JP2866756B2 - Laser device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser device .

[0002]

2. Description of the Related Art In recent years, the field of application of lasers has been expanding more and more. In particular, He- Cd lasers (main oscillation wavelength: 325 nm) have been developed using, for example, a light source for exposing a resist and a photocurable resin. Light source for curing the photo-curable resin when designing a model or mold , CT data
A light source for photocuring of making the body structure and models of bone using, as a light source or the like for the fluorescence analysis, the use of in various fields are expected.

[0003] mirrors constituting a laser resonator, a small internal mirror type He-Ne laser, except for a semiconductor laser device, generally Invar (trade name) thermal expansion coefficient small three or four rods, such as And the optical axis of the mirror is designed to be kept stable. However, the optical axis of the mirror changes due to the temperature gradient caused by the heat generated inside the laser head during the operation of the laser device, and the temporal change of the residual strain of the laser resonator. also it changes (decreases) output, to stop the record over the operation for various trouble occurs or, also the optical axis readjustment
There was a problem that required a long time . However , conventionally, a fixing plate is fixed to the rod, and the fixing plate is
The movable plate to which the mirror is fixed is attached in the direction approaching with a spring, and a mirror angle adjustment screw is screwed into, for example, two corners of the movable plate, and the tip of the screw is brought into contact with the fixed plate to make a laser. By manually changing the feed amount of the mirror angle adjustment screw while detecting the output intensity and monitoring the change in the intensity, the laser output intensity is maximized and the angle of the movable plate , that is, the angle of the mirror is adjusted. I was adjusting.

[0004]

However, in such a method, it takes considerable time and effort to properly adjust the angle of the mirror so that the laser output is maximized. Since the angle of the mirror is displaced from the optimum value in a short time, there has been an inconvenience that many time-consuming adjustment operations are required. Meanwhile, recent piezo actues
Over data, small Riniaa actuator by the DC motor
With these actuators ,
Adjusting the angle of the mirror came to be considered
Came . However, at present, it is only a technology at the laboratory level
Therefore, practical and economical technology has not been established yet.
That is, Japanese Patent Laid-Open Publication No.
Once the A / D converter the analog signal from the Rezabi over-time
The digital signal is converted to a digital signal by the
Compared one after another daisy Tal signal to front and rear in accordance grams
There is disclosed a technology for detecting and adjusting the maximum output . I
However, in this technology, expensive A / D converters and
Requires microcomputer and its software
And Therefore, expensive carbon dioxide laser devices
Although laser devices are practicable, they are usually used well.
In the laser device used, the device for automatic adjustment
Price is too high, lack of cost-Pas-performance
Therefore, there is a problem in terms of economy. The present invention has been made to solve the above problems, and aims to adjust the laser output maximizing provide a simple record over <br/> The device.

[0005]

To achieve the above object, according to an aspect of the laser device of the present invention, the mirror Hor <br/> loaders having a movable plate which mirror is held on the outside of the fixed plate fixed to the rod A laser device comprising: an alignment mechanism attached to the mirror holder; a laser output detecting means; and a control means for controlling the alignment mechanism. The alignment mechanism includes a drive motor fixed to the fixed plate and a displacement motor. a micrometer f head adjustment, a flexible coupling for connecting the drive motor and the micrometer head, more becomes the pressed manual adjustment screw to the movable portion of the screwed micrometer heads on the movable plate, wherein The controller intermittently intermittently increases the laser output based on the detection result detected by the laser output detector. Characterized in that to drive the dynamic motor.

[0006]

[Function] The mirror angle can be roughly adjusted with the manual adjustment screw.
Since the control means drives the drive motor intermittently in the direction of increasing the laser output based on the detection result detected by the laser output detection means, automatic optical axis adjustment can be performed. The distance of the drive motor and the micrometer heads which varies by the optical axis adjustment is absorbed by the flexible coupling is connected.

[0007]

Embodiments of the present invention will be described below. FIG.
He- Cd laser in the laser device according to this embodiment
FIG. 2 is a schematic view of the entire head , showing a mirror holder 1 and an alignment head .
Ment mechanism 2, a pair of mirrors 3, super invar
Rod 4, laser tube 5, case 6, laser output detection
Means 8 and control means 9 . And Mira
-Holder 1 is fixed to fixing plate 11 fixed to rod 4
A movable plate 12 to which the mirror 3 is attached, and a pair of mirrors.
3 including the mirror holder 1 and the alignment mechanism 2
Laser resonator by the error angle regulatory mechanism and the rod 4
Is configured. Or in the laser tube 5, a discharge tubule
51, an anode 52, a cathode 53 and the like are arranged.
You.

The alignment mechanism 2 intermittently minutely changes the angle of a mirror constituting the laser resonator. The alignment mechanism 2 includes a laser output detection unit 8
In order to increase the laser output based on the detection result detected by the mirror 3, as shown in FIG. 2, a mirror 3 is set with reference to an XY plane perpendicular to a preset optical axis Z.
So that one angle A of the fixing plate 11 can be displaced.
Are attached to the corners B and C located on both sides of the fulcrum. That is, the movable plate 12
At the fulcrum provided at the corner A, with respect to the fixed plate 11
Point supported so that it can be tilted in all directions,
Corner A located in the X direction with respect to section A, and corner A with respect to corner A
And the corner C located in the −Y direction,
They are connected by an alignment mechanism 2 provided.
This alignment mechanism 2 is apparent from the following description.
Thus, the movable plate 1 at the position of the alignment mechanism 2
2 to finely adjust the distance from the fixing plate 11.
You. Therefore, the two alignment mechanisms 2 are appropriately adjusted.
The angle of the movable plate 12 with respect to the fixed plate 11
Control in such a way that the state is tilted in all directions.
Can be As a result, the fixing plate 11 is the reference plane
When tilted from the XY plane,
By adjusting the angle state of the moving plate 12, the fixed plate 11
Of the movable plate 12 as the reference plane so that the inclination of
An angle state along the Y plane can be set.

More specifically, as shown in an enlarged manner in FIG. 3, the alignment mechanism 2 has a built-in drive motor 22 composed of a stepping motor.
Micrometer f for the displacement adjustment of the rotary shaft 23 through a flexible coupling 25 of the bellows head 26
It is connected to. The movable portion 26A of the micrometer head 26 is inserted into a through hole 13 provided in the fixed plate 11 and is free to advance and retreat. A ball 27 is disposed in the through hole 13 as a buffer member. A manual adjustment screw 29 is screwed into the movable plate 12, and the tip of the manual adjustment screw 29 is inserted into the through hole 13. Between the fixed plate 11 and the movable plate 12, there is provided a spring 28 for applying an elastic force in a direction to approach the two.
The manual adjustment screw 29 moves the ball 2
6A is constantly pressed.

Therefore, when the rotation shaft 23 of the drive motor 22 is rotated by the control means 9 based on the detection result of the laser output detection means 8 after the coarse adjustment by the manual adjustment screw 29, The movable portion 26A of the micrometer head 26 moves forward or backward. For example, when the movable portion 26A moves forward (in the direction indicated by the arrow L in FIG. 3), the manual adjustment screw 29 is pressed via the ball 27, so that the corresponding corner of the movable plate 12 is
8 in a direction away from the fixed plate 11. Conversely, when the movable portion 26A retreats, the corresponding corner of the movable plate 12 is displaced by the spring 28 in a direction approaching the fixed plate 11.

Hereinafter , the mirror angle will be described with reference to FIGS.
A description will be given of the automatic adjustment. Figure 4 is a block diagram showing an example of a laser output detection means 8 and control means 9, Figure 5 is their time chart of the laser output detection means 8 and control means 9. Les over The output detection means 8
Is for comparing and detecting the laser output before and after the intermittent minute displacement of the mirror angle. Control means 9, the mirror angle in the same direction when the laser output after small displacement relative to the laser output of the previous minute displacement <br/> is large, the mirror angle in the case where the laser output after the minute displacement is small It is controlled so as to be slightly displaced in the opposite direction. In the laser output detecting means 8, reference numeral 81 denotes a photoamplifier for detecting a laser output; 82, a sample and hold circuit for holding the laser output immediately before the minute displacement; and 83, a comparator for comparing and detecting the laser output before and after the minute displacement. That is,
The laser output immediately before the drive motor 22 is driven is
It is detected by the Toanpu 81, beforehand sample Anne
Is held by Dohorudo circuit 82, the signal of this is
The signal is input to the non-inverting input terminal of the comparator 83. Soshi
Te, the laser output immediately after driving of the driving motor 22 is comparator
Is input to the inverting input terminal of the over data 83.

In the control means 9, reference numeral 91 denotes a timing circuit, 92 denotes a monomultivibrator, 93 denotes a monomultivibrator, 94 denotes an AND circuit, and 95 denotes a toggle flip-flop circuit. In this embodiment , the toggle
J of the flip-flop circuit 95, the K input and H level
Then, at the CLK input, the output signal M ₅ of the AND circuit 94 is output.
When There go up falling, toggle flip-flop circuit 95
Output signal M ₆ is inverted from H level to L level.
It has become. When the output signal M ₂ of the mono-multi vibrator 92 is at the H level,
Drive signal becomes for driving the motor 22, the output signal M ₆ of the toggle flip-flop circuit 95 becomes the turn signal of the minute displacement. When this output signal M ₆ is at H level
Is an instruction signal for setting the rotation direction of the drive motor 22 to the clockwise direction.
Next, at the L level is the rotational direction of the drive motor 22
It is set to be an instruction signal to the counter-clockwise direction. Soshi
Te, determined et the output signal M ₁ of the timing circuit 91
Out of the mono-multi-vibrator 92 at a constant period T ₀ to be
When the force signal M ₂ becomes an H level drive signal,
Depending on the output signal M ₆ of the toggle flip-flop circuits 95
Direction indicated, ie clockwise or counterclockwise
The rotation shaft 23 of the drive motor 22 of the alignment mechanism 2 is driven to rotate in either direction .

The timing circuit 91 will be described in detail.
Output signal M ₁ of a rectangular wave as shown in FIG. 5, this
When the output signal M ₁ falls to L level hold signal
The laser output is held. Also, this output signal
M ₁ is also input to the monostable multivibrator 92, the
Mono multivibrator when the output signal M ₁ falls
The output signal M ₂ of motor 92 becomes H level, driving this time
A drive signal for rotating the motor 22 is provided . Sand
Chi, when the output signal M ₁ falls, the laser output E
Together are over field, the monostable multivibrator 92
The output signal M ₂ becomes H level. After that, this H level
Output signal M ₂ , whether clockwise or counterclockwise
Drive motor receives the output signal M ₆ instructing Kano direction
22 is rotated in the indicated direction, and the angle of the mirror 3 is
Is slightly displaced. The E output signal M ₁ is at L level
The output of the sample and hold circuit 82 is
Shin force signal that is held before the mirror 3 is small displacement
And this is connected to the non-inverting input terminal of the comparator 83.
Is entered. The drive motor 22 is rotated and the mirror 3 is finely moved.
Les the laser output immediately after a small displacement is detected by a photo amplifier 81, which is input to the inverting input terminal of the direct comparator 83, which is hold in the laser output and the previous
User output . In other words, the minute displacement of the mirror
The front and rear laser outputs are compared.

Here, when the laser output after the minute displacement of the mirror is low, the output signal M ₄ of the comparator 83 becomes H level. This H level signal is input to the AND circuit 94.
It is input to, at the timing when the output signal M ₃ of the monostable multivibrator 93 becomes H level, the output signal M
₅ becomes H level. Is I to H-level output signal M ₅
Then , the output signal of the toggle flip-flop circuit 95
M _6, i.e. towards direction instruction signal is <br/> inverted from H level to L level, direction of rotation of the drive motor 22 is reverse.

Next, the actual control contents will be described with reference to FIG . For example, a difference in elongation occurs to a temperature change between the rods 4 and 4, the movable plate 12 holding the mirror 3 is displaced from the XY plane, the mirror 3 which is fixed thereto
Is displaced. If the angle of the mirror 3 is Ru <br/> be displaced, Les chromatography The output changes. In FIG. 6, 10
0 is a laser output curve, and θ (O) indicates the angle of the mirror 3 when the laser output reaches the maximum P (O) , that is, the optimum angle.

Next, referring to FIG. 7, the output signal shown in FIG.
And based on the No. M _2, it is adjusted how the laser output P is
I will explain. In FIG. 7, symbols N ₁ ′ to N ₅ ′
Are H-level signals N _{1 to} N of the output signal M ₂ shown in FIG.
The direction and magnitude of the mirror angle displaced corresponding to ₅
This is indicated by the length of the arrow. For example, at any time
Thus, the angle of the mirror 3 is reflected in the laser output curve 100 .
Assuming that the laser output deviates from the optimum angle θ (F) at which the laser output becomes maximum to θ (D ) , the laser output P (D) at this angle is obtained.
, When held at the timing of the output signal M ₁ of the timing circuit 91 to <br/> sample and hold circuit 82 DOO
Monitor the output signal M ₂ mono multivibrator 92 is H
It becomes a level drive signal. And the drive motor 22
Is based on the output signal M ₆ of the toggle flip-flop circuit 95 .
Ri is rotated in the indicated direction, by one of the alignment mechanism 2 is the angle of the mirror 3 is is finely displaced by one step. Amount corresponding mirror 3 shown in 'N ₁ assuming that a direction of the arrow indicated by' this time the displacement direction if N ₁
And the angle of the mirror 3 becomes θ (E) ,
The laser output at this time is P (E) .

Next, the laser output P (E) is
Detected by the amplifier 81 and input to the comparator 83
Is, laser power P before small displacement (D) and the laser output P (E) after small displacement <br/> and is Ru are compared. After small displacement
Laser output P (E) is smaller than laser output P (D)
The output signal M ₄ of the comparator 83 becomes L level.
Is Le, therefore, the output signal from the AND circuit 94 M ₅
Is also at L level, the output of the toggle flip-flop circuit 95 is
Force signal M ₆ ie turn signal is not inverted, the rotational direction of the drive motor 22 is maintained, the alignment
The next intermittent minute displacement is performed by the mechanism 2 . vice versa,
When the angle of the mirror 3 is displaced in the theta (G) from theta (F), since the laser power P after small displacement (G) is smaller than the laser output P (F) of the front small displacement, the comparator
83 the output signal M ₄ becomes H-level. Therefore, the monomer
The output signal M ₃ of Ruchi vibrator 93 becomes H level
The output signal M ₅ is H level of the AND circuit 94 at the timing
And the output signal M of the toggle flip-flop circuit 95
_6, that is, the direction indication signal is inverted, the rotational direction of the drive motor 22 is inverted, by the alignment mechanism 2 follows
Intermittent minute displacement is performed.

By repeating such intermittent minute displacement, for example, at a constant period T ₀ determined by the output signal M ₁ of the timing circuit 91, the angle of the mirror 3 can be set within the range of the resolution of the laser output detecting means 8. The laser output is adjusted so that it is always maintained near the peak P (F).
Alignment machine attached to corner B by the above procedure
By adjusting the structure 2, the corners A and C
The separation distance of the movable plate 12 from the fixed plate 11 is maintained.
As it is, the movable plate 12 at the corner B is moved from the fixed plate 11
As the separation is increased or decreased, substantially the distance of FIG.
Fixed in the direction of rotation about the axis extending in the Y-axis direction
The state where the angle state of the movable plate 12 with respect to the plate 11 is adjusted
And the automatic adjustment of the angle of the mirror 3 in the rotation direction.
Alignment work is achieved. Next, the arm attached to the corner C
By adjusting the lightment mechanism 2 in the same procedure as described above,
Similarly, the axis substantially extends in the X-axis direction in FIG.
The movable plate 12 with respect to the fixed plate 11 in the rotation direction
Angle state is adjusted, and in the rotation direction
The operation of automatically adjusting the angle of the mirror 3 is achieved. this
Thus, the state of inclination of the movable plate 12 with respect to the fixed plate 11 is X
Results achieved in both direction and Y direction, fixed
The movable plate 12 is tilted with respect to the plate 11 in all directions.
The mirror fixed to the movable plate 12
Automatic adjustment of the angle of 3 was performed, and the laser
Power will always be maintained at near maximum.

According to the present embodiment, manual adjustment screw 29 makes coarse adjustment of the angle of the mirror 3 Rutotomoni, the drive motor 22 in a direction to increase the laser output based on the detection result of the laser output detection means 8 driving Therefore, the optical axis can be automatically adjusted. And even if the distance between the drive motor 22 and the micrometer head 26 by the automatic adjustment of the optical axis is changed, it is possible to absorb the displacement of the distance by the flexible coupling 25 connecting these.

Although the embodiment of the present invention has been described above, in the present invention, the drive motor 22 of the alignment mechanism 2 is not limited to a stepping motor, and may be a DC motor or the like. Further, as the laser output detecting means 8 and the control means 9, other various means can be used. The mirror holder 1 alignment mechanism 2, faces
If the angles of two opposing mirrors are alternately adjusted, the optical axis can be adjusted more accurately.

[0021]

As described above, according to the present invention,
As well as a possible coarse adjustment of the laser output Ri by manually,
The laser output can be adjusted to the maximum to a simple record over laser device.

[Brief description of the drawings]

FIG. 1 shows He- Cd in a laser device according to an embodiment .
FIG. 2 is a schematic view of the entire laser head .

FIG. 2 is a perspective view showing a mounting position of an alignment mechanism.

FIG. 3 is an enlarged view of an alignment mechanism.

FIG. 4 is an explanatory diagram of a laser output detection unit and a control unit.

FIG. 5 is a time chart of the laser output detection means and the control means shown in FIG.

FIG. 6 is a graph showing a relationship between a mirror angular displacement and a laser output.

FIG. 7 is a graph showing a relationship between a mirror angular displacement and a laser output in a control state.

[Explanation of symbols]

 1mirrorHolder 2 alignment machine
Structure 3mirror 4rod 5 Laser tube 51 Discharge tube 52 anode 53 cathode 6 cases 8 Laser output detection
Means 9 Control means 11 Fixed plate 12 Movable plate 13 Through hole 22 Drive motor 23 Rotary shaft 25 Flexible coupling 26 Micrometerhead 26A Moving part 27 Ball 28 Spring 81 Photo amplifier 82 Sample and hold circuit 83 Comparator 91timingCircuit 92 Mono multivibrator 93 Mono multivibrator
Blazer 94 AND circuit 95 Toggle flip-flop circuit

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01S 3/086

Claims (1)

(57) [Claims] A mirror is provided outside a fixed plate fixed to a rod.
A mirror holder having a movable plate over is held, this
In a laser device comprising an alignment mechanism attached to a mirror holder, a laser output detection unit, and a control unit for the alignment mechanism, the alignment mechanism includes a drive motor fixed to the fixed plate and a displacement adjusting micro A meter head , a flexible coupling for connecting these drive motors and the micrometer head , and a manual adjustment screw screwed into the movable plate and pressed against a movable portion of the micrometer head. A laser device intermittently driving the drive motor in a direction to increase a laser output based on a detection result detected by an output detection unit.