Heat-assisted, light-sensitive sensor device with automatic foreign object removal
Patent Information
- Application Number
- DE202024107495
- Authority / Receiving Office
- DE · DE
- Patent Type
- Utility models
- Current Assignee / Owner
- Filing Date
- 2024-12-20
- Publication Date
- 2025-04-10
- Estimated Expiration
- 2034-12-31
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
CROSS REFERENCE TO RELATED APPLICATIONThis application claims priority to Taiwan Patent Application No. 113200224 filed on Jan. 6, 2024, which is hereby incorporated by reference.BACKGROUND OF THE INVENTION1. Technical Field of the InventionThe present invention relates to a heat-assisted apparatus for an automatic foreign matter removal type light-sensitive sensing device, particularly to an optical detection system using a design mold having flexible and rigid materials to seal the light-sensitive sensing device and transmit the vibrations generated by piezoelectric elements, and equipped with heating elements, thereby optimizing the automatic foreign matter removal function.2. The Prior ArtAn optical sensor device is a device equipped with a light-sensitive sensor that acquires optical information from the external environment through a light-transmissive observation window. The optical information is converted by a photosensor into electrical signals which are then processed by a processor to produce corresponding reactions. The system includes an optical sensor device that receives only light, such as video cameras, cameras, and partially passive photosensors, and also includes a light emitting device that actively projects light, such as structured light devices, time-of-flight cameras. (ToF) and Radar Optical Systems. However, in outdoor or complex environments of full foreign matter, the light-sensitive sensor device is liable to be affected by contaminants of the observation window caused by adhesion of foreign matter. For example, raindrops (water drops), snow, frost, mud, and other foreign objects may stick to the observation window, thereby blocking, refracting, or reflecting the incident light, thereby affecting the light signals received from the photosensor, resulting in degradation or impairment of the signals.In this regard, many developers have proposed appropriate cleaning solutions. US 11002954 B2 discloses an image pickup apparatus having a cleaning device wherein the surface of the light transmissive body is cleaned by vibrating the light transmissive body with a vibrator. However, the vibrator needs to have a barrel-shaped structure (e.g., first and second cylindrical members) to provide a space for vibration. Such a vibratory apparatus results in larger and more complicated designs of the optical sensing system (which is a camera in accordance with the disclosure). The inventor has also filed the patent US 11489988 B2 which discloses a method for removing foreign bodies from a camera system, and an instant clear view system (ICVS), wherein in the ICVS, a piezoelectric component is arranged on a transparent cover of a camera device and the piezoelectric component generates vibrations to remove foreign bodies from the transparent cover, and wherein a soft sealing material is used to surround the transparent cover and seal the optical sensor device. However, in such a concept using a soft sealing material (e.g., an O-ring) as an interface between the vibration source (i.e., the piezoelectric element) and the environment, there is a trade-off between water-tightness and vibration capability. Especially when it is intended to improve the water-tightness of the sensor optical system, higher pressing of the O-ring is required, which restricts the vibration capability of the vibration source to the environment, thereby reducing the performance of foreign matter removal. In contrast, moisture or even water can easily enter (leak) the sealed space of the optical sensor system when the pressure on the O-ring is decreased to increase the vibration capability. Therefore, the inventor has proposed an optical recognition system ICVS (Instant Clear View System) and a method by which foreign bodies can be automatically removed in the other patent JP 281843B2. In this case, a material with flexibility and rigidity is used for sealing the optical sensor device and for transmitting the oscillations generated by the piezoelectric element, which material differs from the prior art, whereby a stable and effective automatic removal of foreign bodies from the optical sensor system is made possible.Even if the above-mentioned optimized methods are applied to improve the transmission of the vibration from the vibration source, the small liquid droplets remaining after the removal of foreign matters by vibration still present an urgent problem to be solved. The conventional technology uses the thermal energy generated from a vibration source such as lead titanate zirconate during high-frequency vibration to heat and evaporate the small liquid droplets on the observation window. However, high-frequency vibrations are associated with high energy consumption. In this type of vibration source, high frequency voltage driving rapidly raises the temperature of the vibration source itself, and heat generation at continuously high temperatures deteriorates the vibration capability of the vibration source. In severe cases, this may even lead to permanent depolarization and thus loss of vibration capability. In the patent US 11366076 B2, the operating temperature of the piezoelectric transducer is controlled by providing a temperature sensor and setting a temperature threshold value, thereby achieving the advantage of protecting the vibration source and maintaining its vibration capability. However, this method for protecting vibration sources also limits the efficiency of removal of foreign bodies and is not suitable for applications requiring rapid cleaning, such as optical detection systems in unmanned vehicles or driver assistance systems. Even in the case of fixed optical monitoring devices, it is of decisive importance to avoid the extent of the blind zone on the observation time axis as far as possible, so that the feasibility of the aforementioned solution is greatly limited.SUMMARY OF THE INVENTIONIn this connection, in view of the above-mentioned optical sensors of foreign matter removing optical sensor systems, the inventor has developed a heat-assisted photosensitive sensor with automatic foreign matter removal.The present invention provides a heat-assisted device for an automatic foreign matter removal type photosensitive sensor device, the improved device comprising: a housing having an opening on one side thereof; a transparent protective cover disposed at the opening, the housing and the transparent protective cover together forming an inner space of the photosensitive sensor device; a photosensor disposed in the inner space of the photosensitive sensor device; a lens module provided between the transparent protective cover and the photosensor; a piezoelectric element provided at an edge of the transparent protective cover in the inner space of the photosensitive sensor device; a sealing material having flexibility and rigidity, the sealing material being annularly flaked, the sealing material being disposed between the edge of the transparent protective cover and an edge of the piezoelectric element and extending to and fixed to the housing, thereby sealing the interior of the photosensitive sensor device; and a heating element provided between a lateral edge of the transparent protective cover and the sealing material; wherein the piezoelectric element generates vibrations and the vibrations are transmitted through the sealing material to the transparent protective cover to remove foreign matters from the transparent protective cover, wherein the heating element generates thermal energy and the thermal energy is transmitted through the sealing material to the transparent protective cover to remove small droplets of liquid from the transparent protective cover.In another embodiment, a lens module is disposed at the opening and includes: an upper lens forming the transparent protective cover of the light-sensitive sensor device and disposed at an outermost side of the lens module with respect to the interior space of the light-sensitive sensor device; a side housing, the housing of the light-sensitive sensor device including: the side housing, the upper lens and the housing of the light-sensitive sensor device accommodating the side housing together forming the interior space of the light-sensitive sensor device; a lower lens disposed at an opposite side of the upper lens, the upper lens, the side housing and the lower lens together forming an interior space of the lens module; and one or more inner lens(s) disposed between the upper lens and the lower lens in the interior of the lens module, wherein the heating element is provided between a lateral edge of the upper lens and the sealing material; wherein the piezoelectric element is provided at an edge of the upper lens in the interior of the lens module; wherein the sealing material is disposed between the edge of the upper lens and the edge of the piezoelectric element and extends toward and is fixed to the lateral housing, thereby sealing the interior of the photosensitive sensor device; and wherein the piezoelectric element generates vibration and the vibrations are transmitted to the upper lens through the sealing material to remove foreign matter from the upper lens.In a preferred embodiment, the light-sensitive sensor device further includes: a soft shielding material having an annular flake shape and disposed on an outer side of the housing and an outer side of the transparent protective cover, thereby shielding a gap between the housing, the transparent protective cover, and the sealing material.In a preferred embodiment, the improved construction form or the light-sensitive sensor device further comprises: a thermally insulating buffer element which is arranged between the piezoelectric element and the sealing material and is mechanically connected to the piezoelectric element or the sealing material.In a further preferred embodiment, the thermally insulating buffer element is arranged between the piezoelectric element and the heating element and is mechanically connected to the heating element or the piezoelectric element.BRIEF DESCRIPTION OF THE DRAWINGSFig. 1 shows a preferred embodiment of a heat-assisted automatic foreign matter removal type light-sensitive sensor device according to the present invention, in a sectional view. FIG. 2 is a sectional view showing another preferred embodiment of a heat-assisted automatic foreign matter removal type light-sensitive sensor device according to the present invention. FIG. 3 is a sectional view showing another preferred embodiment of a heat-assisted automatic foreign matter removal type light-sensitive sensor device according to the present invention. FIG. 4 is a sectional view of a lens module for the preferred embodiment of a heat-assisted automatic foreign matter removal type light-sensitive sensor device of FIG. 3. FIG. 5A shows in a schematic illustration the manner in which a sealing material, a heating element and a piezoelectric element according to any embodiment of the present invention are connected to one another. FIG. 5B shows how a sealing material, a heating element, a piezoelectric element and a heat insulating buffer element are connected to each other according to a preferred embodiment of the present invention, in a schematic representation. FIG. 5C shows how a sealing material, a heating element, a piezoelectric element and a heat insulating buffer element according to another preferred embodiment of the present invention are connected to each other in a schematic illustration. FIG. 5D shows how a sealing material, a heating element, a piezoelectric element and a heat insulating buffer element according to another preferred embodiment of the present invention are connected to each other in a schematic illustration.DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTHereinafter, structural details of the heat-assisted automatic foreign matter removal type light-sensitive sensor device according to the present invention will be described with reference to the drawings, wherein FIG. 1 illustrates an exemplary heat-assisted automatic foreign matter removal type light-sensitive sensor device 20 of the present invention, and FIGS. 2 to 4 illustrate structural details of an automatic foreign matter removal type light-sensitive sensor device 20 according to various embodiments of the present invention. Because the following description focuses on the structural features, some of the elements described below with reference to FIGS. 5A, 5B, and 5C may not be further described or illustrated in FIGS. 1-4. However, it should be understood that such elements may be integrated into the light sensitive sensor device (20 in Figures 2 to 4) and provided in the optical sensing system (not shown). The detection optical system may be a photo system, and the light-sensitive sensor device 20 may be a camera, without being particularly limited thereto.As can be seen from Fig. 1, the present invention provides a heat-assisted photosensitive sensor device with automatic foreign matter removal. In the illustrated embodiments of the present invention, the light-sensitive sensor device 20 includes: a housing 260; a transparent protective cover 240; a photosensor 210; a lens module 230; a sealing material 241 having flexibility and rigidity; a piezoelectric element 244; and a heating element 245. FIG. 3 shows an embodiment in which the transparent cover 240 is formed in a planar manner (e.g., as a planar lens), and FIG. 4 shows an embodiment in which the transparent cover 240 is formed in a curved manner (e.g., as a convex lens or as a concave lens).The housing 260 has an opening on one side (e.g., on the top side in FIGS. 3 and 4 ). The transparent protective cover 240 is disposed at the opening. The housing 260 and the transparent protective cover 240 together form an interior of the light-sensitive sensor device 20. A photosensor 210 is disposed in the interior of the photosensitive sensor device 20. The lens module 230 is disposed between the transparent protective cover 240 and the photosensor 210.The piezoelectric element 244 is provided at an edge of the transparent protective cover 240 in the interior of the light-sensitive sensor device 20. The piezoelectric element 244 includes a piezoelectric material such as PZT or the like. The piezoelectric element 244 is electrically connected to a circuit board 220 via a cable 222. The sealing material 241 has an annular flake shape or plate shape or film shape that is disposed (attached) between the edge of the transparent protective cover 240 and the edge of the piezoelectric element 244 and extends to and is fixed to the housing 260, thereby sealing the internal space of the photosensitive sensor device 20. The piezoelectric element 244 generates vibrations that are transmitted to the transparent protective cover 240 via the sealing material 241 to remove foreign matter from the transparent protective cover 240.Preferably, the piezoelectric element 244 may be formed annularly and disposed at the periphery on the inner side of the transparent protective cover 240, thereby enabling removal of foreign matter more efficiently and gently. The piezoelectric element 244 may be attached to the transparent protective cover 240. The piezoelectric element 244 may be disposed around a periphery of the lens module 230.The sealing material 241 is flexible to transmit vibrations and perform a sealing function also on uneven sealing surfaces or upon thermal expansion of the components, and rigid not to flow under pressure so as to maintain contact between the sealing surfaces, and preferably comprises one or more of aluminum, steel (e.g., SUS304), titanium alloy, magnesium-aluminum alloy, polyimide (Pl), polycarbonate (PC), and polyethylene terephthalate (PET). The sealing material 241 is formed, for example, as a metal foil made of aluminum, steel, a titanium alloy or a magnesium-aluminum alloy; or it may be a flake or foil or thin layer with polyimide, polycarbonate or polyethylene terephthalate. Preferably, the sealing material 241 has a thickness of 10 μm to 200 μm. The sealing material 241 is waterproof and therefore can seal the internal space of the light-sensitive sensor device 20. The sealing material 241 having flexibility and rigidity effectively transmits the vibrations generated by the piezoelectric element 244 to the transparent protective cover 240 while reducing the vibrations transmitted to other environments (except the transparent protective cover 240). Moreover, a vibration amplitude caused by the vibrations will not exceed the allowable strain. Therefore, the sealing material 241 provides sufficient support strength as an interface between the vibration source and the environment without risk of the sealing material breaking.On the other hand, in the present invention, a gap may be formed between the case 260, the transparent protective cover 240, and the sealing material 241 because the sealing material 241 having flexibility and rigidity is used as a sealing material between the transparent protective cover 240 and the case 260 instead of a soft sealing material of the related art. Therefore, the sealing material 241 may be exposed to the environment through such a gap, whereby water or other substances may stick to the sealing material 241. Therefore, in order to prevent water or other substances from adhering to the sealing material 241, a thin, soft material is used as the shielding material and is disposed on the transparent shielding cover 240 and the sealing material 241, thereby shielding such a gap, which in turn prevents water or other substances from adhering directly to the sealing material 241. Therefore, in a preferred embodiment, the light-sensitive sensor device 20 further includes: a soft shielding material 243 having an annular flake shape and disposed on the outside of the housing 260 and the outside of the transparent protective cover 240, thereby shielding the gap between the housing 260, the transparent protective cover 240, and the sealing material 241.The heating element 245 is disposed between the transparent protective cover 240 and the sealing material 241. When small droplets of liquid adhere to the transparent protective cover 240, the heating element 245 is independently activated to heat, thereby generating heat energy, and the heat energy is transferred to the transparent protective cover 240 through the sealing material 241, or the transparent protective cover 240 is directly heated by contact heat conduction, so that small droplets of liquid are removed.According to some embodiments, the housing 260 may include a first housing 262, a lens module holder 264, and a second housing 266. A sealing member such as an O-ring is provided between each of two adjacent members of the first housing 262, the lens module holder 264, and the second housing 266 for sealing. In the embodiments shown in FIGS. 1 and 2, an opening of the housing 260 is provided on the second housing 266 (in particular on the top side). In various embodiments of the present invention, the lens module 230 is embedded in the light-sensitive sensor device 20 (as shown in FIGS. 1 and 2 ) or the lens module 230 at least partially rises from the light-sensitive sensor device 20 (as shown in FIG. 3 ).As shown in FIG. 3, in another embodiment, the lens module 230 is disposed at the opening of the housing 260. In this case, the housing 260 includes only the first housing 262 and the lens module holder 264, and the opening of the housing 260 is provided at the lens module holder 264 (more specifically, at the upper side). As shown in FIG. 4, the lens module 230 includes an upper lens 230A, a side housing 230B, one or more inner lenses 230C, and a lower lens 230D. The upper lens 230A, the inner lens 230C, and the lower lens 230D each have a planar or curved surface, i.e., each of them may be a plane lens, a convex lens, or a concave lens.As illustrated in FIG. 4, in this embodiment, the upper lens 230A is the transparent cover 240 of the light-sensitive sensor device 20, and is disposed at an outermost side of the lens module 230 with respect to the internal space of the light-sensitive sensor device 20. The side housing 230B is a barrel-shaped member that forms the interior of the light-sensitive sensor device 20 together with the upper lens 230A and the housing 260 as part of the housing 260 of the light-sensitive sensor device 20. The lower lens 230D is disposed on the opposite side to the upper lens 230A. The upper lens 230A, the side housing 230B, and the lower lens 230D together form the interior of the lens module 230. The one or more inner lens(s) 230C is(are) disposed between the upper lens 230A and the lower lens 230D in the interior of the lens module 230. In addition, in this embodiment, the piezoelectric element 244 is disposed at the edge of the upper lens 230A in the interior of the lens module 230. The sealing material 241 is provided (attached) between the edge of the upper lens 230A and the edge of the piezoelectric element 244 and extends toward and is fixed to the side housing 230B, thereby sealing the internal space of the light-sensitive sensor device 20. The piezoelectric element 244 generates vibrations that are transmitted to the upper lens 230A via the sealing material 241 to remove foreign matter from the upper lens 230A.The heating element 245 is disposed between the transparent protective cover 240 and the sealing material 241. When small droplets of liquid adhere to the transparent protective cover 240, the heating element 245 is independently activated to heat, thereby generating heat energy, and the heat energy is transferred to the transparent protective cover 240 or the upper lens 230A through the sealing material 241, or the transparent protective cover 240 or the upper lens 230A is directly heated by contact heat conduction, so that small droplets of liquid are removed.The light-sensitive sensor device 20 further includes the circuit board 220 electrically connected to the photosensor 210.As shown in FIGS. 5A, 5B, 5C, and 5D, a heat insulating buffer member 247 is added in another preferred embodiment. In a combination without the heat insulating buffer member 247, the heating member 245 is disposed on a side of the sealing material 241 opposite to the piezoelectric element 244 to prevent the heat conduction from interfering with the piezoelectric element 244 by direct contact. Preferably, in the case where the heat insulating buffer member 247 is provided, the heat insulating buffer member 247 forms combined sandwich structures as illustrated in FIGS. 5B, 5C, and 5D, respectively. In FIG. 5B, the heating element 245 is disposed on a side of the sealing material 241 facing away from the piezoelectric element 244, and the buffer heat insulating member 247 is disposed between the sealing material 241 and the piezoelectric element 244 to achieve a better thermal insulation advantage. Alternatively, as illustrated in FIG. 5C, the buffer heat insulating member 247 is disposed between the heating element 245 and the piezoelectric element 244, thereby preventing the thermal conduction by direct contact from affecting the piezoelectric element 244 through the buffer heat insulating member 247. Alternatively, as illustrated in FIG. 5D, the heat insulating buffer member 247 is disposed below the piezoelectric element 244 to more effectively use the thermal energy generated by the heating element 245 and avoid thermal energy losses, thereby enabling a faster removal of small liquid droplets.Each of the above embodiments can be manufactured by bonding, welding or in another way, wherein an adhesive with good tensile properties and low hygroscopicity is preferably used for the bonding.The piezoelectric element 244, the sealing material 241, the soft shielding material 243, the heating element 245, and the buffer heat insulating member 247 may be arranged in any suitable annular shape as long as they do not obstruct the incident light entering the photosensor 210.In summary, the present invention relates to a heat-assisted, light-sensitive sensor device 20 with automatic foreign body removal, in particular using a structure with flexible and rigid materials for sealing the light-sensitive sensor device 20 and for transmitting vibrations generated by piezoelectric elements. The light-sensitive sensor device 20 includes a housing 260, a transparent cover 240, a photosensor 210, a lens module 230, a sealing material 241 having flexibility and rigidity, and a piezoelectric element 244. The apparatus is also provided with a heating element 245 to optimize the automatic foreign matter removal function, reduce the frequency of use of the piezoelectric element 244, thereby reducing power consumption, extending the life, and improving the small liquid droplet removal efficiency.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedUS 11002954 B2
[0004] US 11489988 B2
[0004] JP 281843B2
[0004] US 11366076 B2
[0005]
Claims
A heat-assisted automatic foreign matter removal type light-sensitive sensor device (20), the light-sensitive sensor device (20) comprising: a housing (260) having an opening at one side; a transparent protective cover (240) disposed at the opening, the housing (260) and the transparent protective cover (240) together forming an inner space of the light-sensitive sensor device (20); a photosensor (210) disposed in the inner space of the light-sensitive sensor device (20); a lens module (230) disposed between the transparent protective cover (240) and the photosensor (210); a piezoelectric element (244) disposed at an edge of the transparent protective cover (240) in the inner space of the light-sensitive sensor device (20); a sealing material (241) having flexibility and rigidity, having an annular flake shape and being disposed between the edge of the transparent protective cover (240) and an edge of the piezoelectric element (244), and extending toward and being fixed to the housing (260), thereby sealing the interior of the photosensitive sensor device (20); and a heating element (245) disposed between a lateral edge of the transparent protective cover (240) and the sealing material (241); wherein the piezoelectric element (244) generates vibrations transmitted through the sealing material (241) to the transparent protective cover (240) to remove foreign matter from the transparent protective cover (240), wherein the heating element (245) generates thermal energy transmitted through the sealing material (241) to the transparent protective cover (240) to remove small droplets of liquid from the transparent protective cover (240).The heat-assisted automatic foreign matter removal type light-sensitive sensor device (20) according to claim 1, wherein the heating element (245) is disposed between a bottom surface of the transparent protective cover (240) and the sealing material (241).The heat-assisted automatic foreign matter removal type light-sensitive sensor device (20) according to claim 1, wherein the lens module (230) is disposed at the opening, and the lens module (230) comprises: an upper lens (230A) forming the transparent protective cover of the light-sensitive sensor device (20) and disposed at an outermost side of the lens module (230) with respect to the internal space of the light-sensitive sensor device (20); a lateral housing (230B), the housing (260) of the light-sensitive sensor device (20) further accommodating the lateral housing (230B), the upper lens (230A) and the housing (260) of the light-sensitive sensor device (20) accommodating the lateral housing together forming the internal space of the light-sensitive sensor device (20); a lower lens (230D) disposed on an opposite side with respect to the upper lens (230A), and wherein the upper lens (230A), the lateral housing (230B), and the lower lens (230D) together form an inner space of the lens module; and one or more inner lens(s) (230C) disposed between the upper lens (230A) and the lower lens (230D) in the inner space of the lens module (230), the heating element (245) being disposed between a lateral edge of the upper lens (230A) and the sealing material (241); wherein the piezoelectric element (244) is disposed at an edge of the upper lens (230A) in the inner space of the lens module (230); wherein the sealing material (241) is disposed between the edge of the upper lens (230A) and the edge of the piezoelectric element (244) and extends to and is fixed to the lateral case (230B), thereby sealing the interior of the light-sensitive sensor device (20); and wherein the piezoelectric element (244) generates vibrations and the vibrations are transmitted to the upper lens (230A) via the sealing material (241) to remove foreign matters from the upper lens (230A), wherein the heating element (245) generates thermal energy and the thermal energy is transmitted to the upper lens (230A) through the sealing material (241) to remove small liquid droplets from the upper lens (230A).The heat-assisted automatic foreign matter removal type light-sensitive sensor device (20) according to claim 3, wherein the heating element (245) is disposed between a bottom surface of the upper lens (230A) and the sealing material (241).The heat-assisted automatic foreign matter removal type light-sensitive sensor device (20) according to claim 1 or 2, wherein the light-sensitive sensor device (20) further comprises a soft shielding material (243) having an annular flake shape and disposed on an outer side of the housing (260) and an outer side of the transparent protective cover (240), thereby shielding a gap between the housing (260), the transparent protective cover (240), and the sealing material (241).The heat-assisted automatic foreign matter removal type light-sensitive sensor device (20) according to claim 3 or 4, wherein the light-sensitive sensor device (20) further comprises a soft shielding material (243) having an annular flake shape and disposed on an outer side of the housing (260) and an outer side of the transparent protective cover (240), thereby shielding a gap between the housing (260), the transparent protective cover (240), and the sealing material (2431).The heat-assisted automatic foreign matter removal type light-sensitive sensor device (20) according to any one of claims 1 to 4, wherein the light-sensitive sensor device (20) further comprises a heat insulating buffer member (247) disposed between the piezoelectric element (244) and the sealing material (241) and mechanically connected to the piezoelectric element (244) and the sealing material (241), respectively.The heat-assisted automatic foreign matter removal type light-sensitive sensor device (20) according to any one of claims 1 to 4, wherein the light-sensitive sensor device (20) further comprises a heat insulating buffer member (247) disposed between the piezoelectric element (244) and the heating element (245) and mechanically connected to the heating element (245) and the piezoelectric element (244), respectively.The heat-assisted automatic foreign matter removal type light-sensitive sensor device (20) according to any one of claims 1 to 4, wherein the light-sensitive sensor device (20) further comprises a heat insulating buffer member (247) disposed below the piezoelectric element (244) and mechanically connected to the piezoelectric element (244).