Automatically dimmable laser safety filter and welding helmet

Abstract

An automatically dimmable laser protection filter comprising a light filter set and a control circuit system (4), the light filter set comprising a light filter (1) and a liquid crystal light valve disc (2) electrically connected to the control circuit system (4) for changing the transmittance of visible light, the light filter (1) being coated on at least one side with a reflective film for reflecting infrared rays, ultraviolet rays and laser beams, the light filter (1) being attached to a side adjacent to the light source, while the liquid crystal light valve disc is located on a side adjacent to human eyes, the light filter (1) and the liquid crystal light valve disc (2) being adhesively bonded to one another.

Description

[0001] The utility model relates to laser welding filter technology, in particular to an automatically dimmable laser protection filter and a related welding helmet.

[0002] Compared to the conventional arc welding process, the laser welding process is characterized by high efficiency and high quality and requires less expertise from the operator, so that the laser welding process is rapidly becoming popular and the demand for laser welding protection agents on the market is increasing.

[0003] The welding helmets available on the market are primarily used for arc welding. The automatically dimmable light filters integrated into the welding helmets do not provide any protection against the laser beam during the laser welding process and therefore cannot be used for laser welding. To improve the protection against the laser beam, state-of-the-art technology, such as theA protective filter with variable darkness and related protective equipment suitable for a plurality of different welding types, according to CN 220632353 U, wherein the protective filter comprises a liquid crystal light valve connected to a control circuit for changing the transmittance of visible light, and a first barrier filter layer and a second barrier filter layer, each attached to a single side of the liquid crystal light valve, wherein the first barrier filter layer serves to reduce the transmittance of infrared and ultraviolet light, while the second barrier filter layer acts to block the laser infrared waves.

[0004] Although the above-mentioned protective filters block laser infrared waves with the help of the second barrier filter layer, the laser beam passing through the first barrier filter layer into the liquid crystal light valve can still damage the liquid crystal and shorten the service life of the liquid crystal light valve. Furthermore, the addition of the second barrier filter layer leads to increased manufacturing costs and increased technological complexity.

[0005] The utility model is based on the task of providing an automatically dimmable laser safety filter and a related welding helmet in order to eliminate the conventional deficiencies in terms of increased manufacturing costs or increased technological complexity and damage to the liquid crystal by the laser beam entering the liquid crystal light valve, which are due to the fact that the safety filter must be equipped with multi-layer barrier filters for filtering out ultraviolet, infrared and laser beams.

[0006] To achieve this objective, an automatically dimmable laser safety filter according to claim 1 is proposed. The dependent claims relate to embodiments and a welding helmet with such a laser safety filter. The description explains the invention and provides further embodiments.

[0007] To achieve the object, an automatically dimmable laser protection filter is provided which comprises a light filter set and a control circuit system, wherein the light filter set has a light filter and a liquid crystal light valve disc which is electrically connected to the control circuit system for changing the transmittance of visible light, wherein the light filter is coated on at least one side with a reflective film for reflecting infrared ray, ultraviolet ray and laser beam, wherein the light filter is attached to a side adjacent to the light source, while the liquid crystal light valve disc is located on a side adjacent to the human eyes, wherein the light filter and the liquid crystal light valve disc are adhesively bonded to each other.

[0008] It may further be provided that the liquid crystal light valve disc is provided on the side facing human eyes with a transparent protective membrane which is glued to the liquid crystal light valve disc.

[0009] It may further be provided that the transmittance of the visible light wave through the brightened light filter set is greater than 3.2%.

[0010] It may further be provided that the transmittance of the visible light wave through the darkening light filter set is between 3.2% and 0.00016%.

[0011] It may further be provided that the degree of protection of the light filter set against the laser beam with a wavelength between 900 nm and 1100 nm reaches OD6 or more when brightening or darkening.

[0012] It can further be provided that the reflective film is formed into several layers by vacuum coating.

[0013] It may further be provided that the light filter has a transmittance of less than 0.003% for ultraviolet light with a wavelength of 200 nm to 400 nm and a transmittance of less than 0.014% for infrared light with a wavelength of 780 nm to 2000 nm.

[0014] It may further be provided that the light filter has a transmittance of more than 30% for visible light with a wavelength of 500 nm to 780 nm.

[0015] It can further be provided that the light filter, the liquid crystal light valve disc and the transparent protective membrane are bonded to one another with an optical adhesive, wherein at least one liquid crystal light valve disc is provided.

[0016] To achieve the object, a welding helmet is also provided, comprising a mask body and a previously described automatically dimmable laser protection filter, wherein the mask body is formed on the front side with a transparent window, while the automatically dimmable protection filter is removably inserted into the transparent window.

[0017] The present design has the following advantages over the state of the art: The automatically dimmable laser safety filter according to the invention filters the infrared, ultraviolet, and laser beams through a reflective film attached to the light filter. Specifically, the reflective film can reflect the ultraviolet and infrared rays generated during laser welding and has a protection class of OD6 or higher against laser beams with a wavelength between 900 nm and 1100 nm, while the transmittance of visible light is even higher. Thanks to the direct reflection of the laser beam by the reflective film, the laser beam is prevented from entering the liquid crystal light valve, thus extending the service life of the liquid crystal light valve. The transmittance of visible light is mainly controlled by the control circuit system and the liquid crystal light valve disc. The visible light with appropriate transmittance meets the requirements for protection during laser and electric welding.For monitoring workpieces prior to arcing. Compared to conventional designs, the light filter set according to the invention is even more compact and simpler in design, allowing the filtering of ultraviolet, infrared, and laser beams to be achieved solely by a single light filter. This reduces the thickness, weight, and manufacturing costs of the light filter set, while improving wearing comfort.

[0018] Of course, the components or features described in the preceding embodiments may also be used in other embodiments, either alone or in combination.

[0019] The dimensions and proportions in the attached figures do not correspond to the dimensions and proportions of the actual product. The attached figures are for illustrative purposes only and may omit some non-essential elements or features. Fig. 1 shows a view I of the light filter set according to the invention; Fig. 2 shows a view II of the light filter set according to the invention; Fig. 3 shows a protection principle diagram of the light filter according to the invention; Fig. 4 shows a protection principle diagram of the liquid crystal light valve disc according to the invention; Fig. 5 shows a protection principle diagram of the light filter set according to the invention; Fig. 6 shows a spectral profile of the light filter according to the invention; Fig. 7 shows a spectral profile of the light filter set according to the invention when brightening the liquid crystal light valve.

[0020] The present utility model is described in detail below using exemplary embodiments and figures. Only the preferred embodiments of the utility model are described here. Other variants of how the utility model could be implemented based on the preferred embodiments are conceivable for those skilled in the art.

[0021] As from Fig. 1 to Fig. As can be seen from Figure 7, the present automatically dimmable laser safety filter comprises a light filter set and a control circuit system 4. The light filter set includes a light filter 1 and a liquid crystal light valve disc 2, the liquid crystal light valve disc 2 being electrically connected to the control circuit system 4 to change the transmittance of visible light. The light filter 1 is provided on one or both sides with reflective foil for reflecting infrared, ultraviolet, and laser beams. The light filter 1 filters the laser beam using a reflection method, whereby the ability of the light filter set to filter the laser beam weakens over time. Compared to conventional embodiments, the light filter set according to the invention is even more compact and simpler in construction, so that the filtering of ultraviolet, infrared, and laser beams can be achieved exclusively by one light filter.This reduces the thickness and weight of the light filter set, simplifies manufacturing technology, and improves wearing comfort. Specifically, the reflective film can reduce the ultraviolet and infrared rays generated during the process.

[0022] Laser welding reflects and has a protection class of OD6 or higher against laser beams with a laser wavelength between 900 nm and 1100 nm. Thanks to the direct reflection of the laser beam by the reflective film, the laser beam is prevented from entering the liquid crystal light valve 2 and the service life of the liquid crystal light valve 2 is extended. The transmittance of visible light is primarily controlled by the control circuit system and the liquid crystal light valve disc. The visible light with variable transmittance meets the requirements for protection during laser and electric welding or for observing workpieces from arc flashover. The light filter 1 is attached to a side adjacent to the light source to pre-reflect the ultraviolet, infrared, and laser beams emerging from the light source during welding.The liquid crystal light valve disc 2 is located on a side adjacent to the human eyes, wherein the light filter 1 and the liquid crystal light valve disc 2 are bonded together to enhance the optical performance of the dimming filter.

[0023] A frame is mounted outside the dimming filter, into which the control circuit system 4 and the light filter set are inserted. The frame also provides a protective effect for the light filter set. The liquid crystal light valve disc 2 can be designed in a conventional manner for an automatically dimmable welding filter to control the transmittance of visible light in the present embodiment. The liquid crystal light valve disc 2 can be made of E-glass, liquid crystal, polarizer, and electrode pins. The control circuit system 4 is provided with a circuit board, electronic elements, battery, solar cell, infrared receiver tubes, and wires, all of which can be designed in various ways. This also belongs to the prior art and will not be described further here.

[0024] To improve the scratch resistance of the light filter set, the liquid crystal light valve disc 2 is in a certain embodiment of the invention with reference to Fig. 1 and Fig. 2 is provided on the side facing the human eye with a transparent protective membrane 3, which is glued to the liquid crystal light valve disc 2. The liquid crystal light valve disc 2 is enclosed by the light filter 1 and the transparent protective membrane 3, thus forming a protective mechanism for the liquid crystal light valve disc 2. The transparent protective membrane 3 is made of E-glass, PMMA, or PC to ensure the scratch resistance of the light filter set. It may further be provided that the light filter 1, the liquid crystal light valve disc 2, and the transparent protective membrane 3 are glued together with an optical adhesive. This ensures the optical performance and moisture resistance of the light filter set. The optical adhesive consists of optical UV adhesive or optical silicone adhesive.At least one liquid crystal light valve disc 2 is provided, and possibly two or three as needed. It should be understood that the light filter 1 is made of glass, PMMA, or PC by optical coating.

[0025] As from Fig. 3, Fig. 4 and Fig. As shown in Figure 5, the light filter 1 partially reflects laser beams, infrared rays, ultraviolet rays, and visible light. Part of the visible light passes through the light filter 1 to the liquid crystal light valve disc 2, while the liquid crystal light valve disc 2 controls the transmittance of the visible light through the control circuit system 4 so that visible light suitable for human eyes passes through the liquid crystal light valve disc 2 and the transparent protective membrane 3 into the human eye. This allows operators to observe the welds and the welded workpieces. The light filter assembly consisting of the light filter 1, the liquid crystal light valve disc 2, and the transparent protective membrane is characterized by super-high reflectivity, wide bandwidth, high visible light transmittance, continuous reflection without attenuation, precise spectral control, and scratch resistance.The reflective film is formed into several layers by vacuum deposition. This specially designed multilayer film exhibits highly selective reflection for harmful wavelengths. This maintains visible light transmission and simplifies the design of the light filter set.

[0026] It may further be provided that the light filter has a transmittance of more than 30% for visible light with a wavelength of 500 nm to 780 nm (see Fig. 6), resulting in partially higher transmittance of visible light. The light filter has a transmittance of less than 0.003% for ultraviolet light with a wavelength of 200 nm to 400 nm, a transmittance of less than 0.014% for infrared light with a wavelength of 780 nm to 2000 nm, and a transmittance of almost 0 for blue light with a wavelength of 400 nm to 500 nm, representing better filtering ability.

[0027] As from Fig. As can be seen in Figure 7, the transmittance of the visible light wave through the brightened light filter set is greater than 3.2%. Note that the brightened state means no operation of the liquid crystal light valve disc 2 or no obscured visible light, and the darkened state means ongoing operation of the liquid crystal light valve disc 2 or partially obscured visible light.

[0028] The transmittance of visible light waves through the darkening filter set ranges from 3.2% to 0.00016%. The protection class of the filter set against laser beams with a wavelength between 900 nm and 1100 nm when brightening or darkening reaches OD6 or higher, and if necessary, OD7, OD8 or higher.

[0029] The welding helmet according to the invention comprises a mask body and a preceding automatically dimmable laser safety filter. The mask body is formed with a transparent window on the front, while the automatically dimmable safety filter is removably inserted into the transparent window. The welding helmet's ability to filter laser beams does not diminish over time. Furthermore, the automatically dimmable safety filter is disassembled, which facilitates maintenance and replacement.

[0030] It should be noted that the terms used in describing the present embodiments, such as "front," "rear," "left," "right," "top," "bottom," "upper," "lower," "inside," and "outside," refer to the orientations or positional relationships shown in the accompanying drawings and are intended to facilitate understanding of the embodiments of the invention. They do not represent instructions for actual positioning of components or practical operating directions. In this context, these positional terms do not represent limitations of the embodiment of the invention. The terms "first" and "second" represent a categorization and do not signify or imply relative importance.

[0031] In this utility model, the terms "installation," "connection," and "connection" are to be understood broadly, unless otherwise clearly stated and limited. For example, it may refer to a fixed connection, a detachable connection, or an integral body; a mechanical connection, an electrical connection; a direct connection, an indirect connection via an intermediary; an internal communication between two elements; or an interaction between two elements. Professionals in the industry may understand the specific meanings of the above terms in this utility model depending on the situation.

[0032] Only the listed claims are valid for the scope of protection of the present utility model. The present utility model is not limited to the described embodiments, but may be varied in many ways within the scope of the disclosure. In this context, all new individual and combined features disclosed in the description and / or drawings are considered essential to the invention.

[0033] In summary: The utility model relates to laser welding filter technology, in particular to an automatically dimmable laser safety filter and a related welding helmet, wherein the automatically dimmable laser safety filter comprises a light filter set and a control circuit system, wherein the light filter set has a light filter and a liquid crystal light valve disc which is electrically connected to the control circuit system for changing the transmittance of visible light, wherein the light filter is coated on at least one side with a reflective film for reflecting infrared rays, ultraviolet rays and laser beams, wherein the light filter is attached to a side adjacent to the light source, while the liquid crystal light valve disc is located on a side adjacent to the human eyes, wherein the light filter and the liquid crystal light valve disc are adhesively bonded to one another.According to the present utility model, the laser beams are filtered by reflection through the reflective film coated on the light filter. This eliminates any potential damage to the liquid crystal light valve due to laser beam penetration into the liquid crystal light valve, so that the filtering ability of the light filter set against the laser beam will not diminish over time. List of reference symbols 1 light filter 2 liquid crystal light valve disc 3 transparent protective membrane 4 Control circuit system QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] CN 220632353 U

[0003]

Claims

[1] An automatically dimmable laser protection filter comprising a light filter set and a control circuit system (4), the light filter set comprising a light filter (1) and a liquid crystal light valve disc (2) electrically connected to the control circuit system (4) for changing the transmittance of visible light, the light filter (1) being coated on at least one side with a reflective film for reflecting infrared ray, ultraviolet ray and laser beam, the light filter (1) being attached to a side adjacent to the light source, while the liquid crystal light valve disc is located on a side adjacent to the human eyes, the light filter (1) and the liquid crystal light valve disc (2) being adhesively bonded to each other. [2] Automatically dimmable laser protection filter according to claim 1, characterized bythat the liquid crystal light valve disc (2) is provided on the side facing human eyes with a transparent protective membrane (3) which is glued to the liquid crystal light valve disc (2). [3] Automatically dimmable laser protection filter according to one of the preceding claims, characterized by that the transmittance of the visible light wave through the brightened light filter set is greater than 3.2%. [4] Automatically dimmable laser protection filter according to claim 3, characterized by that the transmittance of the visible light wave through the darkening light filter set is between 3.2% and 0.00016%. [5] Automatically dimmable laser protection filter according to one of the preceding claims, characterized by that the protection class of the light filter set against the laser beam with a wavelength between 900 nm and 1100 nm reaches OD6 or more when brightening or darkening. [6] Automatically dimmable laser protection filter according to one of the preceding claims, characterized by that the reflective film is formed into several layers by vacuum coating. [7] Automatically dimmable laser protection filter according to one of the preceding claims, characterized by that the light filter (1) has a transmittance of less than 0.003% for ultraviolet light with a wavelength of 200 nm to 400 nm and a transmittance of less than 0.014% for infrared light with a wavelength of 780 nm to 2000 nm. [8] Automatically dimmable laser protection filter according to one of the preceding claims, characterized by that the transmittance of visible light with a wavelength of 500 nm to 780 nm through the light filter (1) is greater than 30%. [9] Automatically dimmable laser protection filter according to one of the preceding claims 2 to 8, characterized bythat the light filter (1), the liquid crystal light valve disc (2) and the transparent protective membrane (3) are glued to one another with an optical adhesive, wherein at least one liquid crystal light valve disc is provided. [10] Welding helmet, characterized by that the welding helmet comprises a mask body and an automatically dimmable laser protection filter according to one of claims 1 to 9, wherein the mask body is formed with a transparent window on the front side, while the automatically dimmable laser protection filter is removably inserted into the transparent window.

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