Focus control device of laser device and focus control system of laser device

Abstract

The present specification relates to a focus control device and system of a laser device, wherein a line-shaped laser beam which is offset from an optical central axis and can pass through an optical component of a laser scanner and reach a processing surface is emitted, the laser beam that is reflected from the processing surface and returns is sensed through an image sensor, a focus deviation value is calculated through comparison with a line image of an initial state, and a motion controller or a Z-axis servo motor controller adjusts focus on the basis of the deviation value.

Description

Focusing device of a laser device and focusing system of a laser device

[0001] The present invention relates to a focus adjustment device and a focus adjustment system for adjusting the focus of a laser device.

[0002] The present invention relates to a technique for adjusting the focus of a laser device.

[0003] In laser-based processes (such as laser welding and notching), laser focus management is critical. However, deviations from the initial focus setting occur due to various causes, including variations in the thickness of the incoming material, clamping jig deviations, and foreign matter jamming. This reduces laser energy density, thereby weakening the intensity of the laser beam delivered to the workpiece. In this case, the welding process results in weak welding defects that fail to meet tensile strength specifications, while the notching process results in uncut defects, leading to material loss and reduced product productivity.

[0004] However, since there is currently no process to accurately measure focus before operation, perfect focus management is difficult because focus is controlled solely through material or process control. Additionally, although separate displacement sensors are installed inside process equipment, there is a problem where measurement accuracy is significantly reduced due to external factors (interference with equipment components, welding fumes, sensor contamination by spatter, etc.). Focus that is not managed before the process causes defects, and since defects can only be detected after they occur, it results in reduced material consumption and productivity.

[0005] The present invention aims to improve upon the limitations of the prior art as described above.

[0006] Accordingly, the present specification aims to provide an embodiment capable of accurately measuring the height of a processed surface.

[0007] In addition, we intend to provide an embodiment that can accurately adjust the focus of the laser according to the height of the processed surface.

[0008] Furthermore, we intend to provide an embodiment in which the focus of the laser can be adjusted even during the process.

[0009] The present invention, for solving the problem described above, utilizes a coaxial laser light source to measure the focus deviation before revolution and corrects the focus in real time using the measured output value as a solution means.

[0010] More specifically, the technical feature is to irradiate a laser in the form of a line deviated from the optical center axis that passes through the optical components of a laser scanner and reaches the processing surface, sense the laser reflected back from the processing surface through an image sensor, calculate a focus deviation value by comparing it with an initial line image, and adjust the focus by a motion controller or a Z-axis servo motor controller based on the deviation value.

[0011] Such technical features may be applied to all process devices utilizing lasers, such as welding devices, cutting devices, notching devices, or scanning devices, and may also be implemented in all laser devices utilizing lasers, laser device focus alignment devices, laser device focus alignment systems, laser device focus alignment methods, laser device focus correction devices, laser device focus correction systems, and laser device focus correction methods. The present specification aims to provide embodiments of a laser device focus adjustment device and a laser device focus adjustment system that utilize the above technical features as a means of solution.

[0012] A focus adjustment device for a laser device according to an embodiment comprises: a processing unit that irradiates a processing beam to be irradiated onto a processing surface in a first direction; a mirror unit that reflects the processing beam in a second direction where the processing surface is located; a lens unit that focuses the processing beam reflected from the mirror unit to a point on the processing surface; and a driving unit that adjusts the position of the lens unit. The device further comprises: a measuring unit that irradiates the measurement beam in the first direction so that the measurement beam is irradiated onto a specific area of ​​the mirror unit where the central axis of the lens unit does not intersect and is reflected in the second direction; a sensing unit that senses a reflected image in which the measurement beam is reflected in the order of the mirror unit, the processing surface, and the mirror unit; and a control unit that measures the height displacement of the processing surface based on the reflected image and controls the driving unit so that the height of the lens unit is adjusted based on the height displacement.

[0013] In an embodiment of the focus adjustment device described above, the processing unit may include an irradiation unit that generates the processing beam and irradiates it in the second direction, and a reflection unit that is positioned on the same vertical axis as the irradiation unit and on the same horizontal axis as the mirror unit to reflect the processing beam in the first direction.

[0014] In an embodiment of the focus adjustment device above, the measuring unit is positioned on the same horizontal axis as the mirror unit and can irradiate the measuring beam in the first direction.

[0015] In an embodiment of the above-described focus adjustment device, the measuring unit can irradiate the measuring beam in the form of a line of a specific length.

[0016] In the embodiment of the focus adjustment device above, the specific length may be 4 to 8 [mm].

[0017] In an embodiment of the above-described focus adjustment device, the measuring unit may irradiate the measuring beam at a specific wavelength different from the processing beam.

[0018] In the embodiment of the focus adjustment device above, the specific wavelength range may be 530 to 620, 680 to 740 [nm].

[0019] In an embodiment of the focus adjustment device above, the control unit can compare the reflected image with a reference image and measure the height displacement according to the comparison result.

[0020] In an embodiment of the focus adjustment device described above, the control unit can calculate a deviation value of the focus corresponding to the height displacement and control the driving unit so that the height of the lens unit is adjusted according to the deviation value.

[0021] In an embodiment of the focus adjustment device described above, the control unit can calculate a position value of the lens part such that the focus aligns with a reference position from the deviation value, and control the driving unit so that the height of the lens part is adjusted to the position value.

[0022] Additionally, the focus adjustment system of the laser device according to the embodiment includes: an irradiation unit that irradiates a processing beam to be irradiated onto a processing surface in a downward direction; a reflection unit positioned perpendicular to the irradiation unit and reflecting the processing beam in a direction orthogonal to the downward direction; a mirror unit positioned horizontally to the reflection unit and reflecting the irradiated beam in the downward direction; a lens unit positioned perpendicular to the mirror unit and the processing surface and focusing the irradiated beam to a point on the processing surface; a driving unit that adjusts the position of the lens unit; a measuring unit positioned horizontally to the reflection unit and the mirror unit and irradiating a measuring beam in the direction orthogonally to a specific area of ​​the mirror unit where the central axis of the lens unit does not intersect; a sensing unit that senses a reflected image in which the measuring beam is reflected in the order of the mirror unit, the processing surface, and the mirror unit; and a control unit that measures the height displacement of the processing surface based on the reflected image and controls the driving unit based on the height displacement to adjust the height of the lens unit.

[0023] In an embodiment of the focus adjustment system above, the measurement beam may be a line-shaped beam of a specific length.

[0024] In an embodiment of the above-described focus adjustment system, the measurement beam may be a beam of a specific wavelength range different from the processing beam.

[0025] In an embodiment of the focus adjustment system above, the measuring beam is irradiated from the measuring unit to the mirror unit, is reflected once in the downward direction from the mirror unit, is reflected twice in the upward direction opposite to the downward direction from the processing surface, is reflected a third time in the other direction opposite to the one-sided direction from the mirror unit, and is incident on the sensing unit.

[0026] In an embodiment of the focus adjustment system above, the control unit compares the reflected image with a reference image, measures the height displacement according to the comparison result, calculates a deviation value of the focus corresponding to the height displacement, and controls the driving unit according to the deviation value to adjust the height of the lens unit.

[0027] In an embodiment of the focus adjustment system above, the control unit can calculate a position value of the lens unit at which the focus aligns with a reference position from the deviation value, and control the driving unit to adjust the height of the lens unit to the position value.

[0028] The embodiments of the laser device focus adjustment device and the laser device focus adjustment system described above are not limited to those described above and may include embodiments described in the specific description below or inferred / derived from the specific description.

[0029] According to the embodiment of the laser device focus adjustment device and laser device focus adjustment system described above, by using an optical path coaxial with the laser device to irradiate the laser, the laser irradiation and measurement can be performed without the influence of contamination within the facility and interference from structures.

[0030] Accordingly, this enables convenient measurement without structural constraints, as well as the effect of ensuring accurate laser irradiation and measurement.

[0031] In addition, by irradiating a line-shaped laser deviating from the optical center axis and measuring the height of the processed surface based on the image of the reflected laser, there is an effect of accurately measuring the height deviation when the height of the processed surface changes.

[0032] Accordingly, this improves the limitation where the height deviation of the processed surface cannot be measured when a laser is irradiated on the central axis, and has the effect of enabling accurate focus alignment based on the precisely measured height deviation.

[0033] Furthermore, as the focus is aligned, it has the effect of enabling the focus alignment of the laser device before the start of the process.

[0034] Accordingly, it is possible to prevent process defects caused by poor focus in advance, which has the effect of reducing material consumption resulting from poor focus and increasing productivity.

[0035] In addition, as the focus is aligned, it has the effect of enabling focus correction during the process.

[0036] As a result, uniform focus management becomes possible, which has the effect of stabilizing the process and improving quality.

[0037] The effects according to the embodiments of the laser device focus adjustment device and laser device focus adjustment system as described above are not limited to those described above, and may include effects described in the specific description below or inferred / derived from the specific description.

[0038] FIG. 1 is a configuration diagram of a focus adjustment device and a focus adjustment system according to an embodiment.

[0039] FIG. 2 is an illustrative diagram showing a specific example of the focus adjustment device illustrated in FIG. 1.

[0040] FIG. 3 is an exemplary diagram showing the irradiation area of ​​the measurement beam of a different focus adjustment device in an embodiment.

[0041] FIG. 4 is an exemplary diagram illustrating the measurement of height displacement of a machined surface of a focus adjustment device and focus adjustment system according to an embodiment.

[0042] FIG. 5 is an exemplary diagram illustrating the measurement of height displacement of a machined surface of a focus adjustment device and focus adjustment system according to an embodiment.

[0043] FIG. 6 is an exemplary diagram 1 for explaining the laser irradiation form of a focus adjustment device and a focus adjustment system according to an embodiment.

[0044] FIG. 7 is an exemplary diagram illustrating the laser irradiation form of a focus adjustment device and a focus adjustment system according to an embodiment.

[0045] FIG. 8 is an exemplary diagram illustrating the concepts of illumination and reflection of a focus adjustment device and a focus adjustment system according to an embodiment.

[0046] FIG. 9 is an exemplary diagram illustrating line-shaped measurement beam irradiation of a focus adjustment device and a focus adjustment system according to an embodiment.

[0047] FIG. 10 is an exemplary diagram illustrating line-shaped measurement beam irradiation of a focus adjustment device and a focus adjustment system according to an embodiment.

[0048] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings; however, in describing the embodiments disclosed in this specification, if it is determined that a detailed description of related known technology may obscure the essence of the embodiments disclosed in this specification, such detailed description will be omitted.

[0049] In addition, the attached drawings are intended only to facilitate understanding of the embodiments disclosed in this specification, and the technical concept disclosed in this specification is not limited by the attached drawings; it should be understood that all modifications, equivalents, and substitutions included within the concept and technical scope of the present invention are included.

[0050] The focus adjustment device of the laser device according to the embodiment means a device for adjusting the focus of the laser device.

[0051] The above laser device refers to a device that irradiates a laser beam onto the processing surface of a workpiece to be measured.

[0052] The above laser device may be, for example, a laser welding device.

[0053] In this case, the laser beam may be a processing beam for welding the processing surface.

[0054] The laser device can receive a reflected beam that is reflected from the processing surface after irradiating the processing beam onto the processing surface.

[0055] Meanwhile, if the laser device is further equipped with a computational means for measuring one or more states of the processing surface, it may measure one or more states based on the reception result of the reflected beam.

[0056] Here, the above one or more states may include, for example, one or more of the thickness (height), shape, and surface condition of the workpiece.

[0057] The above-mentioned focus adjustment device is a device that adjusts the focus of the processing beam irradiated onto the processing surface in the above-mentioned laser device, and may be included in the laser device or may be formed as a separate device from the laser device and mounted / coupled to the laser device.

[0058] The above focus adjustment device may be a device that adjusts the focus of the laser device by irradiating a measurement beam, which is a laser beam different from the processing beam irradiated by the laser device, onto the processing surface and measuring one or more states based on the reflection result of the measurement beam.

[0059] The configuration of the laser device and the focus adjustment device may be as shown in FIG. 1.

[0060] The laser device (10) is positioned above the processing surface (T) and irradiates the processing beam from above the processing surface (T) to the processing surface (T).

[0061] The laser device (10) comprises a processing unit (11), a mirror unit (12), a lens unit (13), and a driving unit (14), and irradiates the processing beam onto the processing surface (T).

[0062] The focus adjustment device (20) is positioned on one side of the laser device (10) and adjusts the focus of the laser device (10) on one side of the laser device (10).

[0063] The focus adjustment device (20) includes a measuring unit (21), a sensing unit (22), and a control unit (23) to adjust the focus of the laser device (10).

[0064] The specific configuration of the laser device (10) including the processing unit (11), the mirror unit (12), the lens unit (13), and the driving unit (14), and the focus adjustment device (20) including the measuring unit (21), the sensing unit (22), and the control unit (23) may be as shown in FIG. 2.

[0065] In addition, the laser device (10) and the focus adjustment device (20) may be implemented as an embodiment of the focus adjustment system (1) as shown in FIGS. 1 and FIGS. 2.

[0066] In the laser device (10), the processing unit (11) irradiates the processing beam in a first direction, the mirror unit (12) reflects the processing beam in a second direction where the processing surface (T) is located, the lens unit (13) focuses the processing beam reflected from the mirror unit (12) to a point on the processing surface (T), and the driving unit (14) adjusts the position of the lens unit (13).

[0067] The processing part (11) may be provided on the upper part of the laser device (10).

[0068] The processing unit (11) above may be a device that generates the processing beam and irradiates it in the first direction.

[0069] Here, the first direction may be a direction horizontal to the processing surface (T).

[0070] The processing unit (11) may include an irradiation unit (111) that generates the processing beam and irradiates it in the second direction, and a reflection unit (112) that is positioned on the same vertical axis as the irradiation unit (111) and on the same horizontal axis as the mirror unit (12) to reflect the processing beam in the first direction.

[0071] Here, the second direction may be a direction perpendicular to the processing surface (T).

[0072] That is, the second direction may be a direction perpendicular to the first direction.

[0073] The above investigation unit (111) can be positioned above the above reflection unit (112).

[0074] The above-mentioned irradiation unit (111) may be a laser device that generates the processing beam.

[0075] The above irradiation unit (111) can generate the processing beam and irradiate the processing beam in the second direction in which the reflection unit (112) is positioned.

[0076] That is, the above-mentioned irradiation unit (111) can irradiate the processing beam in a downward direction.

[0077] The above-mentioned reflector (112) may be a reflector that reflects a laser beam.

[0078] The reflection part (112) is positioned on the same vertical axis as the irradiation part (111), so that the processing beam can be irradiated from the irradiation part (111).

[0079] That is, the reflection part (112) is positioned perpendicular to the irradiation part (111) and can reflect the processing beam in one direction perpendicular to the downward direction.

[0080] The reflection part (112) is preferably positioned at a 45-degree angle between the irradiation part (111) and the mirror part (12) so as to reflect the processing beam irradiated from the irradiation part (111) to the mirror part (12).

[0081] Accordingly, when the processing beam is generated in the irradiation unit (111) and irradiated in the second direction, it can be reflected in the first direction through the reflection unit (112) and transmitted to the mirror unit (12).

[0082] The mirror portion (12) can reflect the processing beam reflected from the reflection portion (112) in the second direction where the processing surface (T) is located.

[0083] The mirror portion (12) can be positioned on the upper part of the lens portion (13).

[0084] The mirror part (12) can be positioned on the same vertical axis as the lens part (13).

[0085] The mirror portion (12) can also be positioned on the same horizontal axis as the reflection portion (112).

[0086] The above mirror part (12) may be a reflector that reflects a laser beam.

[0087] The mirror part (12) is positioned on the same horizontal axis as the reflection part (112) and on the same vertical axis as the lens part (13), so that when the processing beam reflected from the reflection part (112) is transmitted, it can be reflected to the lens part (13).

[0088] That is, the mirror part (12) is positioned horizontally with respect to the reflection part (112) so as to reflect the irradiated beam in the downward direction.

[0089] The mirror portion (12) is preferably positioned at a 45-degree angle between the reflection portion (112) and the lens portion (13) so as to reflect the processing beam reflected from the reflection portion (112) to the lens portion (13).

[0090] In the laser device (10), the lens portion (13) can focus the processing beam reflected from the mirror portion (12) to a point on the processing surface (T).

[0091] The lens portion (13) can be positioned below the mirror portion (12).

[0092] The lens portion (13) can also be positioned on the upper part of the processing surface (T).

[0093] The lens portion (13) can be positioned on the same vertical axis as the mirror portion (12) and the processed surface (T).

[0094] That is, the lens portion (13) is positioned perpendicular to the mirror portion (12) and the processing surface (T), so that a beam irradiated from the mirror portion (12) can be focused to a point on the processing surface (T).

[0095] The above driving unit (14) may be a driving device that adjusts the position of the above lens unit (13).

[0096] The above driving unit (14) can adjust the position of the lens unit (13) by moving the lens unit (13) along at least one axis.

[0097] The above driving unit (14) may include, for example, a Z-axis STAGE or a Z-axis motor that moves the position of the lens unit (13) to the Z-axis corresponding to the second direction.

[0098] Accordingly, the lens part (13) can be moved along the Z-axis corresponding to the second direction by the driving part (14), and its height can be adjusted.

[0099] The focus adjustment device (20) controls the driving unit (14) so ​​that the height of the lens unit (13) of the laser device (10) is adjusted, thereby adjusting the focus of the laser device (10).

[0100] In the focus adjustment device (20), the measuring unit (21) irradiates the measuring beam in the first direction so that the measuring beam is irradiated to a specific area of ​​the mirror unit (12) where the central axis of the lens unit (13) does not intersect and is reflected in the second direction, the sensing unit (22) senses the reflected image in which the measuring beam is reflected in the order of the mirror unit (12), the processing surface (T), and the mirror unit (12), and the control unit (23) measures the height displacement of the processing surface (T) based on the reflected image and controls the driving unit (14) so ​​that the height of the lens unit (13) is adjusted based on the height displacement.

[0101] That is, the focus adjustment device (20) may irradiate the measurement beam onto the processing surface (T), measure the height displacement based on the result of the measurement beam irradiation, and adjust the focus of the laser device (10) according to the result of measuring the height displacement.

[0102] Here, the measurement beam irradiated from the focus adjustment device (20) to the processing surface (T) may be a laser beam different from the processing beam.

[0103] The above measurement beam may have a different irradiation area than the above processing beam.

[0104] The above measurement beam can preferably be irradiated into an area including the region where the above processing beam is irradiated.

[0105] For example, as shown in FIG. 3, the measuring beam can be irradiated onto the processing surface (T) with an irradiation area wider than the processing beam.

[0106] That is, the measurement beam can be generated with a wider diameter than the processing beam and irradiated onto the processing surface (T).

[0107] The measuring unit (21) is positioned on the same horizontal axis as the mirror unit (12) so as to irradiate the measuring beam in the first direction.

[0108] The measuring unit (21) is positioned horizontally with respect to the reflecting unit (112) and the mirror unit (12), so that the measuring beam can be directed in the direction of one side to the specific area where the central axis of the lens unit (13) does not intersect.

[0109] That is, the measurement beam can be irradiated at a position off the central axis of the lens part (13) as shown in FIG. 4.

[0110] In this case, the measuring unit (21) can irradiate the measuring beam so that the measuring beam is irradiated at a position corresponding to the specific area of ​​the mirror unit (12) and reflected to the lens unit (13).

[0111] For example, the measurement beam may be directed at a position off-center horizontal axis of the mirror part (12).

[0112] Accordingly, the measurement beam is reflected from the mirror part (12) and can be irradiated onto the specific area.

[0113] In this way, the measurement beam is irradiated at a position off-center from the central axis of the lens part (13), so that the measurement beam is irradiated onto the processing surface (T) at a certain angle of incidence relative to the central axis due to the focusing of the lens part (13), and then is reflected at a reflection angle corresponding to the certain angle of incidence and passes through the lens part (13).

[0114] Subsequently, the reflected beam is incident on the sensing unit (22), and the sensing unit (22) can sense the reflected image of the measurement beam reflected from the processing surface (T) based on the reflected beam.

[0115] In this way, the measurement beam is irradiated onto the specific area of ​​the lens part (13) and irradiated onto the processing surface (T) at a certain angle of incidence, so that when the height of the processing surface (T) changes (T(0) -> T(1)) as shown in FIG. 5, the position where the reflected beam is incident on the sensing part (22) changes, and thus the change in the height of the processing surface (T) can be measured from the difference in the position of incidence.

[0116] That is, the height displacement of the processing surface (T) can be accurately measured through the position of the reflection image, which varies according to the height of the processing surface (T).

[0117] The above measuring unit (21) can irradiate the measuring beam in the form of a line of a specific length as shown in FIG. 6.

[0118] That is, the above-mentioned measuring beam may be a line-shaped beam of a specific length.

[0119] Here, the specific length may be 4 to 8 [mm].

[0120] That is, the above measurement beam can be irradiated as a line beam of 4 to 8 [mm].

[0121] When the measurement beam is irradiated as a point-shaped beam as shown in FIG. 7, the measurement beam may react to even minute curvatures, such as the roughness of the processing surface (T), making it difficult to check the focus deviation.

[0122] Accordingly, as shown in FIG. 6, the measurement beam is irradiated as a line-shaped beam, and the average value of the line is calculated to measure the focus deviation, thereby making it easier to measure the height displacement and focus deviation of the processing surface (T).

[0123] The above measuring unit (21) can irradiate the measuring beam at a specific wavelength different from the processing beam.

[0124] That is, the measurement beam may be a beam of a specific wavelength different from the processing beam.

[0125] In this case, the specific wavelength range may be 530 to 620, 680 to 740 [nm].

[0126] Accordingly, the processing beam may be irradiated with a beam of wavelengths other than 530 to 620 and 680 to 740 [nm], and the measurement beam may be irradiated with a beam of wavelengths of 530 to 620 and 680 to 740 [nm].

[0127] As shown in FIG. 8, the above-mentioned measuring beam is irradiated from the measuring unit (21) to the mirror unit (12) (a), is reflected once in the downward direction (second direction) from the mirror unit (12) (b), is reflected twice in the upward direction opposite to the downward direction from the processing surface (T) (c), is reflected three times in the other direction opposite to the one-sided direction (first direction) from the mirror unit (12) (d), and can be incident on the sensing unit (22).

[0128] Accordingly, the sensing unit (22) can sense a reflected image in which the measurement beam is reflected in the order of the mirror unit (12), the processing surface (T), and the mirror unit (12).

[0129] The sensing unit (22) can sense the reflected image from the incident result by having the reflected beam incident at a reflection angle corresponding to the constant incident angle as shown in FIGS. 4 and 5.

[0130] The sensing unit (22) can sense the reflection image and transmit the sensing result to the control unit (23).

[0131] The control unit (23) receives the sensing result of the reflection image from the sensing unit (22) and can measure the height displacement of the processing surface (T) based on the reflection image.

[0132] The control unit (23) can compare the reflection image with a reference image and measure the height displacement according to the comparison result.

[0133] For example, as shown in FIG. 5, the height displacement can be measured from the difference in the position where the reflected beam is incident by comparing a reference image for a state of height A (T0) and a reflected image for a state of height B (T1).

[0134] Here, the reference image may be an image incident on the sensing unit (22) when the measurement beam is irradiated at the standard / set / reference height of the processing surface (T).

[0135] The control unit (23) can control the driving unit (14) based on the height displacement to adjust the height of the lens unit (13).

[0136] The control unit (23) can calculate a deviation value of the focus corresponding to the height displacement and control the driving unit (14) so ​​that the height of the lens unit (13) is adjusted according to the deviation value.

[0137] That is, the control unit (23) can compare the reflected image with a reference image, measure the height displacement according to the comparison result, calculate the deviation value of the focus corresponding to the height displacement, and control the driving unit (14) according to the deviation value to adjust the height of the lens unit (13).

[0138] The control unit (23) can calculate a position value of the lens unit (13) such that the focus matches the reference position from the deviation value, and control the driving unit (14) so ​​that the height of the lens unit (13) is adjusted to the position value.

[0139] That is, the control unit (23) can calculate the position value from the deviation value and control the driving unit (14) to adjust the height of the lens unit (13) to the position value.

[0140] Meanwhile, the control unit (23) may move the position of the measurement unit (21) while the measurement beam is being irradiated from the measurement unit (21), so that the measurement unit (21) may irradiate the measurement beam to a certain area.

[0141] For example, as shown in FIG. 9, the position of the measuring unit (21) can be moved in the up / down direction so that the measuring beam is irradiated to the range of P1 to P2 of the mirror unit (12), thereby causing the measuring beam to be irradiated to the area corresponding to P1 to P2 of the processing surface (T), or as shown in FIG. 10, the position of the measuring unit (21) can be moved in the left / right direction so that the measuring beam is irradiated to the range of P1 to P2 of the mirror unit (12), thereby causing the measuring beam to be irradiated to the area corresponding to P1 to P2 of the processing surface (T).

[0142] In this way, by moving the position of the measuring unit (21) by the control unit (23), the irradiation of the measuring beam onto the processing surface (T) can be performed in a scanning manner, and thus, the measurement of height displacement over the entire area of ​​the processing surface (T) and the corresponding focus adjustment can be performed.

[0143] As a more specific example of application, while the processing surface (T) is mounted on a rail moving in one direction, the position of the measuring unit (21) is moved in the other direction perpendicular to the one direction, thereby allowing for the measurement of height displacement and corresponding focus adjustment over the entire area of ​​the processing surface (T) in an environment where the processing surface (T) moves along the rail, such as during the process (In-line).

[0144] Although embodiments of the focus adjustment device and focus adjustment system described above have been explained so far, the described embodiments may be modified in various ways without departing from the scope of the present invention, and the scope of the present invention should not be limited to the described embodiments, but should be defined by the claims set forth below as well as equivalents thereof.

Claims

1. A processing unit that irradiates a processing beam to be irradiated onto a processing surface in a first direction; A mirror part that reflects the processing beam in a second direction where the processing surface is located; A lens unit that focuses the processing beam reflected from the mirror unit to a point on the processing surface; and A focus adjustment device for adjusting the focus of a laser device comprising a driving unit for adjusting the position of the lens unit, A measuring unit that irradiates the measuring beam in the first direction so that the measuring beam is irradiated to a specific area of ​​the mirror unit where the central axis of the lens unit does not intersect, and is reflected in the second direction; A sensing unit that senses a reflected image reflected by the above measuring beam in the order of the mirror part, the processing surface, and the mirror part; and A focus adjustment device characterized by including a control unit that measures the height displacement of the processing surface based on the above reflection image and controls the driving unit so that the height of the lens part is adjusted based on the height displacement.

2. In Paragraph 1, The above processing part is, An irradiation unit that generates the above processing beam and irradiates in the above second direction; and A focus adjustment device characterized by including a reflector that is positioned on the same vertical axis as the above-mentioned investigation unit and on the same horizontal axis as the above-mentioned mirror unit, and reflects the above-mentioned processing beam in the above-mentioned first direction.

3. In Paragraph 1, The above measuring unit is, A focus adjustment device characterized by being positioned on the same horizontal axis as the mirror part and irradiating the measurement beam in the first direction.

4. In Paragraph 1, The above measuring unit is, A focus adjustment device characterized by irradiating the above-mentioned measurement beam in the form of a line of a specific length.

5. In Paragraph 4, The above specific length is, A focus adjustment device characterized by being 4 to 8 [mm].

6. In Paragraph 1, The above measuring unit is, A focus adjustment device characterized by irradiating the above-mentioned measurement beam at a specific wavelength different from the above-mentioned processing beam.

7. In Paragraph 6, The aforementioned specific wavelength range is, A focus adjustment device characterized by being 530 to 620, 680 to 740 [nm].

8. In Paragraph 1, The above control unit is, A focus adjustment device characterized by comparing the above-mentioned reflected image with a reference image and measuring the above-mentioned height displacement according to the comparison result.

9. In Paragraph 1, The above control unit is, A focus adjustment device characterized by calculating a deviation value of the focus corresponding to the height displacement and controlling the driving unit so that the height of the lens part is adjusted according to the deviation value.

10. In Paragraph 9, The above control unit is, A focus adjustment device characterized by calculating a position value of the lens part such that the focus aligns with a reference position from the above deviation value, and controlling the driving part so that the height of the lens part is adjusted to the above position value.

11. An irradiation unit that irradiates a processing beam to be irradiated on the processing surface in a downward direction; A reflector positioned perpendicular to the above-mentioned investigation unit and reflecting the processing beam in a direction perpendicular to the downward direction; A mirror part positioned horizontally to the reflection part above and reflecting the irradiated beam in the downward direction; A lens portion positioned perpendicular to the mirror portion and the processing surface, for focusing an irradiated beam to a point on the processing surface; A driving unit for adjusting the position of the above-mentioned lens part; A measuring unit positioned horizontally to the reflection unit and the mirror unit, which irradiates a measuring beam in the one-sided direction to a specific area of ​​the mirror unit where the central axis of the lens unit does not intersect; A sensing unit that senses a reflected image reflected by the above measuring beam in the order of the mirror part, the processing surface, and the mirror part; and A focus adjustment system for a laser device characterized by including a control unit that measures the height displacement of the processing surface based on the above-mentioned reflection image and controls the driving unit based on the height displacement to adjust the height of the lens unit.

12. In Paragraph 11, The above measurement beam is, A focus adjustment system for a laser device characterized by being a line-shaped beam of a specific length.

13. In Paragraph 11, The above measurement beam is, A laser device focus adjustment system characterized by being a beam of a specific wavelength range different from the processing beam above.

14. In Paragraph 11, The above measurement beam is, A focus adjustment system for a laser device characterized by being irradiated from the measuring unit to the mirror unit, being first reflected in the downward direction from the mirror unit, being secondarily reflected in the upward direction opposite to the downward direction from the processing surface, and then being thirdly reflected in the other direction opposite to the one-sided direction from the mirror unit and incident on the sensing unit.

15. In Paragraph 11, The above control unit is, A focus adjustment system for a laser device characterized by comparing the above-mentioned reflected image with a reference image, measuring the height displacement according to the comparison result, calculating the deviation value of the focus corresponding to the height displacement, and controlling the driving unit according to the deviation value to adjust the height of the lens unit.

16. In Paragraph 15, The above control unit is, A focus adjustment system for a laser device characterized by calculating a position value of the lens part such that the focus aligns with a reference position from the above deviation value, and controlling the driving part to adjust the height of the lens part to the above position value.

Images