JP4499538B2 - Light beam control apparatus and stereolithography apparatus - Google Patents

Description

  The present invention relates to a light beam control apparatus and an optical modeling apparatus, and more particularly to a technique for controlling a beam diameter and a focal position at high speed in a light beam control apparatus and an optical modeling apparatus that use a laser beam as a light beam.

Conventionally, a photo-curing modeling method using a photo-curing resin is known as a method for modeling a three-dimensional object (for example, see Patent Document 1).
In the photo-curing modeling method, for example, the liquid surface of the photo-curing resin is irradiated while being scanned with a laser beam so as to correspond to the contour section of the shape to be modeled. Then, the liquid surface of the photocurable resin irradiated with the laser beam is photocured, and a cross-section cured layer is formed. In the photo-curing modeling method, the cross-section hardened layer is formed in this way, and at the same time, the newly formed cross-section hardened layer is continuously and three-dimensionally laminated and integrated with the previously formed cross-section hardened layer. Perform modeling. By doing in this way, the cross-section hardening layer was laminated and integrated, and the three-dimensional object which has the shape of modeling object as a whole was modeled.
JP 56-144478 A

By the way, when irradiating a photocurable resin with a laser beam, it is necessary to control the beam diameter and the focal position at the same time, but in the conventional photocuring modeling apparatus, a focal position control device for controlling the focal position is configured, Since the entire focal position control device is driven in the direction of the optical axis of the laser beam, there is a problem that the beam diameter cannot be changed at high speed.
Accordingly, an object of the present invention is to provide a light beam control device having a simple device configuration and capable of changing the beam diameter and focus position of a laser beam at high speed, and an optical modeling device using the light beam control device. There is.

In order to solve the above problems, the present invention is arranged between a laser beam emitting device and a scanner unit that scans the laser beam, and a lens for adjusting a focal position and a beam diameter is provided on the optical axis of the laser beam. In the light beam control device that moves along and changes the focal position and the beam diameter of the laser beam incident from the emission device , the lens is carried, and the light of the laser beam is based on an external drive control signal. A voice coil motor having a bobbin that moves linearly in the axial direction, a guide member that supports the bobbin and guides the bobbin linear movement, and detects the lens position, and detects the position for generating the drive control signal. comprising an encoder for outputting a signal, wherein the voice coil motor, during scanning of the laser beam by the scanner unit, based on the drive control signal And linear motion of the bobbin had to move to the reference position corresponding to the beam diameter to be changed the lens to change the beam diameter of the laser beam on the irradiation surface, wherein following the scanning of the laser beam characterized by moving the lens relative to the said reference position to adjust the focus position.

According to the above configuration, the voice coil unit of the voice coil motor carries the lens directly or indirectly, and moves directly in the optical axis direction of the light beam based on the drive control signal from the outside.
At this time, the guide member supports the voice coil unit and guides the linear motion of the voice coil unit.
In parallel with this, the encoder detects the lens position and outputs a position detection signal.

  The encoder may include a scale that moves linearly in conjunction with the linear movement of the voice coil unit, and an encoder head that reads the scale and outputs the position detection signal.

  Furthermore, the position of the lens corresponding to the beam diameter may be set as a reference position, and the position of the lens may be moved from the reference position by a predetermined distance according to the focal position.

An optical modeling apparatus includes a laser beam emitting device, the light beam control device according to any one of claims 1 to 3, and an objective lens that condenses the laser beam that has passed through the light beam control device. A voice coil of the light beam control device based on a scanner unit for scanning the irradiation surface with a laser beam , modeling data corresponding to a three-dimensional shape to be modeled, and a lens position detection signal of the light beam control device And a modeling controller that outputs a motor drive control signal.

According to the above configuration, the laser beam emitting device emits the laser beam to the light beam control device.
Accordingly, the modeling controller outputs a drive control signal to the light beam control device based on the modeling data corresponding to the three-dimensional shape to be modeled.
On the other hand, the voice coil unit that constitutes the light beam control device carries the lens directly or indirectly, and moves directly in the optical axis direction of the light beam based on the drive control signal from the modeling controller. While supporting a voice coil part, the linear motion of the said voice coil part is guided.

In parallel with this, the encoder detects the lens position and outputs a position detection signal to the modeling controller.
As a result, the modeling controller outputs a new drive control signal based on the modeling data corresponding to the three-dimensional shape to be modeled and the position detection signal.
Further, the objective lens condenses the laser beam that has passed through the light beam control device, and the scanner unit scans the laser beam to perform photo-curing modeling.

  According to the present invention, the beam diameter and focal position of a laser beam can be changed at high speed with a simple apparatus configuration.

Next, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of an optical modeling apparatus according to an embodiment.
The photocuring modeling apparatus 10 has passed through a laser beam emitting apparatus 11 that emits a laser beam L, a light beam control apparatus 12 that controls a focal position and a beam diameter of the emitted laser beam L, and a light beam control apparatus 12. An objective lens 13 that condenses the laser beam L, a scanner unit 14 for scanning the laser beam L, a resin storage tank 15 that has an elevator device (not shown) and stores a photo-curing resin, and the photo-curing modeling apparatus 10 as a whole. A modeling controller 16 for controlling the optical system, an optical system controller 17 for controlling the optical system in the laser beam emitting device 11, the light beam control device 12, the scanner unit 14 and the like under the control of the modeling controller 16, and a resin storage tank 15. A table elevating control unit 18 that performs control for elevating by a table (not shown), and a photocuring tree in the resin storage tank 15 It includes a knife controller for controlling a knife (not shown) for leveling the surface of the liquid level control unit 20 which performs the liquid level control of the photocurable resin in the resin reservoir 15, the.

  The scanner unit 14 includes two galvano scanners 14A and 14B, and two mirrors 14C and 14D attached to the galvano scanners 14A and 14B.

  FIG. 2 is a plan view of the light beam control apparatus when the case is removed. FIG. 3 is a front view of the light beam control apparatus when the case is removed. FIG. 4 is a rear view of the light beam control apparatus when the case is removed. FIG. 5 is a side view of the light beam control apparatus when the case is removed. FIG. 6 is a cross-sectional view of the voice coil motor unit of the light beam control apparatus. FIG. 7 is an exploded perspective view of the light beam control apparatus. 8 is a cross-sectional view taken along the line AA in FIG.

  The light beam control device 12 is roughly classified into a voice coil motor unit 21 and a guide unit 23 for guiding the cylindrical bobbin 22 constituting the voice coil motor unit 21 along the optical axis direction of the laser beam L. The encoder unit 24 for detecting the position of the bobbin 22, the voice coil motor unit 21, the guide unit 23, and the base unit 25 that supports the encoder unit 24, the drive control signal is input from the outside, and the encoder unit is externally A lead wire portion 26 that outputs 24 detection signals and a temperature sensor 27 for measuring the temperature of the bobbin 22 are provided.

  The voice coil motor unit 21 includes a bobbin 22, coils 31 </ b> A and 31 </ b> B (see FIGS. 6 and 7) wound around both ends of the bobbin 22, and a focal position and beam diameter adjustment accommodated in the bobbin 22. Lens 32 (see FIG. 6) and magnet yoke portions 33A and 33B having substantially double tube shapes in which at least a part of the coils 31A and 31B are respectively housed.

  As shown in FIG. 6, the magnet yoke portion 33 </ b> A includes a cylindrical permanent magnet 33 </ b> A <b> 1, a cylindrical yoke portion 33 </ b> A <b> 2, and a guide cylinder 34 </ b> A that is inserted into the bobbin 22 and guides the bobbin 22. Similarly, the magnet yoke portion 33B includes a cylindrical permanent magnet 33B1, a cylindrical yoke portion 33B2, and a guide tube 34B that is inserted into the bobbin 22 and guides the bobbin 22.

  In this case, the laser beam L enters the bobbin 22 from the opening of one end of one magnet yoke portion 33A through the guide tube 34A, passes through the lens 32, and guide tube 34B of the other magnet yoke portion 33B. The light is emitted from the opening.

  The guide portion 23 is fixed to the support block 41 having a substantially U-shaped support portion for supporting the bobbin 22 so as not to contact the magnet yoke portions 33A and 33B, and one side portion of the support block 41 with screws. The bearing guide block 42 is supported from the lower side of the other side of the support block 41, and in cooperation with the bearing guide block 42, the support block 41 is integrated with the bobbin 22 in the direction of the optical axis of the laser beam. The linear guide block 43 and the guide shaft 44 fixed in the positioning groove 25 </ b> A provided in the base portion 25 are provided.

  The bearing guide block 42 has a pair of bearings 45A and 45B at positions corresponding to the guide shaft 44, and the bearings 45A and 45B roll on the guide shaft 44 so that the bearing guide block 43 can be smoothly moved to the laser beam L. Slide linearly in the direction of the optical axis.

  The encoder unit 24 has an encoder guide 51 fixed to the other side portion of the support block 41 with a screw. The encoder guide 51 has a flat scale (encoder tape) 52 for detecting the amount of movement. Is provided. An encoder head 53 for reading the scale 52 is fixed at a predetermined position of the base portion 25 at a position facing the scale 52. Here, the encoder guide 51 functions as the first terminal plate 54, and the second terminal plate 55 is fixed to the encoder head 53.

  And between the 1st terminal board 54 and the 2nd terminal board 55, it electrically connects with the flexible harness 56 so that the smooth motion of the bobbin 22 may not be obstructed, and also the 2nd terminal board 55 is connected to the bobbin 22 by two or more. A lead wire group 56 composed of lead wires is guided. A drive current is supplied to the coils 31A and 31B via the lead wire group 56, and a detection signal of the temperature sensor 27 is output to the outside.

In these cases, since the bobbin 22 moves at a high speed, there is a possibility that a force acts in the direction in which the bobbin 22, the support block 41, the bearing guide block 42, and the encoder guide 51 are lifted together. In order to prevent this, a suction yoke 61 is provided on the surface of the support block 41 opposite to the bobbin 22, and a magnet 62 and a suction yoke 63 are embedded at a position facing the suction yoke 61 of the base portion 25. . Accordingly, the bobbin 22, the support block 41, the bearing guide block 42, and the encoder guide 51 are integrally sucked to the base portion 25 side, and the bobbin 22 can be driven stably.
The modeling controller 16 controls the modeling data processing unit 16A that processes various modeling data, and the optical system controller 17, the table lifting control unit 18, the knife control unit 19, and the liquid level control unit 20 based on the modeling data. A control unit 16B.

Next, the operation of the embodiment will be described.
FIG. 9 is a processing flowchart of the embodiment.
First, when CAD data (modeling data) in one contour section of a modeling target is input to the modeling controller 16 of the photo-curing modeling apparatus 10 (step S1), a laser beam scanning procedure (scanning direction, scanning shape). , Scanning order, etc.), modeling control data including laser beam diameter setting and laser beam focal position setting corresponding to each scanning procedure is generated (step S2).

Next, the modeling controller 16 starts scanning in accordance with the operation procedure, and the laser beam emitting device 11 so that the energy density of the laser beam at the time of laser beam irradiation is always constant based on the scanning speed and the laser beam diameter. Is controlled to adjust the energy intensity of the emitted laser beam L and to control whether or not the laser beam can be emitted (step S3).
Subsequently, the modeling controller 16 controls the light beam control device 12 and adjusts the focal position stored in the bobbin 22 and the position of the lens 32 for adjusting the beam diameter according to the required light beam diameter (step S4). .

As a result, the modeling controller 16 supplies a drive signal to the first terminal board 54 via the lead wire portion 26. The drive signal supplied to the first terminal board 54 is supplied to the second terminal board 55 via the flexible harness 56, and further, a lead wire group 56 composed of a plurality of lead wires from the second terminal board 55 to the bobbin 22. Has been led. A drive current is supplied to the coils 31A and 31B via the lead wire group 56, and the bobbin 22 and thus the lens 32 are driven.
In parallel with this, the actual position of the lens 32 is read by a scale (encoder tape) 52 provided on the encoder guide 51 by the encoder head 53 and fed back to the molding controller 16 as a position detection signal via the lead wire portion 26. Then, feedback control of the position of the lens 32 is performed, and the lens 32 is moved to a desired position.

FIG. 10 is an explanatory diagram of an example of a control table of a lens for adjusting the focal position and the beam diameter.
As shown in FIG. 10, when adjusting the beam diameter, the lens 32 is driven between 10 mm and 15 mm.
That is, when the beam diameter is 0.1 mmφ, the position where the lens 32 is driven 10.00 mm is set as the reference position, and when the beam diameter is 0.2 mmφ, the position where the lens 32 is driven 10.20 mm is set as the reference position. When the beam diameter is 0.3 mmφ as the reference position, the position where the lens 32 is driven 10.40 mm is set as the reference position, and when the beam diameter is 0.4 mmφ, the lens 32 is driven 10.60 mm. The position is the reference position.

Next, the modeling controller 16 controls the light beam control device 12 to adjust the focus position housed in the bobbin 22 and the position of the lens 32 for adjusting the beam diameter according to the focus position corresponding to the irradiation position (step). S5).
FIG. 11 is an explanatory diagram of the relationship between the mirror and the laser beam irradiation position. In FIG. 11, only the mirror 14D is shown for the sake of simplicity.
As shown in FIG. 10, when the focal position is adjusted in correspondence with the irradiation position, the lens 32 is driven between 0.00 mm and 0.15 mm from the reference position.

Specifically, the irradiation position P1 where the irradiation position is directly below the mirror 14D, the irradiation position P3 which is the farthest irradiation position, and the irradiation position P2 located between the irradiation position P1 and the irradiation position P3 will be described.
Since the irradiation position P1 is closest to the mirror 14D, the lens 32 is set to 0.00 mm from the reference position, that is, the reference position is left as it is.
At the irradiation position P2, the lens 32 is driven by 0.05 mm from the rough reference position.
Further, since the irradiation position P3 is the farthest irradiation position, the lens 32 is set to a position driven by 0.15 mm from the reference position.

More specifically, when irradiating the irradiation position P1 with a laser beam diameter of 0.2 mmφ, the lens 32 is
10.20 + 0.00 = 10.20 (mm)
It will drive to the position. Similarly, when irradiating the irradiation position P2 with a beam diameter of 0.2 mmφ, the lens 32 is
10.20 + 0.05 = 10.25 (mm)
It will drive to the position. In the case of irradiating the irradiation position P3 with a beam diameter of 0.2 mmφ, the lens 32 is
10.20 + 0.15 = 10.35 (mm)
It will drive to the position. That is, when the beam diameter is 0.2 mmφ and the irradiation positions P1 to P3 are continuously scanned, the lens 32 is driven in the range of 10.20 to 10.35 mm.

Subsequently, the modeling controller 16 determines whether or not scanning corresponding to CAD data (modeling data) in all the contour sections of the modeling target is completed (step S6), and all the contour sections of the modeling target object. Until the scan corresponding to the CAD data (modeling data) is completed, the process proceeds to step S1 again and the same process is performed.
As described above, according to the present embodiment, the light beam control device 12 employs a configuration in which the focus position and beam diameter adjusting lens 32 is driven by the voice coil motor unit 21 that can be easily reduced in weight. Therefore, the beam diameter and the focal position can be changed and controlled at high speed and with high accuracy.

In the above description, the lens 32 constituting the light beam control device 12 is arranged in the bobbin 32. However, for example, the bobbin is provided on the bearing guide block 42 or on the outer peripheral upper surface of the bobbin 22. It is also possible to configure it so as to be provided outside of 32.
In the above description, the scanner unit 14 is configured by a galvano scanner. However, other scanners such as a scanner using a polygon mirror and a scanner using a servo motor may be used.

It is a schematic block diagram of the optical modeling apparatus of embodiment. It is a top view of the light beam control apparatus at the time of removing a case. It is a front view of the light beam control apparatus at the time of removing a case. It is a rear view of the light beam control apparatus when a case is removed. It is a side view of the light beam control apparatus when a case is removed. It is sectional drawing of the voice coil motor part of a light beam control apparatus. It is a disassembled perspective view of a light beam control apparatus. FIG. 3 is a cross-sectional view taken along the line AA in FIG. 2. It is a processing flowchart of an embodiment. It is explanatory drawing of an example of the control table of the lens for a focus position and beam diameter adjustment. It is explanatory drawing of the relationship between a mirror and a laser beam irradiation position.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Light-curing modeling apparatus, 11 ... Laser beam emission apparatus, 12 ... Light beam control apparatus, 13 ... Objective lens, 14 ... Scanner part, 15 ... Resin storage tank, 16 ... Modeling controller, 17 ... Optical system controller, 18 ... Table lifting control unit, 19 ... Knife control unit, 20 ... Liquid level control unit, 21 ... Voice coil motor unit, 22 ... Bobbin, 23 ... Guide unit (guide member), 24 ... Encoder unit, 25 ... Base unit, L ... Laser beam.

Claims (4)

And emitting device of the laser beam, the disposed between the scanner unit for scanning the laser beam moves along the lens for a focal position and a beam diameter adjusting the optical axis of the laser beam, incident from the emitting device In the light beam control device for changing the focal position and the beam diameter of the laser beam ,
A voice coil motor that carries the lens and has a bobbin that linearly moves in the optical axis direction of the laser beam based on an external drive control signal ;
A guide member for supporting the bobbin and guiding the linear movement of the bobbin;
An encoder that detects the lens position and outputs a position detection signal for generating the drive control signal;
The voice coil motor, during scanning of the laser beam by the scanner unit, and the linear motion of the bobbin on the basis of the driving control signal, to change the lens to change the beam diameter of the laser beam on the irradiated surface It should move to a reference position corresponding to the beam diameter, the beam controller to follow the scanning of the laser beam, characterized in that moving the lens relative to the said reference position in order to adjust the focal position. The light beam control device according to claim 1 .
The encoder is a scale that linearly moves in conjunction with the linear movement of the voice coil unit;
An encoder head that reads the scale and outputs the position detection signal;
A light beam control device comprising: The light beam control device according to claim 1 or 2 ,
A coil is wound around each end of the bobbin , a magnet yoke portion is provided for each coil , the lens is housed in the bobbin, and the lens is linearly moved together with the bobbin between the magnet yoke portions. Light beam control device. A laser beam emitting device;
The light beam control device according to any one of claims 1 to 3,
An objective lens for condensing the laser beam that has passed through the light beam control device;
A scanner unit for scanning the irradiation surface with a laser beam;
Based on modeling data corresponding to a three-dimensional shape to be modeled and a lens position detection signal of the light beam control device, a modeling controller that outputs a drive control signal of a voice coil motor of the light beam control device;
An optical modeling apparatus comprising:

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