Multi-laser devices and housing caps for multi-laser devices

Abstract

The present invention relates to a multi-laser device with multiple lasers, a housing cap for such a multi-laser device, and a method for manufacturing the housing cap, wherein the housing cap has a top wall, a side wall integrally formed with the top wall and terminating at a bottom edge, and an opening for passing electromagnetic radiation, wherein the side wall has a first thickness measured in a direction perpendicular to a surface of the side wall and a second thickness measured at the bottom edge, particularly in the same direction, the second thickness being less than or equal to the first thickness.

Description

[Technical Field]

[0001] The present invention relates to a multi-laser device, particularly an RGB laser module, as well as a housing cap for such a multi-laser device. [Background technology]

[0002] Multi-laser devices are particularly used in products for reproducing augmented reality (AR) or virtual reality (VR), such as AR or VR glasses. A multi-laser device is a component with multiple lasers that can project an image onto the user's retina. In this case, three edge-emitting lasers (EELs) are often used, where one of these lasers emits in the red wavelength range, one in the green wavelength range, and one in the blue wavelength range.

[0003] These three lasers are advantageously encapsulated in a hermetically sealed housing for reliable durability, particularly to exclude moisture, with the blue laser diode in particular typically requiring such a housing to achieve the desired durability.

[0004] Users' requirements for AR or VR products, especially AR or VR glasses, are an unobtrusive appearance that is indistinguishable or barely distinguishable from conventional products or glasses, maximum wearing comfort, and high-quality images. Therefore, there is an increasing demand for miniaturization, weight reduction, and optimization of multi-laser devices. Summary of the Invention [Problem to be solved by the invention]

[0005] The problem underlying the present invention is therefore to provide a multi-laser device, in particular an RGB laser module, which allows for miniaturization, weight reduction and / or image optimization, a housing cap for such a multi-laser device, and a method for manufacturing the housing cap. [Means for solving the problem]

[0006] To achieve this object, the present invention provides a multi-laser device, particularly an RGB laser module, including a housing and a plurality of lasers disposed within the housing.

[0007] The housing includes a bottom plate and a housing cap attached to the bottom plate, the housing cap including at least one opening, the opening including a transparent member disposed in the opening for allowing electromagnetic radiation to pass therethrough.

[0008] The lasers are in particular configured as a first laser emitting in the red spectral region, a second laser emitting in the green spectral region, and a third laser emitting in the blue spectral region.

[0009] The lasers are each disposed within the housing, spaced apart from the bottom surface of the bottom plate, preferably on pedestals. The lasers are preferably configured as edge-emitting lasers (EELs).

[0010] The housing cap of the housing includes a top wall and a side wall integrally formed with the top wall, the side wall terminating at a lower edge mounted on the base plate.

[0011] Furthermore, the side wall has a first thickness measured in a direction perpendicular to the surface of the side wall and a second thickness measured at the lower edge, particularly in the same direction, which second thickness is less than or equal to the first thickness.

[0012] This advantageously allows smaller constructional dimensions to be realized and / or lateral overhangs at the lower edge to be eliminated or minimized, and in particular the width of the metallization (pad width) on the counter element (especially the bottom plate, e.g. the ceramic substrate) can be reduced, which helps to miniaturize the unit or increases the construction space in the housing.

[0013] According to one preferred embodiment, the side wall has an outwardly curved surface on the inner surface of the housing cap at its lower edge, and is configured in particular so that the thickness of the side wall gradually decreases towards the lowest position of the side wall.

[0014] The side wall can be formed without a protrusion on the outer surface at the lower edge, or the side wall can have a protrusion, which is preferably thinner than the first thickness, particularly preferably thinner than half the first thickness, and even more preferably thinner than a quarter of the first thickness.

[0015] Preferably, the lower edge of the side wall is attached to the bottom plate in such a way that a joining material (e.g., solder material) is trapped between the lower edge of the side wall and the bottom plate, particularly along the direction of the first or second thickness of the side wall and over an area shorter than the first or second thickness of the side wall.

[0016] The lower edges of the side walls can be attached to the bottom plate in such a way that a bonding material (e.g., solder material) is trapped between the outwardly bent surface on the inner surface of the housing cap and the bottom plate, in particular so that the bonding material protrudes higher from the bottom plate at the inner surface of the housing cap than between the lower edges of the side walls and the bottom plate.

[0017] Alternatively or additionally, the lower edges of the side walls can be attached to the base plate in such a way that a bonding material is trapped between the outer surface of the side walls and the base plate, for example between the protrusion and the base plate, in particular so that the bonding material protrudes from the base plate higher at the outer surface of the housing cap than between the lower edges of the side walls and the base plate.

[0018] The sidewall may be formed such that it is tapered at the lower edge, particularly along a direction extending from the upper edge toward the lower edge.

[0019] Preferably, the second thickness of the side wall measured at the lower edge can be at least 5% thinner than the first thickness of the side wall, preferably at least 10% thinner, particularly preferably at least 15% thinner, and even more preferably at least 20% thinner, or at least 25% thinner, or at least 30% thinner than the first thickness of the side wall.

[0020] The second thickness measured at the bottom edge can correspond to the thickness of the sidewall at the bottommost position of the sidewall.

[0021] The first thickness of the side wall measured perpendicular to the surface of the side wall can be equal to the thickness of the side wall adjacent to the upper wall, and / or can be equal to the thickness of the side wall between the upper wall and the lower edge, particularly in the region 25 to 75% between the upper wall and the lower edge, and / or can be equal to the average thickness of the side wall.

[0022] The second thickness of the side wall measured at the lower edge is in particular measured in the same direction as the first thickness of the side wall, or in a direction that differs from said direction by less than 45°, less than 25°, or less than 10°.

[0023] The second thickness of the side wall measured at the lower edge is in particular measured in a direction extending substantially parallel to the surface of the upper wall and / or the bottom surface of the bottom plate, or in a direction differing from said direction by less than 45°, less than 25°, or less than 10°.

[0024] According to one preferred embodiment, the housing cap is hat-shaped, in particular as a lateral peripheral wall with four flat side walls, the side walls being integrally formed with the upper wall.

[0025] At least one opening in the housing cap is preferably located in the side wall or in one of the side walls.

[0026] Preferably, a plurality of openings are provided in the side wall or in one side wall, preferably according to the number of lasers, particularly preferably three openings.

[0027] At least one opening, and in particular each of the plurality of openings, preferably has an extent along a direction from the top wall towards the bottom edge that is greater than the extent along a direction extending in the side wall perpendicular to this direction.

[0028] At least one opening, and in particular each of the plurality of openings, may be elliptical in shape, particularly having a major axis along a direction from the upper wall towards the lower edge.

[0029] The housing cap may include a transparent member disposed in the at least one opening. The transparent member may be attached to the sidewall including the at least one opening, for example, by a bonding material, to hermetically seal the at least one opening. Preferably, the transparent member is configured as an integral part to hermetically seal each of the multiple openings.

[0030] According to one preferred embodiment, the transparent member is attached to the outer surface of the housing cap, in particular to the outer surface of said side wall or one of the side walls, in particular to the outer surface of the side wall comprising at least one opening, in particular by means of a bonding material (e.g. a solder material, e.g. a glass solder).

[0031] The transparent member is preferably mounted at an angle relative to the surface of the side wall, and in particular so that the transparent member is spaced greater from the side wall toward the bottom edge of the side wall than toward the top wall.

[0032] This can very effectively suppress the reflected radiation from the transparent member back towards the laser or lasers.

[0033] Preferably, the transparent member is mounted at its lower edge on a protrusion formed on the outer surface of the side wall, particularly so that it can be positioned obliquely relative to the surface of the side wall.

[0034] According to one preferred embodiment, the upper wall of the housing cap has a thickness, measured perpendicular to the surface of the upper wall, that is less than the first thickness of the side wall, in particular at least 10% less, or at least 20% less, or at least 30% less than the first thickness of the side wall.

[0035] This advantageously allows a weight saving to be achieved and / or a lightweight construction to be realized.

[0036] Moreover, the upper wall of the housing cap can have a thickness measured perpendicular to the surface of the upper wall that is less than the second thickness of the side wall, and in particular at least 10% less, or at least 20% less, or at least 30% less than the second thickness of the side wall.

[0037] The top wall and the side walls integrally formed therewith may comprise or consist of metal.

[0038] The base plate may include or consist of a ceramic, or may include or consist of a metal.

[0039] The transparent member may comprise or consist of glass or sapphire, and / or the optical coating may in particular have an anti-reflection layer.

[0040] The invention further relates to a housing cap for a multi-laser device, in particular for a multi-laser device as described above, which may in particular include one or more of the features described above in relation to the multi-laser device.

[0041] The invention further relates to a method for manufacturing a housing cap, in particular as described above, in particular as described above in connection with a multi-laser device.

[0042] The method according to the invention comprises the following steps: providing a flat starting material, in particular comprising or consisting of metal, preferably forming one or more, in particular round, openings in the flat starting material, deep-drawing the flat starting material to produce a housing cap with a top wall and side walls integrally formed with the top wall, in particular such that the one or more openings are oval openings arranged in one side wall and / or such that the top wall has a thickness less than that of the side walls, cutting the side wall at its lower edge in such a way that the side wall has a first thickness measured perpendicular to the surface of the side wall and a second thickness measured at its lower edge, in particular in the same direction, the second thickness being less than or equal to the first thickness, and preferably attaching a transparent element, preferably by means of a joining material, to the side wall containing the at least one opening, in particular such that the transparent element is oblique to the surface of the side wall, in order to hermetically seal the opening.

[0043] Finally, the invention relates to a device including a multi-laser device such as the one described above, in particular an RGB laser module.

[0044] The invention particularly relates to a head mounted display, in particular an AR eyepiece or glasses, comprising a multi-laser device and / or a housing cap according to the above description.

[0045] The invention further relates to a head-up display including a multi-laser device and / or a housing cap according to the above description.

[0046] Additionally, the present invention relates to a motorcycle helmet including a head-up display according to the above description.

[0047] Furthermore, the invention relates to a projector including a multi-laser device and / or a housing cap according to the above description.

[0048] Finally, the invention also relates to a projector for a mobile device comprising a multi-laser device and / or a housing cap according to the preceding description.

[0049] German Patent Application No. 102020110658.0 and German Utility Model Application No. 202021102072.5, from which priority is claimed, are hereby incorporated by reference and are therefore fully attributed to the disclosure content of the present application as if they were incorporated herein. The features of these documents incorporated herein correspond in particular, where there is a corresponding designation, to the features within the framework of this specification.

[0050] Therefore, in particular, multi-laser devices a housing having a housing cap and a bottom plate; At least one opening is formed in the housing cap, the opening having a transparent member associated with the opening for allowing electromagnetic radiation to pass therethrough; in this case, a first laser emitting in the visible spectrum, particularly in the red spectral region; a second laser emitting in the visible spectrum, particularly in the green spectral region; a third laser, preferably emitting in the visible spectrum, particularly in the blue spectral region; Located in the housing, in this case Electrical leads are routed through the housing to the individual lasers, When the laser is operating, a major portion of the emitted light of the laser passes through the transparent member; In this case, each laser is i) preferably on a pedestal, ii) spaced apart from the bottom surface of the bottom plate; iii) the lasers are aligned with each other, where: The main direction of laser radiation occurs substantially parallel to the bottom plate of the housing.

[0051] The use of a pedestal allows for a precisely defined arrangement of the laser within the housing and further allows for an optimization of the housing geometry, particularly its miniaturization, while simultaneously providing the majority of the laser radiation as useful light, where the majority of the laser radiation is understood to mean more than 80%, preferably more than 85%, most preferably more than 90% of the light emitted from the individual laser through its end face emitting in the direction of the transparent element.

[0052] Furthermore, the base may comprise a material having a heat capacity and specific thermal conductivity that is also determined by its size, thereby allowing the individual lasers to dissipate heat in a desired manner during operation, and thus removing heat from the lasers in a desired manner, thereby dissipating the heat outside the housing.

[0053] Advantageously, in the case of this multi-laser device, the individual lasers can also be electronically controlled separately, particularly with the involvement of the bottom plate, in which case, depending on the color or intensity to be displayed, i.e., depending on the brightness or chromaticity of the displayed image signal as the case may be, not all lasers can emit at the same time, and there can be no emission at all during blanking or dark phases, so that there is almost no optical interaction between the individual lasers within the housing, and even a relatively strong emission, i.e., even if one of the lasers is electronically adjusted to its maximum level, does not result in optical interaction with one of the other lasers, especially if that laser emits, for example, with only a very low intensity.

[0054] For example, an advantage over semiconductor devices that emit a beam perpendicular to the base plate is that the integration of the RGB laser module is improved, especially in applications where only limited space is available, since in this case the base plate can be formed as a supporting unit that can accommodate, for example, further optical units, particularly in a state adjusted to the light emitted by the laser.

[0055] Generally, within the scope of the present disclosure, the blue spectral region is contemplated as a wavelength range from 450 nm to 490 nm, the green spectral region is contemplated as a wavelength range from greater than 490 nm to 560 nm, and the red spectral region is contemplated as a wavelength range from 630 nm to 700 nm, and thus the microlaser device disclosed herein can provide an advantageous color space for displaying virtual signals.

[0056] Alternatively, two or more or all of these lasers may emit light in the same spectral region, which may be advantageous, for example, when the multi-laser device is used for illumination purposes.

[0057] Within the scope of the present disclosure, the main direction of laser radiation is understood to mean the optical axis of the laser light emitted from an individual laser, or at least the propagation direction of the maximum intensity associated with the maximum of the transverse intensity distribution of the emitted laser light, i.e. the direction of axial translation of the transverse intensity maximum.

[0058] As a synonym, for the sake of simplicity within the framework of this disclosure, the term main emission direction is also used for the main direction of laser emission.

[0059] The statement that the main direction of laser radiation occurs substantially parallel to the bottom plate of the housing specifies that this main direction of laser radiation is not higher than 5° from the plane defined by the lower surface of the bottom plate or bottom surface, or is not inclined below this surface by more than 5°.

[0060] A particularly advantageous arrangement is obtained if the housing cap comprises or consists of metal and the base plate comprises or consists of metal, the housing cap being joined to the base plate by welding.

[0061] By the term "comprises a metal", it is intended to be understood that a body made of metal, for example, can be partially or completely covered with a non-metallic coating, for example an oxide layer or a lacquer, in particular a highly absorbent matte lacquer.

[0062] Joining the housing cap to the base plate by welding or melting offers particular advantages with regard to the durability of the multi-laser device in continuous operation, since in this way a liquid-tight and gas-tight joint can be provided between the housing cap and the base plate, for example in accordance with standard MIL-STD 883, Method 1014.

[0063] When soldering such housings, for example when soldering a housing cap to a preferably metal-coated ceramic substrate as a bottom plate, fluxes such as formic acid are often used in a nitrogen or hydrogen atmosphere, residues of which subsequently remain in the housing and, even if only as traces, can already interact with and damage the semiconductor material of the semiconductor laser emitting in the blue spectral region.

[0064] This is not the case in the embodiment described here, since in this case the transparent element can be attached to the housing cap first by a soldering process, and only then can the welding process with the bottom plate be carried out, especially after cleaning the housing cap. This ensures that the atmosphere in the housing contains less than 5000 ppm of HO and that the partial pressure of this water, which is still permitted by the gas-tight design of the housing, does not exceed the limit over the entire service life of the component, which complies with standard MIL883, Method 1018.

[0065] If the base is formed integrally with the base plate, this offers manufacturing advantages, since a correspondingly shaped base plate can then be provided at low cost by means of a material-removing surface treatment or stamping process.

[0066] However, if the base plate includes or is made of a metal such as cold-rolled steel CRS1010, and the base plate includes or is made of a different material from the base plate, in particular oxygen-free high conductive copper (OFHC), preferably press-fitted, soldered, or welded to the base plate, this provides a base with a defined and advantageous specific heat conductivity, the heat capacity of which is determined by its structural dimensions, its specific heat capacity, and the material selection. In this way, efficient temperature management is achieved through targeted heat dissipation of the individual lasers.

[0067] In this case, the aforementioned materials are merely mentioned as examples, and other materials may be used instead, such as aluminum, steel or special steel, as well as austenitic and ferritic special steels, preferably as long as they remain stainless steel for the purposes of the present invention. Furthermore, titanium, copper-rich Monel alloys, or low-melting alloys, including NiFe or NiFeCo alloys, may also be used.

[0068] According to yet another advantageous embodiment, a fast-axis collimating lens (FAC lens) is arranged on the base, preferably at a distance from the end face of the laser, which reduces the intensity loss due to shading of the divergent beam bundle of the emitted laser light and ensures the most efficient possible beam shaping.

[0069] Particularly preferably, the transparent element can comprise or consist of glass, which can comprise, for example, quartz glass or borosilicate glass, and can also consist of sapphire or comprise sapphire, in particular as the crystalline material.

[0070] However, in general, the transparent member has a transmittance of more than 80%, particularly preferably more than 90%, in the spectral range having a wavelength of 250 to 2000 nm, when the transmittance is measured in the direction of the radiation emitted by the laser.

[0071] For the purposes of this disclosure, the phrases light emitted from a laser and radiation emitted from a laser are to be understood interchangeably and used synonymously.

[0072] According to yet another embodiment, the transparent member can be formed as a FAC lens (Fast-Axis-Collimating lens), or similarly the transparent member can include a FAC lens (Fast-Axis-Collimating lens), in particular attached to the transparent member.

[0073] Alternatively, the transparent member may be formed as or include a fiber plate.

[0074] According to a preferred embodiment, the transparent member is held to the housing cap using glass solder, or is held to a frame disposed in the housing cap using glass solder.

[0075] In yet another preferred embodiment, which is desirably smaller in size than the previously described embodiment that uses glass solder to bond the transparent member to the housing cap, a metallic solder, preferably AuSn solder, can be used to hold the transparent member to the housing cap.

[0076] Yet another embodiment includes a transparent member welded to the housing cap.

[0077] At least if the wall of the housing cap on which the transparent element is arranged is inclined relative to the base plate, the inclination angle of the wall of the housing cap relative to the normal to the bottom surface of the base plate being in the range of 35° to 60°, preferably in the range of 40° to 50°, and particularly preferably in the range of 43° to 48°, the reflection of the emitted light at the transparent element back into the laser or lasers can be suppressed very effectively. This configuration generally makes it possible to dispense with an anti-reflection coating of the transparent element, without any drawbacks in terms of the functionality of the multi-laser device due to reflected or scattered light.

[0078] The tilt angle is preferably selected to intentionally create a back reflection, which is used to measure the laser output using a monitor photodiode, also referred to herein as a monitor diode.

[0079] However, smaller angles, typically 7° to 15° for example, are already sufficient to suppress direct back reflections into the laser resonators of the individual lasers of an RGB laser module.

[0080] In this case, it is particularly advantageous to arrange a monitor diode below the transparent member, so that the laser light reflected from the transparent member strikes the monitor diode, thereby obtaining a sensing signal for the intensity of the light emitted by each laser assigned to the monitor diode. In this way, a fast and effective feedback signal can be obtained, which allows for accurate control and management of the multi-laser system.

[0081] In this case, the term "downward" should be understood as a direction relative to the base plate and relative to the housing cap. A direction perpendicular to the base plate, i.e., normal to the direction of the housing cap, is understood to be an upward direction. In this respect, an object can therefore be located above, below, or at the same height as another object in this direction. If we refer to a Cartesian coordinate system, which will be explained further below, the upward direction also represents the positive Z direction of this coordinate system.

[0082] Alternatively or additionally, monitor diodes can be arranged behind the lasers, in particular on a support associated with the lasers, with each laser preferably being assigned at least one dedicated monitor diode, and the support can further have a conductive coating as an electrical conductor for the individual monitor diodes.

[0083] For the purposes of this disclosure, the light output surface of the laser facing the transparent member is defined as the front surface, and the propagation direction of the laser light emerging through this light output surface is defined as emitting or being emitted in the "forward direction." The expression "located behind the laser" defines a position that is in front of a further light output surface of the laser located on the opposite side from the transparent member.

[0084] In this case, the monitor diode can be preferably arranged on a support, which preferably comprises or consists of ceramic, and the normal to the surface of the support on which the monitor diode is arranged can be inclined relative to the main radiation direction of at least one of the lasers, the inclination being in the angle range of 3° to 15°, preferably 5° to 10°, particularly preferably 6° to 8° relative to the main radiation direction, such that light emerging from the rear surface of the laser is reflected very effectively from the monitor diode, so that this light no longer strikes one of the lasers again and thus no undesired optical interactions, such as mode coupling of the resonator modes of the individual lasers, occur.

[0085] According to yet another preferred embodiment, at least the normal to the wall of the housing cap, on which the transparent element is arranged, is inclined relative to the main radiation direction of at least one of the lasers, the inclination being in the range of 3° to 15°, preferably 5° to 10°, particularly preferably 6° to 8°, relative to the main radiation direction, such that light emerging from the front face of the laser is reflected very effectively from the surface of the transparent element, so that this light no longer strikes one of the lasers again and thus no undesired optical interactions, such as coupling of resonator modes of the individual lasers, occur.

[0086] According to an alternative embodiment, the housing cap can include a plurality of openings, with one transparent element being assigned to each of these openings or one transparent element being assigned to all of these openings in common.

[0087] According to a further advantageous embodiment, the housing cap comprises a plurality of openings, wherein a transparent element is respectively arranged in one of the openings, which openings form an optical element for beam shaping, which optical element comprises: Spherical plano-convex or concave-convex lenses, spherical or hemispherical lenses, aspherical plano-convex or concave-convex lenses The optical element is selected from the group of optical elements including:

[0088] This allows the multi-laser device to be integrated into an external optical system in a very compact manner, and due to its precise dimensions, it can be optically pre-adjusted as needed, i.e., already adjusted in terms of the axial and lateral positions of the optical elements. In this case, if necessary, the base plate of the multi-laser device can be inserted into a pre-shaped, precisely positioned recess of the further optical system, and can be accommodated in a state already adjusted relative to the further optical system due to its positioning. Furthermore, the contact between the base plate and the further optical system allows heat from the multi-laser device to be dissipated in a defined manner, and additional heat from the lasers of the multi-laser device can be dissipated via the further optical system.

[0089] If the light-conducting fiber is connected to the housing, in particular to the housing cap, preferably by means of a fiber connector, in particular by means of a detachably connectable fiber connector or by means of a permanently connectable fiber connector, a further degree of structural freedom is provided, since this allows the multi-laser device to be arranged, for example, at a distance from further optics, which will be explained in more detail further on, purely by way of example, with respect to further optics provided by the AR glasses.

[0090] If one light-conducting fiber is assigned to each laser of the multi-laser device and the fibers assigned to the lasers are grouped into a fiber bundle in which the fibers are preferably arranged closely adjacent to one another by their individual fiber cores, preferably surrounding these fiber cores by a common fiber cladding, this can further contribute to a more compact construction of the system comprising the multi-laser device and further optical systems. In this case, for example, if multiple optical fibers are arranged adjacent to one another in a plane in which the rows of the associated imager extend, and if further optical systems are associated that generate images for each row, for example, a superposition in the row direction of light components of a first laser emitting in the red spectral region of the visible spectrum, light components of a second laser emitting in the green spectral region of the visible spectrum, and light components of a third laser emitting in the blue spectral region of the visible spectrum can be produced so rapidly in each row that the color changes are no longer resolvable by the human eye, thus already producing a white color impression to the human eye. This allows the individual fibers of this embodiment to be made significantly shorter, eliminating the potentially length-extending fiber splicing process.

[0091] Within the framework of this disclosure, the terms fiber, optical fiber and light-conducting fiber are used for fibers suitable for guiding the light of lasers emitting in the blue, green and red wavelengths, respectively, throughout the spectral range emitted by these lasers, and transmitting it with little loss from its input end to its output end. Such fibers are well known to those skilled in the art of this disclosure and do not require further description.

[0092] Advantageously, the multi-laser device may include glass-to-metal feedthroughs for the leads to the lasers and / or monitor diodes.

[0093] If the monitor diodes each have a color filter, in particular a color filter formed as a bandpass filter for the emission wavelength of the associated laser, the light of the other lasers can be suppressed, and an improved signal-to-interference signal ratio or an improved signal-to-noise ratio of the sensing signal of the monitor diode can be obtained.

[0094] If the bottom plate of the housing is configured to conduct current as a reference potential, this can simplify the electronic wiring of the multi-laser device and provide an operationally safe housing for the user.

[0095] According to a further advantageous embodiment, the base plate can be configured as a support for the optical unit, in particular so as to project structurally below the housing cap.

[0096] To suppress scattered light, the inside of the housing cap can be made black, in particular black with a matte finish, by applying a lacquer or coating such as black chrome or a zinc-nickel coating, in particular also as an electrolytic coating, so that in the spectral range of the light emitted by the laser, more than 98% of the light striking it can be absorbed by the surface coated in this way.

[0097] Advantageously, the housing can have a protection device for the glass of the transparent element, which protection device is in particular formed as a section that projects laterally beyond the transparent element.

[0098] For example, if the housing includes housing dimensions of a height of 1.0 to 3.5 mm, particularly in the X direction, and / or a width of 4 to 10 mm, particularly in the Y direction, and / or a length of 4 to 10 mm, particularly in the Z direction, a structurally attractive multi-laser device can be provided for many, particularly mobile application cases.

[0099] The directions mentioned here, in particular the respective X, Y and Z directions, will be explained in more detail in the framework of the detailed description below, in particular with reference to the Cartesian coordinate system depicted in FIG.

[0100] Such a mobile application case may for example relate to AR glasses or spectacles comprising such a multi-laser device, or may for example relate to a head-up display for a helmet visor, for example a head-up display for a helmet visor of a protective helmet such as a motorcycle helmet or a police or security forces helmet, or a head-up display for an avionics device or apparatus.

[0101] Projectors can also benefit from the multi-laser device disclosed herein and its extremely small dimensions, especially when applied to mobile devices.

[0102] The present invention will now be described in more detail with reference to preferred embodiments based on the accompanying drawings. [Brief explanation of the drawings]

[0103] [Figure 1] FIG. 1 is a perspective view showing a multi-laser device shown for comparison. [Figure 2] 1A-1C are two perspective views of a housing cap according to the present invention for a multi-laser device. [Figure 3] FIG. 10 is a cross-sectional view showing a multi-laser device shown for comparison. [Figure 4] 1 is a cross-sectional view showing a multi-laser device according to the present invention; [Figure 5] FIG. 10 is a cross-sectional view showing yet another multi-laser device according to the present invention. [Figure 6] FIG. 4 is a cross-sectional view showing the lower edge of the side wall. [Figure 7]FIG. 10 is a cross-sectional view showing yet another multi-laser device according to the present invention. [Figure 8] FIG. 10 is a cross-sectional view showing the lower edge of the side wall with bonding material. [Figure 9] FIG. 10 is a cross-sectional view showing the lower edge of the side wall with bonding material. [Figure 10] FIG. 10 is a cross-sectional view showing yet another multi-laser device according to the present invention. [Figure 11] FIG. 10 is a cross-sectional view showing yet another multi-laser device according to the present invention. [Figure 12] FIG. 10 is a cross-sectional view showing a sidewall including an opening together with a transparent member. [Figure 13] FIG. 10 is a cross-sectional view showing yet another multi-laser device according to the present invention. [Figure 14] 10 is a perspective view of yet another housing cap according to the present invention for a multi-laser device. FIG.

[0104] In the following description of preferred embodiments, the same reference signs each denote the same or identically acting units or parts, as also applies to incorporated German patent application No. 102020110658.0 and incorporated German utility model application No. 20202102072.5.

[0105] For comparison, FIG. 1 shows a multi-laser device 1 with a housing 2 which includes a housing cap 3 which is held in a liquid-tight and gas-tight manner on a bottom plate 4 .

[0106] Between the housing cap 3 and the bottom plate 4 there is a weld line S (not shown in FIG. 1) which extends over substantially the entire contact surface between the housing cap 3 and the bottom plate 4, below the lateral overhang A5 of the housing cap 3 which forms the weld flange.

[0107] For the purposes of this disclosure, when an object, such as the housing of a multi-laser device, is filled with He and there is a pressure difference of 1 bar, the laser energy density is 1×10 at room temperature. -3An object would be considered airtight or equivalently liquid-tight if it had a leak rate of less than mbar·l / sec.

[0108] However, preferably, when filled with He and there is a pressure difference of 1 bar, the -8 A leak rate of 1000 mbar·l / s is achieved. However, since the seal value to be achieved may depend on the internal volume of the housing, the seal achieved here ensures that the partial pressure of water in the housing of the multi-laser device will not exceed a value of 5000 ppm over the entire service life of the component.

[0109] A pedestal 5 is arranged on the base plate 4 (not shown in FIG. 1) or is formed by the base plate 4 itself.

[0110] According to a preferred embodiment, arranged inside the housing 2 are a first laser 6 (not shown in Figure 1) emitting in the red spectral region of the visible spectrum, a second laser 7 (not shown in Figure 1) emitting in the green spectral region of the visible spectrum, and a third laser 8 (not shown in Figure 1) emitting in the blue spectral region of the visible spectrum.

[0111] Each of the above-mentioned lasers 6, 7, and 8 is disposed on a base 5, and is attached to the base 5 so as to have a specified distance from the bottom surface 9 of the bottom plate 4. The bottom surface 9 of the bottom plate refers to the lower surface of the bottom plate.

[0112] An opening 13 is formed in the housing cap 3 in front of the light emitting surfaces 10, 11, 12 (not shown in FIG. 1) on the front side of the lasers 6, 7, 8, and a transparent member 14 is attached to this opening 13.

[0113] The transparent member 14 is, according to one preferred embodiment, held to the housing cap 3 by, for example, glass solder.

[0114] According to an alternative embodiment, the transparent member 14 is held to the housing cap 3 itself by means of gold solder, for example by AuSn solder.

[0115] By using gold solder, the window 14 can be attached directly to the housing cap 3 with little demand on the structural dimensions of either the transparent element 14 or the housing cap 3 .

[0116] 2 shows two housing caps 3 according to the invention for a multi-laser device 1. The housing caps 3 each have three separate, in particular circular, openings 13, each of which is provided for the laser light of one of the three lasers 6, 7, 8.

[0117] Furthermore, the housing caps 3 each include one transparent element 14, which is hermetically bonded to the side wall of the housing cap 3 having the opening 13 by means of a bonding material, in particular a solder, for example a glass solder and / or a metal solder.

[0118] The housing cap 3 incorporating an optical window can be used in particular for hermetic encapsulation of an RGB laser, and is therefore sometimes referred to as an RGB cap.

[0119] The embodiment shown on the left side of Figure 2 is a housing cap 3 (RGB cap) that can be or has been manufactured using turning and milling techniques, which may be advantageous in particular in terms of delivery time, cost and / or design flexibility.

[0120] The housing cap 3 therefore comprises a milled metal housing in which a concentric opening 13 (emitter opening) is fabricated. The transparent element 14 forms the optical window and can be made of sapphire or glass. In addition, it can be provided with an anti-reflection coating to increase the transmittance, thereby minimizing radiation losses. The optical window is hermetically joined to the metal housing by a soldering process (e.g., a solder made of glass solder or metal solder).

[0121] The embodiment shown on the right side of Figure 2 is a housing cap 3 (RGB cap) that can be or has been manufactured using a deep drawing process, which can be advantageous for economic reasons and can also provide further manufacturing advantages, which will be explained in more detail below.

[0122] The housing cap 3 therefore comprises a deep-drawn metal housing in which a concentric opening 13 (emitter opening) is formed. The transparent element 14 forms an optical window and may also consist of sapphire or glass. Furthermore, an anti-reflection coating may also be provided to increase the transmittance, thereby minimizing radiation losses. The optical window is hermetically joined to the metal housing by a soldering process (e.g., a solder consisting of glass solder or metal solder).

[0123] The housing cap 3 specifically includes a top wall 100 and a side wall 200 integrally formed with the top wall 100, which in this embodiment is circumferentially formed around the z-axis. In this embodiment, the side wall 200 is formed as a lateral peripheral wall with four flat side walls. A rounded edge 101 is present between the top wall 100 and the side wall 200. A rounded edge 204 may also be present between the preferably flat side walls. The rounded edge 101 or 204 may be represented by an outer radius on the outer surface of the housing cap 3 and / or an inner radius on the inner surface of the housing cap 3. The inner radius may, for example, be the same as the thickness d1 or may be within a range from half the thickness d1 to twice the thickness d1.

[0124] For comparison, FIG. 3 shows a multi-laser device 1 with a housing 2, which has a housing cap 3 hermetically attached to a bottom plate 4, on which a base is arranged, on which a first laser 6, a second laser 7 and a third laser 8 (not shown in FIG. 3) are arranged.

[0125] The illustrated housing cap 3 has a lateral overhang A5 or a laterally protruding flange, which may, however, limit the structural space and / or lateral extent of the housing 2 and the height of the position of the transparent member 14 or emitter opening 13.

[0126] 4 shows a multi-laser device 1 in which the metal body of the housing cap 3 is produced or can be produced by a deep drawing process. An additional process step can be performed to cut off any flanges that may occur, which can serve to give the desired shape.

[0127] The housing cap 3 of this multi - laser device 1 has dimensions that are more favorable than those of the embodiment shown in FIG. 3 for comparison, that is, H1 < H2, L1 < L2 and / or P1 < P2, and in the case of the even smaller dimension L1 < L2, it can bring advantages particularly clearly and advantageously. However, the cutting of the flange can also be made useful for the even smaller dimensions H1 < H2 or P1 < P2.

[0128] The housing cap 3 has an upper wall 100 and side walls 200 integrally formed with this upper wall 100, and these side walls 200 terminate at a lower edge 201 attached to the bottom plate 4. The lower edge 201 is attached to the bottom plate 4 by a bonding material 300.

[0129] The side wall has a first thickness d1 measured in a direction perpendicular to its surface and a second thickness d2 measured at the lower edge 201, particularly in the same direction, and this second thickness d2 is thinner than or equal to (equal in this case) the first thickness d1.

[0130] As described above, the housing cap 3 can generally have one or more rounded edges 101 or 204 (not shown in the cross - sectional view).

[0131] FIG. 5 shows the multi - laser device 1 equipped with the housing cap 3. In this case, the side wall 200 has a surface 202 bent outward at the lower edge 201 on the inner surface of the housing cap 3. In this case, the second thickness d2 is made thinner than the first thickness d1, and the thickness of the side wall is configured to gradually become thinner towards the lowermost position of the side wall.

[0132] The bonding material 300 extends over a region shorter than the first thickness d1 or the second thickness d2 along the direction of the first thickness d1 or the second thickness d2 of the side wall.

[0133] In particular, the deep-drawing manufacturing process results in an outward radius on the inner surface of the cap's legs. For subsequent use (for soldering to the base plate 4), the wall thickness is tapered in particular at the cap's legs, which allows the joining material to extend along a reduced width (reduced pad width or metallization on the counter element, e.g., the base plate). This contributes to the miniaturization of the unit or increases the construction space within the housing 2.

[0134] 6 shows the lower edge 201 of the side wall 200 of the housing cap 3, where the outwardly curved surface 202 on the inner surface of the housing cap 3 is curved according to a radius R. The housing cap 3 also has a second thickness d2 at the lower edge 201 that is less than the first thickness d1.

[0135] Furthermore, the side wall 200 has a protrusion 203 on its outer surface at the lower edge 201, the protrusion 203 being thinner than the first thickness d1, in particular thinner than one-fifth of the first thickness d1, and which is also thinner than the second thickness d2.

[0136] 7 shows a multi-laser device 1 with a housing cap 3, where the lower edge 201 of the side wall 200 is attached to the bottom plate 4 such that a bonding material 301 is trapped between the outwardly bent surface 202 on the inner surface of the housing cap and the bottom plate 4. In this case, the bonding materials 300 and 301 are a continuous bonding material, and the bonding material 301 attached to the bent surface 202 protrudes higher from the bottom plate than the bonding material 300 between the lower edge 201 of the side wall 200 and the bottom plate 4.

[0137] In particular, the deep-drawing manufacturing process allows for the creation of an outwardly drawn radius on the inner surface of the cap's leg, which provides the advantage that the radius formed on the inner wall surface increases the effective soldering area of ​​the housing cap (particularly the metal component) for later use (for soldering to the bottom plate), and also allows for a larger meniscus angle of the joining material (particularly the solder). Furthermore, a larger material volume (particularly the solder volume) can be applied while the joining material width (pad width) remains the same. These three points result in a more stable joint (particularly the solder joint) and, therefore, a more durable product.

[0138] Figure 8 shows the lower edge 201 of the side wall 200 of the housing cap 3, which has a protrusion 203 that is thinner than the first thickness d1, in particular thinner than one-fifth of the first thickness d1, and integral bonding material 300, 301 attached to the lower edge 201, where the portion 301 of the bonding material that is bonded to the curved surface 202 protrudes higher.

[0139] FIG. 9 shows yet another embodiment with the lower edge 201 of the side wall 200 of the housing cap 3, in which a bonding material 303 is provided between the bottom plate 4 (not shown in FIG. 9) and the side wall, the bonding material 303 being applied to the outer surface of the side wall 200, e.g., a protruding portion. The bonding material 300 can thus form a solder meniscus on the outer surface of the housing cap 3. The bonding material 303 adjacent to the outer surface of the side wall 200 can protrude from the bottom plate 4 higher than the bonding material 300 preferably additionally present between the lower edge 201 of the side wall 200 and the bottom plate 4. Preferably, the bonding material 301 adjacent to the inner surface of the side wall 200 can also be applied as described above. The bonding material 303 and the optional bonding materials 300 and / or 301 are preferably a continuous bonding material. Generally, a thickness d2 at the lower edge that is smaller than the thickness d1, in particular by tapering and / or rounding, can advantageously achieve a narrower joining material web (in particular a solder web), which can achieve dimensional advantages in particular for components with sharp corners and / or flanged components (with or without a solder meniscus).

[0140] FIG. 10 shows a multi-laser device 1 with a housing cap 3, which has an outwardly curved surface 202 on the inner surface of the housing cap 3 at the lower edge 201, such that the second thickness d2 is thinner than the first thickness d1, and the thickness of the side wall is gradually reduced toward the lowest position of the side wall.

[0141] The outwardly bent surface 202 serves in this case as a guiding aid when joining the housing cap 3 and the bottom plate 4. The bottom plate 4 can therefore be at least partially recessed within the housing cap 3, which makes it possible to further minimize the height of the unit. For this purpose, the bottom plate 4 can have a laterally bent end face which can be joined to the bent surface 202 of the side wall 200 of the housing cap 3 by means of a joining material (not shown in FIG. 9).

[0142] In particular, the deep drawing process allows for the formation of an outwardly drawn radius on the inner surface of the leg of the cap, which has the advantage that the radius formed on the inner wall surface can be used for later use, in particular as an improved guide aid when joining the cap and the base plate. This additionally allows for a reduction in the overall length and width of the package, in particular H1 <H2およびL1<L2、をもたらすことができる。

[0143] 11 shows the multi-laser device 1 with a housing cap 3, which has a protrusion 203 at a lower edge 201 on the outer surface of a side wall 200. The transparent member 14, which is attached to the outer surface of the housing cap 3, in particular by means of a bonding material 302, is attached to the protrusion 203 at the lower edge 201 so that the transparent member is positioned at an angle to the surface of the side wall 200.

[0144] In particular, the manufacturing process, which is a deep-drawing process, can result in protrusions 203 on the inner radius as well as on the outer surface of the housing cap 3 or the metal housing. This protrusion has the advantageous effect, among other things, of slightly tilting the attached (soldered) window. In laser applications in general (and EEL in particular), it is desirable to avoid a portion of the emitted laser beam 400 from reflecting back into the laser cavity. Due to the tilted orientation of the transparent member 14, a portion of the reflected beam 401 is deflected to a non-critical position inside the housing 2.

[0145] FIG. 12 shows a multi-laser device 1 in which the transparent member is attached to the side wall 200 of the housing cap 3 around the opening 13 by means of a joining material 302 (in particular solder, e.g. glass solder and / or metal solder).

[0146] 13 shows a multi-laser device 1 in which the top wall 100 of the housing cap 3 has a thickness d3 that is less than the first thickness d1 of the side wall, with the advantage being reduced weight and / or a lightweight construction.

[0147] The different wall thicknesses can be achieved, for example, by pre-embossing the starting material (eg, metal strip starting material) prior to the deep drawing process.

[0148] 14 shows a housing cap 3 with an opening 13, which has a larger extent along the direction from the upper wall 100 to the lower edge 201 of the side wall 200 (z-direction) than along a direction extending perpendicularly to this direction within the side wall (y-direction). According to a specific embodiment, the opening 13 is elliptically shaped. This has the advantage in particular of adapting to an elliptical laser beam profile, thus reducing the dimension in the y-direction. The beam profile of an EEL laser in particular typically has elliptical characteristics. A further advantage is that the mechanical stability of the housing cap 3 is improved.

[0149] In particular, in the cap manufacturing process, if a starting material with an opening (e.g., a stamped strip) is used, an elliptical opening can be formed by a subsequent deep-drawing process. One advantage of this is that less material needs to be removed than for a concentric opening, which reduces tool wear or extends the tool's service life (tool life, less waste during stamping). Furthermore, pre-stamped strip allows caps to be manufactured with a lower height for process reasons.

[0150] As will be apparent to those skilled in the art, the features and / or advantages described above can be realized individually or in combination.

Claims

1. A multi-laser device (1), comprising: a housing (2) having a bottom plate (4) and a housing cap (3) mounted on the bottom plate (4); a plurality of lasers; Including, The housing cap (3) comprises at least one opening (13), the opening (13) having a transparent element (14) assigned to the opening for the passage of electromagnetic radiation, The lasers are each disposed within the housing (2) and spaced apart from the bottom surface (9) of the bottom plate (4); The housing cap (3) of the housing (2) comprises an upper wall (100) and a side wall (200) integrally formed with the upper wall, the side wall (200) terminating in a lower edge (201) mounted on the bottom plate (4); The side wall (200) has a first thickness (d1) measured perpendicular to the surface of the side wall (200) and a second thickness (d2) measured at the lower edge (201), the second thickness (d2) being less than the first thickness (d1); the second thickness (d2) measured at the lower edge (201) corresponds to the thickness of the side wall (200) at its lowest point, and the side wall (200) has, on its inner surface at its lowest point, a curved surface with a radius R; The top wall (100) and the side wall (200) integrally formed with the top wall (100) comprise or consist of metal; Multi-laser device (1).

2. the sidewall has an outwardly curved surface (202) on the inner surface of the housing cap at the lower edge, such that the thickness of the sidewall tapers towards the bottommost position of the sidewall; and / or The side wall is formed without a protrusion on the outer surface at the lower edge, or has a protrusion (203), the protrusion (203) being thinner than the first thickness.

2. A multi-laser device (1) according to claim 1.

3. the lower edge of the side wall is attached to the bottom plate such that a bonding material (300) is trapped between the lower edge of the side wall and the bottom plate along the direction of the first thickness or the second thickness of the side wall and over an area shorter than the first thickness or the second thickness of the side wall; and / or the lower edge of the side wall is attached to the base plate in such a way that a bonding material (301) is trapped between the bottom plate and the surface (202) bent outwards on the inner surface of the housing cap, and the bonding material (301) protrudes from the bottom plate higher than the space between the lower edge of the side wall and the bottom plate on the inner surface of the housing cap; and / or the lower edge of the side wall is attached to the bottom plate as follows: the lower edge of the side wall is attached to the bottom plate in such a way that a bonding material (303) is trapped between the outer surface of the side wall and the bottom plate, for example between the protrusion (203) and the bottom plate, and the bonding material (301) protrudes from the bottom plate higher on the outer surface of the housing cap than between the lower edge of the side wall and the bottom plate; 3. A multi-laser device (1) according to claim 2.

4. the sidewalls are tapered at the lower edges; and / or the second thickness of the sidewall measured at the bottom edge is at least 5% less than the first thickness of the sidewall; A multi-laser device (1) according to any one of claims 1 to 3.

5. The first thickness of the side wall measured perpendicular to the surface of the side wall corresponds to the thickness of the side wall at a position adjacent to the upper wall, corresponds to the thickness of the side wall at a position between the upper wall and the lower edge, and / or corresponds to the average thickness of the side wall. A multi-laser device (1) according to any one of claims 1 to 4.

6. the second thickness of the sidewall measured at the bottom edge is measured in the same direction as the first thickness of the sidewall; and / or the second thickness of the side wall measured at the lower edge is measured in a direction extending substantially parallel to a surface of the top wall and / or the bottom surface of the bottom plate. A multi-laser device (1) according to any one of claims 1 to 5.

7. the housing cap is hat-shaped with four flat side walls that are integrally formed with the top wall; and / or the at least one opening in the housing cap is located in the side wall or in one of the side walls; and / or A plurality of openings are provided in the side wall or in one of the side walls. A multi-laser device (1) according to any one of claims 1 to 6.

8. Each of the plurality of openings has an extent along a direction from the upper wall toward the lower edge that is greater than an extent along a direction extending within the side wall perpendicular to said direction, and / or Each of the plurality of openings has an elliptical shape having a major axis extending along a direction from the upper wall toward the lower edge. A multi-laser device (1) according to any one of claims 1 to 7.

9. the housing cap includes a transparent member disposed in the at least one opening; the transparent member is attached to the sidewall including the at least one opening to hermetically seal the at least one opening; the transparent member hermetically seals each of the plurality of openings; A multi-laser device (1) according to any one of claims 1 to 8.

10. The transparent member is attached to the outer surface of the housing cap. A multi-laser device (1) according to any one of claims 1 to 9.

11. the transparent member is attached at an angle to the surface of the side wall; Multi-laser device (1) according to claim 10.

12. the top wall of the housing cap has a thickness measured perpendicular to a surface of the top wall, the thickness being less than the first thickness of the side wall; and / or the top wall of the housing cap has a thickness measured perpendicular to a surface of the top wall, the thickness being less than the second thickness of the side wall; A multi-laser device (1) according to any one of claims 1 to 11.

13. The base plate comprises or consists of ceramic, or comprises or consists of metal, and / or the transparent member comprises or consists of glass or sapphire, and / or the optical coating comprises an anti-reflection layer; A multi-laser device (1) according to any one of claims 1 to 12.

14. A housing cap for a multi-laser device according to any one of claims 1 to 13, comprising: a top wall, a side wall integrally formed with said top wall and terminating at a lower edge, and an opening for passing electromagnetic radiation therethrough; the sidewall has a first thickness measured perpendicular to a surface of the sidewall and a second thickness measured at the bottom edge, the second thickness being less than the first thickness; the second thickness measured at the lower edge corresponds to the thickness of the side wall at a lowest point of the side wall, the side wall (200) having a curved surface with a radius R on an inner surface at the lowest point; The top wall (100) and the side wall (200) integrally formed with the top wall (100) comprise or consist of metal; Housing cap.

15. the sidewall has an outwardly curved surface on the inner surface of the housing cap at the lower edge, the thickness of the sidewall gradually decreasing towards the lowermost position of the sidewall; and / or the sidewall is formed without a protrusion on an outer surface at the lower edge, or has a protrusion, the protrusion being thinner than the first thickness; The housing cap of claim 14.

16. the sidewalls are tapered at the lower edges; and / or the second thickness of the sidewall measured at the bottom edge is at least 5% less than the first thickness of the sidewall; 16. The housing cap according to claim 14 or 15.

17. The first thickness of the side wall measured perpendicular to the surface of the side wall corresponds to the thickness of the side wall at a position adjacent to the upper wall, corresponds to the thickness of the side wall at a position between the upper wall and the lower edge, and / or corresponds to the average thickness of the side wall.

17. A housing cap according to any one of claims 14 to 16.

18. the second thickness of the sidewall measured at the bottom edge is measured in the same direction as the first thickness of the sidewall; and / or the second thickness of the side wall measured at the bottom edge is measured in a direction extending substantially parallel to a surface of the top wall.

18. A housing cap according to any one of claims 14 to 17.

19. the housing cap is hat-shaped with four flat side walls that are integrally formed with the top wall; and / or the at least one opening in the housing cap is located in the side wall or in one of the side walls; and / or A plurality of openings are provided in the side wall or in one of the side walls.

19. A housing cap according to any one of claims 14 to 18.

20. Each of the plurality of openings has an extent along a direction from the upper wall toward the lower edge that is greater than an extent along a direction extending within the side wall perpendicular to said direction; and / or Each of the plurality of openings has an elliptical shape having a major axis extending along a direction from the upper wall toward the lower edge.

20. A housing cap according to any one of claims 15 to 19.

21. the housing cap includes a transparent member disposed in the at least one opening; the transparent member is attached to the sidewall including the at least one opening to hermetically seal the at least one opening; the transparent member hermetically seals each of the plurality of openings; 21. A housing cap according to any one of claims 14 to 20.

22. The transparent member is attached to the outer surface of the housing cap.

22. The housing cap according to any one of claims 14 to 21.

23. the transparent member is attached at an angle to the surface of the side wall; 23. The housing cap of claim 22.

24. the top wall of the housing cap has a thickness measured perpendicular to a surface of the top wall, the thickness being less than the first thickness of the side wall; and / or the top wall of the housing cap has a thickness measured perpendicular to a surface of the top wall, the thickness being less than the second thickness of the side wall; 24. A housing cap according to any one of claims 14 to 23.

25. The transparent member comprises or consists of glass or sapphire, and / or the optical coating has an anti-reflection layer.

25. A housing cap according to any one of claims 14 to 24.

26. A method for manufacturing a housing cap according to any one of claims 14 to 25, said method comprising: Providing a flat starting material comprising or consisting of a metal; forming one or more openings in the planar starting material; drawing the flat starting material so that the one or more openings are arranged as elliptical openings within one side wall and / or the top wall has a smaller thickness than the side wall, to produce a housing cap having a top wall and a side wall integrally formed with the top wall; cutting the sidewall at the lower edge such that the sidewall has a first thickness measured perpendicular to a surface of the sidewall and a second thickness measured at the lower edge, the second thickness being less than the first thickness; attaching a transparent member to the sidewall containing the at least one opening to hermetically seal the opening; Including, method.

27. ​​The step of attaching the transparent member is performed so that the transparent member is positioned at an angle to the surface of the side wall.

27. The method of claim 26.

28. A head-mounted display comprising a multi-laser device according to any one of claims 1 to 13 and / or a housing cap according to any one of claims 14 to 25.

29. A head-up display comprising a multi-laser device as described in any one of claims 1 to 13 and / or a housing cap as described in any one of claims 14 to 25.

30. A motorcycle helmet including a head-up display as described in claim 29.

31. A projector comprising a multi-laser device according to any one of claims 1 to 13 and / or a housing cap according to any one of claims 14 to 25.

32. A projector for a mobile device comprising a multi-laser device according to any one of claims 1 to 13 and / or a housing cap according to any one of claims 14 to 25.

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