JP3499209B2 - Optical component focus detection method and apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a focus detection method and apparatus for optical components constituting laser optical equipment.

[0002]

2. Description of the Related Art Normally, as a laser optical device utilizing a laser beam, for example, a laser processing device or a laser measuring device is adopted. In this type of laser optical device, various kinds of optical components such as a lens system and a reflecting mirror are incorporated in order to guide the laser light to a predetermined irradiation position. Further, the reflecting mirror has various forms such as a plane mirror, a parabolic mirror and an ellipsoidal mirror.

Therefore, when assembling a laser optical device, it is desired to accurately perform layout adjustment of various optical components and alignment adjustment such as focus position measurement.
This is to ensure that high-quality laser processing work and high-precision laser measurement work are performed.

[0004]

Generally, in the work of measuring the focus position of a focus optical system such as a parabolic mirror or an ellipsoidal mirror, a wall or the like is actually irradiated with reflected light from the focus optical system, This is done by directly observing the condensed state.

However, the focal position of the above-mentioned focusing optical system changes due to the parallelism of the incident light, the layout, the surface accuracy, etc., and it is difficult to ensure the reproducibility of the measurement. Due to this, it has been pointed out that the focus position of the focus optical system cannot be detected accurately.

The present invention solves this kind of problem, and provides a focus detection method and apparatus for an optical component capable of detecting the focus position of a focus optical system with high accuracy by a simple process and configuration. The purpose is to do.

[0007]

In a focus detecting method and apparatus for an optical component according to the present invention, a reference light unit for deriving a reference laser light whose optical axis is set is translated or tilted with respect to the optical axis. At the same time, the reference laser light is emitted from the reference light unit to the non-planar mirror which is an optical component.

Next, the reflected light from the non-planar mirror irradiated with the reference laser light is incident on the optical axis detection unit, while the optical axis detection unit is moved in the optical axis direction of the reflected light. Then, by setting the position where the movement of the optical axis (light spot) of the reflected light detected by the optical axis detection unit is the smallest as the focus position of the non-planar mirror, the focus position is a simple process and configuration. Highly accurate and efficient detection.

Here, in the parabolic mirror, the reference laser unit guides the reference laser light while moving the reference light unit in parallel. The reference laser light is reflected by the parabolic mirror and introduced into the optical axis detection unit, and the optical axis detection unit is moved in the optical axis direction of the reflected light. Then, the position where the movement of the optical axis of the reflected light detected by the optical axis detection unit is the smallest is set as the focus position of the parabolic mirror.

On the other hand, in the ellipsoidal mirror, while the reference light unit is tilted, the reference laser light is applied to the ellipsoidal mirror, the reflected light from the ellipsoidal mirror is introduced into the optical axis detection unit, and the optical axis is also reflected. The detection unit is moved in the optical axis direction. Then, the position where the movement of the optical axis position of the reflected light introduced into the optical axis detection unit is the smallest is actually measured as the focus position of the ellipsoidal mirror.

Furthermore, the reference laser beam is irradiated to the optical axis detecting unit, the optical axis measurement surface of the optical axis detecting unit with the match to the rotation axis of the optical-axis detecting unit, wherein the reference laser and the optical axis measurement surface Move it back and forth in the direction of the optical axis of the light,
The measurement position of the optical axis measurement surface is adjusted. Therefore, the optical axis measurement surface of the optical axis detection unit is adjusted with high accuracy, and the optical axis measurement work is performed with high accuracy.

Further, in the present invention, the focus position of the parabolic mirror is automatically measured. That is, while irradiating the parabolic mirror with the reference laser light and introducing the reflected light into the optical axis detection unit, the optical axis measurement surface of this optical axis detection unit is rotated around an axis intersecting the optical axis, It is determined whether or not the optical axis position of the reflected light applied to the optical axis measurement surface changes. At that time, when the optical axis position changes, the rotation center position of the optical axis detection unit is moved and the optical axis measurement surface position is detected.

Next, the reference light unit is moved in parallel, and the optical axis measuring surface of the optical axis detecting unit is rotated if necessary, so that the optical axis position of the reflected light irradiated on the optical axis measuring surface is changed. Whether or not to do is determined. When the optical axis position changes, the focal position is determined by moving the optical axis detection unit in the optical axis direction, and automatic measurement of the focal length is performed.

Furthermore, the present invention uses a reference light unit for deriving the reference laser light as collimated light,
The non-planar mirror is irradiated with this collimated light and the reflected light is introduced into the optical axis detection unit. As a result, only the optical axis detection unit needs to be moved, and the focus detection work of the non-planar mirror can be efficiently performed by a simpler process.

[0015]

1 is a perspective view of a reference light unit 10 which constitutes a focus detection device for an optical component according to a first embodiment of the present invention, and FIG.
0 is a side view, and FIG. 3 is a plan view of the reference light unit 10.

The reference light unit 10 has a function of irradiating the reference laser light L used for measurement of various optical parts and the like, and a laser light unit 14 in which a laser oscillator 12 such as a He-Ne laser is incorporated. A rotation mechanism 18 for rotating the laser light unit 14 around the optical axis with respect to the support cylinder 16; and an optical axis of the reference laser light L derived from the laser light unit 14 with respect to the reference light unit 10.
And a light center adjusting mechanism 20 for matching the rotation center of

The reference light unit 10 includes a unit base 24 fixed on the measurement base 22, and the support barrel 16 is mounted on the unit base 24 via a horizontal slide mechanism 26 and a vertical slide mechanism 28. The left and right slide mechanism 26 has a guide rail 30 provided on the unit base 24 so as to extend in the arrow B direction orthogonal to the optical axis direction (arrow A direction).
A slide base 32 that can move back and forth in the direction of arrow B is arranged at 0. The first micrometer 34 is fixed on the unit base 24 in the horizontal direction, and the rod 36 of the first micrometer 34 is fixed to the slide base 32.

A column 38 is provided on the slide base 32, and a pair of guide rails 40 constituting the vertical slide mechanism 28 are fixed to the inner surface of the column 38 in the vertical direction. A pair of guide portions 42 that engage with the guide rails 40 and can move up and down are provided on both sides of the support cylinder 16, and a second micrometer 44 is provided vertically downward in the upper part of one end side of the column 38. It is installed.
Rod 46 protruding downward from the second micrometer 44
Are fixed to the support cylinder 16.

A rotary cylinder 50 is rotatably supported in the support cylinder 16 via a pair of bearings 48 constituting the rotary mechanism 18, and the laser oscillator 12 is accommodated in the rotary cylinder 50. . The holding member 52 is attached to both ends of the laser oscillator 12, and the small diameter portion 54 of the holding member 52 is inserted into the rotary cylinder 50.

The optical center adjusting mechanism 20 is provided with three adjusting screws 56 which are respectively screwed into the both ends of the rotary cylinder 50 at equal angular intervals, and the tip of the adjusting screw 56 has a small diameter portion of the holding member 52. By touching 54, the optical axis of the laser oscillator 12 is tilted and adjusted.

As shown in FIGS. 2 and 3, the reference light unit 10 has a tilting mechanism capable of tilting and fixing the reference light unit 10 in a direction (arrow B direction) intersecting the optical axis direction (arrow A direction). 58 is provided. The tilting mechanism 58 includes knock pins 60a and 60b provided on the measurement base 22. The knock pin 60a fits into a hole 62 formed on the tip side of the unit base 24 in the direction of arrow A, while the knock pin 60b is The unit base 24 is selectively fitted into three holes 64a, 64b and 64c provided on the rear end side in the direction of arrow A.

As shown in FIG. 2, the laser light unit 14
A beam diameter enlarging means 66 for enlarging the beam diameter of the reference laser light L is detachably provided on the tip side of the.
The beam diameter expanding means 66 has, for example, a diameter of 0.8 mm.
A lens that includes a filter unit 68 that combines various types of pinhole assemblies and a focusing lens, and a lens set for a beam expander, which converts a standard reference laser beam L into a parallel beam (collimated beam) having a diameter of 25 mm. And a unit 69.

FIG. 4 shows the optical axis (light spot) of the reference laser light L emitted from the reference light unit 10 which constitutes the focus detection device.
FIG. 6 is a perspective explanatory view of an optical axis detection unit 100 for detecting a position, and FIG. 5 is a side view explanatory view of the optical axis detection unit 100.

The optical axis detection unit 100 comprises a measurement base 2
2 includes a unit base 102 fixed onto the unit base 102, and a first slide base 104 is provided on the unit base 102.
Are arranged so as to be movable back and forth in the optical axis direction (arrow A direction) via the moving back and forth mechanism 105. An end of a first slide knob 106, which constitutes an advancing / retreating mechanism 105 and is supported by the unit base 102, is fixed to the side of the first slide base 104, and the first slide knob 106 is rotated to rotate the first slide knob 106. The first slide base 104 can move back and forth in the direction of arrow A.

On the first slide base 104, a rotary base 110 which constitutes a rotary mechanism 108 is provided, and this rotary base 110 is operated by operating a rotary knob 112 so as to cross the optical axis of the reference laser beam L. It is rotatable around the axis (vertical axis). On the rotating base 110,
The second slide base 114 is arranged so that it can move back and forth in the direction of arrow A. An end portion of a second slide knob (measuring position adjusting mechanism) 116 is connected to the second slide base 114, and the second slide knob 116 is rotated so that the second slide knob 116 can advance and retreat in the direction of arrow A by a minute distance.

An optical axis position detecting sensor 118 is mounted on the second slide base 114. The optical axis position detecting sensor 1
A monitor 122 is connected to 18 (see FIG. 6). As will be described later, on the monitor 122, the position of the reference laser light L introduced onto the light spot (optical axis) measurement surface 120 of the optical axis position detection sensor 118 is displayed as a visible image.

Next, the operation of the focus detecting device having the above-described structure will be described below in connection with the focus detecting method according to the first embodiment of the present invention.

First, the optical axis adjustment work of the reference laser light L is performed so that the optical axis of the reference laser light L derived from the reference light unit 10 coincides with the rotation center of the reference light unit 10. Next, the optical axis alignment work of the optical axis detection unit 100 is performed using the reference laser light L having the optical axis set.

Specifically, as shown in FIG. 7, an optical axis detection unit 100 is arranged on the optical axis of the reference light unit 10 at a predetermined position. Therefore, when the reference laser light L is derived from the reference light unit 10, the reference laser light L is applied to the light spot measurement surface 120 forming the optical axis detection unit 100. In this state, the rotation base 110 constituting the rotation mechanism 108 is swung, and the second
Under the action of the slide knob 116, the second slide base 1
14 is moved back and forth in the optical axis direction.

Then, as shown in FIG.
The second slide base 114 is stopped at a position where the upper optical axis position P does not move. As a result, the light spot measurement surface 120 and the rotation axis of the rotating mechanism 108 coincide with each other, and the light spot measurement surface 1
Twenty positions will be detected.

FIG. 8 is a perspective explanatory view of the position adjusting unit 140 to which the focus detecting method according to the first embodiment of the present invention is applied, and FIG. 9 is a side view of the position adjusting unit 140. .

The position adjusting unit 140 includes a non-planar mirror (including a parabolic mirror and an ellipsoidal mirror) 14 which is an optical component.
2 is integrally mounted on a laser processing device, a laser measuring device, or the like, and has a function of adjusting the position and angle of the non-planar mirror 142 in advance.

The position adjustment unit 140 includes the measurement base 2
2 is provided with a unit base 144, and a support block 146 is provided on the unit base 144. On the support block 146, a first tilting member 150 whose angle can be adjusted in the horizontal direction is provided via a first knob 148. The first tilting member 150 has a second knob 152.
A second tilting member 154, which is tiltable in the vertical direction, is supported via the, and the non-planar mirror 142 is attached to the second tilting member 154.

Therefore, by using the reference light unit 10 and the light spot detection unit 100, focusing is performed in accordance with the respective procedures shown below when the non-planar mirror 142 is a parabolic mirror and when it is an ellipsoidal mirror. Position measurements are taken.

First, in the parabolic mirror, as shown in FIG. 10, the reference light unit 10 is translated in the horizontal direction (arrow B direction) under the rotating action of the first micrometer 34 constituting the left and right slide mechanism 26. Meanwhile, the reference laser light L is derived. On the other hand, the optical axis detection unit 100 arranged in the vicinity of the focal position of the non-planar mirror 142 includes the first slide base 104 under the rotating action of the first slide knob 106.
Moves back and forth in the direction of the optical axis S2. The reference laser light L derived from the reference light unit 10 is reflected by the non-planar mirror 142 to form the light spot measurement surface 12 that constitutes the optical axis detection unit 100.
It is irradiated to 0. At this time, the position where the optical axis moves the least is measured as the focal position (distance) of the non-planar mirror 142.

On the other hand, in the ellipsoidal mirror, as shown in FIG. 11, the reference light unit 10 irradiates the reference laser light L while being tilted in the horizontal direction, and the optical axis detection unit 1
00 moves in the front-rear direction along the optical axis S2. Then, the position where the movement of the optical axis detected on the light spot measurement surface 120 of the optical axis detection unit 100 is the smallest is measured as the focus position (distance) of the ellipsoidal mirror.

Further, in the parabolic mirror, as shown in FIG. 12, the beam diameter expanding means 66 is attached to the reference light unit 10 and the focal position of the non-planar mirror 142 can be measured using the collimated light L1. .

In the reference light unit 10, the reference laser light L derived from the laser light unit 14 is converted into the collimated light L1 via the beam diameter expanding means 66, and the collimated light L1 is reflected by the non-planar mirror 142. The light spot measurement surface 120 that constitutes the optical axis detection unit 100 is irradiated. Here, the optical axis detection unit 100 moves back and forth in the optical axis S2 direction, and the position where the area of the light spot on the light spot measurement surface 120 is the smallest is measured as the focus position of the non-planar mirror 142. Therefore, it is not necessary to move the reference light unit 10, and the focus position of the parabolic mirror can be quickly measured by a simple process.

FIG. 13 is a perspective view of a reference light unit 160 which constitutes a focus detection device according to the second embodiment of the present invention, and FIG. 14 shows an optical axis detection unit 170 which constitutes the focus detection device. It is a perspective view.

The reference light unit 160 is a left and right slide mechanism 1 for automatically moving the laser light unit 14 forward and backward in the direction of arrow B, which is orthogonal to the optical axis direction (direction of arrow A).
62 is provided. The left and right slide mechanism 162 includes a rotary drive source, for example, a motor 164.
A ball screw 166 connected to the drive shaft of the is screwed to the column 38. The vertical slide mechanism 28 can be automated similarly to the horizontal slide mechanism 162.

As shown in FIG. 14, the optical axis detection unit 1
Reference numeral 70 designates the first slide base 104 in the optical axis direction (arrow A
Direction), and a rotation mechanism 174 capable of automatically rotating the rotation base 110.
And the second slide base 11 on the rotary base 110.
4 is provided with a minute advancing / retreating mechanism 176 capable of automatically advancing / retreating in the direction of arrow A.

The advancing / retreating mechanism 172 includes the unit base 102.
A first motor 178 fixed to the first slide base 104 is screwed to the ball screw 180 connected to the first motor 178. The rotation mechanism 174 includes a second motor 182 fixed on the first slide base 104, and the ball screw 18 connected to the second motor 182.
4 is screwed onto the rotation base 110. Micro advance / retreat mechanism 176
Includes a third motor 186 fixed to the rotation base 110, and a ball screw 188 connected to the third motor 186 is screwed to the second slide base 114.

Therefore, as shown in FIG. 15, a method for automatically measuring the focus of the non-planar mirror 142 which is a parabolic mirror will be described below with reference to the flow chart shown in FIG.

In the reference light unit 160, the reference laser light L derived from the reference light unit 160 is adjusted in advance (step S1 in FIG. 16). Therefore,
The reference laser beam L is emitted from the reference light unit 10, and the optical axis detection unit 170 is automatically swung about the vertical axis under the action of the second motor 182 that constitutes the rotation mechanism 174 (step S2). ).

In this state, it is determined whether or not the optical axis position of the reflected light La incident on the light spot measuring surface 120 constituting the optical axis detecting unit 170 changes (step S3).
When the position of the optical axis changes, the process proceeds to step S4, the third motor 186 that constitutes the minute advancing / retreating mechanism 176 is driven, and the light spot measurement surface 120 is automatically moved along the optical axis S2.

Since the optical axis position does not fluctuate, the light spot measuring surface 120 and the rotation axis of the rotating mechanism 174 coincide with each other, and the position of the light spot measuring surface 120 is detected. Next, in step S5, the light spot measurement surface 120
After the position is stored, the reference light unit 160 automatically translates in the direction intersecting the optical axis S1 under the action of the motor 164 that constitutes the left and right slide mechanism 162 (step S6). Here, when the optical axis position measured by the optical axis detection unit 170 changes (N in step S7)
O), proceeding to step S8, the optical axis detecting unit 17
0 is moved in the front-rear direction along the optical axis S2. On the other hand, when the optical axis position does not change, the process proceeds to step S9, the stored position is determined as the focal position, and the focal length is automatically measured.

Further, FIG. 17 shows a flowchart for carrying out another focus detection method for automatically measuring the focus of the non-planar mirror 142 which is a parabolic mirror. The flowchart shown in FIG. 17 is basically the same as the flowchart shown in FIG. 16, and will be briefly described below.

First, steps S1a to S5a are performed to store the optical axis measurement surface position of the non-planar mirror 142, and then the process proceeds to step S6a. In this step S6a,
The reference light unit 10 emits the reference laser light L while the reference light unit 10 moves parallel to the optical axis S1. On the other hand, in the optical axis detection unit 170, the light spot measurement surface 120 is automatically rotated via the rotation mechanism 174 (step S7a), and in this state, the light spot measurement surface 12 is rotated.
It is determined whether or not the optical axis position of the reflected light La irradiated on 0 changes (step S8a).

When the optical axis position fluctuates, the process proceeds to step S9a, and the optical axis detection unit 170 automatically moves in the front-back direction along the optical axis S2. Then, when it is determined that the optical axis position does not change, the process proceeds to step S10a and the focus position is determined. This will automatically measure the focus of the non-planar mirror 142.

[0050]

According to the focus detecting method and apparatus of the optical component of the present invention, the reference laser beam having the optical axis set is applied to the optical component, and the reflected light from the optical component is applied to the optical axis detecting unit. As a result, focus detection work for various optical components can be performed with high accuracy.

Moreover, it is sufficient to use the reference light unit and the optical axis detection unit, and the focus detection and adjustment work of various optical components can be performed with high accuracy and efficiency by a simple process and structure.

[Brief description of drawings]

FIG. 1 is a perspective view of a reference light unit that constitutes a focus detection device according to an embodiment of the present invention.

FIG. 2 is a side view of the reference light unit.

FIG. 3 is a plan view of the reference light unit.

FIG. 4 is a perspective explanatory view of an optical axis detection unit that constitutes the optical axis detection device.

FIG. 5 is a side view of the optical axis detection unit.

FIG. 6 is an explanatory diagram of a display screen of a monitor that constitutes the optical axis detection unit.

FIG. 7 is a plan view illustrating an adjustment work of the optical axis detection unit.

FIG. 8 is a perspective explanatory view of a position adjustment unit.

FIG. 9 is a side view of the position adjustment unit.

FIG. 10 is an explanatory diagram for detecting a focal position of a parabolic mirror.

FIG. 11 is an explanatory diagram for detecting the focal position of the ellipsoidal mirror.

FIG. 12 is an explanatory diagram when detecting the focal position of the parabolic mirror using collimated light.

FIG. 13 is a schematic perspective view of a reference light unit that constitutes a focus detection device according to a second embodiment of the present invention.

FIG. 14 is a perspective explanatory view of an optical axis detection unit that constitutes the focus detection apparatus according to the second embodiment.

FIG. 15 is an explanatory diagram when detecting the focus position of a parabolic mirror using the focus detection device according to the second embodiment.

FIG. 16 is a flowchart for automatically measuring the focus position of the parabolic mirror in the second embodiment.

FIG. 17 is another flowchart for automatically measuring the focus position of the parabolic mirror in the second embodiment.

[Explanation of symbols]

10, 160 ... Reference light unit 12 ... Laser oscillator 14 ... Laser light unit 18 ... Rotation mechanism 20 ... Optical center adjusting mechanism 26, 162 ... Horizontal slide mechanism 28 ... Vertical slide mechanism 58 ... Tilt mechanism 66 ... Beam diameter expanding means 100, 170 ...
Optical axis detection units 104, 114 ... Slide bases 105, 172 ...
Advancement / retraction mechanism 108, 174 ... Rotation mechanism 110 ... Rotation base 118 ... Optical axis position detection sensor 120 ... Light spot measurement surface 122 ... Monitor 140 ... Position adjustment unit 142 ... Non-planar mirror L ... Reference laser light L1 ... Collimated light

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01B 11/00-11/30 G01M 11/00-11/08 G02B 7/00 G02B 7/18-7 / 28

Claims (9)

(57) [Claims] 1. A method for detecting a focus of an optical component constituting a laser optical device, wherein a reference light unit for deriving a reference laser light having an optical axis set is translated or tilted with respect to the optical axis. A step of irradiating the non-planar mirror, which is an optical component, from the reference light unit with the reference laser light, and a step of causing reflected light from the non-planar mirror irradiated with the reference laser light to enter an optical axis detection unit, The optical axis detection unit is moved in the optical axis direction of the reflected light from the non-planar mirror, and the position where the movement of the optical axis of the reflected light detected by the optical axis detection unit is the smallest is set as the focus position of the non-planar mirror. And a focus detection method for an optical component. 2. The focus detection method according to claim 1, wherein the reference laser light is applied to a parabolic mirror which is the non-planar mirror, and reflected light from the parabolic mirror is introduced into the optical axis detection unit. In addition, the method of detecting a focus of an optical component further comprises the step of rotating the optical axis measurement surface of the optical axis detection unit around an axis intersecting the optical axis of the reflected light. 3. The focus detection method according to claim 1, wherein the reference laser light is applied to a parabolic mirror which is the non-planar mirror, and reflected light from the parabolic mirror is introduced into an optical axis detection unit. together, or a step of rotating the optical-axis measuring surface of the optical-axis detecting unit around the axis intersecting the optical axis of the reflected light, the optical axis position of the reflection light irradiated to the optical axis measurement surface varies A step of determining whether or not the optical axis position of the reflected light changes, a step of moving the rotation center position of the optical axis detection unit, and the reference light unit when the optical axis position does not change are moved in parallel, the steps of the optical axis position of the reflected light to determine whether varying irradiated to the optical axis measurement surface, the optical axis position of the reflected light by parallel movement of the reference optical unit fluctuates When the optical axis detection unit A step of moving in a direction, the position of the optical axis measurement plane optical axis position does not change in the reflected light, the optical component, characterized in that and a step of setting a focal position of the parabolic mirror Focus detection method. 4. The focus detection method according to claim 1, wherein the reference laser light is applied to a parabolic mirror which is the non-planar mirror, and reflected light from the parabolic mirror is introduced into an optical axis detection unit. together, or a step of rotating the optical-axis measuring surface of the optical-axis detecting unit around the axis intersecting the optical axis of the reflected light, the optical axis position of the reflection light irradiated to the optical axis measurement surface varies A step of determining whether or not the optical axis position of the reflected light changes, a step of moving the rotation center position of the optical axis detection unit, and the reference light unit when the optical axis position does not change the is moved parallel, the optical axis measurement surface of the optical-axis detecting unit is rotated around the axis intersecting the optical axis of the reflected light, the optical axis position of the reflection light irradiated to the optical axis measurement surface variation A step of determining whether or not to perform The translation and rotation of the optical axis measurement surface of the knit in the optical axis position of the reflected light varies, the step of moving the optical axis detecting unit in the optical axis direction, the optical axis position of the reflected light And a step of setting a position of the optical axis measurement surface that does not change as a focus position of the parabolic mirror, the focus detecting method of the optical component. 5. A method for detecting a focus of an optical component constituting a laser optical device, wherein a reference light unit for deriving a reference laser light having an optical axis set as collimated light is prepared, and the optical component is operated from the reference light unit. A step of irradiating the non-planar mirror with the collimated light, a step of causing reflected light from the non-planar mirror irradiated with the collimated light to enter into an optical axis detection unit, and the optical axis detection unit with the light of the reflected light. And a step of moving the optical axis of the reflected light detected by the optical axis detection unit in the axial direction to minimize the movement of the optical axis of the reflected light, as a focus position of the non-planar optical component. Focus detection method for parts. 6. The focus detecting method according to claim 1, wherein the optical axis detecting unit is irradiated with the reference laser beam, and an optical axis measuring surface of the optical axis detecting unit is provided on the optical axis detecting unit. of the step of matching the rotational axis, the optical axis measurement surface is moved in the optical axis direction of the reference laser beam, optical components, characterized in that and a step of adjusting the measurement position of the optical axis measurement surface Focus detection method. 7. A focus detection device for an optical component constituting a laser optical device, comprising: a reference light unit for deriving a reference laser light whose optical axis is set; and an optical component irradiated with the reference laser light. And an optical axis detecting unit for detecting the optical axis position of the reflected light, wherein the optical axis detecting unit includes an advancing / retreating mechanism capable of advancing / retreating in the optical axis direction of the reflected light. A focus detection device for an optical component, which is characterized in that 8. The focus detection device according to claim 7, wherein the optical axis detection unit has an optical axis measurement surface for detecting an optical axis position of the reflected light, and the optical axis measurement surface is an optical axis of the reflected light. A rotation mechanism that rotates about an axis that intersects with, and a measurement position adjustment mechanism that advances and retracts the optical axis measurement surface in the optical axis direction with respect to the optical axis of the reflected light; Detection device. 9. The focus detection device according to claim 7, wherein the reference light unit includes a beam diameter expansion means for expanding the beam diameter of the reference laser light in order to guide the reference laser light as collimated light. A focus detection device for optical components.