Optical cover for lidar and method for manufacturing the same, lidar

Abstract

This invention provides a photomask for lidar and its fabrication method, as well as a lidar itself. The lidar includes a photomask fixing part, on which the photomask is mounted. The photomask comprises: a body having an inner surface and an outer surface opposite to the inner surface; and a first light-transmitting conductive film disposed on the body, covering the inner or outer surface. The first light-transmitting conductive film is connected and conductive to the photomask fixing part, enabling the lidar to shield against electromagnetic interference. The photomask designed in this invention can greatly enhance the lidar's ability to shield against electromagnetic interference, reduce the lidar's external electromagnetic radiation, and thus enable the lidar to possess electromagnetic compatibility, meeting automotive-grade electromagnetic compatibility requirements.

Description

Technical Field

[0001] This invention relates to the field of photoelectric detection, and more particularly to photomasks for lidar and their preparation methods, and lidar. Background Technology

[0002] With the rise of autonomous driving technology, lidar (LiDAR) is receiving increasing attention as a crucial detection component. As the name suggests, lidar is a radar system that uses laser beams to detect the position, velocity, and other characteristics of a target. Its working principle involves emitting a detection beam towards the target, then comparing the received echo beam reflected from the target with the detection beam. After appropriate processing, information about the target can be obtained, such as its distance, azimuth, altitude, speed, attitude, and even shape. This allows for the detection, tracking, and identification of targets such as aircraft and missiles.

[0003] As an automotive-grade product, LiDAR has very high requirements for electromagnetic compatibility (EMC). It must not be affected by interference from external devices, and at the same time, LiDAR must not interfere with the operation of other devices.

[0004] Most existing lidar systems use snap-on photomasks made of PC material, such as... Figure 1a As shown, since PC material is an insulator, it cannot conduct electricity with the photomask fixing part, so the lidar after the photomask is installed cannot shield electromagnetic interference and cannot meet the requirements of automotive-grade electromagnetic compatibility. Figure 1b for Figure 1a The enlarged view shows that in this snap-fit ​​photomask design, the groove is filled with adhesive. When the protrusion at the lower end of the photomask presses into the side groove of the photomask fixing part, it will be squeezed downwards, causing the adhesive to overflow from the left and right sides of the groove (the gap of the snap), resulting in obvious glue overflow problem, which affects the appearance.

[0005] The content of the background section only discloses the technology known to the inventors and does not necessarily represent the prior art in this field. Summary of the Invention

[0006] To ensure the electromagnetic compatibility of lidar, meeting automotive-grade electromagnetic compatibility requirements, and to improve the appearance of the photomask, this invention relates to a photomask for lidar. The lidar includes a photomask fixing part, and the photomask is mounted on the photomask fixing part. The photomask includes:

[0007] The body has an inner surface and an outer surface opposite to the inner surface;

[0008] A first light-transmitting conductive film is disposed on the body, covering the inner or outer surface. The first light-transmitting conductive film is connected and conductive to the photomask fixing part, so that the lidar can shield electromagnetic interference.

[0009] According to one aspect of the present invention, the first transparent conductive film includes a first anti-reflection optical layer and a first semiconductor transparent conductive layer. When the first transparent conductive film covers the inner surface of the body, the first anti-reflection optical layer is disposed outside the first semiconductor transparent conductive layer; when the first transparent conductive film covers the outer surface of the body, the first anti-reflection optical layer is disposed inside the first semiconductor transparent conductive layer.

[0010] According to one aspect of the invention, the surface area of ​​the first anti-reflection optical layer is smaller than the surface area of ​​the first semiconductor transparent conductive layer, and is configured to correspond to the scanning range of the lidar detection beam on the photomask.

[0011] According to one aspect of the invention, the sheet resistance of the first semiconductor transparent conductive layer does not exceed 200 ohms.

[0012] According to one aspect of the invention, the sheet resistance of the first semiconductor transparent conductive layer is between 50 and 130 ohms.

[0013] According to one aspect of the invention, the photomask further includes:

[0014] A first hardened film is disposed on the outer surface of the body and configured to protect the body and / or the first light-transmitting conductive film.

[0015] According to one aspect of the present invention, when the first light-transmitting conductive film covers the inner surface of the body, the first hardened film covers the outer surface of the body; when the first light-transmitting conductive film covers the outer surface of the body, the first hardened film covers the first light-transmitting conductive film.

[0016] According to one aspect of the invention, the photomask further includes:

[0017] A second hardened film is disposed on the inner surface of the body, and when the first light-transmitting conductive film covers the inner surface of the body, the second hardened film covers the first light-transmitting conductive film; when the first light-transmitting conductive film covers the outer surface of the body, the second hardened film covers the inner surface of the body.

[0018] According to one aspect of the invention, the body has an upper end and a lower end, and the photomask further includes:

[0019] The first shielding structure is disposed near the lower end of the body and protrudes outward along the outer surface of the body. When the photomask is mounted on the photomask fixing part, the first shielding structure shields the gap between the photomask and the photomask fixing part.

[0020] According to one aspect of the present invention, the upper end of the photomask fixing part is provided with a second connecting structure, and the photomask further includes:

[0021] The first connecting structure is disposed between the first shielding structure and the lower end of the main body, and engages with the second connecting structure of the photomask fixing part.

[0022] According to one aspect of the invention, the photomask further includes:

[0023] The top cover is located at the upper end of the body and has a lower surface and an upper surface opposite to the lower surface.

[0024] According to one aspect of the invention, the photomask further includes:

[0025] A second conductive film is applied to the lower surface of the top cover, and the second conductive film is connected to the first light-transmitting conductive film.

[0026] According to one aspect of the invention, the sheet resistance of the second conductive film is no more than 200 ohms.

[0027] According to one aspect of the invention, the sheet resistance of the second conductive film is between 50 and 130 ohms.

[0028] According to one aspect of the invention, the top cover further includes a second shielding structure disposed near the upper end of the body and protruding from the lower surface of the top cover toward the upper end of the body, wherein when the top cover is mounted on the body, the second shielding structure shields the gap between the top cover and the body.

[0029] According to one aspect of the invention, the top cover and the body are integrally constructed, and the top cover and the body have different reflectivities, the first light-transmitting conductive film covers the inner or outer surface of the body and the top cover, and the first hardened film covers the outer surface of the body and the top cover.

[0030] According to one aspect of the invention, the body comprises a first material, the top cover comprises a second material, the first material being a material that is transparent to infrared light but not transparent to visible light, and the second material being a material that has high reflectivity to infrared light.

[0031] The present invention also relates to a lidar, comprising:

[0032] The transmitting unit is configured to emit a probe beam;

[0033] The receiving unit is configured to receive the echo beam of the detection beam after it has been reflected by an object; and

[0034] The photomask described above has an accommodating space, in which the transmitting unit and the receiving unit are disposed;

[0035] The detection beam passes through the photomask to probe the outside of the lidar, and the echo beam passes through the photomask and is received by the receiving unit. The photomask is also configured to be connected and conductive with the photomask fixing part, so that the lidar can shield electromagnetic interference.

[0036] The present invention also relates to a method for fabricating a photomask for a lidar, the lidar including a photomask fixing part, the photomask being mounted on the photomask fixing part, the fabrication method comprising:

[0037] S11: Provides a body having an inner surface and an outer surface opposite to the inner surface;

[0038] S12: A first light-transmitting and conductive film is formed on the inner or outer surface of the body, so that when the photomask is installed on the photomask fixing part of the lidar, the first light-transmitting and conductive film is connected to the photomask fixing part, so that the lidar can shield electromagnetic interference.

[0039] According to one aspect of the present invention, the preparation method further includes:

[0040] S13: Hardening treatment is performed on the outer surface of the body to form a first hardened film, and when the first light-transmitting conductive film covers the inner surface of the body, the first hardened film covers the outer surface of the body; when the first light-transmitting conductive film covers the outer surface of the body, the first hardened film covers the first light-transmitting conductive film.

[0041] According to one aspect of the present invention, the preparation method further includes:

[0042] S14: Harden the inner surface of the body to form a second hardened film, and when the first light-transmitting conductive film covers the inner surface of the body, the second hardened film covers the first light-transmitting conductive film; when the first light-transmitting conductive film covers the outer surface of the body, the second hardened film covers the inner surface of the body.

[0043] According to one aspect of the present invention, the preparation method further includes:

[0044] S15: Provides a top cover having a lower surface and an upper surface opposite to the lower surface;

[0045] S16: A second conductive film is formed on the lower surface of the top cover, so that when the top cover is disposed on the upper end of the body, the second conductive film is connected and conductive with the first light-transmitting conductive film.

[0046] According to one aspect of the present invention, the preparation method further includes: integrally molding the top cover and the body using materials with different reflectivities, and forming the first light-transmitting conductive film on the inner surface of the body and the lower surface of the top cover or the outer surface of the body and the upper surface of the top cover; forming the first hardening film on the outer surface of the body and the upper surface of the top cover; and forming the second hardening film on the inner surface of the body and the lower surface of the top cover.

[0047] The photomask designed in this invention can greatly enhance the electromagnetic interference shielding capability of lidar and reduce its electromagnetic radiation, thereby enabling the lidar to achieve electromagnetic compatibility and meet automotive-grade electromagnetic compatibility requirements. Furthermore, this invention also includes a shielding structure that covers any areas where adhesive overflow may occur after the photomask is installed on the photomask fixing part, thus improving the appearance of the photomask. Attached Figure Description

[0048] The accompanying drawings, which form part of this disclosure, are used to provide a further understanding of this disclosure. The illustrative embodiments of this disclosure and their descriptions are used to explain this disclosure and do not constitute an undue limitation of this disclosure. In the drawings:

[0049] Figures 1a-1b A schematic diagram of the photomask of an existing lidar is shown;

[0050] Figure 2a A cross-sectional view of a lidar with a mounting photomask according to an embodiment of the present invention is shown;

[0051] Figure 2b It shows Figure 2a A schematic diagram of the photomask structure;

[0052] Figure 2c It shows Figure 2a A magnified view of a portion of the photomask structure;

[0053] Figure 3a A schematic diagram of a first light-transmitting conductive film covering the inner surface of a body according to an embodiment of the present invention is shown;

[0054] Figure 3b A schematic diagram of a first light-transmitting conductive film covering the outer surface of a body according to an embodiment of the present invention is shown;

[0055] Figure 4 A top view of a lidar detection according to an embodiment of the present invention is shown;

[0056] Figure 5aA cross-sectional view of a lidar with a mounting mask according to another embodiment of the present invention is shown;

[0057] Figure 5b It shows Figure 5a A schematic diagram of the structure of a photomask;

[0058] Figure 5c It shows Figure 5b A schematic diagram of another type of photomask;

[0059] Figure 6 A schematic diagram of the top cover structure according to an embodiment of the present invention is shown;

[0060] Figure 7a A schematic diagram of the structure of a photomask according to another embodiment of the present invention is shown;

[0061] Figure 7b A schematic diagram of the structure of a photomask according to another embodiment of the present invention is shown. Detailed Implementation

[0062] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0063] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0064] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0065] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0066] The following disclosure provides many different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0067] This invention provides a photomask for lidar and its fabrication method, as well as a lidar itself. The lidar includes a photomask fixing part, on which the photomask is mounted. The photomask comprises: a body having an inner surface and an outer surface opposite to the inner surface; and a first light-transmitting conductive film disposed on the body, covering the inner or outer surface. The first light-transmitting conductive film is connected and conductive to the photomask fixing part, enabling the lidar to shield against electromagnetic interference. The photomask designed in this invention can greatly enhance the lidar's ability to shield against electromagnetic interference, reduce the lidar's external electromagnetic radiation, and thus enable the lidar to possess electromagnetic compatibility, meeting automotive-grade electromagnetic compatibility requirements.

[0068] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0069] Figure 2a A cross-sectional view of a lidar 300 according to an embodiment of the present invention is shown. The lidar 300 includes a lidar fixing part 301, and the lidar 100 is mounted on the lidar fixing part 301 of the lidar 300. Figure 2b It shows Figure 2a A schematic diagram of the photomask structure is shown below, wherein the photomask 100 includes a body 110, a first transparent conductive film 120, and a first hardening film 130, as detailed below:

[0070] Continue to refer to Figure 2b The body 110 has an inner surface S1 and an outer surface S2 opposite to the inner surface S1. The body 110 is usually made of a light-transmitting and non-conductive material and forms the main body of the photomask 100. It is coated with a film as needed. This invention does not limit the method of coating.

[0071] Continue to refer to Figure 2b The first light-transmitting conductive film 120 is disposed on the body 110, covering the inner surface S1 or the outer surface S2. Figure 2b (The dashed line indicates that it can be set in either of two positions), the first light-transmitting conductive film 120 is connected and conductive to the photomask fixing part 301. Combined with Figure 2a For example, the photomask fixing part 301 is provided with a groove. The photomask fixing part 301 is made of a conductive material (e.g., aluminum alloy). When the first light-transmitting conductive film 120 is coated on the inner surface S1, it connects and conducts with the groove wall on the inner side of the groove, thereby forming a conductive equipotential body with the photomask fixing part 301. When the first light-transmitting conductive film 120 is provided on the outer surface S2, it connects and conducts with the groove wall on the outer side of the groove, thereby forming a conductive equipotential body with the photomask fixing part 301. After the first light-transmitting conductive film 120 and the photomask fixing part 301 form a conductive equipotential body, it will greatly enhance the laser radar's ability to shield electromagnetic interference and reduce the laser radar's electromagnetic radiation to the outside, thereby enabling the laser radar to have electromagnetic compatibility and meet the requirements of automotive-grade electromagnetic compatibility.

[0072] Continue to refer to Figure 2b The first hardened film 130 is disposed on the outer surface S2 of the body 110 and is configured to protect the body 110 and / or the first light-transmitting conductive film 120.

[0073] According to a preferred embodiment of the present invention, when the first light-transmitting conductive film 120 covers the inner surface S1 of the body 110, the first hardening film 130 covers the outer surface S2 of the body 110; when the first light-transmitting conductive film 120 covers the outer surface of the body 110, the first hardening film 130 covers the first light-transmitting conductive film 120.

[0074] Typically, the first hardened film 130 is disposed on the outer surface S2 of the body 110. If other film layers are disposed on the outer surface S2, the first hardened film 130 is disposed on the outermost layer of these film layers. The first hardened film 130 can protect the film layers coated on the outer surface S2 of the body 110. Its hardened coating plays a protective and scratch-resistant role and can improve the performance of the outer surface S2 of the body 110, meeting the performance requirements of automotive-grade outer surfaces. When the first light-transmitting conductive film 120 covers the outer surface S2 of the body 110, the first hardened film 130 covers the first light-transmitting conductive film 120, which can improve the adhesion of the first light-transmitting conductive film 120. Furthermore, the first hardened film 130 has a high light transmittance that meets the requirements of lidar.

[0075] The basic structure of the photomask 100 has been described above. The novel photomask design adopted in this invention transforms the PC material photomask into a conductor, forming a conductive equipotential body with the photomask fixing part 301. This enables the lidar to possess electromagnetic compatibility, meeting automotive-grade electromagnetic compatibility requirements. Further description follows through embodiments.

[0076] According to a preferred embodiment of the present invention, the first transparent conductive film includes a first anti-reflection optical layer and a first semiconductor transparent conductive layer. When the first transparent conductive film covers the inner surface S1 of the body, the first anti-reflection optical layer is disposed on the outer side of the first semiconductor transparent conductive layer; when the first transparent conductive film covers the outer surface S2 of the body, the first anti-reflection optical layer is disposed on the inner side of the first semiconductor transparent conductive layer.

[0077] The first semiconductor transparent conductive layer is, for example, an ITO (Indium Tin Oxides) thin film. ITO is an N-type oxide semiconductor—indium tin oxide. An ITO thin film, i.e., an indium tin oxide semiconductor transparent conductive film, typically has two performance indicators: resistivity and transmittance, where 10-1 is the transmittance. -4 With a low thin-film resistivity on the order of Ω·cm, ITO thin films exhibit the conductivity of semiconductors. Several factors influence the conductivity of the first semiconductor transparent conductive layer: sheet resistance R, film thickness d, and resistivity ρ. The formulas for calculating these three are:

[0078] R = ρ / d

[0079] The sheet resistance R can usually be changed by altering the film thickness d.

[0080] According to a preferred embodiment of the present invention, the sheet resistance of the first semiconductor transparent conductive layer does not exceed 200 ohms. When the maximum sheet resistance R does not exceed 200Ω, the lidar with the photomask installed has good electromagnetic compatibility.

[0081] According to a preferred embodiment of the present invention, the sheet resistance R of the first semiconductor transparent conductive layer is between 50 and 130 ohms.

[0082] Based on the foregoing analysis, when the maximum surface resistance R does not exceed 200Ω, the lidar 300 with the photomask 100 installed exhibits good electromagnetic compatibility. However, the lidar with the photomask installed needs to be used in autonomous vehicles, therefore it must meet automotive-grade requirements, meaning that the lidar must maintain good electromagnetic compatibility within the automotive-grade temperature range. The surface resistance R changes with temperature, specifically, its value increases with temperature. Furthermore, the optimal range for the surface resistance R fully considers the automotive-grade temperature range required for the lidar in autonomous vehicles. When the resistance value changes with temperature, its variation range is between -20% and 50%, while the maximum resistance does not exceed 200Ω overall. The resistance value also cannot be too small, as excessively small resistance values ​​would impose excessively high process requirements, making them difficult to achieve and negatively impacting transmittance. Therefore, the surface resistance R is preferably between 50 and 130Ω.

[0083] Figure 3a This diagram illustrates a first transparent conductive film covering the inner surface of a body according to an embodiment of the present invention. The photomask 200 includes a body 210, a first transparent conductive film 220, and a first hardened film 230. The first transparent conductive film 220 includes a first anti-reflection optical layer 221 and a first semiconductor transparent conductive layer 222. When the first transparent conductive film 220 covers the inner surface S1 of the body 210, the photomask 200, from the outside to the inside, consists of: the first hardened film 230, the body 210, the first semiconductor transparent conductive layer 222, and the first anti-reflection optical layer 221. When the first semiconductor transparent conductive layer 222 is coated on the inner surface S1, it connects and conducts with the groove wall on the inner side of the groove, thereby forming a conductive equipotential body with the photomask fixing part 301. This enables the lidar to possess electromagnetic compatibility, meeting automotive-grade electromagnetic compatibility requirements.

[0084] Figure 3b A schematic diagram of a first light-transmitting conductive film covering the outer surface of a body according to an embodiment of the present invention is shown. The photomask 200 includes a body 210, a first light-transmitting conductive film 220, and a first hardening film 130. The first light-transmitting conductive film 220 includes a first anti-reflection optical layer 221 and a first semiconductor transparent conductive layer 222. When the first light-transmitting conductive film 220 covers the outer surface S2 of the body 210, the photomask 200 consists of, from the outside to the inside: the first hardening film 230, the first semiconductor transparent conductive layer 222, the first anti-reflection optical layer 221, and the body 210. When the first semiconductor transparent conductive layer 222 is disposed on the outer surface S2, it is connected and conductive to the groove wall on the outer side of the groove, thereby forming a conductive equipotential body with the photomask fixing part 301.

[0085] The first semiconductor transparent conductive layer 222 is typically made of a wide bandgap thin film material. Taking ITO film as an example, its light transmittance in the ultraviolet region is extremely low. Simultaneously, reflection occurs in the near-infrared region due to the plasma vibration of charge carriers, resulting in very low light transmittance in the near-infrared region as well. However, the transmittance of ITO film in the visible light region is excellent. Due to the specific physicochemical properties of the material itself, ITO film possesses good conductivity and high light transmittance in the visible light region. Since lidar emits a detection beam in the near-infrared region, the light transmittance of the ITO film is correspondingly very low. Therefore, a first anti-reflection optical layer 221 needs to be superimposed. The first anti-reflection optical layer 221 is configured to reduce or eliminate reflected light from the photomask 200, increasing the amount of light transmitted. After superimposing the first anti-reflection optical layer 221 on one side of the first semiconductor transparent conductive layer 222, the transmittance for infrared light (e.g., a laser beam with a wavelength of 905 nm) reaches 90%.

[0086] According to a preferred embodiment of the present invention, the surface area of ​​the first anti-reflection optical layer 221 is smaller than the surface area of ​​the first semiconductor transparent conductive layer 222, and is configured to correspond to the scanning range of the lidar detection beam on the photomask.

[0087] Figure 4 The diagram shows a top view of a lidar detection system according to an embodiment of the present invention. The lidar 300 further includes a transmitting unit 302 and a receiving unit 303. The transmitting unit 302 is configured to emit a detection beam L. The detection beam L passes through a photomask 200 and is detected externally by the lidar 300. The echo beam L' of the detection beam L, reflected by an object, passes through the photomask 200 and is received by the receiving unit 302. Good light transmittance is required within the scanning range of the detection beam L on the photomask; therefore, a first anti-reflection optical layer 221 is preferably provided at a corresponding position. Furthermore, the surface area of ​​the first anti-reflection optical layer 221 is smaller than the surface area of ​​the first semiconductor transparent conductive layer 222, so that the first semiconductor transparent conductive layer 222 can be electrically connected to the photomask fixing part 301, thereby enabling the lidar to have electromagnetic compatibility and meeting automotive-grade electromagnetic compatibility requirements.

[0088] According to a preferred embodiment of the present invention, the photomask further includes: a second hardened film disposed on the inner surface of the body, wherein when the first light-transmitting conductive film covers the inner surface S1 of the body, the second hardened film covers the first light-transmitting conductive film; and when the first light-transmitting conductive film covers the outer surface S2 of the body, the second hardened film covers the inner surface S1 of the body.

[0089] Continue to refer to Figure 3aWhen the first transparent conductive film 220 covers the inner surface S1 of the body 210, the photomask 200 consists of, from the outside to the inside: a first hardened film 230, the body 210, a first semiconductor transparent conductive layer 222, a first anti-reflective optical layer 221, and a second hardened film 240. The second hardened film 240 works in conjunction with the first hardened film 230 to further enhance the hardness of the photomask 200, achieving better protection. The second hardened film 240 protects the film layer coated on the inner surface S1 of the body 210; its hardened coating provides protection and scratch resistance, and improves the performance of the inner surface S1 of the body 210, meeting automotive-grade outer surface performance requirements. When the first transparent conductive film 220 covers the inner surface S1 of the body 210, the second hardened film 240 covers the first transparent conductive film 220, improving the adhesion of the first transparent conductive film 220. Similarly, the second hardened film 240 also has high light transmittance, meeting the requirements of lidar.

[0090] Continue to refer to Figure 3b When the first transparent conductive film 220 covers the outer surface S2 of the body 210, the photomask 200 consists of, from the outside to the inside: a first hardened film 230, a first semiconductor transparent conductive layer 222, a first anti-reflective optical layer 221, the body 210, and a second hardened film 240. As mentioned earlier, the second hardened film 240 works in conjunction with the first hardened film 230 to further enhance the hardness of the photomask 200, achieving a better protective effect. Similarly, the second hardened film 240 also has high light transmittance that meets the requirements of lidar.

[0091] The above describes the photomask used in LiDAR through multiple embodiments. The novel photomask design employed in this invention transforms a non-conductive material (such as PC, COC cyclic olefin copolymer, or glass) into a conductor, connecting it to the photomask fixing part to form a conductive equipotential body. This satisfies the photomask's transmittance and conduction requirements for the probe beam / echo beam (e.g., a laser beam with a wavelength of 905nm). Using this design, the LiDAR's ability to shield against electromagnetic interference is greatly enhanced, and its electromagnetic radiation is reduced, thereby enabling the LiDAR to achieve electromagnetic compatibility and meet automotive-grade electromagnetic compatibility requirements. Furthermore, this invention also designs a shielding structure to cover the excess adhesive area, thereby improving the appearance of the photomask, which will be further described below.

[0092] According to a preferred embodiment of the present invention, the body has an upper end H1 and a lower end H2, and the photomask further includes: a first shielding structure disposed near the lower end H2 of the body and protruding outward along the outer surface S2 of the body. When the photomask is mounted on the photomask fixing part 301 of the lidar 300, the first shielding structure shields the gap between the photomask and the photomask fixing part 301.

[0093] Combination Figures 2a-2cWhen the photomask 100 is installed on the photomask fixing part 301, the downward pressure causes the adhesive at the joint to overflow from the gap, affecting the appearance. However, there is an advantage: the overflowing adhesive will cover the top of the photomask fixing part 301, which can prevent the photomask fixing part 301 from being corroded outdoors for a long time, as corrosion can penetrate into the interior of the photomask fixing part 301. The design of the first shielding structure 140 can shield the overflowing area, eliminating the need for additional processes to remove the overflowing adhesive and not affecting the aesthetic appearance of the lidar after the photomask is installed. Preferably, the first shielding structure 140 is provided with a serrated, stepped, or wavy shape on the lower surface of the photomask fixing part 301 to reduce the phenomenon of adhesive overflow.

[0094] According to a preferred embodiment of the present invention, the upper end of the photomask fixing part 301 is provided with a second connecting structure 3011, and the photomask further includes: a first connecting structure 150, which is disposed between the first shielding structure and the lower end H2 of the body, and protrudes outward or recesses inward along the outer surface S2 of the body so as to engage with the second connecting structure 3011 of the photomask fixing part 301.

[0095] Figure 2c It shows Figure 2a In a partially enlarged view of the photomask structure, the first connecting structure 150 protrudes outward along the outer surface S2 of the body 100, and the second connecting structure 3011 is recessed inward. When the photomask 100 is installed on the photomask fixing part 301, the two engage with each other. In another embodiment, the first connecting structure 150 is recessed inward along the outer surface S2 of the body 100, and the second connecting structure 3011 protrudes towards the groove side. When the photomask 100 is installed on the photomask fixing part 301, the two engage with each other.

[0096] According to a preferred embodiment of the present invention, the photomask further includes: a top cover disposed at the upper end H1 of the body, having a lower surface S3 and an upper surface S4 opposite to the lower surface S3.

[0097] Figure 5a A cross-sectional view of a lidar with a photomask installed according to another embodiment of the present invention is shown. The lidar 300 includes: a photomask fixing part 301, a transmitting unit 302, a receiving unit 303, a rotating shaft 304, and an optomechanical rotor 305. The optomechanical rotor 305 is rotatably mounted on the photomask fixing part 301 via the rotating shaft 304. The transmitting unit 302 and the receiving unit 303 (…) Figure 5a (Not shown) It is mounted on the optomechanical rotor 305. Reference Figure 4The transmitting unit 302 is configured to emit a detection beam L into the environment surrounding the lidar 300 to detect objects. The receiving unit 303 is configured to receive the echo beam L' reflected from the object by the detection beam L and convert it into an electrical signal for subsequent signal processing to calculate the object's distance and reflectivity, and generate a three-dimensional point cloud of the surrounding environment. A photomask 400 is mounted on the photomask fixing part 301 and has an accommodating space in which the transmitting unit 302, the receiving unit 303, and the optomechanical rotor 305 are disposed. The photomask 400 includes a body 410 and a top cover 460, wherein the body 410 is generally a cylindrical hollow structure, and the top cover 460 is located at the upper end H1 of the body 410. When the lidar 300 is a non-through-axis lidar, the rotation axis of the lidar 300 and the top cover 460 are not directly connected. The optomechanical rotor is located above the rotation axis, and the rotation axis does not protrude from the optomechanical rotor, i.e., the rotation axis does not penetrate the interior of the optomechanical rotor. For the through-axis type lidar, the rotating shaft reliably engages with the top cover 460 after passing through the inside of the optomechanical rotor.

[0098] According to a preferred embodiment of the present invention, the photomask further includes: a second conductive film covering the lower surface S3 of the top cover, the second conductive film being connected and conductive to the first light-transmitting conductive film.

[0099] Figure 5b It shows Figure 5a A schematic diagram of a photomask structure is shown. The photomask 400 includes a body 410, a first transparent conductive film 420, a top cover 460, and a second conductive film 470. The body 410 has an inner surface S1 and an outer surface S2 opposite to the inner surface S1. The first transparent conductive film 420 is coated on the inner surface S1 of the body. The top cover 460 has a lower surface S3 and an upper surface S4 opposite to the lower surface S3. The second conductive film 470 covers the lower surface S3 of the top cover 460. The first transparent conductive film 420 and the second conductive film 470 are connected and conductive, and together with the photomask fixing part 301, they form a conductive equipotential body, greatly enhancing the electromagnetic interference shielding capability of the lidar 300 and reducing the electromagnetic radiation emitted by the lidar 300. This enables the lidar to possess electromagnetic compatibility, meeting the requirements of automotive-grade electromagnetic compatibility.

[0100] According to a preferred embodiment of the present invention, the surface resistance of the second conductive film does not exceed 200 ohms.

[0101] Figure 5c It shows Figure 5aAnother schematic diagram of the photomask structure is shown. The photomask 400 includes a body 410, a first transparent conductive film 420, a top cover 460, and a second conductive film 470. The body 410 has an inner surface S1 and an outer surface S2 opposite to the inner surface S1. The first semiconductor transparent conductive layer 422 covers the inner surface S1. The top cover 460 has a lower surface S3 and an upper surface S4 opposite to the lower surface S3. The second conductive film 470 covers the lower surface S3 of the top cover 460. The second conductive film 470 is connected and conductive to the first semiconductor transparent conductive layer 422, and together with the photomask fixing part 301, forms a conductive equipotential body, thereby enabling the lidar to have electromagnetic compatibility and meeting automotive-grade electromagnetic compatibility requirements.

[0102] According to a preferred embodiment of the present invention, the sheet resistance R of the second conductive film is between 50 and 130 ohms.

[0103] The sheet resistance of the second conductive film needs to be determined by comprehensively considering electromagnetic compatibility, ambient temperature range, and process requirements, as described in the previous analysis of the sheet resistance of the first conductive film, and will not be repeated here. However, those skilled in the art should understand that the sheet resistance value of the second conductive film can be the same as or different from that of the first conductive film.

[0104] According to a preferred embodiment of the present invention, the top cover further includes a second shielding structure disposed near the upper end H1 of the body and protruding from the lower surface of the top cover toward the upper end of the body. When the top cover is installed on the body, the second shielding structure shields the gap between the top cover and the body.

[0105] Continue to refer to Figure 5a The top cover 460 and the body 410 can be bonded together with adhesive. However, after the top cover 460 is installed on the body 410, downward pressure may cause excess adhesive, affecting the appearance. In some embodiments, such as... Figure 6 As shown, sufficient clearance can be left in the design to reduce side glue overflow, the rounded corners of the body 410 can be enlarged, and gaps can be avoided to reduce interference with the top cover 460. In some other embodiments, a second shielding structure 461 protruding towards the upper end of the body 410 is provided on the lower surface of the top cover 460. Figure 6 (Not shown in the image) The second shielding structure 461 shields the gap between the top cover 460 and the body 410, thus shielding the area even if adhesive overflow occurs. Preferably, the lower surface of the second shielding structure 461 facing the photomask fixing part 301 is provided in a serrated, stepped, or wavy shape to reduce adhesive overflow.

[0106] According to a preferred embodiment of the present invention, the top cover is made of a metal material, and the body is made of PC material or glass. The top cover has high reflectivity to reduce received solar radiation, and the body has high light transmittance. Utilizing the conductive properties of the metal material, the top cover is connected and conductively linked to the first transparent conductive film and the photomask fixing part, thereby enabling the lidar to have electromagnetic compatibility.

[0107] According to a preferred embodiment of the present invention, the top cover and the body are integrally constructed, and the top cover and the body have different reflectivities. A first light-transmitting conductive film covers the inner or outer surface of the body and the top cover, and a first hardened film covers the outer surface of the body and the top cover.

[0108] Figure 7a A schematic diagram of a photomask according to another embodiment of the present invention is shown. The body 510 includes a first plastic component, and the top cover 560 includes a second plastic component. The body 510 and the top cover 220 are formed into the integral structure by two-color injection molding or ultrasonic welding. Specifically, the body 510 is generally a cylindrical hollow structure, i.e., the upper end H1 is open and has an opening. The top cover 560 is joined by point bonding (e.g., ...). Figure 7a The two-color injection molding process (as shown by the circle in the image) covers the opening at the upper H1. Then, a coating process is used to form a first transparent conductive film and a first hardened film (as shown in the image). Figure 7a (not shown in the figure), wherein the first light-transmitting conductive film covers the inner or outer surface of the body 510 and the top cover 560, and the first hardened film covers the outer surface of the body 510 and the top cover 560.

[0109] Figure 7b A schematic diagram of the structure of a photomask according to another embodiment of the present invention is shown, and... Figure 7a The difference in the embodiment is that the upper end H1 of the body 510 is closed and has an end face, so the top cover 560 can be joined by surface bonding (e.g. Figure 7b The coating is applied to the body 510 using a two-color injection molding or ultrasonic welding method (as shown in the circle). In contrast, surface bonding provides stronger adhesion between the body 510 and the top cover 560. A first transparent conductive film and a first hardened film are then formed through a coating process. Figure 7b (not shown in the figure), wherein the first light-transmitting conductive film covers the inner or outer surface of the body 510 and the top cover 560, and the first hardened film covers the outer surface of the body 510 and the top cover 560.

[0110] According to a preferred embodiment of the present invention, the top cover 560 is formed by spraying conductive paint onto a high-reflectivity plastic to achieve electromagnetic compatibility.

[0111] According to a preferred embodiment of the present invention, the body comprises a first material and the top cover comprises a second material.

[0112] According to a preferred embodiment of the present invention, the first material is a material that is transparent to infrared light but not to visible light, and the second material is a high-reflectivity engineering plastic.

[0113] Continue to refer to Figure 7a and 7b The body 510 includes a first material, preferably PC plastic that is transparent to infrared light but not to visible light, and the top cover 560 includes a second material, preferably a high-reflectivity engineering plastic, such as white engineering plastic.

[0114] In summary, when the top cover and the body are separate components, the top cover is preferably made of metal, and the body is made of PC or glass, and the covering films of the top cover and the body can be different. When the top cover and the body are an integral structure, the top cover and the body have different reflectivities; for example, the top cover is made of high-reflectivity engineering plastic, and the body is made of PC plastic that is transparent to infrared light but not visible light. Furthermore, when the top cover and the body are an integral structure, the covering films can be the same or different. Specifically, the body and the covering films need to be light-transmitting, wherein the first semiconductor transparent conductive layer has good conductivity, and the first anti-reflection optical layer can improve the light transmittance. The top cover needs to be as reflective as possible; when the top cover is made of metal, the first light-transmitting conductive film does not need to cover the lower surface of the top cover; when the top cover is made of high-reflectivity engineering plastic, the first anti-reflection optical layer in the first light-transmitting conductive film does not need to extend to the lower surface of the top cover.

[0115] The above describes the photomask used for LiDAR through multiple embodiments. The photomask designed by this invention can greatly enhance the LiDAR's ability to shield electromagnetic interference and reduce the LiDAR's external electromagnetic radiation, thereby enabling the LiDAR to have electromagnetic compatibility and meet the requirements of automotive-grade electromagnetic compatibility.

[0116] This invention also relates to a lidar, such as... Figure 4 As shown, the lidar 300 includes:

[0117] The transmitting unit 302 is configured to emit a detection beam L;

[0118] Receiving unit 303 is configured to receive the echo beam L' of the detection beam L after it has been reflected by an object; and

[0119] As described above, the photomask 100 / 200 / 400 / 500 has an accommodating space, and the transmitting unit 302 and the receiving unit 303 are disposed in the accommodating space;

[0120] The detection beam L passes through the photomask 100 / 200 / 400 / 500 to detect the outside of the lidar 300, and the echo beam L' passes through the photomask 100 / 200 / 400 / 500 and is received by the receiving unit 303. The photomask 100 / 200 / 400 / 500 is also configured to be connected and conductive with the photomask fixing part 301, so that the lidar 300 can shield electromagnetic interference.

[0121] This invention also relates to a method for preparing a photomask for lidar, combined with... Figure 2a-6 b. The lidar 300 includes a photomask fixing part 301, and the photomasks 100 / 200 / 400 / 500 are mounted on the photomask fixing part 301 of the lidar 300. The manufacturing method includes:

[0122] In step S11: Provide a body 110 / 210 / 410 / 510 having an inner surface S1 and an outer surface S2 opposite to the inner surface S1;

[0123] In step S12: A first light-transmitting and conductive film 120 / 220 / 420 is formed on the inner surface S1 or outer surface S2 of the body 110 / 210 / 410 / 510, so that when the photomask 100 / 200 / 400 / 500 is mounted on the photomask fixing part 301 of the lidar 300, the first light-transmitting and conductive film 120 / 220 / 420 is connected and conductive with the photomask fixing part 301, so that the lidar can shield electromagnetic interference.

[0124] According to a preferred embodiment of the present invention, the preparation method further includes:

[0125] In step S13: a hardening treatment is performed on the outer surface of the body 110 / 210 / 410 / 510 to form a first hardened film 130 / 230. When the first light-transmitting conductive film 120 / 220 / 420 covers the inner surface S1 of the body 110 / 210 / 410 / 510, the first hardened film 130 / 230 covers the outer surface S2 of the body 110 / 210 / 410 / 510. When the first light-transmitting conductive film 120 / 220 / 420 covers the outer surface S2 of the body 110 / 210 / 410 / 510, the first hardened film 130 / 230 covers the first light-transmitting conductive film 120 / 220 / 420.

[0126] According to a preferred embodiment of the present invention, the preparation method further includes:

[0127] In step S14: a hardening treatment is performed on the inner surface S1 of the body 110 / 210 / 410 / 510 to form a second hardened film 240. When the first light-transmitting conductive film covers the inner surface S1 of the body 110 / 210 / 410 / 510, the second hardened film 240 covers the first light-transmitting conductive film 120 / 220 / 420. When the first light-transmitting conductive film 120 / 220 / 420 covers the outer surface S2 of the body 110 / 210 / 410 / 510, the second hardened film 240 covers the inner surface S1 of the body 110 / 210 / 410 / 510.

[0128] According to a preferred embodiment of the present invention, the preparation method further includes:

[0129] In step S15: Provide a top cover 160 / 460 / 560, having a lower surface and an upper surface opposite to the lower surface;

[0130] In step S16: A second conductive film 470 is formed on the lower surface of the top cover 160 / 460 / 560, such that when the top cover 160 / 460 / 560 is disposed on the upper end of the body 110 / 210 / 410 / 510, the second conductive film 470 is connected and conductive with the first light-transmitting conductive film 120 / 220 / 420.

[0131] According to a preferred embodiment of the present invention, the preparation method further includes: integrally molding the top cover 160 / 460 / 560 and the body 110 / 210 / 410 / 510 using materials with different reflectivities, and forming the first light-transmitting conductive film 120 / 220 / 420 on the inner surface of the body 110 / 210 / 410 / 510 and the lower surface of the top cover 160 / 460 / 560 or the outer surface of the body 110 / 210 / 410 / 510 and the upper surface of the top cover 160 / 460 / 560; forming the first hardening film 130 / 230 on the outer surface of the body 110 / 210 / 410 / 510 and the upper surface of the top cover 160 / 460 / 560; and forming the second hardening film 240 on the inner surface of the body 110 / 210 / 410 / 510 and the lower surface of the top cover 160 / 460 / 560.

[0132] The photomask designed in this invention can greatly enhance the ability of lidar to shield against electromagnetic interference and reduce the external electromagnetic radiation of lidar, thereby enabling lidar to have electromagnetic compatibility and meet the requirements of automotive-grade electromagnetic compatibility.

[0133] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A photomask for a lidar, the lidar including a photomask fixing part, the photomask being mounted on the photomask fixing part, the photomask comprising: The body has an inner surface and an outer surface opposite to the inner surface; A top cover is disposed at the upper end of the body and has a lower surface and an upper surface opposite to the lower surface; A first light-transmitting conductive film is disposed on the body, covering the inner or outer surface. The first light-transmitting conductive film is connected and conductive to the photomask fixing part, so that the lidar can shield electromagnetic interference. and A second conductive film is applied to the lower surface of the top cover, and the second conductive film is connected to the first light-transmitting conductive film for conduction. The first transparent conductive film is a continuous thin film, and includes a first semiconductor transparent conductive layer with a sheet resistance between 50 and 130 ohms; the second conductive film has a sheet resistance between 50 and 130 ohms.

2. The photomask according to claim 1, wherein the first transparent conductive film includes a first anti-reflective optical layer, wherein when the first transparent conductive film covers the inner surface of the body, the first anti-reflective optical layer is disposed outside the first semiconductor transparent conductive layer; and when the first transparent conductive film covers the outer surface of the body, the first anti-reflective optical layer is disposed inside the first semiconductor transparent conductive layer.

3. The photomask according to claim 2, wherein the surface area of ​​the first anti-reflection optical layer is smaller than the surface area of ​​the first semiconductor transparent conductive layer, and is configured to correspond to the scanning range of the laser radar detection beam on the photomask.

4. The photomask according to claim 1, further comprising: A first hardened film is disposed on the outer surface of the body and configured to protect the body and / or the first light-transmitting conductive film.

5. The photomask according to claim 4, wherein when the first light-transmitting conductive film covers the inner surface of the body, the first hardening film covers the outer surface of the body; and when the first light-transmitting conductive film covers the outer surface of the body, the first hardening film covers the first light-transmitting conductive film.

6. The photomask according to claim 4, further comprising: A second hardened film is disposed on the inner surface of the body, and when the first light-transmitting conductive film covers the inner surface of the body, the second hardened film covers the first light-transmitting conductive film; when the first light-transmitting conductive film covers the outer surface of the body, the second hardened film covers the inner surface of the body.

7. The photomask according to any one of claims 1-6, wherein the body has an upper end and a lower end, and the photomask further comprises: The first shielding structure is disposed near the lower end of the body and protrudes outward along the outer surface of the body. When the photomask is mounted on the photomask fixing part, the first shielding structure shields the gap between the photomask and the photomask fixing part.

8. The photomask according to claim 7, wherein the upper end of the photomask fixing part is provided with a second connecting structure, and the photomask further includes: The first connecting structure is disposed between the first shielding structure and the lower end of the main body, and engages with the second connecting structure of the photomask fixing part.

9. The photomask according to claim 1, wherein the top cover further includes a second shielding structure disposed near the upper end of the body and protruding from the lower surface of the top cover toward the upper end of the body, wherein when the top cover is mounted on the body, the second shielding structure shields the gap between the top cover and the body.

10. The photomask according to claim 1, wherein the top cover and the body are integrally constructed, and the top cover and the body have different reflectivities, the first light-transmitting conductive film covers the inner or outer surface of the body and the top cover, and the first hardening film covers the outer surface of the body and the top cover.

11. The photomask according to claim 10, wherein the body comprises a first material, the top cover comprises a second material, the first material being a material that transmits infrared light but not visible light, and the second material being a material that has high reflectivity to infrared light.

12. A lidar, comprising: The transmitting unit is configured to emit a probe beam; The receiving unit is configured to receive the echo beam of the detection beam after it has been reflected by the object; and The photomask as described in any one of claims 1-11, the photomask having an accommodating space, wherein the transmitting unit and the receiving unit are disposed in the accommodating space; The detection beam passes through the photomask to probe the outside of the lidar, and the echo beam passes through the photomask and is received by the receiving unit. The photomask is also configured to be connected and conductive with the photomask fixing part, so that the lidar can shield electromagnetic interference.

13. A method for fabricating a photomask for a lidar, the lidar including a photomask fixing part, the photomask being mounted on the photomask fixing part, the fabrication method comprising: S11: Provides a body having an inner surface and an outer surface opposite to the inner surface; S12: A first light-transmitting and conductive film is formed on the inner or outer surface of the body, so that when the photomask is installed on the photomask fixing part of the lidar, the first light-transmitting and conductive film is connected to the photomask fixing part, so that the lidar can shield electromagnetic interference. Wherein, the first transparent conductive film is a continuous thin film, the first transparent conductive film includes a first semiconductor transparent conductive layer, and the sheet resistance of the first semiconductor transparent conductive layer is between 50 and 130 ohms; S15: Provides a top cover having a lower surface and an upper surface opposite to the lower surface; S16: A second conductive film is formed on the lower surface of the top cover, such that when the top cover is disposed on the upper end of the body, the second conductive film is connected and conductive with the first light-transmitting conductive film, and the surface resistance of the second conductive film is between 50 and 130 ohms.

14. The preparation method according to claim 13, further comprising: S13: Hardening treatment is performed on the outer surface of the body to form a first hardened film, and when the first light-transmitting conductive film covers the inner surface of the body, the first hardened film covers the outer surface of the body; when the first light-transmitting conductive film covers the outer surface of the body, the first hardened film covers the first light-transmitting conductive film.

15. The preparation method according to claim 14, further comprising: S14: Harden the inner surface of the body to form a second hardened film, and when the first light-transmitting conductive film covers the inner surface of the body, the second hardened film covers the first light-transmitting conductive film; when the first light-transmitting conductive film covers the outer surface of the body, the second hardened film covers the inner surface of the body.

16. The preparation method according to claim 13, further comprising: The top cover and the body are integrally formed using materials with different reflectivities, and a first light-transmitting conductive film is formed on the inner surface of the body and the lower surface of the top cover or on the outer surface of the body and the upper surface of the top cover; a first hardened film is formed on the outer surface of the body and the upper surface of the top cover; and a second hardened film is formed on the inner surface of the body and the lower surface of the top cover.

Images