Patent Application
20200150239
The technical field relates generally to lidar sensors and more particularly to flash lidar sensors.
Flash lidar systems often include a laser which generates multiple pulses of insense, focused light. These pulses are then diffused to spread these light pulses over a wider area. A filter element may be utilized to block undesirable wavelengths of light. Unfortunately, use of multiple elements to diffuse and filter light increases cost, complexity, size, energy use.
As such, it is desirable to present a lidar sensor assembly which does not require multiple filter and diffusion elements. In addition, other desirable features and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.
In one exemplary embodiment, a lidar sensor assembly includes a laser light source configured to generate light. The lidar sensor assembly also includes a filter element configured to receive light from the laser light source. The filter element absorbs light at a first wavelength while allowing light at a second wavelength to pass therethrough. The lidar sensor assembly further includes a diffuser element formed integrally with the filter element and configured to scatter the light generated by the laser light source.
In one exemplary embodiment, a method of forming a optic for a lidar sensor assembly includes providing a filter element configured to receive light from a laser light source. The filter element absorbs light at a first wavelength while allowing light at a second wavelength to pass therethrough. The method also includes forming a diffuser element integrally with the filter element and configured to scatter the light generated by the laser light source.
Other advantages of the disclosed subject matter will be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
Referring to the Figures, wherein like numerals indicate like parts throughout the several views, a lidar sensor assembly 100 is shown and described herein.
Referring to
The lidar sensor assembly 100 includes an optic 104 configured to filter and scatter light of certain wavelengths. Said another way, the optic 104 transmits and scatters light at one wavelength and blocks, i.e., absorbs, light at another wavelength.
Referring now to
In the exemplary embodiment, the filter element 200 may be implemented using the model No. RG850 filter manufactured by SCHOTT AG, headquartered in Mainz, Germany. This filter generally blocks wavelengths of light under 830 nm. However, it should be appreciated that other filters may be implemented as the filter element 200.
The optic 104 also includes a diffuser element 202. The diffuser element 202 is configured to scatter the light generated by the laser light source 102. That is, the diffuser element 202 disperses the focused light into a wider field-of-view. In the exemplary embodiment shown in
Referring again to
This diffuser element 202 may be formed by stamping small-feature, three-dimensional patterns on the filter element 200 That is, in one exemplary embodiment, the filter element 200 is pressed against a stamping mold (not shown) to generate the patterns of the diffuser element 202. For example, the stamped patterns may have features sized between about 1 μm and 100 μm.
In another exemplary embodiment, the refractive diffuser element is generated by the patterns being deposited on the filter element 202. In yet another exemplary embodiment, the refractive diffuser element is generated by the patterns being etched on the filter element 202.
In another exemplary embodiment, the diffuser element 202 is reflective. As such, the direction of light wave propagation is changed due to the reflective nature of the patterns of the diffuser element 202. Numerous techniques may be employed to generate the reflective diffuser element 202, including, but not limited to disposition of mirror elements onto the filter element 200.
In another exemplary embodiment, the diffuser element 202 is diffractive. As such, the diffuser element 202 includes obstacles and/or apertures which result in the bending and/or spreading of the light waves. Numerous techniques may be employed to generate the diffractive diffuser element 202, including, but not limited to disposition of a film and subsequent etching of the film to generate apertures.
In the embodiment shown in
The optic 104 described above has numerous advantages over the prior art. For instance, by integrally forming the diffuser element 202 with the filter element 200, the optic 104 has less material-air interfaces than the prior art. This improves energy efficiency, which means that less energy is utilized and less heat is generated. Furthermore, the optic 104 requires less anti-reflective coatings than are typically commonplace in the prior art due to less Fresnel loss. As such, overall cost and complexity of the optic 104 is reduced.
The lidar sensor assembly 100 described above is ideally suited for use in a motor vehicle (not shown), such as an automobile. However, it should be appreciated that the lidar sensor assembly 100 and/or optic 104 shown and described herein may be utilized in many other non-vehicular applications.
One exemplary embodiment of a method 400 of forming the optic 104 for the lidar sensor assembly 100 is shown in
The present invention has been described herein in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. Obviously, many modifications and variations of the invention are possible in light of the above teachings. The invention may be practiced otherwise than as specifically described within the scope of the appended claims.
