WO2024092524A1

WO2024092524A1 - Black adhesion film for lidar cover window structure

Info

Publication number: WO2024092524A1
Application number: PCT/CN2022/129079
Authority: WO
Inventors: Wenbo Zhang; Xiangyan MA
Original assignee: Materion Precision Optics (Shanghai) Limited
Priority date: 2022-11-01
Filing date: 2022-11-01
Publication date: 2024-05-10

Abstract

Provided herein is a LIDAR cover window structure(100). The LIDAR cover window structure(100) includes a first glass layers stack(110); a second glass layers stack(130); and a black adhesion film(120). The black adhesion film(120) is disposed between the first glass layers stack(110) and the second glass layers stack(130), wherein the black adhesion film(110) is IR transmissive. The black adhesion film(120) further includes at least one polymer, at least one black dyestuff and at least one light diffusing agent, wherein the at least one polymer, the at least one black dyestuff, and the at least one light diffusing agent are the main constituents of the black adhesion film(120).

Description

BLACK ADHESION FILM FOR LIDAR COVER WINDOW STRUCTURE

BACKGROUND

LIDAR is used in the field of driverless vehicles (i.e., autonomous vehicles) and robots through its use in control systems and navigation systems. LIDAR (an acronym for “light detection and ranging” or “laser imaging, detection, and ranging” ) is an active measuring system for measuring the precise distance between objects and sensors by emitting laser and measuring the time for the reflected light to return to a transceiver. Through a transceiver array composed of a laser and a detector, combined with beam scanning, LIDAR can perceive the human environment in real time and obtain the accurate distance and contour information about surrounding objects. The positioning accuracy of LIDAR can reach the order of centimetre, which provides a technical basis for autonomous navigation.

Current vehicle LIDAR is exposed to severe environmental test conditions, especially the LIDAR outer cover glass window (hereinafter, the LIDAR cover glass window) . In addition to optical performance, the LIDAR cover glass window is required to have the same level of anti-environmental impact ability as the front windshield and anti-electromagnetic interference ability in a complex electromagnetic environment. At present, LIDAR cover glass window structures often require complex structures and complex alignment of each layer, the use of unreliable adhesive to secure layers together, and susceptibility to cracking and yellowing over time all of which effectively reduce laser detection and negatively impact LIDAR performance.

SUMMARY

This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key factors or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

Provided herein is a lamination structure including a black adhesion film for a LIDAR cover window. The black adhesion film may comprise: a polymer; a black dyestuff; and a light diffusing agent. The polymer, the black dyestuff, and the light diffusing agent are main constituents of the black adhesion film. The amount of the polymer, the black dyestuff, and the light diffusing agent in the black adhesion film is defined by a relative weight relationship of the polymer, the black dyestuff, and the light diffusing agent with respect to each other, wherein the black adhesion film comprises 100g of polymer, between 4g to 10g of black dyestuff, and between 3g and 15 grams of light diffusing agent.

Provided herein is a LIDAR cover window structure. The LIDAR cover window structure may comprise a first glass layers stack; a second glass layers stack; and a black adhesion film. The black adhesion film is disposed between the first glass layers stack and the second glass layers stack, wherein the black adhesion film is IR transmissive. The black adhesive film may comprise a polymer, a black dyestuff, and a light diffusing agent, wherein the polymer, the black dyestuff, and the light diffusing agent are main constituents of the black adhesion film.

Provided herein is a method of forming a lamination structure for a LIDAR cover window. The method may comprise cutting a first glass layers stack, a second glass layers stack, and a black adhesion film to a specified size; stacking, the first glass layers stack, the black adhesion film, and the second glass layers stack such that the black adhesion film is disposed between the first glass layers stack and the second glass layers stack; and aligning the first glass layers stack, the black adhesion film, and the second glass layers stack along their respective edge to make the lamination structure, the lamination structure comprising laminated glass. The method may further comprise prefixing by adhesive the edge of the laminated glass and pressing the laminated glass with a roller at least once. Additionally, the method comprises curing, at elevated temperature, the laminated glass at vacuum in either an autoclave or a vacuum package; and trimming the adhesive from the edge of the laminated glass after cooling the laminated glass to room temperature.

BRIEF DESCRIPTION OF DRAWINGS

The following is a brief description of the drawings, which are presented for the purposes of illustrating the exemplary embodiments disclosed herein and not for the purposes of limiting the same.

FIGURE 1 is a cross-sectional view illustrating an example embodiment of a LIDAR cover window that includes a black adhesion film with high infrared (IR) transmission in accordance with this disclosure.

FIGURES 2A through 2B are cross-sectional views of components of the LIDAR cover window structure shown in FIGURE 1. FIGURE 2A is a cross-sectional view of the first glass layers stack comprising part of the LIDAR cover window structure shown in FIGURE 1. FIGURE 2B is a cross-sectional view of the second glass layers stack comprising part of the LIDAR cover window structure shown in FIGURE 1.

FIGURE 3 is a schematic flow diagram illustrating an example implementation of an exemplary method for manufacturing a LIDAR cover window with black adhesion film as shown in FIGURE 1.

FIGURE 4 is a schematic flow diagram illustrating an example implementation of another exemplary method for manufacturing a LIDAR cover window with black adhesion film as shown in FIGURE 1.

FIGURE 5 is a flow diagram illustrating an example implementation of an exemplary method for making the black adhesion film with high IR transmission in accordance with this disclosure.

DESCRIPTION OF EMBODIMENTS

A more complete understanding of the processes and apparatuses disclosed herein can be obtained by reference to the accompanying drawings. These figures are merely schematic representations based on convenience and the ease of demonstrating the existing art and/or the present development, and are, therefore, not intended to indicate relative size and dimensions of the assemblies or components thereof.

Although specific terms are used in the following description for the sake of clarity, these terms are intended to refer only to the particular structure of the embodiments selected for illustration in the drawings, and are not intended to define or limit the scope of the disclosure. In the drawings and the following description below, it is to be understood that like numeric designations refer to components of like function.

The singular forms "a, " "an, " and "the" include plural referents unless the context clearly dictates otherwise.

As used in the specification and in the claims, the terms "comprise (s) , " "include (s) , " "having, " "has, " "can, " "contain (s) , " and variants thereof, as used herein, are intended to be open-ended transitional phrases, terms, or words that require the presence of the named ingredients/steps and permit the presence of other ingredients/steps. However, such description should be construed as also describing compositions or processes as "consisting of" and "consisting essentially of the enumerated ingredients/steps, which allows the presence of only the named ingredients/steps, along with any unavoidable impurities that might result therefrom, and excludes other ingredients/steps.

Numerical values in the specification and claims of this application should be understood to include numerical values which are the same when reduced to the same number of significant figures and numerical values which differ from the stated value by less than the experimental error of conventional measurement technique of the type described in the present application to determine the value.

All ranges disclosed herein are inclusive of the recited endpoint and independently combinable (for example, the range of "from 2 grams to 10 grams" is inclusive of the endpoints, 2 grams and 10 grams, and all the intermediate values) .

The modifier "about" used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (for example, it includes at least the degree of error associated with the measurement of the particular quantity) . When used with a specific value, it should also be considered as disclosing that value. For example, the term “about 2” also discloses the value “2” and the range “from about 2 to about 4” also discloses the range “from 2 to 4. ”

In one aspect of this disclosure there is provided a composition for a black adhesion film with high infrared (IR) transmission and the application of the black adhesion film in a LIDAR cover window. In another aspect of this disclosure there is provided a method for forming the black adhesion film composition and a method of manufacturing a compact lamination structure comprising the black adhesion film which can be used in a LIDAR cover window.

The black adhesion film may comprise at least one polymer, at least one black dyestuff with IR transmission, and at least one light diffusing agent. It is to be appreciated that the composition of the black adhesion film may be configured to permit the black adhesion film to be transmissive over the IR spectrum range from about 900nm -1600nm. As an example, the composition of the black adhesion film may be configured to permit the black adhesion film to be transmissive through the near-infrared (NIR) and short-wave infrared (SWIR) light wavelengths and to be non-transmissive to visible (VIS) light. It should be apparent from this disclosure that the black adhesion film can be included in a LIDAR cover window by lamination thereby simplifying the LIDAR cover window structure by reducing the number of layers, reducing the high-cost and material usage, and improving the reliability of the resulting LIDAR cover window under tough environmental conditions.

There are two objectives when constructing a LIDAR device. First, is to construct a LIDAR cover window that is highly transmissive to save the laser emission energy and collect more energy reflected by the object. Second, in order to hide the internal structure of the LIDAR device, the cover window generally needs to display black colour in order to block the visible light.

Referring now to FIGURES 1 through 2B, an example embodiment of a LIDAR cover window is illustrated and includes a black adhesion film with high IR transmission in accordance with this disclosure. The LIDAR cover window 100 may comprise a first glass layers stack 110, a black adhesion film 120, and a second glass layers stack 130 arranged in sequence with the black adhesion film 120 disposed between (e.g., sandwiched between) the first glass layers stack 110 and the second glass layers stack 130. The black adhesion film 120 may comprise one or more layers. The first glass layers stack 110 and/or the second glass layers stack 130 may comprise a stack consisting of a single layer or of a plurality of layers.

The first glass layers stack 110 may include a first non-coating surface 112 and the second glass layers stack 130 may include a second non-coating surface 132 which faces the first non-coating surface 112. The first and second

non-coating surfaces

112 and 132 do not include an optical coating. In some embodiments, the first non-coating surface 112 of the first glass layers stack 110 and the second non-coating surface 132 of the second glass layers stack 130 may be laminated by the black adhesion film 120 having high IR transmission, as described in more detail below.

The black adhesion film 120 may comprise at least one polymer, at least one black dyestuff with IR transmission, and at least one light diffusing agent. In some embodiments, the black adhesion film 120 is characterized as having high IR transmission. As an example, the black adhesion film 120 can provide IR transmission of more than 93%when the angle of incident light is 0°, which is the case of normal incidence. The at least one polymer, the at least one black dyestuff, and the at least one light diffusing agent are the main constituents of the composition which forms the black adhesion film 120 with high IR transmission. But, as described in more detail below, the black adhesion film 120 may include one or more additional constituents in addition to the main constituents. For example, the black adhesion film 120 may further comprise one or more of: a coupling agent, a crosslinker, an initiator, an antioxidant, a light stabilizer, a heat stabilizer, and a tackifier.

It is envisioned that the LIDAR cover window 100 of FIGURE 1, which comprises the first glass layers stack 110, the second glass layers stack 130, and the black adhesion film 120 sandwiched between the first glass layers stack 110 and the second glass layers stack 130, can be used in the automotive market, especially in the field of driverless vehicles and robotics.

It is to be appreciated that one of the many advantages of the black adhesion film 120 provided herein is the ability to provide a more compact LIDAR cover window structure. For example, the black adhesion film disclosed herein may replace existing 3-layer structures consisting of: adhesive layer + black film layer + adhesive layer, by acting as an adhesive and thereby eliminating the need for the two separate adhesive layers. For example, the composition of the black adhesion film 120 may be configured to promote the black adhesion film, which is disposed between the first and second glass layers stacks 110 and 130, to serve as an adhesive and bond to, and between, the first and second glass layers stacks 110 and 130. In some implementations, the black adhesion film 120 of the LIDAR cover window 100 may be transmissive for infrared (IR) light, thereby allowing IR light to pass therethrough, while being non-transmissive for visible (VIS) light, thereby blocking VIS light, and all the while bonding the first and second glass layers stacks 110 and 130 as the adhesive layer between the first and second glass layers stacks 110 and 130. It is to be appreciated that the black adhesion film 120 disclosed herein avoids the reliability concerns associated with using a separate UV adhesive which may shrink from an edge of the LIDAR cover window structure after more than 150H in a combination trial of 85℃ /85RH%and salt fog.

Thus, the number of layers in a LIDAR cover window lamination structure can be reduced from 5-layers to 3-layers on the basis of this disclosure. The resulting 3-layer structure can comprise the first glass layers stack 110, the black adhesion film 120, and the second glass layers stack 130 arranged as shown in FIGURE 1. Reducing the number of layers in the LIDAR cover window structure reduces the size of the LIDAR cover window and provides for a more compact LIDAR cover window structure. Thus, it is to be appreciated that the black adhesion film described herein provides for a simpler LIDAR cover window structure that is also more compact and reduces the costs of manufacturing a LIDAR cover window by 70% (for adhesive bonding in the 5-layer structure) or 30% (for lamination structures currently on the market) . Further, transmissivity at near-infrared (NIR) and short-wave infrared (SWIR) of the 3-layer LIDAR cover window structure disclosed herein is about 93%-95%, whereas transmissivity at VIS light is lower than about 3%.

FIGURE 2A is a cross-sectional view of the first glass layers stack 110 that comprises part of the LIDAR cover window structure shown in FIGURE 1. The first glass layers stack 110 may comprise a stack consisting of a single layer or a plurality of layers. In some embodiments, the first glass layers stack 110 may comprise a first glass layer 114 and at least one of an anti-reflective (AR) coating or an oleophobic coating. The first glass layer 114 may have a thickness from about 0.5mm -7mm and, in some embodiments, between 0.1mm -7mm. In some embodiments, the first glass layer 114 may be made of general silica glass, float glass, and/or other various strengthened glasses.

As shown in the embodiment of FIGURE 2A, the first glass layers stack 110 may comprise a first glass layer 114, an AR coating 116, and an oleophobic coating 118 arranged in sequence with the AR coating 116 disposed between (e.g., sandwiched between) the first glass layer 114 and the oleophobic coating 118. The AR coating 116 may include a general AR coating and/or a hard AR coating. The oleophobic coating 118 may have a contact angle greater than 110°.

The black adhesion film 120 may have a thickness between about 0.05mm -1mm and, in some embodiments, between 0.1mm -1mm. The exact thickness of the black adhesion film 120 may be at least partly based on the thickness and/or material of the first glass layer 114 of the first glass layers stack 110 such that different first glass layers stacks 110 are configured to match with different black adhesion films 120. As a general example, when the first glass layer 114 of the first glass layers stack 110 has a thickness of about 3mm, the black adhesion film 120 has a thickness of about 0.2mm -0.3mm which is less than or equal to 1/10 the thickness of the first glass layer 114. Thus, in some such embodiments, a ratio of the thickness of the black adhesion film 120 to the thickness of the first glass layer 114 is in a range of between 1/20 and 1/10.

FIGURE 2B is a cross-sectional view of the second glass layers stack 130 that comprises part of the LIDAR cover window structure shown in FIGURE 1. The second glass layers stack 130 may comprise a stack consisting of a single layer or a plurality of layers. In some embodiments, the second glass layers stack 130 may comprise a second glass layer 134 and at least one of an anti-reflective (AR) coating or a conductive layer. The second glass layer 134 may have a thickness from about 0.5mm -7mm and, in some embodiments, between 0.1mm -7mm. In some embodiments, the second glass layer 134 may be made of general silica glass, float glass, and/or other various strengthened glasses.

As shown in the embodiment of FIGURE 2B, the second glass layers stack 130 may comprise a second glass layer 134, a conductive layer 136, and an AR coating 138 arranged in sequence with the conductive layer 136 disposed between (e.g., sandwiched between) the second glass layer 134 and the AR coating 138. The AR coating 116 may include a general AR coating and/or a hard AR coating. The conductive layer 136 may comprise a conductive film. In some embodiments, the conductive layer 136 may comprise, but is not limited to, indium tix oxide (ITO) , indium zinc oxide (IZO) , and aluminum-doped zinc oxide (AZO) . It is to be appreciated that the conductive layer 136 is an optional layer and, in some embodiments, may not be present.

Referring now to FIGURES 3-4, which illustrate two processes for manufacturing a LIDAR cover window with black adhesion film in accordance with this disclosure. In one implementation, a laminated glass structure can be achieved by using an autoclave and, in the other implementation, a laminated glass structure can be achieved by using a laminated vacuum package (or laminated vacuum bag) . It is to be appreciated that the two processes for manufacturing the laminated glass structure of this disclosure offers manufacturing flexibility.

FIGURE 3 is a schematic flow diagram illustrating an example implementation of an exemplary method 300 for manufacturing a LIDAR cover window with black adhesion film, as shown in FIGURES 1-2B. In this exemplary method 300, an autoclave may be used.

In this exemplary method, at 310, the glass layers and the black adhesion film may be cut to a specified size. The glass layers may comprise a first glass layers stack (e.g., 110 in FIGURES 1, 2A) and a second glass layers stack (e.g., 130 in FIGURES 1, 2B) similar to those described above with respect to FIGURES 1-2B. The black adhesion film (e.g., 120 in FIGURE 1) may be of a similar thickness and composition to that described above with respect to FIGURES 1-2B. A cutting tool 312 may be used to cut the glass layers and the black adhesion film. In some implementations, the cutting is performed using IR transmission.

In this exemplary method, at 320, the glass layers and the black adhesion film are stacked and aligned to make a laminated glass. Assembly tooling 322 may be used to stack and orientate the glass layers and black adhesion film. As an example, assembly tooling 322 may be used to receive and orientate the first glass layers stack (e.g., 110 in FIGURES 1, 2A) . Then, the black adhesion film (e.g., 120 in FIGURE 1) may be disposed on the first glass layers stack followed by the second glass layers stack (e.g., 130 in FIGURES 1, 2B) being disposed on the black adhesion film. Next, an edge of the first glass layers stack, an edge of the black adhesion film, and an edge of the second glass layers stack are aligned to make the laminated glass.

In this exemplary method, at 330, the laminated glass 332 may be prefixed by adhesive 334, such as tape and/or glue, at the edge of the laminated glass 332.

In this exemplary method, at 340, the laminated glass 332 may be pressed with a roller 342 at least once. In some non-limiting examples, the laminated glass 332 is pressed with a roller 342 more than two (2) times. The roller 342 exerts a predetermined amount of pressure on the laminated glass 332 and has a predefined scroll speed. In some implementations, the roller 342 exerts a pressure on the laminated glass 332 between about 0.15MPa -0.2MPa. In some implementations, the roller 342 has a scroll speed of about 50RPM -250RPM.

In this exemplary method, at 350, the laminated glass 332 may be sent to the autoclave 352, in particular the autoclave chamber, for curing. The autoclave 352 may have predefined curing parameters that are initiated at specific stages in the curing process/sequence. As an example, the curing process may commence by first evacuating the autoclave chamber to a vacuum pressure of less than 1mbar without heating for about 10 minutes to 20 minutes. Next, the autoclave chamber may be heated to 80℃ -100℃ for about 20 minutes to 40 minutes while maintaining the vacuum pressure at about 0.09MPa -0.1Mpa. Then, the autoclave chamber may continue to be heated to a temperature of about 110℃ -140℃ and this temperature may be maintained for about 20 minutes to 40 minutes. Finally, the temperature of the autoclave chamber may be reduced to room temperature for a period of 20 minutes to 60 minutes after which the pressure may be relieved.

In this exemplary method, at 360, the cured laminated glass 332 may be removed from the autoclave 352 once the temperature has reached room temperature (e.g., about 25℃) . Then, the residual adhesive 334, such as glue and/or tape, along the edge of the laminated glass 332 may be trimmed/removed.

FIGURE 4 is a schematic flow diagram illustrating an example implementation of another exemplary method 400 for manufacturing a LIDAR cover window with black adhesion film, as shown in FIGURES 1-2B. In this exemplary method 400, a silicone vacuum bag (or vacuum package) may be used instead of an autoclave.

In this exemplary method, at 410, the glass layers and the black adhesion film may be cut to a specified size. The glass layers may comprise a first glass layers stack (e.g., 110 in FIGURES 1, 2A) and a second glass layers stack (e.g., 130 in FIGURES 1, 2B) similar to those described above with respect to FIGURES 1-2B. The black adhesion film (e.g., 120 in FIGURE 1) may be of a similar thickness and composition to that described above with respect to FIGURES 1-2B. A cutting tool 412 may be used to cut the glass layers and the black adhesion film. In some implementations, the cutting is performed using IR transmission.

In this exemplary method, at 420, the glass layers and the black adhesion film are stacked and aligned to make a laminated glass. Assembly tooling 422 may be used to stack and orientate the glass layers and black adhesion film. As an example, assembly tooling 422 may be used to receive and orientate the first glass layers stack (e.g., 110 in FIGURES 1, 2A) . Then, the black adhesion film (e.g., 120 in FIGURE 1) may be disposed on the first glass layers stack followed by the second glass layers stack (e.g., 130 in FIGURES 1, 2B) being disposed on the black adhesion film. Next, an edge of the first glass layers stack, an edge of the black adhesion film, and an edge of the second glass layers stack are aligned to make the laminated glass.

In this exemplary method, at 430, the laminated glass 432 may be prefixed by adhesive 434, such as tape and/or glue, at the edge of the laminated glass 432.

In this exemplary method, at 440, the laminated glass 432 may be pressed with a roller 442 at least once. In some non-limiting examples, the laminated glass 432 is pressed with a roller 442 more than two (2) times. The roller 442 exerts a predetermined amount of pressure on the laminated glass 432 and has a predefined scroll speed. In some implementations, the roller 442 exerts a pressure on the laminated glass 432 between about 0.15MPa -0.2MPa. In some implementations, the roller 442 has a scroll speed of about 50RPM -250RPM.

In this exemplary method, at 450, the laminated glass 432 may be sent to a vacuum bag 452, which is then placed in an oven 454, for curing. In some implementations, the vacuum bag 452 used for curing may be made of silicone. As an example, the laminated glass 432 may be placed in the silicone vacuum bag 452 to cure in an oven 454 according to predefined curing parameters that are initiated at specific stages in the curing process/sequence. As an example, the curing process may commence by first evacuating the vacuum bag 452 to a vacuum pressure of less than 1mbar. The vacuum bag 452, such as a silicone vacuum bag, may be evacuated via an external vacuum pump (not shown) . The evacuation process may be performed without heating for about 10 minutes to 20 minutes. Next, the oven 454 and, by extension, the vacuum bag 452 within said oven 454 may be heated to about 70℃ -80℃ by introducing incremental temperature increases, or heat ramp ups, of 1℃ -2℃/minute. Once the temperature reaches about 70℃ -80℃, the temperature may be maintained at about 70℃ -80℃ for about 30 minutes to 50 minutes. Then, the oven 454 and, by extension, the vacuum bag 452 may continue to be heated to a temperature of about 110℃ -140℃ and this temperature may be maintained for about 20 minutes to 40 minutes. Next, the temperature of the oven 454 and, by extension, the temperature of the vacuum bag 452 may be reduced to room temperature (e.g., about 25℃) by introducing incremental temperature decreases, or heat ramp downs, of 1℃ -2℃/minute. Finally, the pressure may be relieved.

In this exemplary method, at 460, the cured laminated glass 432 may be removed from the oven 454 and vacuum bag 452 once the temperature has reached room temperature (e.g., about 25℃) . Then, the residual adhesive 434, such as glue and/or tape, along the edge of the laminated glass 432 may be trimmed/removed.

The black adhesion film with high IR transmission may comprise at least one polymer, at least one black dyestuff with IR transmission, and at least one light diffusing agent. The at least one polymer, the at least one black dyestuff, and the at least one light diffusing agent are the main constituents of the composition that forms the black adhesion film with high IR transmission.

In some embodiments, the black adhesion film may consist essentially of the main constituents. In some non-limiting examples, the black adhesion film may be formed from a composition comprising about 100g of polymer, between about 4g -10g of black dyestuff with IR transmission, and between about 3g -15g of light diffusing agent. In one non-limiting example, the black adhesion film may be formed from a composition comprising about 100g of polymer, about 5g of black dyestuff with IR transmission, and about 5g of light diffusing agent. Table 1 below shows the weight or weight range of each constituent that makes up of the black adhesion film. It is to be appreciated that these amounts can be scaled up or scaled down as long as the relative weight relationships between the constituents are maintained.

Table 1. Main Constituents of Black Adhesion Film

Material	Amount/Weight	Example Composition
Polymer	100g	100g
Black Dyestuff	4g -10g	5g

Light Diffusing Agent

3g -15g

5g

The polymer of the black adhesion film generally possesses certain characteristics, or features, that make the polymer particularly suitable for integration into the composition for making the black adhesion film with high IR transmission. A first characteristic of the polymer is that the polymer may be processed by the thermal curing process of lamination at temperatures ranging from 100℃ -150℃. A second characteristic of the polymer is that the polymer may provide more than 91%transmission at visible (VIS) and short-wave infrared (SWIR) wavelengths after thermal curing. A third characteristic of the polymer is that the polymer may have a heat resistance of greater than 105℃. It is to be appreciated that the polymer is capable of withstanding moderately high temperatures. A fourth characteristic of the polymer is that the polymer may have a degree of crosslinking that exceeds at least 50%.

Any suitable polymer, or combination of polymers, may be selected that has the aforementioned characteristics and that is capable of effecting/providing the beneficial technical effects described herein. By way of example and not limitation, the polymer may comprise ethylene-vinyl acetate copolymer (EVA) , ethylene-methyl methacrylate copolymer, ethylene-octene copolymer, ethylene-pentene copolymer, polyvinyl butyral (PVB) , or any combination thereof. In some embodiments, it may be preferred that the polymer comprises ethylene-vinyl acetate copolymer (EVA) or polyvinyl butyral (PVB) . In embodiments where the polymer comprises PVB, the polymer may further include about 20%-40%plasticizer in PVB resin. As an example, the polymer may comprise PVB and include a plasticizer content in PVB of about 30%. In this example, the plasticizer can be triethylene glycol (TGE) and oxalic acid. In some implementations, the main component of the black adhesion film is a polymer with high IR transmission and high heat resistance. As an example, the black adhesion film can include polymer that renders the black adhesion film highly transmissive for IR light but non-transmissive (e.g., blocks) for VIS light.

The black dyestuff with IR transmission of the black adhesion film generally possesses certain characteristics, or features, that make the black dyestuff particularly suitable for integration into the composition to make the black adhesion film that provides high IR transmission. In particular, the black dyestuff is responsible for the black color (i.e., appearance) of the black adhesion film. Any suitable black dyestuff, or combination of black dyestuffs, may be selected that has the aforementioned characteristics and that is capable of effecting/providing the beneficial technical effects described herein. By way of example and not limitation, the black dyestuff may comprise carbon black, nigrosine, perylene dyestuff, copper chromite black pigment, or any combination thereof in which the black dyestuffs can be mixed in any proportion. In some embodiments, the black dyestuff may have a particle size between about 0.5μm -20μm. As an example, the black dyestuff may have a particle size between about 2μm -5μm.

Any suitable light diffusing agent, or combination of light diffusing agents, may be selected that is capable of effecting/providing the beneficial technical effects described herein. By way of example and not limitation, the light diffusing agent may include, but is not limited to, micro/nano calcium fluoride, micro/nano magnesium fluoride, micro/nano quartz, micro/nano low melting point glass powder, fumed silica, titanium dioxide (TiO ₂) , aluminum oxide (Al ₂O ₃) . It is to be appreciated that some of the light diffusing agents are present as a mixture of different sized particles characterized by micro-particles and nano-particles. In some embodiments, the light diffusing agent may have a particle size between about 1μm -50μm. As an example, the light diffusing agent may have a particle size between about 5μm -10μm.

In some embodiments, the black adhesion film may comprise one or more additional constituents in addition to the main constituents, which comprise the polymer, the black dyestuff, and the light diffusing agent. For example, the black adhesion film with high IR transmission may further comprise one or more of: a coupling agent, a crosslinker, an initiator, an antioxidant, a light stabilizer, a heat stabilizer, and a tackifier. In some embodiments, the black adhesion film may be formed from a composition comprising the following (in terms of relative proportions) : about 100g of main constituents comprising a polymer, black dyestuff with IR transmission and light diffusing agent; between about 0.1g -1.0g of coupling agent; between about 0.3g -2.0g of crosslinker; between about 0.2g -0.8g of initiator; between about 0.5g -5g of antioxidant; between about 0.1g -2g of light stabilizer; between about 0.1g -2g of heat stabilizer; and between about 0.05g -0.4g of tackifier. In one non-limiting example, the black adhesion film may be formed from a composition comprising the following: about 100g of main constituents including a polymer, a black dyestuff and a light diffusing agent; about 0.5g of coupling agent; about 1.5g of crosslinker; about 0.4g of initiator; about 1.5g of antioxidant; about 0.8g of light stabilizer; about 0.8g of heat stabilizer; and about 0.1g of tackifier. Table 2 below shows the weight or weight range of various constituent that may be present in the composition of the black adhesion film. It is to be appreciated that these amounts can be scaled up or scaled down as long as the relative weight relationships between the constituents is maintained.

Table 2. Constituents of Black Adhesion Film

Material	Amount/Weight	Example Composition
Main Constituents	100g	100g
Coupling Agent	0.1g -1.0g	0.5g
Crosslinker	0.3g -2.0g	1.5g
Initiator	0.2g -0.8g	0.4g
Antioxidant	0.5g -5g	1.5g
Light Stabilizer	0.1g -2g	0.8g
Heat Stabilizer	0.1g -2g	0.8g
Tackifier	0.05g -0.4g	0.1g

Any suitable coupling agent, or combination of coupling agents, may be selected that is capable of effecting/providing the beneficial technical effects described herein. By way of example and not limitation, the coupling agent may include, but is not limited to, silane coupling agent, titanates, and aluminates. In some embodiments, the coupling agent comprises a silane coupling agent including, but not limited to, vinyl trimethoxysilane, methacryloxysilane, aminopropyl triethoxysilane, vinyl trimethoxysilane prepolymer, or any combination thereof in which the coupling agents can be mixed in any proportion.

Any suitable crosslinker, or combination of crosslinkers, may be selected that is capable of effecting/providing the beneficial technical effects described herein. In some embodiments, the crosslinker may comprise a peroxide with good thermal stability. As an example, a crosslinker with good thermal stability may be defined as having a half-life temperature from about 90℃ -130℃. Further, the free radicals may have higher activity after decomposition which may match the melt process of ethylene-vinyl acetate copolymer (EVA) . By way of example and not limitation, the peroxide crosslinker may include, but is not limited to, alkyl dipropyl carbonate (DPC) , benzoyl peroxide (BPO) , peroxide ketal, trimethylolpropane triacrylate (TMPTA) , Triallyl isocyanate (TAIC) , pentaerythritol triacrylate (PETA) , isopropyl methacrylate, ethoxylated trimethylolpropane triacrylate (ETPTA) , isooctyl acrylate, or any combination thereof in which the crosslinkers can be mixed in any proportion.

Any suitable initiator, or combination of initiators, may be selected that is capable of effecting/providing the beneficial technical effects described herein. In some embodiments, the initiator may comprise a peroxide initiator. By way of example and not limitation, the peroxide initiator may include, but is not limited to, one or more of tert-butyl peroxybenzoate (TBPB) ; 1, 1-di- (tert-butylperoxy) -3, 3, 5-trimethylcyclohexane (TMCH) ; diisopropyl peroxydicarbonate; tert-butylperoxy-2-ethylhexylcarbonate (TBEC) ; benzoyl peroxide (BPO) ; cumene hydroperoxide (CMHP) ; tert-butyl hydroperoxide (TBHP) ; tert-amyl 2-ethylhexanoate (TAPO) ; 1, 3-bis (tert-butylperoxy isopropyl) benzene; and tert-butylperoxy 2-ethylhexyl carbonate.

Any suitable antioxidant, or combination of antioxidants, may be selected that is capable of effecting/providing the beneficial technical effects described herein. In some embodiments, the antioxidant may comprise hindered phenolic antioxidants. By way of example and not limitation, the hindered phenolic antioxidant may include, but is not limited to, one or more of pentaerythritol esters, n-octadecanol propionate esters, phosphorous esters, and thioesters. In some non-limiting examples, the hindered phenolic antioxidants comprise antioxidant 1010 or antioxidant 1790 from HT/T 3713- 2010 which is the Chemical Industry Standard of the People's Republic of China. Antioxidant 1010 is pentaerythritol tetrakis 3- (3, 5-ditert-butyl-4-hydroxyphenyl) propionate. The molecular formula of antioxidant 1010 is C ₇₃H ₁₀₈O ₁₂. Antioxidant 1790 is tris (4-tert-butyl-3-hydroxy-2, 6-dimethyl-benzyl) . The molecular formula of antioxidant 1790 is C ₄₂H ₅₇N ₃O ₆.

Any suitable light stabilizer, or combination of light stabilizers, may be selected that is capable of effecting/providing the beneficial operation described herein. In some embodiments, the light stabilizer may comprise hindered amine antioxidants. By way of example and not limitation, the light stabilizer may include, but is not limited to, one or more of bis (1, 2, 2, 6, 6-pentamethyl-4-piperidyl) sebacate, bis (2, 2, 6, 6-tetramethyl-4-piperidyl) sebacate, and 3, 5-bis (1, 1-dimethylethyl) -4-hydroxy-benzoicacihexadecylester.

Any suitable heat stabilizer, or combination of heat stabilizers, may be selected that is capable of effecting/providing the beneficial operation described herein. By way of example and not limitation, the heat stabilizer may include, but is not limited to, a fatty acid soap and a metal soap such as a calcium, zinc and/or barium metal soap, one or more of which are mixed in any proportion.

Any suitable tackifier, or combination of tackifiers, may be selected that is capable of effecting/providing the beneficial operation described herein. By way of example and not limitation, the tackifier may include, but is not limited to, limited terpene resin, terpene phenolic resin, polyresin, and hydrogenated rosin one or more of which are mixed in any proportion.

It is to be appreciated that the composition of the black adhesion film can be configured to provide for high IR transmission and to block visible (VIS) light. For example, the black adhesion film 120 incorporated in the LIDAR window 100 may be transmissive for infrared (IR) light, thereby allowing IR light to pass therethrough, while being non-transmissive for visible (VIS) light, thereby blocking the VIS light. It is to be appreciated that the black adhesion film will not be as susceptible to the yellowing under sunlight as optical materials that are generally transparent. In some embodiments, the composition of the black adhesion film may be configured to provide for a heat resistance between about 40℃ -105℃.

Further, it is to be appreciated that the black adhesion film 120 may be formed from a composition comprising a polymer elastomer which advantageously may cushion the impact of from a stone collision, thereby mitigating the likelihood of chipping. In effect, the impact resistance is improved by the elasticity of the polymer film. In some non-limiting examples, the black adhesive film comprises a polymer such as PVB, EVA, infrared penetrant, black dyestuff, and a coupling agent.

Another aspect of this disclosure comprises a method of making the black adhesion film having high IR transmission. FIGURE 5 is a flow diagram illustrating an example implementation of an exemplary method for making the black adhesion film with high IR transmission. The exemplary method 500 begins at 502. At 504, the method comprises weighing the raw materials selected for inclusion in a mixture used to make the black adhesion film characterized by a high IR transmission. It is to be appreciated that the raw materials are the constituents of the composition which form the black adhesion film.

The black adhesion film has a composition comprising at least the main constituents. As an example, the main constituents comprise at least a polymer, a black dyestuff, and a light diffusing agent. In some implementations, weighing the raw materials may comprise weighing, in relative proportions, about 100g of polymer, between about 4g -10g of black dyestuff with IR transmission, and between about 3g -15g of light diffusing agent. In one non-limiting example, the weighing of raw materials comprises weighing about 100g of polymer, about 5g of black dyestuff, and about 5g of light diffusing agent.

In other implementations, the black adhesion film may comprise one or more additional constituents in addition to the main constituents. For example, the black adhesion film may further comprise one or more of: a coupling agent, a crosslinker, an initiator, an antioxidant, a light stabilizer, a heat stabilizer, and a tackifier. In some implementations, weighing the raw materials may comprise weighing, in relative proportions, about 100g of main constituents including a polymer, black dyestuff with IR transmission and light diffusing agent, and one or more of the following: between about 0.1g -1.0g of coupling agent; between about 0.3g -2.0g of crosslinker; between about 0.2g -0.8g of initiator; between about 0.5g -5g of antioxidant; between about 0.1g -2g of light stabilizer; between about 0.1g -2g of heat stabilizer; and between about 0.05g -0.4g of tackifier. In one non-limiting example, the weighing of raw materials comprises weighing about 100g of main constituents including a polymer, black dyestuff with IR transmission and light diffusing agent; about 0.5g of coupling agent; about 1.5g of crosslinker; about 0.4g of initiator; about 1.5g of antioxidant; about 0.8g of light stabilizer; about 0.8g of heat stabilizer; and about 0.1g of tackifier.

In this exemplary method, at 506, the raw materials are combined and mixed to form a slurry of the black adhesion film. The slurry may be added to an extruder equipment, for example the barrel of a double-screw extruder equipment.

In this exemplary method, at 508, the black adhesion film having a high IR transmission is formed by melt extrusion and tape casting process. In this implementation, the extrusion temperature is controlled at a temperature between about 60℃ and 150℃. It is to be appreciated that the extrusion processing temperature may be dependent on the polymer, or combination of polymers, present in the black adhesion film composition.

In this exemplary method, at 510, the black adhesion film is formed after cooling the black adhesion film composition at room temperature. It is to be appreciated that cooling the black adhesion film evenly at room temperature may mitigate damage to the black adhesion film such as, for example, warping and cracking. Having formed the black adhesion film, the exemplary method 500 ends at 512.

While the embodiments discussed herein have been related to the systems and methods discussed above, these embodiments are intended to be exemplary and are not intended to limit the applicability of these embodiments to only those discussions set forth herein. The embodiments and discussions herein can be readily incorporated into any of these systems and methodologies by those of skill in the art.

The above examples are merely illustrative of several possible embodiments of various aspects of the present innovation, wherein equivalent alterations and/or modifications will occur to others skilled in the art upon reading and understanding this specification and the annexed drawings. In particular regard to the various functions performed by the above described components (assemblies, devices, systems, circuits, and the like) , the terms (including a reference to a “means” ) used to describe such components are intended to correspond, unless otherwise indicated, to any component, or combinations thereof, which performs the specified function of the described component (e.g., that is functionally equivalent) , even though not structurally equivalent to the disclosed structure which performs the function in the illustrated implementations of the innovation. In addition although a particular feature of the innovation may have been disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular application. Also, to the extent that the terms “including” , “includes” , “having” , “has” , “with” , or variants thereof are used in the detailed description and/or in the claims, such terms are intended to be inclusive in a manner similar to the term “comprising. ”

This written description uses examples to disclose the innovation, including the best mode, and also to enable one of ordinary skill in the art to practice the innovation, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the innovation is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that are not different from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.

In the specification and claims, reference will be made to a number of terms that have the following meanings. The singular forms “a” , “an” and “the” include plural referents unless the context clearly dictates otherwise. Approximating language, as used herein throughout the specification and claims, may be applied to modify a quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term such as “about” is not to be limited to the precise value specified. In some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Moreover, unless specifically stated otherwise, a use of the terms “first, ” “second, ” etc., do not denote an order or importance, but rather the terms “first, ” “second, ” etc., are used to distinguish one element from another.

As used herein, the terms “may” and “may be” indicate a possibility of an occurrence within a set of circumstances; a possession of a specified property, characteristic or function; and/or qualify another verb by expressing one or more of an ability, capability, or possibility associated with the qualified verb. Accordingly, usage of “may” and “may be” indicates that a modified term is apparently appropriate, capable, or suitable for an indicated capacity, function, or usage, while taking into account that in some circumstances the modified term may sometimes not be appropriate, capable, or suitable. For example, in some circumstances an event or capacity can be expected, while in other circumstances the event or capacity cannot occur –this distinction is captured by the terms “may” and “may be. ”

The best mode for carrying out the innovation has been described for purposes of illustrating the best mode known to the applicant at the time and enable one of ordinary skill in the art to practice the innovation, including making and using devices or systems and performing incorporated methods. The examples are illustrative only and not meant to limit the innovation, as measured by the scope and merit of the claims. The innovation has been described with reference to preferred and alternate embodiments. Obviously, modifications and alterations will occur to others upon the reading and understanding of the specification. It is intended to include all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof. The patentable scope of the innovation is defined by the claims, and may include other examples that occur to one of ordinary skill in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differentiate from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.

It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. It will be further appreciated that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.

Claims

A lamination structure including a black adhesion film for a LIDAR cover window, the black adhesion film comprising:

a polymer;

a black dyestuff;

and a light diffusing agent,

wherein the polymer, the black dyestuff, and the light diffusing agent are main constituents of the black adhesion film,

wherein an amount of the polymer, the black dyestuff, and the light diffusing agent in the black adhesion film is defined by a relative weight relationship of the polymer, the black dyestuff, and the light diffusing agent with respect to each other, and

wherein the black adhesion film comprises 100g of polymer, between 4g to 10g of black dyestuff, and between 3g and 15 grams of light diffusing agent.
The lamination structure of claim 1, wherein the polymer comprises ethylene-vinyl acetate copolymer (EVA) , ethylene-methyl methacrylate copolymer, ethylene-octene copolymer, ethylene-pentene copolymer, polyvinyl butyral (PVB) , or any combination thereof.
The lamination structure of claim 1 or 2, wherein the black dyestuff comprises carbon black, nigrosine, perylene dyestuff, copper chromite black pigment, or any combination thereof.
The lamination structure of claim 3, wherein the black dyestuff has a particle size between 0.5μm -20μm.
The lamination structure of claim 1 or 2, wherein the light diffusing agent comprises micro/nano calcium fluoride, micro/nano magnesium fluoride, micro/nano quartz, micro/nano low melting point glass powder, fumed silica, titanium dioxide (TiO ₂) , aluminum oxide (Al ₂O ₃) .
The lamination structure of claim 5, wherein the light diffusing agent has a particle size between 1μm -50μm.
The lamination structure of claim 1 or 2, wherein the black adhesion film further includes additional constituents comprising one or more of:

a coupling agent;

a crosslinker;

an initiator;

an antioxidant;

a light stabilizer;

a heat stabilizer; and

a tackifier,

wherein an amount of the main constituents and additional constituents in the black adhesion film is defined by a relative weight relationship of the main constituents and additional constituents with respect to each other.
The lamination structure of claim 7, wherein the black adhesion film comprises 100g of the main constituents; between 0.1g -1.0g of coupling agent; between 0.3g -2.0g of crosslinker; between 0.2g -0.8g of initiator; between 0.5g -5g of antioxidant; between 0.1g -2g of light stabilizer; between 0.1g -2g of heat stabilizer; and between 0.05g -0.4g of tackifier.
A LIDAR cover window structure, comprising:

a first glass layers stack;

a second glass layers stack; and

a black adhesion film, wherein the black adhesion film is disposed between the first glass layers stack and the second glass layers stack, wherein the black adhesion film is IR transmissive and comprises a polymer, a black dyestuff, and a light diffusing agent, and wherein the polymer, the black dyestuff, and the light diffusing agent are main constituents of the black adhesion film.
The LIDAR cover window of claim 9, wherein an amount of the polymer, the black dyestuff, and the light diffusing agent in the black adhesion film is defined by a relative weight relationship of the polymer, the black dyestuff, and the light diffusing agent with respect to each other.
The LIDAR cover window of claim 10, wherein the black adhesion film comprises 100g of polymer, between 4g to 10g of black dyestuff, and between 3g and 15 grams of light diffusing agent.
The LIDAR cover window of any one of claims 9-11, wherein the polymer comprises ethylene-vinyl acetate copolymer (EVA) , ethylene-methyl methacrylate copolymer, ethylene-octene copolymer, ethylene-pentene copolymer, polyvinyl butyral (PVB) , or any combination thereof.
The LIDAR cover window of any one of claims 9-11, wherein the black dyestuff comprises carbon black, nigrosine, perylene dyestuff, copper chromite black pigment, or any combination thereof.
The LIDAR cover window of claim 13, wherein the black dyestuff has a particle size between 0.5μm -20μm.
The LIDAR cover window of any one of claims 9-11, wherein the light diffusing agent comprises micro/nano calcium fluoride, micro/nano magnesium fluoride, micro/nano quartz, micro/nano low melting point glass powder, fumed silica, titanium dioxide (TiO ₂) , aluminum oxide (Al ₂O ₃) .
The LIDAR cover window of claim 15, wherein the light diffusing agent has a particle size between 1μm -50μm.
The LIDAR cover window of any one of claims 9-11, wherein the black adhesion film further includes additional constituents comprising one or more of:

a coupling agent;

a crosslinker;

an initiator;

an antioxidant;

a light stabilizer;

a heat stabilizer; and

a tackifier,

wherein an amount of the main constituents and additional constituents in the black adhesion film is defined by a relative weight relationship of the main constituents and additional constituents with respect to each other.
The LIDAR cover window of claim 17, wherein the black adhesion film comprises 100g of the main constituents; between 0.1g -1.0g of coupling agent; between 0.3g -2.0g of crosslinker; between 0.2g -0.8g of initiator; between 0.5g -5g of antioxidant; between 0.1g -2g of light stabilizer; between 0.1g -2g of heat stabilizer; and between 0.05g -0.4g of tackifier.
The LIDAR cover window of any one of claims 9-11, wherein the first glass layers stack comprises a first glass layer, an AR coating, and an oleophobic coating with the AR coating disposed between the first glass layer and the oleophobic coating.
The LIDAR cover window of any one of claims 9-11, wherein the second glass layers stack comprises a second glass layer, a conductive layer, and an AR coating with the conductive layer disposed between the second glass layer and the AR coating.
The LIDAR cover window of claim 19 or 20, wherein the first glass layer and/or the second glass layer has a thickness between 0.5mm -7mm.
A method of forming a lamination structure for a LIDAR cover window, the method comprising:

cutting a first glass layers stack, a second glass layers stack, and a black adhesion film to a specified size;

stacking, the first glass layers stack, the black adhesion film, and the second glass layers stack such that the black adhesion film is disposed between the first glass layers stack and the second glass layers stack;

aligning the first glass layers stack, the black adhesion film, and the second glass layers stack along their respective edge to make the lamination structure, the lamination structure comprising laminated glass;

prefixing by adhesive the edge of the laminated glass;

pressing the laminated glass with a roller at least once;

curing, at elevated temperature, the laminated glass at vacuum in either an autoclave or a vacuum package; and

trimming the adhesive from the edge of the laminated glass after cooling the laminated glass to room temperature.
The method of claim 22, wherein the cutting is performed using IR transmission.
The method of claim 22 or 23, wherein the adhesive comprises glue and/or tape.