LASER EMITTER ASSEMBLY AND LIDAR SYSTEM

Abstract

A laser emitter assembly that has a laser emitter and a support for the laser emitter. The support has a multiplicity of layers. One of the layers is a thermomechanical door that is designed to thermally regulate the laser emitter. A LiDAR system, to the power supply of which the laser emitter assembly is operatively connected, is also described.

Claims

1-10. (canceled)

11. A laser emitter assembly, comprising: a laser emitter; and a support for the laser emitter, the support having a multiplicity of layers, wherein one of the layers is a thermomechanical door that is configured to thermally regulate the laser emitter.

12. The laser emitter assembly as recited in claim 11, wherein the thermomechanical door is opened in a high temperature situation and is closed in a low temperature situation.

13. The laser emitter assembly as recited in claim 11, wherein the thermomechanical door has two door planes that are displaceable in relation to each other to open or close the thermomechanical door.

14. The laser emitter assembly as recited in claim 13, wherein the thermomechanical door is configured to be opened and closed by lateral contraction and expansion of the two door planes.

15. The laser emitter assembly as recited in claim 13, wherein at least one of the two door planes includes a phase change material.

16. The laser emitter assembly as recited in claim 15, wherein the phase change material is arranged between the two door planes.

17. The laser emitter assembly as recited in claim 11, wherein the thermomechanical door is arranged between a laser ceramic layer and a heat sink layer.

18. The laser emitter assembly as recited in claim 17, wherein a heating element is arranged between the thermomechanical door and the heat sink layer.

19. The laser emitter assembly as recited in claim 17, wherein a Peltier element is arranged between the thermomechanical door and the heat sink layer.

20. A LiDAR system, comprising: a laser emitter assembly, the laser emitter assembly including: a laser emitter; and a support for the laser emitter, the support having a multiplicity of layers, wherein one of the layers is a thermomechanical door that is configured to thermally regulate the laser emitter; and a power supply, the laser emitter assembly being operatively connected to the power supply.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Embodiment examples of the present invention will be discussed in greater detail with reference to the figures and the following description.

[0032] FIG. 1 shows a first specific embodiment of the laser emitter assembly, which has a heating element, in accordance with the present invention.

[0033] FIG. 2 is a detail view of a closed thermomechanical door in the specific embodiment of FIG. 1, in accordance with the present invention.

[0034] FIG. 3 is a detail view of an open thermomechanical door in the specific embodiment of FIG. 1, in accordance with the present invention.

[0035] FIG. 4 shows a second specific embodiment of the invention, which has a Peltier element, in accordance with the present invention.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0036] FIG. 1 shows a first specific embodiment of the laser emitter assembly 1. The laser emitter assembly 1 is part of a LiDAR system, not illustrated further, to the power supply of which the laser emitter assembly 1 is operatively connected.

[0037] The laser emitter assembly 1 has a laser emitter 2. The laser emitter 2 is operatively connected to the power supply of the LiDAR system. The laser emitter assembly 1 further has a support 3 for the laser emitter 2. The support 3 has a multiplicity of layers 4, 5, 6, 7, 8a-c. The layers 4, 5, 6, 7, 8a-c are stacked one above another. Starting from the laser emitter 2, they are, in descending order, a laser ceramic layer 4 that is formed of Al.sub.2O.sub.3, a thermomechanical door 5 that is designed to thermally regulate the laser emitter 2, a heating element layer 6, and a heat sink layer 7. The thermomechanical door 5 is therefore arranged between the laser ceramic layer 4 and the heat sink layer 7. Between the aforementioned functional layers are arranged adhesive layers 8a-c. A first adhesive layer 8a joins the laser ceramic layer 4 to the thermomechanical door 5. A second adhesive layer 8b joins the thermomechanical door 5 to the heating element layer 6. A third adhesive layer 8c connects the thermomechanical door 5 to the heat sink layer 7. The laser emitter 2 is arranged directly on the laser ceramic layer 4, so that the support 3 bears the laser emitter 2 by means of the laser ceramic layer 4.

[0038] The thermomechanical door 5 is opened in a high temperature situation and closed in a low temperature situation. Thus heat can be accumulated in the laser emitter 2 in the low temperature situation, and in the high temperature situation can be dissipated from the laser emitter 2 through the thermomechanical door 5 to the heat sink layer 7.

[0039] FIGS. 2 and 3 show the thermomechanical door 5 in detail. In FIG. 2, the thermomechanical door 5 is closed. In FIG. 3, the thermomechanical door 5 is opened. The thermomechanical door 5 has two door planes 9a, 9b that are displaceable in relation to each other in order to open or close the thermomechanical door 5, namely an upper door plane 9a and a lower door plane 9b. As can be seen in FIGS. 2 and 3, the lower door plane 9b in this specific embodiment has a phase change material 10 that is arranged between the two door planes 9a, 9b. The phase change material 10 prevents the two door planes 9a, 9b from becoming caught upon opening and closing of the thermomechanical door 5.

[0040] In FIG. 2 there is no contact between the upper door plane 9a and the lower door plane 9b. The thermomechanical door 5 is therefore closed, and does not make any heat transfer between the laser emitter 2 and the heat sink layer 7 possible. In FIG. 3 there is contact between the upper door plane 9a and the lower door plane 9b. The thermomechanical door 5 is therefore opened, and makes heat transfer between the laser emitter 2 and the heat sink layer 7 possible.

[0041] The thermomechanical door 5 is designed to be opened and closed by lateral contraction and expansion of the two door planes 9a, 9b. The transition between the low temperature situation in FIG. 2 and the high temperature situation in FIG. 3 takes place gradually over a specified temperature range. If the ambient temperature in the temperature range falls over time, the upper door plane 9a and the lower door plane 9b contract laterally, i.e. perpendicularly to the direction of stacking, and finally come out of contact (low temperature situation, FIG. 2). If the ambient temperature in the temperature range rises upwards over time, the upper door plane 9a and the lower door plane 9b expand laterally and finally come into contact in a laterally overlapping manner (high temperature situation, FIG. 3). It should be noted that the thermomechanical door 5 in the closed state has gaps 11, as illustrated in FIG. 2. Then no heat transfer through the thermomechanical door 5 is possible. In the open state of the thermomechanical door 5, the gaps 11, on the other hand, are closed, and the upper door plane 9a and the lower door plane 9b overlap in portions. Then heat transfer through the thermomechanical door 5 is possible. The thermomechanical door 5 is therefore open when heat transfer through it is possible, the two door planes 9a, 9b therefore overlapping in portions, and is closed when no heat transfer through it is possible, the two door planes 9a, 9b therefore being spaced apart from each other by the gaps 11.

[0042] In the first embodiment of FIG. 1, a heating element is arranged in the heating element layer 6 between the thermomechanical door 5 and the heat sink layer 7. This element serves to additionally heat the laser emitter 2 if it cannot reach its operating temperature by the waste heat which it itself produces. In this case, the heating element in operation, if required, acts first of all on the lower door plane 9b in order to open the thermomechanical door 5. Then the heating element can transfer its waste heat to the laser emitter 2 through the thermomechanical door 5 in order additionally to heat the laser emitter 2.

[0043] In the second embodiment of FIG. 4, the heating element in the heating element layer 6 is replaced by a Peltier element. The Peltier element is therefore arranged therein by way of example between the thermomechanical door 5 and the heat sink layer 7. The Peltier element is designed not only to heat, but if required also to cool, the lower door plane 9b, depending on the situation. In the second embodiment, the laser ceramic layer 4, in a departure from the first embodiment, is formed from AlN. Otherwise, the second embodiment of FIG. 4 corresponds to the first embodiment of FIG. 1.

[0044] In specific embodiments of the present invention, not shown, the laser emitter assembly 2 does not have a heating element layer 6. Then the thermoelastic door 5, in particular the lower door plane 9b, is joined directly to the heat sink layer 7, preferably by the second adhesive layer 8b.

[0045] In summary, compared with previous solutions for thermal regulation: the thermomechanical door 5 illustrated is less complex, and is more cost-effective; no control means is necessary for its operation; it requires fewer components, in particular no heat spreader, no control means, no electronics; no certification of the component is necessary, and it has greater longevity.