JP2748837B2 - Laser device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is to prevent unsafeness due to inadvertent emission of laser light, and particularly to establish safety at the start of laser oscillation with an inexpensive and simple configuration.

[0002]

2. Description of the Related Art FIG. 3 is a schematic block diagram showing one embodiment of a conventional laser device. In FIG. 2, reference numeral 1 denotes a gas laser tube serving as a laser light source, 2 denotes a manual shutter, 3 denotes a housing provided with a laser tube 1 and a shutter 2, and 4 denotes an aperture provided in the housing 3. Immediately before that, a shutter 2 is arranged. Reference numeral 5 denotes a laser beam, and reference numeral 6 denotes a power supply for driving the laser tube 1. FIG. 4 shows B in FIG.
FIG. 3 is a view taken in the direction of the arrow B ′, and a dotted line portion 2 ′ indicates a closed state of the shutter 2.

[0003] Further, as a known example of a configuration for shutting off a laser beam for safety, a laser beam emission time is controlled in accordance with a laser beam intensity for ensuring safety, and a shutter is closed when a laser beam output is low. (Japanese Patent Laid-Open No. 61-112485), a laser beam is separated by a beam splitter, a part of the separated laser beam is received, and it is detected whether or not the shutter is operating normally and abnormal. In such a case, the laser device is configured to be stopped (JP-A-60-233878, JP-A-63-107182).
Japanese Patent Application Laid-Open No. H2-219019) and a configuration including a shutter so that laser light can be emitted only when the output is necessary according to the output.

[0004]

It is specified by the IEC, JIS, and CDRH standards that various measures are taken in a laser device according to the output level and the emission time for safety. Considering this, considering the conventional embodiment, in the example of FIG. 2, when the laser oscillation starts, the rush current of the driving power supply may deviate from the safety classification of the laser set in consideration of the steady state operation state. Occurs instantaneously. At this time, if the shutter is set to the open state, it is not preferable from the viewpoint of safety. Therefore, considering the transient high output at the start of driving, the classification of the laser is set to the upper rank, and the class is requested. There is a disadvantage that the treatment needs to be performed on the laser device, and the laser device is complicated and expensive. In addition, when the laser device is mounted on an application device and used, it must always be opened with the manual shutter, and when the laser operation is stopped, it is opened even when the laser operation is stopped. To reduce the laser output and shorten the life.

In the example of Japanese Patent Application Laid-Open No. 61-112485, the shutter is configured to be opened only at the time of steady low output after the start of driving with a small laser output and only during the period of using laser light. Since the shutter is included in the configuration of the external application device, a transient high output exceeding the laser class set in consideration of the steady operation due to a large rush current at the start of laser driving is generated outside the laser device. Therefore, there is a drawback in that the laser device must be set to a higher class and the treatment required for the class must be performed on the laser device. Further, it is necessary to add equipment such as a beam splitter or the like, and there is a disadvantage that the cost is increased.

Both JP-A-60-233878 and JP-A-63-107182 are shutters for stopping the operation of the laser device itself when the shutter function is abnormal or the laser device is abnormally operated. It is not possible to prevent transient high-power laser light from being emitted outside the laser device due to rush current at the time, and it is necessary to set the laser class to a high-power one again. And has the disadvantage of being expensive. Furthermore, Japanese Patent Laid-Open No.
JP-A-219019 is a shutter mechanism for determining whether or not to emit a laser beam in accordance with the output of a pulse laser and executing it, and is complicated due to a configuration in which the laser output level is detected for each pulse to determine whether or not to emit the laser beam. There was a disadvantage that it became expensive.

[0007]

According to the laser apparatus of the present invention, a laser that oscillates a laser beam, a housing containing the laser, and a laser beam provided in the housing pass when the laser beam is emitted to the outside. And a shutter mounted on the aperture, the shutter receiving a laser beam and detecting the start of laser oscillation, and a mechanical shutter for opening the shutter based on the received light signal. And a control unit that drives the laser and, after a lapse of a few seconds, receives the above-mentioned light receiving signal, drives the mechanical shutter to open and receives the light receiving signal, and maintains the open state until the power for driving the laser is turned off. Power supply.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram of one embodiment of the present invention.
Reference numeral 1 denotes a laser oscillator such as a laser tube serving as a laser light source.
Reference numeral 2 denotes a shutter that controls opening and closing of emission of the laser beam 5 to the outside of the housing 3 through an aperture 4 provided in the housing 3 having the laser oscillation unit 1 therein. The shutter 2 is provided with a light receiving element 7 for detecting laser light such as a solar cell inside the shutter 2 and is in a closed state before laser oscillation, but when the laser light 5 is emitted, the laser light is detected. The electromagnet 8 is driven by the detection signal, and the shutter 2
The shutter 9 is moved to the open state by pulling the iron piece 9 attached to the shutter. The power source 6 for driving the laser oscillator 2 includes a control for driving the electromagnet 8 after a certain period of time has elapsed since the start of driving, in which the electromagnet 8 receives a laser beam detection signal from the light receiving element 7 and outputs an output equal to or greater than the classified laser output. And a control unit is provided. This control unit is a circuit that keeps the shutter open until the power is turned off.

In the embodiment of the present invention, in the event that the electromagnet 8 of the shutter section fails or the power supply 6 fails, the magnetic field of the electromagnet 8 is no longer generated, and the iron piece 9 of the shutter 2 separates from the electromagnet 8 and the aperture. It has a fail-safe structure that prevents the laser light 5 from being emitted to the outside of the laser device by returning to the position where the laser light 4 was closed.

Further, the configuration of the embodiment shown here does not limit the present invention. For example, a semiconductor laser or a solid-state laser may be used as the laser light source instead of the gas laser tube.

[0012]

As described above, according to the present invention, the laser beam 5 is detected by the light receiving element 7 at the start of laser oscillation, and the laser beam output is assumed to be in a steady operation by the rush current at the start of driving of the laser oscillator 1. In the case where the value becomes transient or higher than the set class, the electromagnet 8 is driven so that the shutter 2 is opened after the transient time.
It is possible to provide a safe and inexpensive laser device without exceeding the set class and without requiring the laser device to perform a treatment required for a higher class in consideration of a transient state. When the laser is oscillating, the shutter is open and when the power is turned off, the shutter automatically closes, so the aperture is closed when not needed, so dust adheres to the output mirror of the laser oscillator, There is an advantage that it is possible to prevent a decrease in laser output and a short life.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of one embodiment of the present invention.

FIG. 2 is a view taken in the direction of arrows AA ′ in FIG. 1;

FIG. 3 is a schematic view of a conventional example.

FIG. 4 is a view taken in the direction of arrows BB ′ in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Laser oscillator 2 Shutter (open state) 2 'Shutter (closed state) 3 Housing 4 Aperture 5 Laser light 6 Power supply 7 Light receiving element 8 Electromagnet 9 Iron piece 10 Control part

Claims (4)

(57) [Claims] In a laser device having a shutter piece opening / closing mechanism for controlling emission of laser light from a laser light source to the outside, a light receiving element for directly receiving laser light to detect the presence or absence of laser light in said shutter piece is provided. Receiving a signal from the light receiving element, and moving the shutter piece together with the light receiving element to open the shutter after a predetermined time .
And a shutter opening / closing control unit. 2. The method according to claim 1, wherein the shutter piece is made of an iron piece.
2. The laser device according to claim 1, wherein an electromagnet is used as a means for moving the piece . 3. When the generation of the magnetic field of the electromagnet is stopped.
3. The laser device according to claim 2 , wherein the iron piece returns to a position where the shutter is in a closed state . 4. The open / close control unit drives the laser light source .
2. The laser device according to claim 1, wherein the shutter piece is kept open until the shutter stops .