a vibration damping member, and even if it is excited by an external excitation source, the increase in vibration due to resonance is suppressed because the attenuation is large. Can do. Further, when a viscoelastic body having a high damping effect is used, the damping ratio can be further increased. As described above, the configuration using the vibration damping material is advantageous because vibration can be easily and effectively reduced.

Based on the above results, in order to achieve the above object, the first means of the present invention is to arrange a mirror at the end of the rotating shaft and rotate the mirror around the axis of the rotating shaft, In a scanner device that positions light incident on the mirror at a desired position, a vibration damping member and a holding member that holds the vibration damping member are provided,
The holding member is disposed so that the vibration attenuating member is in contact with the mirror, and the vibration generated in the mirror is attenuated.

  The second means of the present invention is characterized in that the laser is positioned by the scanner device according to claim 1 or 2 as a laser processing machine.

  As described above, according to the present invention, the mirror's falling vibration is attenuated by the vibration damping mechanism, so that the light positioning accuracy can be improved. Further, since precise setting such as centering is unnecessary, assembly is easy, and the mirror's falling vibration can be effectively reduced.

  Hereinafter, the present invention will be described based on illustrated embodiments.

  FIG. 1 is a configuration diagram of a scanner device according to the present invention, in which (a) is a perspective view, and (b) and (c) are views taken in the direction of arrow Z in (a).

  Inside the housing 1 of the scanner device S, a shaft 2 bearing, a coil, an angle sensor, a permanent magnet, and the like are housed. The mirror 4 is fixed to one end of the shaft 2 via the mounter 3. The support member 5 is fixed to the housing 1. The support member 5 may be a member having high rigidity or a member having low rigidity such as a leaf spring.

  A vibration damping member 6 is connected to the support member 5. The vibration damping member 6 has a rectangular parallelepiped shape, and one end thereof is in contact with the vicinity of the rotation center line on the back surface of the mirror 4 as shown in FIG. The surface of the vibration damping member 6 that is in contact with the mirror 4 is formed in an arc shape so that the rotation of the mirror 4 is not hindered.

  Next, the operation of this embodiment will be described.

  When the mirror 4 is positioned, bending vibration is generated on the shaft 2 due to mass imbalance of the shaft 2 or the coil, or imbalance of electromagnetic force, and the mirror 4 is tilted and vibration is generated. Even if there is no unbalance as described above, the mirror 4 falls down due to the transmission of external vibration, and the frequency of the external excitation source is close to the resonance frequency of the bending vibration of the shaft 2. In some cases, particularly large falling vibrations are excited.

  When the mirror 4 falls and vibrations are excited, the vibrations are transmitted to the vibration damping member 6 and energy is consumed. As a result, the falling vibration is attenuated.

  Here, the position where the vibration damping member 6 is brought into contact with the mirror 4 will be described.

  The reason why the vibration transmission member 6 is brought into contact with the mirror 4 is to make a transmission path for the vibration generated in the mirror 4 and not to support the mirror rigidly. Therefore, although the contact point can be arranged at an arbitrary position, it is preferable to provide the contact point on or near the axis of rotation so as not to hinder the rotation of the mirror 4.

  Further, when the vibration transmitting member 6 is brought into contact with a portion where the displacement of the mirror 4 is large, the energy consumption rate can be increased. In the case of FIG. 1, the tip side of the mirror 4 (the free end opposite to the shaft 2) is an antinode of vibration, and the closer to the tip, the larger the amplitude. Is.

  That is, the position where the vibration damping mechanism 6 is brought into contact is preferably a position near the tip of the mirror 4 in the vicinity of the axis of rotation.

  In addition, when making the vibration damping member 6 and the mirror 4 contact, it is not necessary to preload. When contact is made without preloading, when falling vibration occurs, the mirror 4 moves away from the vibration damping member 6 every half cycle, but vibration energy is consumed while it is in contact with the vibration damping member 6, so that the falling vibration occurs. Can be reduced.

  The mirror 4 has a thickness, and is normally arranged so that the center of gravity coincides with the axis of rotation. The contact point between the mirror 4 and the vibration damping member 6 is away from the axis of rotation. For this reason, slip occurs between the mirror 4 and the vibration attenuating member 6 when the mirror 4 rotates, but the swing angle of the mirror 4 is about ± 10 °, and there is almost no problem. However, when slippage between the mirror 4 and the vibration damping member 6 is a problem, as shown in FIG. 5C, the mirror 4 is provided with a recess 10 so that the center of rotation coincides with the contact point. You can do it.

When the contact point is provided outside the vicinity of the rotation center line, the displacement of the contact point increases as the contact point moves away from the rotation center line, so that the spring action of the vibration damping member 6 cannot be ignored. Therefore, when this spring action does not affect the servo characteristics when positioning the mirror 4, the vibration damping member 6 may be provided on the side surface (a surface parallel to the axis of rotation) of the mirror 4. When the vibration damping mechanism is provided on the side surface of the mirror in this way, the influence of the reaction force of the vibration damping member 6 can be reduced by bringing the vibration damping member 6 into contact with the mirror 4 using a member having low rigidity such as a leaf spring. it can.
As the vibration damping member 6, a viscoelastic body or the like can be used. Alternatively, a damper filled with silicone oil may be used.

  In this embodiment, since the front end side of the mirror 4 is not constrained, the reflecting surface is not deformed even when the shaft 2 or the mirror 4 is extended in the axial direction due to heat, for example, so that the laser positioning accuracy is lowered. Never do.

  FIG. 2 is a perspective view of a scanner device showing a first modification of the present invention, in which (a) is a perspective view, and (b) and (c) are views taken in the direction of arrow Z in (a). In addition, the same thing as FIG. 1 or the thing of the same function attaches the same code | symbol, and abbreviate | omits description.

  A vibration transmission member 7 is disposed on the vibration damping member 6. The vibration transmitting member 7 is made of an elastic body such as a steel member or rubber whose contact surface is finished in an arc shape or a spherical shape.

  The vibration transmitting member 7 is in contact with the mirror 4 via an abrasion-resistant member 8 fixed to the back surface of the mirror 4.

Next, the operation of this modification will be described.
When a tilting vibration occurs in the mirror 4, this vibration is transmitted to the vibration damping member 6 via the vibration transmitting member 7, energy is consumed, and the falling vibration of the mirror 4 can be reduced.

  Thus, when the vibration transmission member 7 is provided, the region where the mirror 4 and the vibration damping member 6 are in contact with each other can be reduced, so that the resistance when the mirror 4 rotates can be reduced.

  The wear-resistant member 8 may be attached when a slight amount of wear of the mirror 4 becomes a problem, and need not be provided when such a problem does not occur.

  FIG. 3 is a perspective view of a scanner device showing a second modification of the present invention, and the same or the same functions as those in FIGS.

  A vibration transmission member 7 b is fastened to the support member 5 by screws 9. The vibration transmitting member 7b is made of a soft elastic body such as a leaf spring. A vibration damping member 6b is affixed to the vibration transmitting member 7b. A vibration damping member 6a is fixed to the tip of the vibration transmitting member 7b. A vibration transmitting member 7a is fixed to the vibration damping member 6a. The vibration transmission member 7 a is in contact with the mirror 4 through the wear-resistant member 8.

  Next, the operation of this modification will be described.

  When the tilting vibration is generated in the mirror 4, the vibration is transmitted to the vibration vibration damping member 6a via the vibration transmission member 7a, and vibration energy is consumed. Furthermore, the vibration that cannot be removed is transmitted to the vibration transmitting member 7b. Since the vibration attenuating member 6b is attached to the vibration transmitting member 7b, the vibration energy transmitted to the vibration transmitting member 7b is consumed by the vibration attenuating member 6b and the vibration is reduced. As a result, the falling vibration of the mirror 4 can be reduced.

  In this modification, the vibration transmission member 7b is made of a soft elastic body such as a leaf spring. Therefore, if the vibration transmission member 7a is biased (pre-loaded) toward the mirror 4, the vibration transmission member 7a Can be brought into contact with the mirror 4. As a result, when the falling vibration occurs in the mirror 4, the vibration transmitting member 7a does not move away from the mirror 4, so that the vibration reduction effect can be increased. Further, since the vibration damping member 6b is attached to the vibration transmitting member 7b, the vibration reduction effect can be further increased.

   FIG. 4 is a perspective view of a scanner device showing a third modification of the present invention. Components having the same or the same functions as those in FIGS.

  A cantilever-shaped vibration transmission member 7 b is fastened to the support member 5 with screws 9. The vibration transmitting member 7b is made of a soft elastic body such as a leaf spring or a viscoelastic body. A vibration damping member 6 is attached to the vibration transmitting member 7b. A vibration transmission member 7a is fixed to the tip of the vibration transmission member 7b. The vibration transmitting member 7 a is in contact with the end face of the mirror 4 in the vicinity of the axis of rotation via the wear resistant member 8.

  Next, the operation of this modification will be described.

  When the mirror 4 falls and vibrations occur, the vibration transmitting members 7 a and 7 b vibrate together with the mirror 4. Since the vibration damping member 6 is attached to the vibration transmitting member 7b, the vibration transmitted to the vibration transmitting member 7b is consumed by the vibration damping member 6 and the vibration is reduced. As a result, the falling vibration of the mirror 4 can be reduced.

  In this modification, the vibration transmission member 7b is made of a soft elastic body such as a leaf spring, and the vibration transmission member 7a is preloaded and brought into contact with the end face of the mirror 4 in the vicinity of the rotation axis. The resistance to can be reduced. Further, since the contact point between the vibration transmitting member 7a and the wear resistant member 8 is not separated by the falling vibration, the effect of reducing the falling vibration can be further increased.

  FIG. 5 is a perspective view of a scanner device showing a fourth modified example of the present invention. Components having the same or the same functions as those in FIGS. This modification is a case where the rotation range of the mirror 4 is small and the spring action of the vibration damping member can be ignored.

  The support member 5 holds a vibration damping member 6a and two vibration damping members 6b. The vibration damping member 6 a is in contact with the end surface of the mirror 4 on the front end side. The vibration damping members 6b are in contact with the side surfaces of the mirror 4, respectively.

  Next, the operation of this modification will be described.

  When the mirror 4 falls and generates vibration, the vibration is transmitted to the vibration damping members 6a and 6b, and the vibration energy is consumed by the vibration damping members 6a and 6b. As a result, the falling vibration of the mirror 4 can be reduced.

  In this modification, since the vibration damping members 6a and 6b are disposed around the mirror 4, the vibration reduction effect can be improved. Further, there is an effect of suppressing the peak of torsional vibration of the shaft 2.

  If a member having low rigidity such as a leaf spring is fixed to the support member 5 and the vibration damping members 6a and 6b are brought into contact with the mirror 4 through this member, the spring action of the vibration damping members 6a and 6b is achieved. The impact can be reduced.

  FIG. 7 is a configuration diagram showing an example of a laser processing machine that processes holes in a printed circuit board. In FIG. 7, the laser beam 30 output from the laser oscillator 210 is shaped through an optical beam processing system including a collimator 212, an aperture 214, and the like via a mirror 213a and a mirror 213b. The light enters the mirror 23a of the first galvano scanner 23 through 213d, mirror 213e, and mirror 213f. The mirror 23a reflects the laser beam 30 incident from the right direction in the figure in the neutral position in the front direction in the figure. By changing the angle of the mirror 23a, the path of the laser beam 30 can be changed in the horizontal direction (Y-axis direction) in the drawing at a spot position on the horizontal plane in the drawing, that is, on the XY table.

  The laser beam 30 reflected by the mirror 23 a then enters the mirror 23 b of the second galvano scanner 23. The mirror 23b reflects the laser beam 30 incident from the back in the figure in the neutral position when it is in the neutral position. Then, by changing the angle of the mirror 23b, the path of the laser beam 30 can be changed in the front-rear direction (X-axis direction) in the figure at the spot position on the XY table in the vertical plane in the front-rear direction in the figure. The laser beam 30 reflected by the mirror 23 b is applied to the printed circuit board 252 placed on the XY table 253 via the Fθ lens 241. The XY table 253 is driven in the Y-axis direction by the Y-axis drive mechanism 254, and the Y-axis drive mechanism 254 is driven in the X-axis direction by the X-axis drive mechanism 255, and can be positioned on the bed 256 in the XY direction.

  When the scanner device S according to the present embodiment is used as the galvano scanners 23a and 23b of such a laser beam machine, the mirror damping vibration is reduced by the vibration damping members 6, 6a and 6b, so that the light positioning accuracy is improved. Can be made.

It is a block diagram of the scanner apparatus which concerns on the Example of this invention. It is a perspective view which shows the 1st modification of the scanner apparatus which concerns on the Example of this invention. It is a perspective view which shows the 2nd modification of the scanner apparatus which concerns on the Example of this invention. It is a perspective view which shows the 3rd modification of the scanner apparatus which concerns on the Example of this invention. It is a perspective view which shows the 4th modification of the scanner apparatus which concerns on the Example which concerns on the Example of this invention. It is a figure which shows the vibration model of a 1 degree-of-freedom system, and its impulse response. It is a figure which shows an example of the laser processing machine using the scanner apparatus based on the Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Housing 2 axis | shaft 4 Mirror 5 Holding member 6 Vibration damping member S Scanner apparatus

Claims (6)

In the scanner device for positioning the light incident on the mirror at a desired position by arranging a mirror at the end of the swing shaft and swinging the mirror about the axis of the swing shaft,
A scanner device comprising: a vibration attenuating member that abuts against the back surface of the mirror and attenuates vibration generated in the mirror. The scanner device according to claim 1, wherein the vibration attenuating member abuts along a swing axis of the mirror. The scanner device according to claim 1, wherein the vibration attenuating member is fitted and abutted on a position of a swing axis of the mirror. The scanner device according to claim 1, further comprising a holding member that holds the vibration damping member. The scanner device according to claim 4, wherein the holding member is supported by a support member that supports the rotating shaft. A laser processing machine comprising the scanner device according to any one of claims 1 to 5, wherein a laser is positioned by the scanner device.

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