Automotive glass materials for adas camera system

Abstract

To provide glass materials to be used for a vehicle for automobile including a camera of a type of responding to infrared radiation.SOLUTION: Glass materials include a first transparent body (22) and a second transparent body (34). The first transparent body includes an outer surface (22a) and an inner surface (22b). The first transparent body has a periphery (22c) between an inner surface and an outer surface, and this periphery determines the outer periphery of the first transparent body. The first transparent body also includes an opening (26) between the its inner surface and outer surface, and the opening is located on an inner side of the periphery of the first transparent body. The second transparent body includes an outer surface (34a) and an inner surface (34b). The second transparent body is arranged so as to make the inner surface of the second transparent body face the inner surface of the first transparent body with respect to the first transparent body. At least a portion of the second transparent body covers the opening of the first transparent body. Materials of the second transparent body are selected from a group containing zinc sulfide and polycarbonate.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] This application claims priority to U.S. Provisional Patent Application No. 62 / 894,027, filed August 30, 2019, which is incorporated herein by reference in its entirety.

[0002] The invention disclosed herein relates to car glazing, and more particularly to car glazing that is compatible with infrared cameras of the type used in automotive night vision systems. [Background technology]

[0003] The prior art has proposed the use of night vision systems based on images developed by infrared (IR) cameras. Generally, an infrared camera is a device capable of detecting an object's infrared radiation signature and converting the signature into an electronic or electrical signal. The infrared camera processes the signal to generate an image consistent with the detected infrared illumination variations. Such cameras are often coupled with personal vision devices, such as those used by military personnel, allowing the personal vision device to see well in nighttime environments. U.S. Patent No. 5,629,999 shows an example of an automotive glass material compatible with an IR automotive night vision system that uses an infrared sensor to identify or read objects according to their infrared patterns. IR cameras are often described as sensing a "heat signature" because infrared energy is an indicator of thermal conditions.

[0004] In a common embodiment, an infrared camera has an array of sensors that respond to infrared energy within a certain response wavelength. The array of sensors is combined to collectively respond to energy within a certain portion or band of the infrared spectrum. Typically, thermographic night vision systems are sensitive to radiation with wavelengths in the range of 8-15 μm.

[0005] A difficulty with the use of thermographic infrared cameras when applied in connection with automotive glazing is that glass is opaque to the wavelengths of infrared illumination, which means that thermographic cameras operating in the long wave and higher IR range do not have the field of view to penetrate the glass layer of the glazing.

[0006] The opaque nature of glass to infrared illumination has limited the compatibility of night vision cameras with automotive glass. However, there is an increasing demand for night vision systems for automobiles. The reasons for this increase include the limitations of night vision systems for night driving due to favorable conditions for improved perception, acuity, and range of vision for night drivers. Another driver is the increasing demand for autonomously operating vehicles.

[0007] Therefore, there is a need in the art for an automotive glazing material that allows night vision cameras to be used with automotive vehicles. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] U.S. Patent No. 8,164,543 Summary of the Invention

[0009] According to the invention disclosed herein, an IR camera-compatible cover glass material includes a first transparent body having an outer surface and an inner surface. The inner surface of the first transparent body is located on the opposite side of the first transparent body from the outer surface. The first transparent body also has a periphery between its inner and outer surfaces, which periphery defines the outer periphery of the first transparent body. In addition, the first transparent body also has a portal or opening between its inner and outer surfaces, which is located inside the periphery of the first transparent body. The cover glass material of the invention disclosed herein also includes a second transparent body. The second transparent body also has an outer and inner surface, which is located on the opposite side of the second transparent body from the outer surface. The second transparent body is positioned relative to the first transparent body such that the inner surface of the second transparent body faces the inner surface of the first transparent body, and at least a portion of the second transparent body covers the opening of the first transparent body. The material of the second transparency is selected from the group consisting of zinc sulfide (ZnS) and polycarbonate (PC) materials, which allow IR cameras and LiDAR cameras in the long wave and longer ranges to form a field of view through the glass transparency.

[0010] According to the invention disclosed herein, the glass material may also include a third transparent body. The third transparent body also has an outer surface and an inner surface, and the inner surface is disposed on the opposite side of the outer surface of the third transparent body. The third transparent body is disposed relative to the first transparent body such that the inner surface of the third transparent body faces the inner surface of the first transparent body and a portion of the outer surface of the third transparent body faces a portion of the inner surface of the second transparent body. The third transparent body has a portal or opening on the inside of its periphery, and the opening coincides with the opening of the first transparent body.

[0011] Preferably, the glazing disclosed herein also includes an intermediate layer disposed between the inner surface of the first transparent body and the inner surface of the third transparent body, the intermediate layer having a portal or opening that coincides with the opening of the third transparent body and the opening of the first transparent body.

[0012] Preferably, the second transparent body covers the opening defined by the third transparent body, and the inner surface of the second transparent body may be bonded to the outer surface of the third transparent body with a bonding agent, or may be bonded to the first transparent body with a subframe.

[0013] Additionally, the invention disclosed herein includes a glazing material in which the periphery of a first transparency includes a length that forms the top or uppermost edge of the first transparency when the first transparency is installed on a vehicle. The periphery of a second transparency includes a length that forms the top or uppermost edge of the second transparency when the second transparency is installed on a vehicle. The top edges of the first transparency and the second transparency each have a concave contour that provides a path near the top of the glazing material. Electromagnetic illumination propagates within the concave contour between the outer surface of the second transparency and the outer surface of the first transparency. In this way, IR radiation bypasses the transparency of the glazing material and propagates directly to the vehicle's IR camera.

[0014] Preferred embodiments of the presently disclosed invention are shown and described in connection with the accompanying drawings. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is an illustration of the electromagnetic spectrum with emphasis on the infrared spectrum. [Figure 2] 1 is a diagram of an example of a preferred embodiment of the present specification; [Figure 3] FIG. 10 is a diagram of another example of a preferred embodiment herein. [Figure 4] FIG. 1 shows the transmittance of ZnS as a function of the wavelength of electromagnetic illumination. [Figure 5] FIG. 10 is a diagram of another example of a preferred embodiment herein. [Figure 6] FIG. 10 is a diagram of another example of a preferred embodiment herein. [Figure 7] FIG. 10 is a diagram of another example of a preferred embodiment herein. [Figure 8] FIG. 1 shows the transmittance of polycarbonate as a function of the wavelength of electromagnetic illumination. DETAILED DESCRIPTION OF THE INVENTION

[0016] The electromagnetic spectrum is generally depicted in FIG. 1. FIG. 1 shows that the infrared spectrum generally includes electromagnetic energy having wavelengths ranging from 1 μm to 1 mm. Energy in this frequency range can be further separated into the following wavelength bands: far-infrared (15 μm to 1000 μm), long-wave (8 μm to 15 μm), mid-wave (3 μm to 8 μm), short-wave (1.4 μm to 3 μm), and near-infrared (0.75 μm to 1.4 μm). FIG. 1 further shows that thermographic IR cameras in the long-wave and longer ranges typically operate in the long-wave band from 8 μm to 15 μm, and that light detection and ranging (LiDAR) cameras generally operate in the near-infrared band and a portion of the short-wave band.

[0017] In one aspect of the presently disclosed embodiments, the glass material comprises a lens that is substantially transparent to infrared radiation in the short wave and near infrared wave bands. More particularly, the lens is made of glass whose chemical composition results in approximately 92% transmission of IR radiation and less than 1% absorption of IR radiation.

[0018] Some IR-transparent glasses are known for applications such as optical components in eyeglasses and microscopes. However, such types of IR-transparent glasses are not acceptable for automotive glazing applications due to their relatively high cost and size limitations for manufacturing.

[0019] In the invention disclosed herein, IR transparent LiDAR enabled glass is made with a soda-lime composition matrix produced on an industrial scale in a float furnace, and is compatible with processes typically employed for automotive glass, such as cutting, grinding, bending, tempering, laminating, and coating.

[0020] An example of an auto glass material incorporating the features of IR transparent glass, which is glass material compatible with long-wave and longer range IR cameras, is shown in Figure 2. Figure 2 shows components of an auto glass material 10 in which a standard auto glass (i.e., non-IR glass) sheet 12 contains an aperture 14. Sheet 12 is laminated to an IR glass sheet 16 by a PVB layer 18 or other laminating material. IR energy illuminating the IR glass 16 is substantially transmitted through the IR glass 16 but is blocked by sheet 12 except at aperture 14, where the IR illumination passes through the aperture and is sensed by an IR camera in the long-wave and longer range.

[0021] More specifically, the cover glass 10 is IR camera compatible. The cover glass 10 includes a first transparent body 12 having an outer surface 12a and an inner surface 12b. The inner surface 12b is disposed on the first transparent body 12 opposite the outer surface 12a. The first transparent body 12 also has a perimeter 12c between the inner surface 12b and the outer surface 12a, the perimeter 12c defining the outer periphery of the first transparent body 12. Additionally, the first transparent body 12 also has an opening 14 between the inner surface 12b and the outer surface 12a, the opening 14 being disposed on the first transparent body 12 inside the perimeter 12c. The cover glass 10 also includes a second transparent body 16. The second transparent body 16 has an outer surface 16a and an inner surface 16b, and the inner surface 16b is disposed on the opposite side of the second transparent body 16 from the outer surface 16a. The second transparent body 16 is disposed relative to the first transparent body 12 such that the inner surface 16b of the second transparent body 16 faces the inner surface 12b of the first transparent body 12, and at least a portion of the second transparent body 16 covers the opening 14 of the first transparent body 12. The material of the second transparent body 16 is selected from the group consisting of zinc sulfide (ZnS) or polycarbonate (PC) materials. These materials allow IR cameras and light detection and ranging (LiDAR) cameras in the long wave or longer range to form a field of view through the transparent body of the glass material 10.

[0022] IR glass sheets 16 are relatively expensive compared to other automotive glass. In addition, the modified ZnS lenses described later in this specification are made of ZnS, which is polycrystalline and press-molded and then optically polished. Due to this manufacturing method, such ZnS lenses are not commercially available in sheet form. For this reason, it is preferable to limit the use of IR glass. As an example of limiting the use of IR glass, FIG. 3 shows an alternative embodiment of the invention disclosed herein.

[0023] 3 shows a glazing material 19 including an outer cover glass layer 20 and an inner cover glass layer 22. The outer and inner layers 20 and 22 are laminated together with a PVB sheet 24 or other laminating material. All three layers 20, 22, and 24 have respective apertures 26, 28, and 30, which align to form an overall aperture 32. The overall aperture 32 is covered by a lens 34 of IR glass enclosed therein. The IR glass may be, for example, of a ZnS material.

[0024] More specifically, the embodiment of the invention disclosed herein includes a glass material 19, which includes a first transparent body 22, a second transparent body 34, and a third transparent body 20. The third transparent body 20 has an outer surface 20a and an inner surface 20b, with the inner surface 20b being disposed on the third transparent body 20 opposite its outer surface 20a. The third transparent body 20 is disposed relative to the first transparent body 22 such that the inner surface 20b of the third transparent body 20 faces the inner surface 22b of the first transparent body 22 and a portion of the outer surface 20a of the third transparent body 20 faces a portion of the inner surface 34b of the second transparent body 34. The third transparent body 20 has an opening 26 inside its periphery 20c, which is aligned with the opening 28 of the first transparent body 22.

[0025] 3 also shows an intermediate layer 24 disposed between the inner surface 22b of the first transparent body 22 and the inner surface 20b of the third transparent body 20. The intermediate layer 24 has an opening 30 that aligns with the opening 26 of the third transparent body 20 and the opening 28 of the first transparent body 22.

[0026] Figure 4 shows the transmittance of a ZnS lens as a function of wavelength, and shows that the ZnS lens has good transmittance in the long wavelength band from 8 μm to about 12 μm.

[0027] Another alternative embodiment of the invention disclosed herein is shown in Figure 5. Figure 5 is similar to the embodiment of Figure 3. The ZnS IR lens 36 of Figure 5 is secured to the cover glass by a sub-frame 38 combined with a ring 40 of adhesive material. The advantage of the embodiment of Figure 5 over the embodiment of Figure 3 is that the sub-frame 38 of Figure 5 allows the lens 36 to be secured relatively easily over an opening in the cover glass. This reduces the risk of misuse and waste during the cover glass assembly process.

[0028] 5 is a glass material similar to the embodiment of FIG. 3 in which the second transparency 36 covers the opening 26 defined by the third transparency 20. As shown in FIG. 3, the inner surface 36b of the second transparency 36 may be bonded to the outer surface 20 of the third transparency 20 with a bonding agent. Alternatively, as shown in FIG. 5, the second transparency 36 may be bonded by a subframe 38. The subframe 38 is bonded to the first transparency 22 near the edge of the opening 28 in the first transparency 22. The subframe 38 is also coupled to the second transparency 36 to maintain the second transparency 36 in a covering relationship over the opening 28 in the first transparency 22 and the opening 26 in the third transparency 20. In some cases, a seal 40 may be disposed between the subframe 38 and the outer surface 22a of the first transparency 22.

[0029] Figures 6 and 7 illustrate further variations for establishing a field of view for an automotive IR camera without opacity caused by glass obstruction. The embodiments of Figures 6 and 7 are compatible with both long-wave and higher range IR cameras and light detection and ranging (LiDAR) cameras because the radiation incident on the camera entirely avoids the cover glass. In Figures 6 and 7, the glazing laminate is shaped to avoid a path for the camera's field of view. In addition to the edge contours depicted in the embodiments of Figures 6 and 7, other embodiments are contemplated in which the contour of the top edge of the glazing avoids interference with the field of view of the long-wave and higher range IR camera and / or the light detection and ranging (LiDAR) camera. In such embodiments, the contour of the top edge of the glazing is closer to the bottom edge of the glazing near the middle of the glazing than at the corners of the glazing.

[0030] In FIG. 6, glazing 40 is formed from two sheets of cover glass 42, 44 laminated together with a PVB layer 46 or other lamination. The top edge 48 of glazing 40 is formed concavely, allowing an array of IR sensors of an IR camera to be positioned above the concave edge of the glazing. In FIG. 7, glazing 50 is formed from two sheets of cover glass, as in FIG. 6, but the top edge 52 of glazing 50 has a notch so that an IR camera of an automotive night vision system can be positioned behind a notch 53 in the top edge 52. In both the FIG. 6 and FIG. 7 embodiments, IR illumination of the array of IR cameras of the night vision system is not obstructed by the glass of the cover glass.

[0031] Figure 7 illustrates that the concave morphology of the top edge of a glass element can have a variety of concave shapes, and that the term "concave" as used herein is intended as a general description of the invention disclosed herein, rather than in a mathematical sense. Figure 7 illustrates that glass element 50 can have top edge 52 that includes notch 53 that embodies the concave shape.

[0032] In another alternative embodiment, the IR-transmitting material may be other than ZnS. For example, Figure 8 shows the optical transmittance of a polycarbonate (PC) material as a function of the wavelength of the irradiating radiation. Figure 8 shows that the PC material maintains a high degree of transmittance in the range of 400 nm to 1500 nm, and another relatively high transmittance in the range of 1800 nm to 2000 nm. An example of a polycarbonate material is commercially available from Sheffield Plastics as Makrolon®.

[0033] A lens made of PC having a transmittance as shown in Figure 8 may be substituted for the ZnS lens shown in Figures 3 and 5. Such a combination has the advantage of being compatible with IR cameras operating in the long wave band as described in connection with Figure 1.

[0034] In another alternative embodiment, the ZnS and PC lenses described in connection with Figures 3 and 5 may be modified to create a structure suitable for use with a light detection and ranging camera (LiDAR camera). LiDAR cameras are typically responsive to infrared illumination in the near-infrared waveband (0.75 μm to 1.4 μm) and portions of the shortwave band (1.4 μm to 3 μm). While conventional automotive glass materials are generally not transparent to IR radiation in this waveband, it has been found that the imaging and ranging performance of LiDAR cameras is improved when the transmittance of the automotive glass is relatively high.

[0035] Thus, replacing the ZnS and PC lenses described in connection with FIGS. 3 and 5 with high transmittance glass lenses provides a glass material through which a LiDAR camera can see in order to process the data to develop image and range information. Examples of such glasses include glasses that have high transmittance in the near-infrared and low wavelength portions of the shortwave bands. An example of such glass is sold under the trademark "Solarphire® PV." To further increase the transmittance of "Solarphire® PV" glass, an anti-reflective coating can be applied to the glass specifically designed to increase transmittance at the operating wavelengths of light detection and ranging (LiDAR) lasers.

Claims

1. 1. Glazing for use in a vehicle including a sensing device of a type responsive to infrared radiation, comprising: A first transparent body and a second transparent body are included. the first transparent body has an outer surface and an inner surface, the inner surface of the first transparent body being disposed on the first transparent body opposite its outer surface, the first transparent body having a periphery between its inner and outer surfaces, the periphery defining an outer periphery of the first transparent body, the first transparent body also having an opening between its inner and outer surfaces, the opening being inside the periphery of the first transparent body; The second transparent body has an outer surface and an inner surface, the inner surface of the second transparent body is disposed on the second transparent body opposite to its outer surface, the second transparent body is disposed relative to the first transparent body such that the inner surface of the second transparent body faces the inner surface of the first transparent body layer, and at least a portion of the second transparent body covers the opening of the first transparent body.

2. Further, a third transparent body is provided, 10. The glass material of claim 1, wherein the third transparent body has an outer surface and an inner surface, the inner surface of the third transparent body being disposed on the third transparent body opposite the outer surface of the third transparent body, the third transparent body being disposed relative to the first transparent body such that the inner surface of the third transparent body faces the inner surface of the first transparent body, at least a portion of the outer surface of the third transparent body faces at least a portion of the inner surface of the second transparent body, and the third transparent body has an opening that coincides with the opening of the first transparent body.

3. Further, it has an intermediate layer, 3. The glass material of claim 2, wherein an intermediate layer is disposed between an inner surface of the first transparent layer and an inner surface of the third transparent layer, the intermediate layer having an opening that coincides with the opening of the third transparent layer and coincides with the opening of the first transparent layer.

4. 4. The glass of claim 3, wherein the second transparent body covers an opening in the third transparent body.

5. 5. The glass of claim 4, wherein the inner surface of the second transparent body is bonded to the outer surface of the third transparent body by a bonding agent.

6. Further, the device has a subframe, 5. The glazing of claim 4, wherein the subframe is affixed to the first transparency near the opening in the first transparency, and the subframe is also coupled to the second transparency so as to maintain the second transparency in overlying relationship with the opening in the first transparency.

7. Furthermore, there is a seal, 7. The glazing of claim 6, wherein a seal is disposed between the subframe and the outer surface of the first transparency.

8. 7. The glazing of claim 6, wherein the subframe also maintains the second transparency in overlying relationship with the opening in the third transparency.

9. 1. Glazing for use in a vehicle including a sensing device of a type responsive to infrared radiation, comprising: A first transparent body and a second transparent body are included. The first transparent body has an outer surface and an inner surface, and the inner surface of the first transparent body is a first transparent body disposed opposite the outer surface thereof, the first transparent body having a periphery between the inner surface and the outer surface thereof, the periphery defining an outer periphery of the first transparent body, the periphery including a length portion forming a top edge of the first transparent body when the first transparent body is mounted on the vehicle; the second transparent body has an outer surface and an inner surface, the inner surface of the second transparent body being positioned on the second transparent body opposite the outer surface of the second transparent body, the second transparent body being positioned relative to the first transparent body such that the inner surface of the second transparent body faces the inner surface of the first transparent body, the second transparent body having a periphery between its inner and outer surfaces, the periphery defining an outer periphery of the second transparent body, the periphery including a length that forms a top edge of the second transparent body when the second transparent body is installed in a vehicle, the top edges of the first transparent body and the second transparent body having concave contours, and electromagnetic illumination propagating within the concave contours between the outer surface of the second transparent body and the outer surface of the first transparent body.

10. 10. The glass material of claim 9, wherein the concave contour is in the form of a notch in the top surface of the first transparency and the second transparency.

11. 10. The glass material of claim 9, wherein the sensing device is of a type that responds to electromagnetic radiation having a wavelength longer than 8 μm.

12. 10. The glass material of claim 1, wherein the material of the second transparent body is selected from the group consisting of zinc sulfide and polycarbonate.

13. 13. The glass material of claim 12, wherein the sensing device is of a type that responds to electromagnetic radiation having a wavelength longer than 8 μm.

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