KR102563889B1 - Laser surface treatment method and apparatus thereof - Google Patents

Abstract

The present invention relates to a laser surface treatment device, comprising: a laser generating unit; a beam expander for enlarging the size of the laser beam generated by the laser generator; a beam angle adjusting unit for adjusting a focal position of the laser beam output from the beam expanding unit; a beam concentrating unit for concentrating the laser beam incident from the beam angle adjusting unit to a 3D object; a rotation unit that rotates the 3D object; and a control unit controlling the beam angle adjustment unit and the rotation unit so that the surface of the 3D object can be treated by the laser beam.

Description

Laser surface treatment method and device thereof {LASER SURFACE TREATMENT METHOD AND APPARATUS THEREOF}

The present invention relates to a laser surface treatment method and apparatus, and more particularly, to a method and apparatus for surface treatment of a 3D object using a femtosecond laser beam.

An implant is a treatment that uses materials harmless to the human body to restore function as well as beauty to teeth lost due to tooth decay or gum disease, or parts without bones and gums due to accidents or tumors. That is, after planting a fixture made of a material that does not have a rejection reaction to the human body to replace the lost root, it is a technology to restore the function of the tooth by fixing the artificial tooth after planting it in the alveolar bone.

In the case of general prosthetics or dentures, the surrounding teeth and bones are damaged over time, but the implant can prevent damage to the surrounding dental tissue and can be used stably because there is no secondary caries occurrence factor. In addition, implants have the same structure as natural teeth, so there is no pain and foreign body sensation in the gums, and there is an advantage that they can be used semi-permanently if managed well.

Materials used for such implants should be made of biocompatible materials that are very stable with respect to human biological tissues, and should not have side effects on the human body, other chemical or biochemical reactivity, or rejection by the human body. In addition, it is very important to select an appropriate material because mechanical strength must be very high so that deformation or destruction does not occur even under repeated loads and momentary pressures. Therefore, although various metals and alloys have been attempted to be developed as suitable materials for implants, currently titanium metal or titanium alloys are mainly used. This is because titanium metal or titanium alloy is easy to process and has high biocompatibility, high mechanical strength, and bioinertness to human living tissue.

By the way, titanium metal or titanium alloy itself takes a long time for osseointegration when transplanted into the human body and secures stability compared to other metals due to the formation of an oxide film, but recently there is a need for more improved human body stability. . Accordingly, technologies capable of enhancing osseointegration in a short time by surface treatment of implant materials using nanosecond, picosecond, or femtosecond lasers are being developed and applied.

Conventional laser surface treatment techniques can obtain excellent surface treatment quality by surface treatment of an implant material through ultra-fine region processing by concentrating a laser of a predetermined wavelength band at high density. However, these surface treatment technologies have a problem in that a very long surface treatment time is required due to a slow treatment speed when treating a large area surface.

The present invention aims to solve the foregoing and other problems. Another object is to provide a method and apparatus for surface treatment of a 3D object by irradiating a femtosecond laser beam so as to have a uniform surface treatment area within a focal depth region corresponding to a traveling direction of the laser beam.

Another object is to provide a laser surface treatment method and apparatus for surface treatment of a 3D object at high speed using a 2D scan mirror unit and a stepping rotation unit.

Another object is to provide a laser surface treatment method and apparatus for surface treatment of a 3D object at high speed using a single-axis scan mirror unit and a continuous rotation unit.

According to one aspect of the present invention to achieve the above or other object, the laser generator; a beam expander for enlarging the size of the laser beam generated by the laser generator; a beam angle adjusting unit for adjusting a focal position of the laser beam output from the beam expanding unit; a beam concentrating unit for concentrating the laser beam incident from the beam angle adjusting unit to a 3D object; a rotation unit that rotates the 3D object; and a controller for controlling the beam angle adjuster and the rotation unit so that the surface of the 3D object can be treated by the laser beam.

More preferably, the beam angle adjusting unit is a two-dimensional scanning mirror unit that performs a two-dimensional scanning operation using an X-axis scan mirror and a Y-axis scan mirror. In addition, the rotation unit may be a stepping rotation unit that rotates the 3D object by a predetermined angle for each surface treatment step. In addition, the control unit monitors the surface treatment of one area of the 3D object, and upon completion of the surface treatment of the one area, controls the stepping rotation unit to rotate the 3D object by a predetermined angle, and then rotates the 3D object by a predetermined angle. It is characterized by controlling the surface treatment of the region.

More preferably, the beam angle adjustment unit is a single-axis scan mirror unit that performs a one-dimensional scanning operation using an X-axis scan mirror or a Y-axis scan mirror. In addition, the rotation unit is characterized in that it is a continuous rotation unit that continuously rotates the 3D object. Also, the control unit controls the continuous rotation unit to rotate the 3D object at a predetermined speed, and at the same time controls the laser generator and the single-axis scan mirror unit to perform surface treatment on the 3D object.

More preferably, the laser surface treatment apparatus is characterized in that it further comprises a base rotation stage disposed below the continuous rotation unit to rotate the continuous rotation unit by a predetermined angle. Also, the 3D object is characterized in that it is an implant fixture.

)를 3차원 대상체의 표면처리 임계 세기(

)의 4배로 설정하는 조건임을 특징으로 한다.More preferably, the laser surface treatment apparatus is characterized in that the surface treatment area of the 3D object is located within a depth of focus region (DOF) corresponding to the traveling direction of the laser beam. In addition, the laser surface treatment apparatus is characterized in that it is configured to satisfy the condition of having a uniform surface treatment area within a depth of focus region (DOF) corresponding to the traveling direction of the laser beam. Here, the condition is the peak intensity at the focus of the laser beam (

) to the surface treatment critical intensity of the 3D object (

) It is characterized in that the condition is set to 4 times of.

The effects of the laser surface treatment method and the device according to embodiments of the present invention will be described as follows.

According to at least one of the embodiments of the present invention, there is an advantage in that a 3D object can be subjected to laser surface treatment at a very high speed using the 2D scan mirror unit and the stepping rotation unit.

According to at least one of the embodiments of the present invention, there is an advantage in that a 3D object can be subjected to laser surface treatment at a very high speed using the single-axis scan mirror unit and the continuous rotation unit.

However, the effects that can be achieved by the laser surface treatment method and the device according to the embodiments of the present invention are not limited to those mentioned above, and other effects not mentioned are the technical fields to which the present invention belongs from the following description. will be clearly understood by those skilled in the art.

1 is a view showing the configuration of a laser surface treatment apparatus according to an embodiment of the present invention;
2 is a view referenced to explain a process of laser scanning an upper surface of a 3D object in a horizontal direction using a 2D (XY) scan mirror unit;
3 is a view referenced to explain a process of laser scanning an upper surface of a 3D object in an oblique direction using a 2D (XY) scan mirror unit;
4 is a view referenced to explain a process of rotating a 3D object step by step through a stepping rotation unit and then treating the surface of the object with a laser beam;
5A and 5B are diagrams showing the configuration of a laser surface treatment apparatus according to another embodiment of the present invention;
6 is a view referenced to explain a process of surface treatment of an upper surface of a 3D object in an oblique direction using a single-axis (X) scan mirror unit;
7 is a view referenced to explain a process of surface treatment of an upper surface of a 3D object in a horizontal direction using a single-axis (X) scan mirror unit;
8 is a view comparing an implant fixture surface-treated with a general processing method and an implant fixture surface-treated with a femtosecond laser beam;
9 and 10 are views referenced to explain a method of implementing a laser surface treatment apparatus to have a uniform surface treatment area within a depth of focus region corresponding to a traveling direction of a laser beam;
11 is a view showing the configuration of a rotation unit according to an embodiment of the present invention;
12 is a view showing the configuration of a rotation unit according to another embodiment of the present invention;
13 is a view showing the configuration of a dual rotation unit according to an embodiment of the present invention;
14 and 15 are diagrams illustrating a laser surface treatment apparatus having a plurality of rotating parts.

Hereinafter, the embodiments disclosed in this specification will be described in detail with reference to the accompanying drawings, but the same or similar elements are given the same reference numerals regardless of reference numerals, and redundant description thereof will be omitted. The suffixes "module" and "unit" for components used in the following description are given or used together in consideration of ease of writing the specification, and do not have meanings or roles that are distinct from each other by themselves. In addition, in describing the embodiments disclosed in this specification, if it is determined that a detailed description of a related known technology may obscure the gist of the embodiment disclosed in this specification, the detailed description thereof will be omitted. In addition, the accompanying drawings are only for easy understanding of the embodiments disclosed in this specification, the technical idea disclosed in this specification is not limited by the accompanying drawings, and all changes included in the spirit and technical scope of the present invention , it should be understood to include equivalents or substitutes.

The present invention proposes a method and apparatus for surface treatment of a 3D object by irradiating a femtosecond laser beam to have a uniform surface treatment area within a focal depth region corresponding to a traveling direction of the laser beam. In addition, the present invention proposes a laser surface treatment method and apparatus for surface treatment of a 3D object at high speed using a 2D scan mirror unit and a stepping rotation unit. In addition, the present invention proposes a laser surface treatment method and apparatus for surface treatment of a 3D object at high speed using a single-axis scan mirror unit and a continuous rotation unit.

Hereinafter, in the present specification, an 'implant fixture' is exemplified as a 3D object to be subjected to laser surface treatment, but is not necessarily limited thereto, and surface treatment using nanosecond/picosecond/femtosecond laser beams is exemplified. Include all possible objects. In addition, in this specification, 'beam angle adjuster' is used as a general term for the two-dimensional scan mirror unit and the single-axis scan mirror unit, and 'rotation unit' is used as a general term for the stepping rotation unit and the continuous rotation unit.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the drawings.

1 is a diagram showing the configuration of a laser surface treatment apparatus according to an embodiment of the present invention.

Referring to FIG. 1 , a laser surface treatment apparatus 100 according to an embodiment of the present invention includes a laser generator 110, a beam expander 120, a two-dimensional scan mirror unit 130, and a beam focusing unit 140. , It may include a stepping rotation unit 150 and a control unit 160. The components shown in FIG. 1 are not essential to implement the laser surface treatment device, so the laser surface treatment device described herein may have more or fewer components than those listed above.

The laser generator 110 may generate a laser beam for surface treatment of the 3D object 50 . To this end, the laser generator 110 may use a pulsed laser source. The laser beam generated by the laser generator 110 in units of pulses passes through the beam expanding unit 120, the 2D scan mirror unit 130, and the beam concentrating unit 140 sequentially and is irradiated to the 3D object 50. It can be.

The laser generator 110 may generate any one of nanosecond, picosecond, and femtosecond laser beams, and more preferably, femtosecond laser beams. Here, the femtosecond laser beam is an ultrashort laser beam having a pulse duration time of 1 to 1000 femtoseconds. Accordingly, the laser generator 110 according to a preferred embodiment of the present invention may generate a pulsed laser beam having a pulse duration within a femtosecond range. Here, the pulse repetition rate may be in the range of several to hundreds of kHz or in the range of MHz. As the wavelength of the laser beam, all laser wavelengths located within the range from the infrared region to the ultraviolet region may be used. For example, the wavelength of the laser beam may include an infrared wavelength, a visible ray wavelength, and an ultraviolet wavelength.

The beam expander 120 may adjust the size of the laser beam generated by the laser generator 110 in units of pulses. More specifically, the beam expander 120 may expand the size of the laser beam. In addition, the beam expander 120 may generate a laser beam as a collimated beam with less dispersion or concentration. Accordingly, the size of the laser beam generated by the laser generator 110 may be enlarged through the beam expander 120 and converted into a collimated beam.

The beam expander 120 may change the diameter of the laser beam generated by the laser generator 110 and output the changed laser beam in the direction of the 2D scan mirror 130 . At this time, the beam expander 120 may manually or automatically adjust the size of the laser beam.

The two-dimensional scan mirror unit (or XY scan mirror unit 130) is a beam angle adjusting unit composed of two axes and can adjust the focal position of the laser beam output from the beam expansion unit 120. That is, the 2D scan mirror unit 130 may adjust the focal position of the laser beam irradiated to the 3D object 50, that is, the focal position in the X axis and the Y axis, according to a control signal from the controller 160. .

The 2D scan mirror unit 130 includes an X-axis scan mirror (not shown) and a Y-axis scan mirror (not shown) to perform a 2D scanning operation. Here, the X-axis scan mirror and the Y-axis scan mirror are composed of a pair of scan mirrors having a galvanometer method, and the pair of scan mirrors are each in one direction of axes crossing the X-Y plane. The laser beam can be deflected.

The 2D scan mirror unit 130 may reflect the laser beam in a direction for laser surface treatment through the X-axis scan mirror and the Y-axis scan mirror to irradiate the laser beam to a desired location of the 3D object 50 . Also, the 2D scan mirror unit 130 may finely control the laser beam in the X-axis and Y-axis directions along the upper surface of the 3D object 50 through the X-axis scan mirror and the Y-axis scan mirror.

For example, as an example, as shown in FIG. 2 , the 2D scan mirror unit 130 moves the upper surface of the implant fixture 50 corresponding to the 3D object in the horizontal direction according to the control signal of the controller 160. A laser beam may be irradiated along a predetermined first scanning path 10 (that is, in the longitudinal direction of the implant fixture). Here, the upper surface of the implant fixture 50 may be formed in a curved shape. Also, the predetermined first scanning path 10 may be determined based on 2D focus position data provided from the controller 160 to the 2D scan mirror 130 .

Meanwhile, as another embodiment, as shown in FIG. 3 , the 2D scan mirror unit 130, according to a control signal from the controller 160, moves the upper surface of the implant fixture 50 corresponding to the 3D object in an oblique direction. A laser beam may be irradiated according to a predetermined second scanning path 20 . Similarly, the predetermined second scanning path 20 may be determined based on 2D focus position data provided from the controller 160 to the 2D scan mirror 130 .

The beam focusing unit 140 is disposed below the 2D scanning mirror unit 130 and can focus the laser beam passing through the 2D scanning mirror unit 130 onto the 3D object 50 . Also, the beam focusing unit 140 may change a laser beam incident from the 2D scan mirror unit 130 at a predetermined angle into a direction perpendicular to the longitudinal direction of the 3D object 50 .

The beam concentrator 140 may include a telecentric F-theta lens or an F-theta lens. Thus, the beam concentrating unit 140 may perform micro- or nano-sized laser surface treatment on the upper surface of the 3D object 50 .

The stepping rotator 150 may fix the 3D object 50 so that the 3D object 50 is positioned in the traveling direction of the laser beam, that is, under the beam focusing unit 140 . Also, the stepping rotation unit 150 may rotate the 3D object 50 by a predetermined angle (eg, 120 degrees) for each surface treatment step according to a control signal from the controller 160 .

The controller 160 may control overall operations of the laser surface treatment apparatus 100 . In addition, the controller 160 may control at least some of the aforementioned components 110 to 150 in order to drive an application program stored in a memory (not shown). Furthermore, the controller 160 may combine and operate at least two or more of the components included in the laser surface treatment apparatus 100 to drive the application program.

More specifically, the controller 160 may control the laser generator 110 to adjust the wavelength, pulse duration, pulse repetition rate, and the like of the laser beam generated by the laser generator 110 in units of pulses.

In addition, the controller 160 transmits a control signal including two-dimensional focus position data (ie, X-axis and Y-axis focus position data) of a laser beam for surface treatment of the 3D object 50 having a curved upper surface. generated, and the control signal may be provided to the two-dimensional scan mirror unit 130 . The 2D scan mirror unit 130 may emit a laser beam based on 2D focus position data included in the control signal received from the controller 160 .

In addition, the controller 160 monitors the laser surface treatment process on one area of the 3D object 50 in real time, and controls the stepping rotation unit 150 when the surface treatment on the one area is completed to control the 3D object 50. After rotating 50 by a predetermined angle step by step, it is possible to control the laser surface treatment for other areas of the target object 50 .

For example, as shown in FIG. 4 , the control unit 160 controls the laser generating unit 110 and the two-dimensional scan mirror unit 130 to provide a laser surface for the first upper surface 51 of the implant fixture 50. processing can be performed. Upon completion of the surface treatment of the first upper surface 51, the controller 160 controls the stepping rotation unit 150 to move the implant fixture 50 clockwise or counterclockwise by a predetermined angle (eg, 120 degrees). After rotation, laser surface treatment may be performed on the second upper surface 52 of the implant fixture 50 by controlling the laser generating unit 110 and the two-dimensional scanning mirror unit 130 . Upon completion of the surface treatment of the second upper surface 52, the control unit 160 controls the stepping rotation unit 150 to rotate the implant fixture 50 in the same direction by a predetermined angle (eg, 120 degrees), and then , It is possible to perform laser surface treatment on the third upper surface 53 of the implant fixture 50 by controlling the laser generator 110 and the two-dimensional scan mirror unit 130 . Through this step-by-step rotation process, the implant fixture 50 can be surface treated at a very high speed.

Meanwhile, although not shown in the drawing, as another example, it may be configured to undergo a surface treatment process of fewer or more steps than the three-step surface treatment process described above, depending on the shape of the 3D object. In addition, it may be configured to rotate by different angles for each step instead of the same angle for each step.

The control unit 160 may control the operations of the laser generator 110, the two-dimensional scan mirror unit 130, and the stepping rotation unit 150 to be synchronized with each other. That is, the control unit 160 may control the 2D scan mirror unit 130 based on the generation cycle of the laser beam emitted from the laser generator 110 . In addition, the controller 160 may control the stepping rotation unit 150 in synchronization with the time for surface treatment of the 3D object 50 through the laser generator 110 and the 2D scan mirror unit 130 .

As described above, the laser surface treatment apparatus according to an embodiment of the present invention can perform laser surface treatment on a 3D object at a very high speed using the 2D scan mirror unit and the stepping rotation unit.

5A and 5B are diagrams showing the configuration of a laser surface treatment apparatus according to another embodiment of the present invention.

5A and 5B, a laser surface treatment apparatus 200 according to another embodiment of the present invention includes a laser generator 210, a beam expander 220, a short-axis scan mirror unit 230, and a beam focusing unit. 240, a continuous rotation unit 250 and a control unit 260 may be included. The laser surface treatment apparatus 200 may further include a base rotation stage 270 according to an embodiment.

The laser generating unit 210, the beam expanding unit 220, and the beam focusing unit 240 of the laser surface treatment apparatus 200 are the laser generating unit 110, the beam expanding unit 120, and the beam focusing unit 240 of FIG. 1 described above. Since it is the same as or similar to the focusing unit 140, a detailed description thereof will be omitted.

The laser generator 210 may generate a laser beam for surface treatment of the 3D object 50 . At this time, the laser generator 210 may generate any one of nanosecond, picosecond, and femtosecond laser beams, and more preferably, femtosecond laser beams. .

The beam expansion unit 220 may enlarge the size of the laser beam generated by the laser generator 210 in units of pulses and generate a collimated beam at the same time. The beam expander 220 may output the generated collimated beam toward the single-axis scan mirror 230 .

The short-axis scan mirror unit 230 is a beam angle adjusting unit composed of one axis, and can adjust the focal position of the laser beam output from the beam expanding unit 220 . That is, the short-axis scan mirror unit 230 may adjust the focal position of the laser beam irradiated onto the 3D object 50, that is, the focal position along the X-axis or Y-axis, according to a control signal from the controller 260. .

The single-axis scan mirror unit 230 includes an X-axis scan mirror (not shown) or a Y-axis scan mirror (not shown) to perform a one-dimensional scanning operation. Hereinafter, in this embodiment, the single-axis scan mirror unit 230 will be described as having an X-axis scan mirror as an example. The X-axis scan mirror is composed of a scan mirror having a galvanometer method, and the scan mirror can deflect a laser beam in an X-axis direction.

The single-axis scan mirror unit 230 may reflect the laser beam in a direction for laser surface treatment through the X-axis scan mirror and irradiate the laser beam to a desired location of the 3D object 50 . In addition, the single-axis scan mirror unit 230 may finely control the laser beam in the X-axis direction along the upper surface of the 3D object 50 through the X-axis scan mirror.

For example, as shown in FIGS. 6 and 7 , the short axis scan mirror unit 230 moves the upper surface of the implant fixture 50 corresponding to the 3D object in the horizontal direction (in response to a control signal from the controller 260). That is, the laser beam may be irradiated along the scanning path 30 reciprocating in the X-axis direction. Here, the upper surface of the implant fixture 50 may be formed in a curved shape. Also, the scanning path 30 may be determined based on one-dimensional focus position data provided from the control unit 260 to the short-axis scan mirror unit 230 .

The beam concentrating unit 240 is disposed below the single-axis scanning mirror unit 230 to focus the laser beam passing through the single-axis scanning mirror unit 230 onto the 3D object 50 . In addition, the beam focusing unit 240 may change a laser beam incident at a predetermined angle from the short axis scan mirror unit 230 in a direction perpendicular to the longitudinal direction of the 3D object 50 .

The continuous rotation unit 250 may fix the 3D object 50 so that the 3D object 50 is positioned in the traveling direction of the laser beam, that is, under the beam focusing unit 240 . Also, the continuous rotation unit 250 may rotate the 3D object 50 by 360 degrees at a predetermined speed according to a control signal from the controller 260 .

The base rotation stage 270 is disposed under the continuous rotation unit 250 to rotate the continuous rotation unit 250 and the 3D object 50 by a predetermined angle. This is to process the surface of the 3D object 50 in a horizontal direction using the single-axis scan mirror unit 230 and the continuous rotation unit 250 .

The controller 260 may control overall operations of the laser surface treatment apparatus 200 . In addition, the controller 260 may control at least some of the above-described components 210 to 250 and 270 in order to drive an application program stored in a memory (not shown). Furthermore, the controller 260 may combine and operate at least two or more of the components included in the laser surface treatment apparatus 200 to drive the application program.

More specifically, the controller 260 may control the laser generator 210 to adjust the wavelength, pulse duration, and pulse repetition rate of the laser beam generated by the laser generator 210 in units of pulses.

In addition, the controller 260 generates a control signal including one-dimensional focus position data (ie, X-axis focus position data) of a laser beam for surface treatment of the three-dimensional object 50 having a curved upper surface, The control signal may be provided to the single-axis scan mirror unit 230 . The short-axis scan mirror unit 230 may emit a laser beam based on one-dimensional focus position data included in the control signal received from the controller 260 .

In addition, the controller 260 controls the continuous rotation unit 250 to rotate the 3D object 50 at a predetermined speed, and at the same time controls the laser generator 210 and the short-axis scan mirror unit 230 to rotate the 3D object 50. Laser surface treatment for (50) can be performed. For example, as shown in FIG. 6, the control unit 260 controls the continuous rotation unit 250 to continuously rotate the implant fixture 50 clockwise or counterclockwise at a predetermined speed, and at the same time, the laser generating unit 210 ) and the single-axis scan mirror unit 230 may be controlled to perform a horizontal reciprocating laser scanning operation with respect to the implant fixture 50 . Accordingly, the surface of the implant fixture 50 may be subjected to laser surface treatment in an oblique direction.

In addition, the control unit 260 controls the continuous rotation unit 250 and the base rotation stage 270 to rotate the 3D object 50 inclined at a predetermined angle at a predetermined speed, and at the same time, the laser generator 210 and the axis Laser surface treatment may be performed on the 3D object 50 by controlling the scan mirror unit 230 . For example, as shown in FIG. 7, the controller 260 controls the base rotation stage 270 to tilt the implant fixture 50 at a predetermined angle, and controls the continuous rotation unit 250 to tilt the implant fixture 50 at a predetermined angle. The photo implant fixture 50 is continuously rotated clockwise or counterclockwise at a predetermined speed, and at the same time, the laser generator 210 and the single-axis scan mirror unit 230 are controlled to reciprocate horizontally with respect to the implant fixture 50. of laser scanning operation. Accordingly, laser surface treatment in a horizontal direction may be performed on the surface of the implant fixture 50 . Through this continuous rotation process, the surface of the implant fixture 50 can be treated at a very high speed.

The control unit 260 may control the operations of the laser generator 210, the short-axis scan mirror unit 230, and the continuous rotation unit 250 to be synchronized with each other. That is, the control unit 160 may control the short-axis scan mirror unit 230 and the continuous rotation unit 250 based on the generation cycle of the laser beam emitted from the laser generator 210 . In addition, the controller 160 may control the continuous rotation unit 250 by synchronizing the surface treatment time of the 3D object 50 through the laser generator 210 and the short-axis scan mirror unit 230 .

As described above, the laser surface treatment apparatus according to another embodiment of the present invention can perform laser surface treatment on a 3D object at a very high speed using the single-axis scan mirror unit and the continuous rotation unit.

8 is a view comparing an implant fixture surface-treated with a general processing method and an implant fixture surface-treated with a femtosecond laser beam. As shown in FIG. 8 , when the surface of the implant fixture is treated with a femtosecond laser beam, it can be confirmed that a predetermined pattern 810 is formed on the surface of the implant fixture. Such a certain pattern 810, when the implant fixture is inserted into the human body, can rapidly promote bone recovery, that is, bone fusion occurring around the fixture.

9 and 10 are views referenced to explain a method of implementing a laser surface treatment apparatus to have a uniform surface treatment region within a depth of focus region corresponding to a traveling direction of a laser beam.

More specifically, FIG. 9 is a diagram referenced to explain a method of implementing a laser surface treatment apparatus to have a uniform surface treatment region within a depth of focus region corresponding to a traveling direction of a laser beam. As shown in FIG. 9 , when a laser beam is radiated from the beam concentrating units 140 and 240 in the direction of the 3D object 50 , different laser intensity distributions are provided according to positions in the traveling direction of the laser beam. For example, the first graph 1010 is a laser intensity distribution at the focal point (f ₀ ), and the second graph 1020 is a laser intensity distribution at a point away from the focal point (f ₀ ) by the Rayleigh length (Z _R ). , The third graph 1030 is a laser intensity distribution at a point separated by 1/2 of the Rayleigh length (Z _R ) from the focal point (f ₀ ). And, the fourth graph 1040 shows the critical intensity F _LIAT at which the laser surface treatment is possible according to the material and surface condition of the 3D object 50 . Here, when the peak intensity (fluence) value (1.0) of the first graph 1010 is set to 4 times the threshold intensity (fluence) value (0.25) of the fourth graph 1040, in the traveling direction of the laser beam A uniform surface treatment area within the corresponding depth of focus area (DOF) ( ), it can be confirmed that the surface treatment of the 3D object 50 is possible. Hereinafter, the predetermined laser intensity condition and the diameter of the surface treatment area per laser pulse under the condition ( ) and the depth of focus area (DOF) to have the same surface treatment area is mathematically defined.

First, a condition for having a uniform surface treatment area within a depth of focus area (DOF) corresponding to a traveling direction of a laser beam (or laser pulse) may be defined as in Equation 1 below.

는 레이저 빔의 초점에서의 피크 세기(fluence)이고,

는 3차원 대상체의 표면처리 임계 세기임. 상기 플루언스(fluence)는 레이저 세기의 단위로서

임.here,

is the peak intensity (fluence) at the focus of the laser beam,

is the critical intensity of surface treatment of a 3D object. The fluence is a unit of laser intensity

lim.

The laser beam radius at the focal point ( ), the intensity distribution of the laser beam (F(r, z)), and the peak intensity of the laser beam (F _peak (0, z)) are general laser optical formulas, which are defined as Equations 2 to 4 below. can

는 레이저 빔의 중심 파장이고,

은 레이저 빔의 품질임. Here, NA is the numerical aperture of the optical system,

is the central wavelength of the laser beam,

is the quality of the laser beam.

는 레이저 빔의 피크 세기이고, R은 레이저 펄스 반복률이고, P는 레이저 빔의 평균 출력임.here,

is the peak intensity of the laser beam, R is the laser pulse repetition rate, and P is the average power of the laser beam.

where R is the laser pulse repetition rate and P is the average power of the laser beam.

By substituting Equations 2 and 4 above into Equation 1 above, it can be rearranged as Equation 5 below.

By substituting Equation 5 into Equation 3 above, the radius r of the surface treatment area per laser pulse can be arranged as Equation 6 below.

Therefore, the diameter of the surface treatment area per laser pulse ( ) may be defined as in Equation 7 below, and a depth of focus area (DOF) having a constant surface treatment area may be defined as in Equation 8 below.

As such, by using the above conditions, it is possible to implement a laser surface treatment device that irradiates a laser beam to have a uniform surface treatment area within a depth of focus region corresponding to the traveling direction of the laser beam. Through this laser irradiation method, the entire surface of the 3D object can be uniformly treated by adjusting only the focal position of the laser beam without the need to adjust the focal length of the laser beam according to the shape of the 3D object.

Meanwhile, in this embodiment, it is exemplified that the surface treatment area generated by a unit laser pulse is formed in a circular shape, but is not necessarily limited thereto. Accordingly, it will be apparent to those skilled in the art that the laser surface treatment area can be formed in different shapes according to the pattern of the laser beam.

FIG. 10 is a diagram referenced to explain an appropriate position of a depth of focus region corresponding to a traveling direction of a laser beam for surface treatment of a 3D object. As shown in FIG. 10, when a laser beam is radiated from the beam concentrators 140 and 240 in the direction of the 3D object 50, the depth of focus region (Depth Of Focus, DOF) corresponding to the traveling direction of the laser beam ) corresponds to twice the rayleigh length (Z _R ). Here, the Rayleigh length (Z _R ) is the radius of the laser beam from the focal point (f ₀ ) of the laser beam at the focal point ( )see Indicates the distance to the doubling point.

In this way, the depth of focus area (DOF) generated corresponding to the traveling direction of the laser beam must be located on a portion to be subjected to surface treatment, that is, on the upper surface of the 3D object 50 having a curved shape. This is because uniform surface treatment is possible without the need to adjust the focal length (i.e., the distance between the beam focusing part and the focal point) only when the part to be subjected to surface treatment is located within the DOF of the laser beam. . Therefore, by adjusting the distance between the beam concentrators 140 and 240 and the 3D object 50 or adjusting the optical characteristics of the beam concentrators 140 and 240, the upper part of the 3D object 50 having a curved shape The laser surface treatment apparatuses 100 and 200 may be implemented so that the surface is positioned within a depth of focus region (DOF) corresponding to the traveling direction of the laser beam.

11 is a diagram for explaining the configuration of a rotation unit according to an embodiment of the present invention.

Referring to FIG. 11 , a rotation unit 1100 according to an embodiment of the present invention includes a rotation driving unit 1110, a rotation shaft 1120, a magnet member 1130, a coupling member 1140, and a rotation jig 1150. can do.

The rotation driver 1110 may drive the rotation shaft 1120 according to control signals from the controllers 160 and 260 . The rotating shaft 1120 may transmit rotational force to the magnet member 1130 and the rotating jig 1150 .

The magnet member 1130 is disposed at one end of the rotating shaft 1120 and can attract and fix the rotating jig 1150 with its magnetic force. The coupling member 1140 may be disposed to surround the rotating shaft 1120 and the magnet member 1130, and integrally couple the rotating shaft 1120 and the magnet member 1130.

The rotating jig 1150 may be detachably/attached to one side of the magnet member 1130 . At this time, the rotating jig 1150 may be formed of a material capable of being detachable/attachable to a magnetic object.

The rotating jig 1150 may be formed into a structure that firmly fixes the implant fixture 50 . For example, as shown in the drawing, the rotating jig 1150 may be formed to have a 'c'-shaped structure, and may be formed to be inserted into the inner space of the implant fixture 50.

As such, the rotation unit 1100 according to an embodiment of the present invention may rotate the implant fixture 50 step by step or continuously using the magnet member 1130 and the rotation jig 1150.

12 is a view showing the configuration of a rotation unit according to another embodiment of the present invention.

Referring to FIG. 12 , a rotation unit 1200 according to another embodiment of the present invention includes a rotation driving unit 1210, a main rotation shaft 1220, a plurality of sub rotation shafts 1230, a plurality of magnet members (not shown), a plurality of A coupling member (not shown) and a plurality of rotating jigs 1240 may be included. Here, the main rotation shaft 1220 and the plurality of sub rotation shafts 1230 may be connected through a helical gear (not shown).

The rotation driver 1210 may drive the main rotation shaft 1220 according to control signals from the controllers 160 and 260 . The main rotation shaft 1220 may transmit rotational force to the plurality of sub rotation shafts 1230 through helical gears.

Each of the sub rotational shafts 1230 may transmit rotational force received from the main rotational shaft 1220 to each rotational jig 1240 . Each magnet member may be disposed at one end of the sub rotation shaft 1230 to fix the rotation jig 1240 . Each coupling member may be disposed to surround the sub-rotational shaft 1230 and the magnet member, so that the sub-rotational shaft 1230 and the magnet member may be integrally coupled.

Each rotating jig 1240 may be formed to be detachable/attached to one side of the magnet member. In addition, each rotation jig 1240 may serve to firmly fix the implant fixture 50.

In this way, the rotation unit 1200 according to another embodiment of the present invention may rotate the plurality of implant fixtures 50 step by step or continuously using a plurality of rotation jigs 1240 .

13 is a diagram showing the configuration of a dual rotation unit according to an embodiment of the present invention.

Referring to FIG. 13 , a dual rotation unit 1300 according to an embodiment of the present invention may include a first rotation unit 1200a and a second rotation unit 1200b. Here, the first and second rotating parts 1200a and 1200b may have the same structure as the rotating part 1200 of FIG. 12 described above. Therefore, a detailed description of the configuration of the first and second rotating units 1200a and 1200b will be omitted.

The first rotation unit 1200a and the second rotation unit 1200b may be disposed to face each other. At this time, the plurality of implant fixtures 50 coupled to the plurality of rotation jigs of the first rotation unit 1200a are between the plurality of implant fixtures 50 each coupled to the plurality of rotation jigs of the second rotation unit 1200b. It can be configured to be placed in.

In this way, the dual rotation unit 1300 according to an embodiment of the present invention can rotate a larger number of implant fixtures 50 step by step or continuously within a limited space by arranging the rotation units of the same structure to face each other. .

14 and 15 are diagrams illustrating a laser surface treatment apparatus having a plurality of rotating parts.

As one embodiment, as shown in FIG. 14, the laser surface treatment apparatus 1400 according to an embodiment of the present invention includes a plurality of rotating parts 1410_1 to 1410_N independently controllable through one controller 160 or 260. can be provided. Accordingly, in the case of surface treatment of the implant fixture 50 mounted on the second rotation unit after surface treatment of the implant fixture 50 mounted on the first rotation unit in the laser surface treatment apparatus 1400, the first rotation unit is previously subjected to surface treatment. By rotating by a determined angle (eg, 120 degrees), the next surface treatment step may be prepared. Through this configuration of the rotating part, it is possible to shorten the entire process time for laser surface treatment.

Meanwhile, as another embodiment, as shown in FIG. 15, the laser surface treatment apparatus 1500 according to another embodiment of the present invention includes a plurality of rotating parts 1510_1 to 1510_1 to independently controllable through one controller 160 or 260. 1510_2N) may be provided. At this time, the plurality of rotating parts 1510_1 to 1510_2N may be classified into two groups, and the first group of rotating parts 1510_1 to 1510_N and the second group of rotating parts 1510_N+1 to 1510_2N face each other. can be placed.

The plurality of implant fixtures 50 mounted on the rotating parts 1510_1 to 1510_N of the first group are interposed between the plurality of implant fixtures 50 mounted on the rotating parts 1510_N+1 to 1510_2N of the second group, respectively. It can be configured to be placed. Through this configuration of the rotating part, it is possible to shorten the entire process time for laser surface treatment and to simultaneously process the surface of a larger number of implant fixtures 50 within a limited space.

Meanwhile, although specific embodiments of the present invention have been described above, various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention is not limited to the described embodiments, and should be defined by not only the claims to be described later, but also those equivalent to these claims.

100: laser surface treatment device 110: laser generator
120: beam expansion unit 130: two-dimensional scan mirror unit
140: beam focusing unit 150: stepping rotation unit
160: control unit

Claims (12)

a laser generator generating a femtosecond laser beam;
a beam expander for enlarging the size of the laser beam generated by the laser generator;
a beam angle adjusting unit for adjusting a focal position of the laser beam output from the beam expanding unit;
a beam concentrating unit for concentrating the laser beam incident from the beam angle adjusting unit to a 3D object;
a rotation unit that rotates the 3D object; and
A control unit for controlling the beam angle adjustment unit and the rotation unit so that the surface of the 3D object can be treated by the laser beam,
The beam angle adjustment unit is a two-dimensional scan mirror unit that performs a two-dimensional scanning operation by controlling an X-axis scan mirror and a Y-axis scan mirror based on the two-dimensional focus position data received from the controller,
The laser surface treatment apparatus, characterized in that the rotation unit is a stepping rotation unit that rotates the three-dimensional object by a predetermined angle for each surface treatment step. According to claim 1,
The controller controls the two-dimensional scan mirror unit based on the generation cycle of the laser beam emitted from the laser generator. According to claim 1,
The laser surface treatment apparatus according to claim 1 , wherein the control unit controls the stepping rotation unit in synchronization with a time for surface treatment of the 3D object through the laser generator and the two-dimensional scan mirror unit. According to claim 1,
The control unit monitors the surface treatment of one region of the 3D object, and upon completion of the surface treatment of the one region, controls the stepping rotation unit to rotate the 3D object by a predetermined angle, and then rotates the 3D object by a predetermined angle. A laser surface treatment device characterized in that for controlling the surface treatment for other areas of the. a laser generator generating a femtosecond laser beam;
a beam expander for enlarging the size of the laser beam generated by the laser generator;
a beam angle adjusting unit for adjusting a focal position of the laser beam output from the beam expanding unit;
a beam concentrating unit for concentrating the laser beam incident from the beam angle adjusting unit to a 3D object;
a rotation unit that rotates the 3D object; and
A control unit for controlling the beam angle adjustment unit and the rotation unit so that the surface of the 3D object can be treated by the laser beam,
The beam angle adjusting unit is a single-axis scan mirror unit that performs a one-dimensional scanning operation by controlling an X-axis scan mirror or a Y-axis scan mirror based on the one-dimensional focus position data received from the controller,
The rotation unit is a continuous rotation unit that continuously rotates the 3-dimensional object,
The laser surface treatment apparatus, characterized in that the surface treatment area of the three-dimensional object is configured to be located within a depth of focus (DOF) corresponding to the traveling direction of the laser beam. According to claim 5,
The control unit controls the short-axis scan mirror unit based on the generation cycle of the laser beam emitted from the laser generation unit. According to claim 5,
The controller controls the continuous rotation unit in synchronization with a time for surface treatment of the 3D object through the laser generator and the single-axis scan mirror unit. According to claim 5,
The control unit controls the continuous rotation unit to rotate the 3D object at a predetermined speed and at the same time controls the laser generator and the short-axis scan mirror unit to perform surface treatment on the 3D object. Laser surface treatment device. According to claim 1 or 5,
The laser surface treatment device, characterized in that the three-dimensional object is an implant fixture. According to claim 1,
The laser surface treatment apparatus, characterized in that the surface treatment area of the three-dimensional object is configured to be located within a depth of focus (DOF) corresponding to the traveling direction of the laser beam. According to claim 1 or 5,
The laser surface treatment apparatus, characterized in that configured to satisfy the condition of having a uniform surface treatment area within a depth of focus region (DOF) corresponding to the traveling direction of the laser beam. According to claim 11,
The condition is, the peak intensity at the focus of the laser beam ( ) to the surface treatment critical intensity of the 3D object ( ) Laser surface treatment apparatus, characterized in that the condition set to four times.

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