Laser marker

Abstract

The laser marker (1) comprises: - at least one first chamber (2) provided with a laser assembly (3) adapted to emit at least one laser beam (R) towards an item to be marked (A); - at least one second chamber (4) provided with an electronic control unit (5) configured to electronically control the laser assembly (3); - temperature adjusting means (6) placed between the first chamber (2) and the second chamber (4) and adapted to adjust the temperature of at least one of either the laser assembly (3) or the electronic control unit (5).

Description

[0001] LASER MARKER

[0002] Technical Field

[0003] The present invention relates to a laser marker.

[0004] Background Art

[0005] In numerous industrial sectors, laser appliances are increasingly being used as markers in order to engrave an identifying mark on the manufactured products. As is well known, laser beam generators tend to use high power in order to concentrate the light radiation into a laser beam from the source and to move the laser beam itself according to the identifying mark to be engraved on the item to be marked, resulting in overheating of the marker, which can compromise the operation thereof.

[0006] Therefore, in order to limit this overheating, in known types of laser markers, the components are assembled in a large appliance in order to allow adequate spacing between the components themselves and effective operation of the marker.

[0007] However, this arrangement limits the use of known laser markers directly on board of working machines already present in production plants, with the consequence of having to provide a special marking station along the production line, which can lead to an increase in plant management costs and longer machining times.

[0008] Description of the Invention

[0009] The main aim of this invention is to devise a laser marker that allows a virtually constant temperature to be maintained during use.

[0010] Another object of this invention is to devise a laser marker that is compact in size and can be easily installed on working machines already present in production plants.

[0011] Another object of this invention is to devise a laser marker that allows the aforementioned drawbacks of the prior art to be overcome with a simple, rational, easy and effective to use as well as affordable solution.

[0012] The aforementioned objects are achieved by this laser marker having the characteristics of claim 1.

[0013] Brief Description of the Drawings Other characteristics and advantages of the present invention will become more apparent from the description of a preferred, but not exclusive, embodiment of a laser marker, illustrated by way of an indicative, yet non-limiting example in the accompanying drawings, in which:

[0014] Figure 1 is an axonometric view of a laser marker according to the invention;

[0015] Figure 2 is an axonometric view of the laser marker according to the invention from a different angle;

[0016] Figure 3 is an exploded axonometric view of the laser marker according to the invention;

[0017] Figure 4 is a cross-sectional view of the adjusting plate according to the invention;

[0018] Figure 5 is a plan view of the laser assembly according to the invention;

[0019] Figure 6 is a cross-sectional view along the plane VI-VI in Figure 5;

[0020] Figure 7 is an axonometric view of a detail of the second chamber. Embodiments of the Invention

[0021] With particular reference to these figures, reference numeral 1 globally denotes a laser marker.

[0022] The laser marker 1 according to the invention comprises: at least one first chamber 2 provided with a laser assembly 3 adapted to emit at least one laser beam R towards an item to be marked A; at least one second chamber 4 provided with an electronic control unit 5 configured to electronically control the laser assembly 3.

[0023] The laser marker 1 can be used to make a distinctive mark on the item to be marked A. In this regard, it should be noted that, for the purposes of this disclosure, the item to be marked A can be of any type and made of any material. At the same time, the identifying mark may be a serial number, and / or a code (of the type of a barcode or the like) and / or a distinctive logo / trademark of the manufacturer, and / or any other mark useful for identifying or distinguishing one item or one portion thereof from another. The engraving by the laser beam R can be done by changing the color of the material with which the item is made, by removing the material itself, or in other ways known to those skilled in the art. In actual facts, therefore, the operating part, consisting of the laser assembly 3, and the electronic part, consisting of the electronic control unit 5, are separated into distinct compartments so that they do not overheat each other.

[0024] Specifically, in accordance with the embodiment shown in the figures, the first chamber 2 is arranged below the second chamber 4.

[0025] In the context of this disclosure, the terms “lower” and “upper” relate to the position of the two chambers 2, 4 and of the various components with reference to a position of use wherein the laser marker 1 is placed resting on a work surface where, in fact, the first chamber 2 is in contact with such a work surface.

[0026] The laser marker 1 also comprises temperature adjusting means 6 placed between the first chamber 2 and the second chamber 4 and adapted to cool at least one of either the laser assembly 3 or the electronic control unit 5.

[0027] The temperature adjusting means 6 allow the two chambers 2, 4 to be maintained at an ideal and almost constant working temperature. It is well known, in fact, that the laser devices are subject to considerable overheating and yet only operate effectively at an operating temperature of between 15 °C and 30°C.

[0028] For the purposes of this disclosure, for simplicity’s sake, the temperature adjusting means 6 will be referred to as means for cooling the laser marker 1. It cannot, however, be ruled out that, if the laser marker 1 is used at temperatures significantly below 15 °C, the temperature adjusting means 6 may also have the function of heating the laser marker itself.

[0029] Usefully, the temperature adjusting means 6 are arranged so as to separate the first chamber 2 and the second chamber 4. In this way, it is possible to ensure that the operating part and the electronic part remain separate, in order to effectively cool down both.

[0030] For this purpose, the temperature adjusting means 6 comprise a passage 7 for the electronic connection of the laser assembly 3 to the electronic control unit 5. Specifically, the passage 7 allows the transit of the connection cables needed for connecting the laser assembly 3 to the electronic control unit 5 and / or to additional components. The temperature adjusting means 6 are arranged to close, apart from the passage 7, at least one of either the first chamber 2 or the second chamber 4.

[0031] With reference to the embodiment shown in the figures, the temperature adjusting means 6 are arranged to close both chambers 2 and 4.

[0032] Usefully, the laser marker 1 also comprises hinging means 8 adapted to allow easy opening of the first chamber 2.

[0033] The hinging means 8 allow practical access to the first chamber in order to allow installation of the marker itself or in case of maintenance work. In this case, the hinging means 8 are placed between the first chamber 2 and the temperature adjusting means 6.

[0034] Advantageously, the temperature adjusting means 6 comprise an adjusting plate 9 provided with at least one fluid-operated circuit 10 for the flow of a working fluid.

[0035] The working fluid may be in liquid or gaseous form. Preferably, the working fluid is in liquid form. More preferably, the working fluid is water. It cannot, however, be ruled out that the working fluid may be of a different type and selected, e.g., according to the operating temperature. For example, the working fluid may be a flow of air.

[0036] The adjusting plate 9 is made of a thermally conductive material, preferably a metallic material.

[0037] In accordance with the embodiment shown in Figure 4, the fluid-operated circuit comprises two main stretches that are substantially straight and parallel to each other and a transverse stretch placed between the two main stretches.

[0038] The main stretches extend parallel to a longitudinal direction of development of the laser marker 1.

[0039] The fluid-operated circuit 10 comprises at least one inlet port 11 and at least one outlet port 12 for the flow of the working fluid. The inlet port 11 and the outlet port 12 are each located at one end of a respective main stretch and face at the same side of the laser marker 1. The transverse stretch is located on the opposite side to the inlet port 11 and to the outlet port 12. In actual facts, the working fluid flows through the adjusting plate 9 thus following a “U” path.

[0040] Advantageously, the adjusting plate 9 comprises a recirculation portion 13 provided with the fluid-operated circuit 10 and facing one of either the first chamber 2 or the second chamber 4, and a dissipation portion 14 facing the other of either the second chamber 4 or the first chamber 2 and provided with a plurality of lamellae 15 substantially parallel to each other and transverse with respect to the lying plane of the adjusting plate 9.

[0041] In accordance with the embodiment shown in the figures, the recirculation portion 13 faces the first chamber 2 and the dissipation portion 14 faces the second chamber 4.

[0042] In this way, the coldest part of the adjusting plate 9 is located at the operating part of the laser marker 1, which is the part that requires better temperature adjustment.

[0043] On the opposite side, the dissipation portion 14 contributes to the dissipation of the heat generated by the electronic control unit 5.

[0044] In fact, the presence of the lamellae 15 allows air to flow through and ensures optimal heat exchange with the external environment. In this case, however, it is advisable for the air temperature to be comprised between 20°C and 25°C.

[0045] The temperature adjusting means 6 also comprise a connection plate 16, associated with the adjusting plate 9 at the dissipation portion 14, and supporting the electronic control unit 5.

[0046] The connection plate 16 is in turn made of thermally conductive material, preferably of metallic material, and is in the form of a substantially continuous body, apart from the passage 7 and any holes necessary for fixing to the other components of the laser marker 1.

[0047] The connection plate 16 thus allows heat to be transmitted in a substantially even maimer between the second chamber 4 and the adjusting plate 9.

[0048] Usefully, the laser assembly 3 comprises at least one source unit 17 adapted to emit the laser beam R and comprising at least one pumping diode 18 adapted to generate a light radiation.

[0049] The source unit 17 also comprises a treatment device 19 connected to the pumping diode 18 and adapted to transform the light radiation into a laser beam of coherent rays. In this case, the treatment device 19 is connected to the pumping diode 18 by means of a fiber optic cable 20. In detail, the treatment of the light radiation causes a considerable dispersion of energy; therefore, in order to obtain a laser beam of adequate power, the pumping diode 18 must generate an initial high-power light radiation.

[0050] The pumping diode 18, therefore, involves high energy consumption and undergoes considerable overheating to generate high-power light radiation.

[0051] For this purpose, the pumping diode 18 is advantageously associated with the temperature adjusting means 6.

[0052] Specifically, the pumping diode 18 is placed in contact with the adjusting plate 9 and, more precisely, with the recirculation portion 13.

[0053] Furthermore, the pumping diode 18 is usefully associated with the adjusting plate 9 by interposition of heat exchanging means 21.

[0054] The heat exchanging means 21 allow the cooling of the pumping diode by the adjusting plate 9 to be optimized.

[0055] In accordance with the embodiment shown in the figures, the heat exchanging means 21 comprise at least one Peltier cell. It cannot, however, be ruled out that the heat exchanging means may be of a different type.

[0056] As mentioned above, the pumping diode 18 transmits light radiation to the treatment device 19 via the fiber optic cable 20 in order to transform the light radiation into a consistent laser beam.

[0057] The treatment device 19 comprises an active medium responsible for the transformation of the light radiation, which also determines the wavelength of the laser beam R. In particular, the active medium is selected on the basis of the type of item to be marked A on which the identifying mark is to be engraved. Once it reaches the treatment device 19, the light radiation strikes and excites the active medium, generating the laser beam. The generated radiation is concentrated through a series of reflective elements and then emitted through an output portion 22 of the treatment device 19, thus generating the laser beam R. The active medium can be gaseous, liquid, or solid.

[0058] In accordance with a preferred embodiment, the treatment device 19 comprises an active medium of the solid type.

[0059] Preferably, the active medium is neodymium-doped yttrium aluminum garnet. Advantageously, the laser assembly 3 also comprises cooling means 23 associated with the source unit 17, in this case with the treatment device 19.

[0060] The cooling means 23 are adapted to operate in conjunction with the temperature adjusting means to maintain an optimal operating temperature within the first chamber 2.

[0061] The cooling means 23 comprise at least one fan body 24. The cooling means 23 may also comprise a Peltier cell device, not shown in detail in the figures, placed between the treatment device 19 and the fan body 24.

[0062] Advantageously, the source unit 17 also comprises at least one plug device associated with the treatment device 19 and adapted to generate a laser beam R of the pulsed type.

[0063] In particular, the plug device is internally associated with the treatment device 19 and is of the passive Q-switch type.

[0064] The plug device allows the radiation to be emitted alternately so as to allow the radiation itself to accumulate and generate a high-power laser beam R for a very short time.

[0065] Alternative embodiments cannot however be ruled out wherein the source unit 17 may be of a different type than that described herein and, e.g., may comprise an active medium and / or a plug device of a different type.

[0066] It is also possible that the plug device is not present, so as to obtain a laser beam R of the continuous type.

[0067] The laser beam R is emitted by the laser marker 1 through an emission port 25 to reach the item to be marked A.

[0068] The laser assembly 3 also comprises reflective means 26 adapted to direct the laser beam from the output portion 22 to the emission port 25.

[0069] Specifically, in accordance with the preferred embodiment shown in the figures, the reflective means 26 comprise a pair of mirrors 27a, 27b placed between the output portion 22 and the emission port 25, of which a first mirror 27a, adapted to receive the laser beam R from the output portion 22, is arranged at 45° with respect to the latter, and a second mirror 27b, adapted to reflect the laser beam R towards the emission port 25, is arranged at 90° with respect to the first mirror 27a.

[0070] In actual facts, the laser beam R leaving the source unit 17 travels along a “U” path before exiting the laser marker 1.

[0071] This embodiment solution significantly reduces the overall dimensions and makes the laser marker 1 considerably compact and practical to use.

[0072] The laser assembly 3 also comprises at least one focusing device 28 adapted to focus the laser beam R leaving the source unit 17.

[0073] In detail, the laser beam R leaving the source unit 17 consists of a set of radiations that is substantially parallel to each other; the spot diameter of the laser beam R is defined by the dimensions of the output portion 22 of the treatment device 19 and may result in an insufficient energy density (i.e.’ energy per mm2) to mark the item to be marked A and / or a low resolution in the identifying mark.

[0074] The presence of the focusing device 28 allows the laser beam R to be concentrated on a smaller sectional area (i.e., ideally a point), allowing for a higher energy density and greater marking precision.

[0075] The focusing device 28 is of the lens type and is suitably designed to obtain a laser beam R with converging radiation.

[0076] It cannot be ruled out that the focusing device 28 may be of a different type, e.g., of the electronic liquid lens type.

[0077] The spot diameter of the laser beam R passing through the focusing device 28 therefore tends to decrease as it moves away from the latter until it becomes substantially point-like. The laser beam R thus obtained therefore allows for precise engraving provided with high resolution in the engraved identifying mark.

[0078] Usefully, the focusing device 28 is movable along a direction of focusing F to vary the focal length of the laser beam R.

[0079] In particular, the focal length can be varied according to the shape of the item to be marked A and to the actual distance of the relevant surface to be engraved with respect to the laser marker 1.

[0080] In this way, the laser marker 1 is able to engrave the identifying mark with high resolution on items of various types and shapes.

[0081] For this purpose, the laser assembly 3 comprises movement means 29 adapted to move the focusing device 28. The movement means 29 comprise: a supporting element 30 of the focusing device 28; a guiding element 31 extending along the direction of focusing F and supporting the supporting element 30 by sliding; at least one motor element 32 adapted to set a shaft 33 in rotation, which is of the worm gear type and is associated with the supporting element 30.

[0082] Usefully, the laser assembly 3 also comprises at least one position sensor 34 operationally connected to the electronic control unit 5 and adapted to detect the presence of the focusing device 28 at a predefined position.

[0083] In detail, the position sensor 34 is configured to detect the position of the focusing device 28 at an end-of-stroke position wherein it is at a position of maximum proximity to the emission port 25.

[0084] The position sensor 34 may be of the type of an inductive sensor or the like.

[0085] The electronic control unit 5 also comprises a distortion compensation unit. It is known, in fact, that the deflection of the laser beam R, especially when it generates an output beam parallel to the beam generated by the laser source, generates a distortion in the image being engraved. As a result, the effect obtained does not correspond to the desired one and in some cases may be incomprehensible .

[0086] To overcome this drawback, instead of a simple focusing lens, some laser devices are provided with special lenses, F-theta lenses, adapted to compensate for such distortions in order to obtain an engraved image that corresponds to the original image.

[0087] However, these lenses are very expensive and, above all, are not insignificant in size.

[0088] Therefore, the laser marker 1 according to the present invention is provided with a compensation unit which, using special software, is adapted to deform the identifying mark to be engraved in a maimer complementary to the deformation caused by the deflection of the laser beam R without the need for devices such as F-theta lenses.

[0089] The presence of the compensation unit therefore makes it possible to fix the aforementioned technical problem with a low-cost and space-saving solution. Alternative embodiments wherein the compensation unit is not provided and / or the laser assembly 3 is provided with F-theta lenses or the like cannot however be ruled out.

[0090] Usefully, the laser assembly 3 comprises at least one baffle device 35 adapted to direct the laser beam R towards the item to be marked A.

[0091] The baffle device 35 is placed between the reflective means 26 and the emission port 25 and has the function of moving the laser beam R according to the mark to be engraved on the item to be marked A.

[0092] In particular, the baffle device 35 comprises at least one baffle element 36, of the type of a mirror, movable in rotation around a respective axis to vary the direction of emission of the laser beam R.

[0093] For this purpose, the baffle device 35 comprises a galvanometer 37 adapted to move the baffle element 36.

[0094] The laser marker 1 also comprises at least one electronic driving board 38a, 38b operationally connected to the electronic control unit 5 and to the baffle device 35.

[0095] In order to obtain a precise engraving of the laser beam R, the baffle element 36 must be moved very quickly and accurately. As a result, the electronic driving board 38a, 38b also undergoes significant overheating.

[0096] Usefully, therefore, the electronic driving board 38a, 38b is in turn associated with the temperature adjusting means 6.

[0097] In accordance with the embodiment shown in the figures, the laser assembly 3 comprises at least two baffle devices 35 and the laser marker 1 comprises at least two electronic driving boards 38a, 38b, each operationally connected to a respective baffle device 35.

[0098] In order to optimize the cooling of the electronic driving boards and to reduce the overall dimensions, a first electronic driving board 38a is housed within the first chamber 2 and a second electronic driving board 38b is housed within the second chamber 4.

[0099] In particular, the first electronic driving board 38a is arranged in contact with the recirculation portion 13, while the second electronic driving board 38b is arranged in contact with the connection plate 16. Alternative embodiments of the present invention cannot, however, be ruled out wherein, e.g. two baffle devices 35 are still provided but only one electronic driving board connected to both baffle devices 35, and / or wherein the electronic driving board(s) is / are built into the electronic control unit 5. Advantageously, the laser marker 1 also comprises ventilation means 39 arranged within the second chamber 4 and adapted to cool down at least the electronic control unit 5.

[0100] The ventilation means 39 comprise at least two fan devices 40, in this case two radial fans, which contribute to the cooling of the electronic control unit 5 but also of the second electronic driving board 38b as well as of any further components present in the second chamber 4.

[0101] It has, in practice, been ascertained that the described invention achieves the intended objects and, in particular, the fact should be emphasized that the laser marker according to the invention minimizes overheating during use. Furthermore, this laser marker is compact and small in size and easy to install on working machines already present in production plants.

Claims

CLAIMS1) Laser marker (1) characterized by the fact that it comprises: at least one first chamber (2) provided with a laser assembly (3) adapted to emit at least one laser beam (R) towards an item to be marked (A); at least one second chamber (4) provided with an electronic control unit (5) configured to electronically control said laser assembly (3); temperature adjusting means (6) placed between said first chamber (2) and said second chamber (4) and adapted to adjust the temperature of at least one of either said laser assembly (3) or said electronic control unit (5).2) Laser marker (1) according to claim 1, characterized by the fact that said temperature adjusting means (6) are arranged so as to separate said first chamber (2) and said second chamber (4).3) Laser marker (1) according to one or more of the preceding claims, characterized by the fact that said temperature adjusting means (6) comprise at least one adjusting plate (9) provided with at least one fluid-operated circuit (10) for the flow of a working fluid.4) Laser marker (1) according to one or more of the preceding claims, characterized by the fact that said fluid-operated circuit (10) comprises at least one inlet port (11) and at least one outlet port (12) for the flow of said working fluid.5) Laser marker (1) according to one or more of the preceding claims, characterized by the fact that said adjusting plate (9) comprises a recirculation portion (13) provided with said fluid-operated circuit (10) and facing one of said first chamber (2) and said second chamber (4) and a dissipation portion (14) facing the other of said second chamber (4) and said first chamber (2) and provided with a plurality of lamellae (15) substantially parallel to each other and transverse with respect to the lying plane of said adjusting plate (9).6) Laser marker (1) according to one or more of the preceding claims, characterized by the fact that said temperature adjusting means (6) comprise at least one connection plate (16), associated with said adjusting plate (9) at said dissipation portion (14), and supporting said electronic control unit (5).7) Laser marker (1) according to one or more of the preceding claims,characterized by the fact that said laser assembly (3) comprises at least one source unit (17) adapted to emit said laser beam (R) and comprising at least one pumping diode (18) adapted to generate a light radiation, said pumping diode (18) being associated with said temperature adjusting means (6).8) Laser marker (1) according to one or more of the preceding claims, characterized by the fact that said pumping diode (18) is associated with said adjusting plate (9) by interposition of heat exchanging means (21).9) Laser marker (1) according to one or more of the preceding claims, characterized by the fact that said laser assembly (3) comprises cooling means (23) associated with said source unit (17), said cooling means (23) comprising at least one fan body (24).10) Laser marker (1) according to one or more of the preceding claims, characterized by the fact that said laser assembly (3) comprises at least one baffle device (35) adapted to direct said laser beam (R) towards said item to be marked (A) and by the fact that it comprises at least one electronic driving board (38a, 38b) operationally connected to said electronic control unit (5) and to said baffle device (35) and associated with said temperature adjusting means (6).11) Laser marker (1) according to one or more of the preceding claims, characterized by the fact that said laser assembly (3) comprises at least two baffle devices (35) and by the fact that it comprises at least two electronic driving boards (38a, 38b) each operationally connected to a respective baffle device (35), wherein a first electronic driving board (38a) is housed within said first chamber (2) and a second electronic driving board (38b) is housed within said second chamber (4).12) Laser marker (1) according to one or more of the preceding claims, characterized by the fact that it comprises ventilation means (39) arranged within said second chamber (4) and adapted to cool at least said electronic control unit (5).13) Laser marker (1) according to one or more of the preceding claims, characterized by the fact that said laser assembly (3) comprises at least one focusing device (28) adapted to focus said laser beam (R) at the output fromsaid source unit (17).14) Laser marker (1) according to one or more of the preceding claims, characterized by the fact that said focusing device (28) is movable along a direction of focusing (F) to vary the focal length of said laser beam (R), and by the fact that said laser assembly (3) comprises at least one position sensor (34) operationally connected to said electronic control unit (5) and adapted to detect the presence of said focusing device (28) at a predefined position.

Images