WO2019015963A1 - DEVICE AND METHOD FOR PROTECTING LASER OPTICS - Google Patents

Abstract

Device and method for protecting a laser optical system (2), wherein the device comprises at least one developable on a roll (3), developable glass ribbon (4) for the protection of the laser optics. A section of the glass band (4) can be guided for protection from the laser optics (2), in particular between the laser optics and a workpiece to be machined. The device may comprise means (6) for detecting the number of particles on a section of the glass ribbon, so that the glass ribbon can be continued depending on the number of particles detected, that is to say if the soil is too dirty.

Description

 The invention relates to a device and a method for protecting a laser optic and to the use thereof.

 Devices and methods for protecting laser optics, in particular for protection against external influences (for example, dirt, splashes of material,

Sparks, scratches) when machining workpieces by means of a laser beam, such as the filamentation or separation of glass (for example DE 10 2012 110971 A1) or the cutting, welding, engraving of metal, are basically known.

 Corresponding protective glasses as part of a device or a

Methods for protecting a laser optic are commercially available, e.g. at

 - Laser Components GmbH, Olching, Germany,

 (Http://www.lasercomponents.com/de/produkt/schutzglaeser/);

 - SVS welding GmbH, Mülheim an der Ruhr, Germany, (http://svs-schweisstechnik.de/pages/laserschutzglaeser.php);

 - GVB GmbH, Herzogenrath, Germany, (http://www.g-v-b.de/laserschutzglaeser.htm).

 Known protective glasses are typically about 0.5 mm thick and are screwed or plugged in front of the laser optics. If these protective glasses are soiled or damaged by dust, they must be cleaned or replaced, which results in a shutdown of the laser processing systems. The

Contamination depends on the working distance of the laser optics to the workpiece. This is the case in particular for laser optics with a short focal length, in particular <100 mm. Often one tries by additional air swords before the

Laser optics and / or the protective glasses to reduce pollution. As a result, other negative effects such as carryover and

Turbulence of the environment arise. Based on this, it is an object of the invention to reduce the standstill of laser processing equipment due to negative external influences, in particular by contamination of protective glass, or even to avoid and to provide an improved protective device and an improved protection method for the laser optics.

 The object is achieved according to claim 1 by a device for protecting a laser optics, wherein the device comprises at least one mounted on a roll, developable glass ribbon for protecting the laser optics.

 A portion of the glass ribbon can thus be easily routed and positioned for protection from the laser optics (possibly also at a preferred angle to the laser beam or to the laser optics (see, for example, Fig. 2)) and is as needed, e.g. with negative external influences, e.g. if too dirty or scratched, easy to carry on. This reduces downtime and increases the lifetime of laser optics and lasers, thus improving production quality in a simple way.

 The device is usually the last element in front of a workpiece to be machined by means of a laser beam and is after the laser optics or

can be arranged between the laser optics and the workpiece to be machined or is arranged here.

 Further preferred embodiments of the invention will be described below.

 The device may comprise at least one further roll for winding up the glass ribbon.

 The device may comprise at least one roller for guiding the glass ribbon.

 The device may comprise means for stepwise or continuous guiding of the glass ribbon.

The device may comprise means for detecting the number of particles on at least a portion of the glass ribbon, so that the glass ribbon can be continued depending on the number of particles detected. This allows service life until the intervention (downtime of the Laser processing plant) further and automatically measured the contamination of the glass ribbon and thus improve the process stability. Thus, for example, with the help of a sensor permanently the contamination of the glass ribbon measured (eg scattering / back reflection of the laser beam to the soiled glass ribbon surface which is located to protect against the laser optics) and then based on the measurement result, the glass ribbon in front of the laser optics are continued

 The glass ribbon may have a thickness of 10 μιη to 200 μιη preferably 30 μιη to 100 μιη. The thinner the glass ribbon, the more glass ribbon can be stored and unwound on a roll to save space.

 The widths of the glass bands are usually chosen so that they are larger than the laser optics to be protected are typically in the range between 10 mm to 400 mm, preferably between 30 mm to 200 mm. The length of the glass ribbon may be at least ten times the width of the glass ribbon, preferably at least twenty times, more preferably at least fifty times.

 The glass ribbon may comprise at least one coating,

in particular at least one antireflection coating (for example for increasing the laser beam transmission or reduction of the laser beam reflection), a

Non-stick coating (soiling, particles etc. may not adhere well) or anti-scratch coating (more resistant to external mechanical influences) or combinations of these or other coatings.

 The glass band is preferably made of soda-lime glass, borosilicate glass (Z.B: SCHOTT: D 263 T eco), borosilicate crown glass (eg SCHOTT: BK7), alkali-free glass (eg SCHOTT: AF 37, AF 32 eco,) or quartz glass.

 Preferred production methods of the glass ribbon are downdraw, overflow, fusion or redrawing processes.

 The glass composition of the glass ribbon can be selected in particular according to the wavelength of the laser used and the laser power and should be as transparent as possible for them. Furthermore, the

Glass composition of the glass ribbon according to the present outside Influences are selected (eg necessary temperature or

Thermal shock resistance, chemical resistance, mechanical resistance, etc.). Preferably, the device is part of a device for laser machining of workpieces, in particular of metals, glasses, plastics or composites of these materials.

 Furthermore, the object is achieved according to claim 10 by a method for protecting a laser optics, wherein at least one stored on a roll, developable glass ribbon for protecting the laser optics is used.

 Preferably, at least one further roll is used to wind up the glass ribbon. Preferably, at least one further roller can be used to guide the glass ribbon. Preferably, the glass ribbon can be guided stepwise or continuously.

 The number of particles on at least a portion of the glass ribbon is preferably detected, so that the glass ribbon can be continued depending on the number of detected particles.

 Preferably, a glass ribbon with a thickness of 10 μιη to 200 μιη preferably 30 μιη to 100 μιτι used.

 In a further embodiment of the method, the glass ribbon may have at least one coating, in particular at least one

Anti-reflective coating, a non-stick coating or a

 Anti-scratch coating or combinations of these coatings.

 The glass band used may consist of soda-lime glass, borosilicate glass (eg SCHOTT: D 263 T eco), borosilicate glass (eg SCHOTT: BK7), alkali-free glass (eg SCHOTT: AF 37, AF 32 eco,) or quartz glass.

 The method can be used during the laser machining of workpieces, in particular of metals, glasses, plastics or composites of these materials.

 Basically, therefore, a glass ribbon (a Dünststglasrolle) as

Protective glass can be used for a laser optics, which then before the

Laser optics is vorbeiziehbar or is passed by. If e.g. a

Contamination is detected, the glass ribbon is further wound, so a new one Section of the glass ribbon to be used as protection. At very homogeneous

Contamination can also be a system without detection can be used, in which a continuous movement of the glass ribbon is set.

 The glass ribbon may be mounted on two rollers similar to a video cassette and be passed over at least two other pulleys very close to the laser optics. By a housing, the glass ribbon can also be mechanically protected. The enclosure can be designed so that it flush with the laser optics, so as to prevent any contamination of the laser optics. The attachment of the protection system to the laser optics can be done via quick connection systems, whereby a simple assembly and disassembly is guaranteed.

 In a particular embodiment, the glass ribbon permanently under

Tension or tension are maintained in order to prevent warping of the glass ribbon from a plane perpendicular to the optical axis, in particular during movement of the laser optics. This can be done by a

 Speed difference during roller movement, friction or

Braking effect or similar mechanisms can be realized.

 The invention is of particular use for laser processing processes with fixed, low focal length laser optics, e.g. the

Cutting or filament glass, or laser ablation

 Material surfaces or any existing coatings. These processes typically work with focal lengths <30mm and are very

performance-sensitive. As a result, for example, the low level of contamination due to particle ejection during the process of filamentation of glass resulting channels during continuous operation is critical for process stability. By preventive maintenance (experience about once a day in continuous operation), the process stability can be ensured by cleaning the laser optics or changing the protective glass.

 In the following the invention with reference to the embodiments and Figures 1 to 8 will be explained in more detail.

FIG. 1 shows a device 1 for protecting a laser optical system 2. The apparatus 1 comprises a roll-on glass band 4, which is mounted on a roll 3 and protects the laser optical system 2, has a further roll 5 for winding the glass ribbon 4 and two further rolls for guiding the roll

Glass bands 4 on. The other two rollers are arranged below the laser optics 2 left and right. Furthermore, the device has a housing 7 for mechanical protection of the glass ribbon 4. Means for incrementally or continuously guiding the glass ribbon 4 are not shown (e.g.

Roller drive or motor shaft).

 FIG. 2 shows the device according to FIG. 1, wherein the glass band 4 is guided past the laser optics 2 by means of the two further rollers for guiding the glass band 4 at a specific angle or can be guided past them.

 FIG. 3 shows the device according to FIG. 1, the device 1 having a means 6 for detecting the number of particles on at least one section of the glass band 4, so that the glass band 4 can be continued depending on the number of particles detected.

 FIG. 4 shows a further variant of the device 1 according to the invention. In this case, the glass band 4 can be guided out of the enclosure 7 by means of the three further rollers and held in tension.

 Figure 5 shows the device according to the invention from Figure 1, wherein the black box in the middle represents a structure with a laser scanner.

 Figures 6 to 8 are three-dimensional representations of a device according to the invention for better clarity.

 LIST OF REFERENCE NUMBERS

 1. Device for protecting a laser optics 2

 2. Laser optics.

 3. roll for unwinding the glass ribbon 4

 4. Unwindable glass ribbon

 5. Another role for winding the glass ribbon 4

 6. means for detecting the number of particles on at least a portion of the glass ribbon 4th

 7. Housing

Claims

claims 1. Device for protecting a laser optic,  characterized,  in that the device comprises at least one unrollable glass band mounted on a roll for protecting the laser optics. 2. Apparatus according to claim 1,  characterized,  the device comprises at least one further roll for winding up the glass ribbon. 3. Device according to one of the preceding claims,  characterized,  in that the device comprises at least one roller for guiding the glass ribbon. 4. Device according to one of the preceding claims,  characterized,  in that the device comprises means for stepwise or continuous guiding of the glass ribbon. 5. Device according to one of the preceding claims,  characterized,  in that the device comprises means for detecting the number of particles on at least one section of the glass ribbon, so that the glass ribbon can be continued depending on the number of particles detected. 6. Device according to one of the preceding claims, characterized, that the glass ribbon has a thickness of 10 μιη to 200 μιη. 7. Device according to one of the preceding claims, characterized, in that the glass ribbon comprises at least one coating, in particular at least one antireflective coating, a non-stick coating or an anti-scratch coating or combinations thereof Coatings. 8. Device according to one of the preceding claims, characterized, that the glass ribbon is made of soda-lime glass, borosilicate glass, Borosilikatkronglas, alkali-free glass or quartz glass consists. 9. Device according to one of the preceding claims, characterized, the device is part of a device for the laser machining of workpieces, in particular of metals, glasses, plastics or composites of these materials. 10. Method for protecting a laser optic characterized, in that at least one unrollable glass band stored on a roll is used to protect the laser optics.