Lens heating device and vehicle camera

Abstract

The utility model relates to a kind of lens heating device and vehicle-mounted camera, lens heating device, for heating lens main body, comprising: magnetic lens compression ring, magnetic lens compression ring is installed in the lens main body;Heating assembly, heating assembly includes the shell of the outside of magnetic lens compression ring and the induction coil of the shell inside being set around;And circuit module, circuit module is electrically connected to induction coil;Replace ordinary lens compression ring in traditional lens by the magnetic lens compression ring made of magnetic material, and heating assembly is externally placed in the outside of magnetic lens compression ring, when high-frequency alternating current is passed into induction coil, alternating magnetic field can be generated, magnetic lens compression ring is located in alternating magnetic field, can directly generate induced current and generate heat, realize lens heating function, avoid the problem such as imaging distortion, light path obstruction or thermal stress damage possibly caused by heating element directly attached or embedded lens surface.

Description

Technical Field

[0001] This utility model relates to the field of camera module technology, and in particular to lens heating devices and vehicle cameras. Background Technology

[0002] With the rapid development of automotive camera technology, multi-functional integrated cameras have become an industry trend. For example, to enable camera modules to adapt to low-temperature environments, a heating module can be integrated into the camera module. This heating module can heat the lens to meet the needs of lens defogging or defrosting.

[0003] However, current technologies typically involve directly attaching the heating element of the heating module to the lens surface or embedding it within the lens. This heating element can easily affect the optical system, causing problems such as light path obstruction, image distortion, or impacting core optical performance indicators like MTF (Mean Transmission Frequency). It may even lead to thermal stress damage to the lens. The lens heating module has become a key technological bottleneck restricting the performance improvement of automotive cameras, urgently requiring a design breakthrough. Utility Model Content

[0004] Therefore, it is necessary to provide a lens heating device and a vehicle-mounted camera to address the problem that existing lens heating solutions, in which heating elements are directly attached to the lens surface or embedded in the lens, affect the optical system.

[0005] On one hand, this application provides a lens heating device for heating a lens body, comprising: a magnetic lens retaining ring, the magnetic lens retaining ring being mounted on the lens body; a heating assembly, the heating assembly comprising a housing disposed around the outside of the magnetic lens retaining ring and an induction coil disposed within the housing; and a circuit module, the circuit module being electrically connected to the induction coil.

[0006] In one embodiment, the housing is clearance-fitted with the magnetic lens retainer.

[0007] In one embodiment, the housing has an annular cavity, and the induction coil is uniformly wound inside the annular cavity.

[0008] In one embodiment, the outer casing is made of insulating and heat-resistant material.

[0009] In one embodiment, the circuit module includes a DC power supply module and a full-bridge inverter module electrically connected to the DC power supply module.

[0010] In one embodiment, the full-bridge inverter module includes a first switch, a second switch, a third switch, a fourth switch, and a control module controllably connected to the first switch, the second switch, the third switch, and the fourth switch, respectively. The first electrode and the second electrode of the first switch are electrically connected to the positive terminal of the DC power supply module and the first electrode of the third switch, respectively. The first electrode and the second electrode of the second switch are electrically connected to the first electrode of the first switch and the first electrode of the fourth switch, respectively. The second electrode of the third switch is electrically connected to the negative terminal of the power supply module. The second electrode of the fourth switch is electrically connected to the second electrode of the third switch. The first end and the second end of the induction coil are electrically connected to the second electrode of the first switch and the first electrode of the fourth switch, respectively.

[0011] In one embodiment, the first switch, the second switch, the third switch, and the fourth switch are metal-oxide-semiconductor field-effect transistors.

[0012] In one embodiment, the DC power supply module includes a DC power supply and a DC-DC synchronous boost module electrically connected to the DC power supply.

[0013] In one embodiment, the DC power supply module further includes a heating function switch disposed between the DC power supply and the DC-DC synchronous boost module, and an ECU module electrically connected to the heating function switch.

[0014] On the other hand, this application provides a vehicle-mounted camera, including: a lens heating device as described in any of the above; and a lens body, wherein the lens heating device is mounted on the lens body.

[0015] In summary, this application replaces the conventional lens retainer with a lens retainer made of magnetically conductive material, and places the heating component outside the magnetically conductive lens retainer. When a high-frequency alternating current is applied to the induction coil, an alternating magnetic field is generated. The magnetically conductive lens retainer, located within this alternating magnetic field, directly generates an induced current and heat, thus achieving the lens heating function. By cleverly utilizing the principle of electromagnetic induction to place the heating component in the lens retainer area, the original optical lens assembly structure of the vehicle camera does not need to be altered, thereby completely avoiding problems such as imaging distortion, optical path obstruction, or thermal stress damage that may occur when the heating element is directly attached to or embedded in the lens surface. The entire lens heating device has a simple and compact structure, making it easy to integrate into existing vehicle cameras. Attached Figure Description

[0016] Figure 1 A schematic diagram of a vehicle-mounted camera provided for one embodiment of this application;

[0017] Figure 2A circuit diagram of a lens heating device provided for one embodiment of the application;

[0018] Figure 3 A schematic diagram of the alternating magnetic field of a lens heating device provided in one embodiment of this application;

[0019] Figure 4 This is a schematic diagram showing the dimensions of a lens heating device in one embodiment of this application.

[0020] Reference numerals: 10, magnetic lens retaining ring; 20, heating assembly; 21, housing; 22, induction coil; 30, circuit module; 31, DC power supply module; 311, DC power supply; 312, DC-DC synchronous boost module; 313, heating function switch; 314, ECU module; 32, full-bridge inverter module; 321, first switch; 322, second switch; 323, third switch; 324, fourth switch; 40, lens body; 41, lens housing; 42, photosensitive assembly; 43, lens. Detailed Implementation

[0021] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0022] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to 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 this utility model.

[0023] 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 as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0024] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; 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, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0025] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0026] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0027] To address the issue that existing lens heating solutions, which involve directly attaching heating elements to the lens surface or embedding them within the lens, can negatively impact the optical system, this application provides a lens heating device and an in-vehicle camera.

[0028] On the one hand, this application provides a lens heating device that can efficiently and non-contactly heat the lens body using the principle of electromagnetic induction.

[0029] Specifically, please refer to Figure 1 , Figure 2 and Figure 3The lens heating device may include a magnetic lens retainer 10, a heating assembly 20, and a circuit module 30. The magnetic lens retainer 10 is a lens retainer made of magnetic material and is mounted on the lens body 40. The heating assembly 20 may include a housing 21 and an induction coil 22. The housing 21 is arranged around the outside of the magnetic lens retainer 10, and the induction coil 22 is disposed inside the housing 21. The circuit module 30 is electrically connected to the induction coil 22 and is used to supply high-frequency alternating current to the induction coil 22.

[0030] Understandably, this application replaces the conventional lens retainer 10 in a lens with a lens retainer 10 made of a magnetically conductive material, and places the heating component 20 outside the magnetically conductive lens retainer 10. When a high-frequency alternating current is passed through the induction coil 22, an alternating magnetic field is generated. The magnetically conductive lens retainer 10 is located within this alternating magnetic field, directly generating an induced current and heat, thus achieving the lens heating function. By cleverly utilizing the principle of electromagnetic induction, the heating component 20 is placed in the lens retainer area without altering the original optical lens assembly structure of the vehicle camera, thereby completely avoiding problems such as imaging distortion, optical path obstruction, or thermal stress damage that may occur due to the heating element being directly attached to or embedded in the lens surface. The entire lens heating device has a simple and compact structure, making it easy to integrate into existing vehicle cameras.

[0031] It is worth noting that the magnetic lens retaining ring 10 of this application can also be replaced with other parts of the lens that need to be heated, such as making a magnetic lens barrel with a magnetic material and setting the heating component 20 on the outside of the magnetic lens barrel so that the magnetic lens barrel generates heat and realizes the lens heating function.

[0032] Optionally, in some embodiments, the magnetic lens retaining ring 10 may be made of magnetically conductive stainless steel or ferrite material.

[0033] Optionally, such as Figure 1 As shown, in some embodiments, the housing 21 and the magnetic lens retaining ring 10 are fitted with a clearance. This configuration ensures that the housing 21 and the magnetic lens retaining ring 10 are non-contact, eliminating any physical hard connection between them. This, in turn, ensures that the housing 21 is not physically connected to the entire lens optical structure, completely eliminating the possibility of negative impacts on the camera's precision optical structure and image quality due to installation stress or differences in thermal expansion, while simultaneously guaranteeing efficient transfer of magnetic field energy.

[0034] Optionally, in some embodiments, the housing 21 has an annular cavity, and the induction coil 22 is uniformly wound inside the annular cavity. This arrangement provides the induction coil 22 with a uniform and tight winding space, and the uniformly wound induction coil 22 ensures that the magnetic field strength of the generated alternating magnetic field is uniform, thereby causing the magnetic lens pressure ring 10 to heat up uniformly.

[0035] Optionally, in some embodiments, the outer casing 21 is made of insulating and heat-insulating material. This arrangement, using insulating and heat-insulating material to fabricate the outer casing 21 of the heating assembly 20, ensures that the induction coil 22 inside the outer casing 21 generates an alternating magnetic field while isolating it from the influence of the external environment, and also prevents short circuits in the induction coil 22.

[0036] Furthermore, since the vehicle power supply is generally a DC power supply 311, while the induction coil 22 requires a high-frequency AC current to generate an alternating magnetic field, therefore, if Figure 2 As shown, in some embodiments, circuit module 30 includes a DC power supply module 31 and a full-bridge inverter module 32 electrically connected to the DC power supply module 31. The DC power supply module 31 can be supplied by an on-board power supply. The full-bridge inverter module 32 can serve as a core power conversion stage, converting the low-voltage DC power output from the DC power supply module 31 into suitable high-frequency AC power required for the induction coil 22 to generate electromagnetic induction. This high-frequency AC power can range from tens of kilohertz to hundreds of kilohertz.

[0037] Optionally, such as Figure 2 As shown, in some embodiments, the full-bridge inverter module 32 may include a first switch 321, a second switch 322, a third switch 323, a fourth switch 324, and a control module. The first and second electrodes of the first switch 321 are electrically connected to the positive terminal of the DC power supply module 31 and the first electrode of the third switch 323, respectively. The first and second electrodes of the second switch 322 are electrically connected to the first electrode of the first switch 321 and the first electrode of the fourth switch 324, respectively. The second electrode of the third switch 323 is electrically connected to the negative terminal of the power supply module. The second electrode of the fourth switch 324 is electrically connected to the second electrode of the third switch 323. The first and second ends of the induction coil 22 are electrically connected to the second electrodes of the first switch 321 and the first electrode of the fourth switch 324, respectively. The control module is controllably connected to the first switch 321, the second switch 322, the third switch 323, and the fourth switch 324, respectively, for controlling the on / off state of the first switch 321, the second switch 322, the third switch 323, and the fourth switch 324.

[0038] Understandably, when the first switch 321 and the fourth switch 324 are connected, and the second switch 322 and the third switch 323 are disconnected, the DC power module 31, the first switch 321, the induction coil 22, and the fourth switch 324 form a circuit. The DC power output from the positive terminal of the DC power module 31 enters the induction coil 22 from the first end through the first switch 321, and then returns to the negative terminal of the DC power module 31 from the second end through the fourth switch 324. When the second switch 322 and the third switch 323 are connected, and the first switch 321 and the fourth switch 324 are disconnected, the DC power module 31, the second switch 322, the induction coil 22, and the third switch 323 form a circuit. The DC power output from the positive terminal of the DC power module 31 enters the induction coil 22 from the second end through the second switch 322, and then returns to the negative terminal of the DC power module 31 from the first end through the third switch 323. Therefore, by repeatedly and alternately switching on the first switch 321 and the fourth switch 324 and switching off the second switch 322 and the third switch 323, and switching on the second switch 322 and the third switch 323 and switching off the first switch 321 and the third switch 323, the DC power output from the DC power module 31 can be converted into AC power.

[0039] Optionally, in some embodiments, the first switch 321, the second switch 322, the third switch 323, and the fourth switch 324 are metal-oxide-semiconductor field-effect transistors (MOSFETs). The drain (D) of the MOSFET can serve as the first electrode of the switch, the source (S) of the MOSFET can serve as the second electrode of the switch, and the gate (G) of the MOSFET can be used to connect to the control module. MOSFETs have a fast switching speed and can operate at frequencies above 100kHz. Using MOSFETs as switches, the DC power output from the DC power module 31 can be converted into high-frequency AC power.

[0040] The voltage of the vehicle-mounted DC power supply 311 is typically 12V, and its voltage is not stable, requiring voltage boosting and stabilization. Therefore, as... Figure 2 As shown, in some embodiments, the DC power supply module 31 includes a DC power supply 311 and a DC-DC synchronous boost module 312 electrically connected to the DC power supply 311. The DC-DC synchronous boost module 312 is a DC-DC power converter based on synchronous rectification technology, which can boost and regulate the unstable 12V DC power provided by the DC power supply 311 to a high-voltage DC power suitable for the operation of the full-bridge inverter module 32, for example, boosting the 12V DC power to tens of volts.

[0041] Optionally, such as Figure 2 As shown, in some embodiments, the DC power supply module 31 further includes a heating function switch 313 disposed between the DC power supply 311 and the DC-DC synchronous boost module 312, and an ECU module 314 electrically connected to the heating function switch 313. The ECU module 314 can be an on-board ECU. By connecting the heating function switch 313 to the ECU module 314, the ECU module 314 can remotely control the opening or closing of the lens heating device, thereby achieving intelligent management.

[0042] The working principle of the lens heating device in the application will be further described below with specific examples.

[0043] DC power supply 311 voltage The voltage is boosted and stabilized to the required boost voltage via a synchronous boost DC-DC module. The boosted and regulated DC input is converted into a full-bridge inverter circuit composed of metal-oxide-semiconductor field-effect transistors. Under the control of the control module, the DC voltage is converted into a higher voltage. The current is inverted into a high-frequency alternating square wave. The high-frequency alternating current flowing through the induction coil 22 generates a strong magnetic field with high intensity, high density, and rapidly alternating direction around it. The alternating magnetic field acts on the magnetic lens retaining ring 10, inducing a current inside the magnetic lens retaining ring 10 according to Faraday's law of electromagnetic induction. When this current flows through the magnetic material with resistive properties, it generates a large amount of heat energy. The heat is concentrated inside the magnetic lens retaining ring 10 and rapidly diffuses to the entire lens through thermal conduction, thereby achieving the heating function.

[0044] Setting the vehicle DC power supply 311 The boost voltage is obtained by using a DC-DC synchronous boost module 312. The full-bridge inverter module 32 can boost the voltage. The voltage is inverted to a high-frequency AC voltage of 100kHz. The equivalent inductance L of the induction coil 22 is set to 20μH, and the impedance of the induction coil 22 is... The resistance is 0.5Ω, according to the following formula:

[0045] ;

[0046] ;

[0047] The inductive reactance of induction coil 22 was calculated. The impedance is 12.6Ω and the total impedance Z is 12.6Ω.

[0048] Therefore, we can derive the following relationship:

[0049] ;

[0050] The calculated coil current I is 1.27A.

[0051] like Figure 4 As shown, the size of the magnetic lens retaining ring 10 is set as the outer diameter. , inner diameter ,high The outer diameter of the housing 21 of the heating component 20 is [missing information]. , inner diameter ,high The heating component 20 has 2000 turns of induction coil 22. The magnetic material used for the lens retaining ring has a resistivity of... relative permeability Hysteresis loss coefficient .

[0052] First, calculate the volume of the magnetic lens retaining ring 10. According to the following relationship:

[0053] ;

[0054] The calculated volume of the magnetic lens retaining ring 10 is: .

[0055] Then, calculate the magnetic field strength. Average length of magnetic circuit It can be approximated as 0.023m, according to the following relationship:

[0056] ;

[0057] Calculated magnetic field strength for .

[0058] Then calculate the absolute permeability and peak magnetic flux density According to the following relationship:

[0059] ;

[0060] ;

[0061] The absolute permeability was calculated. for Peak magnetic flux density for .

[0062] Assuming the saturation magnetic flux of the magnetically conductive lens retainer ring 10 is 1T, the heat generated by electromagnetic induction can be calculated based on the saturation magnetic flux of the lens retainer ring.

[0063] Calculate eddy current loss and heating power According to the following relationship:

[0064] ;

[0065] × ;

[0066] Calculation of eddy current loss for This indicates that the induced current achieves a heating power of 1.5W on the lens retainer made of magnetic material.

[0067] Given that the specific heat capacity of the magnetic material is C = 600 J / (kg·K), its density is 4800 kg / m³, and the mass of the lens retainer is 0.0013 kg, based on the following relationship:

[0068] (No heat dissipation).

[0069] The calculated rate of temperature rise without heat dissipation is... for .

[0070] Therefore, it can be seen that the lens heating device of this application can achieve high-efficiency lens heating.

[0071] On the other hand, such as Figure 1 As shown, this application provides a vehicle-mounted camera, including: a lens heating device as described above; and a lens body 40, with the lens heating device mounted on the lens body 40. This vehicle-mounted camera uses a non-contact heating method with an external heating component 20, which avoids problems such as imaging distortion, light path obstruction, or thermal stress damage that may occur if the heating component 20 is directly attached to or embedded in the lens surface, resulting in better imaging performance.

[0072] The lens body 40 may include a lens housing 41, a photosensitive component 42, and multiple lenses 43. The photosensitive component 42 and the multiple lenses 43 are all fixed inside the lens housing 41. The magnetic lens retaining ring 10 of the lens heating device is mounted on the lens housing 41 to press the lenses 43 together. The heating component 20 of the lens heating device is located outside the magnetic lens retaining ring 10. When a high-frequency alternating current is applied to the induction coil 22 of the heating component 20, the magnetic lens retaining ring 10 can generate heat to heat the lenses 43.

[0073] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0074] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A lens heating device for heating the lens body, characterized in that, include: A magnetic lens retaining ring is mounted on the lens body; A heating assembly, comprising a housing disposed around the outside of the magnetic lens pressure ring and an induction coil disposed within the housing; as well as A circuit module, wherein the circuit module is electrically connected to the induction coil; The circuit module includes a DC power supply module and a full-bridge inverter module electrically connected to the DC power supply module; the full-bridge inverter module includes multiple switches electrically connected between the DC power supply module and the induction coil, and a control module electrically connected to the switches and used to control the switching on and off to convert DC power into AC power.

2. The lens heating device according to claim 1, characterized in that, The outer casing is fitted with the magnetic lens retaining ring with a clearance.

3. The lens heating device according to claim 1, characterized in that, The outer casing has an annular cavity, and the induction coil is uniformly wound inside the annular cavity.

4. The lens heating device according to claim 1, characterized in that, The outer shell is made of insulating and heat-insulating material.

5. The lens heating device according to any one of claims 1 to 4, characterized in that, The full-bridge inverter module includes a first switch, a second switch, a third switch, a fourth switch, and a control module controllably connected to the first switch, the second switch, the third switch, and the fourth switch. The first electrode and the second electrode of the first switch are electrically connected to the positive terminal of the DC power supply module and the first electrode of the third switch, respectively. The first electrode and the second electrode of the second switch are electrically connected to the first electrode of the first switch and the first electrode of the fourth switch, respectively. The second electrode of the third switch is electrically connected to the negative terminal of the power supply module. The second electrode of the fourth switch is electrically connected to the second electrode of the third switch. The first end and the second end of the induction coil are electrically connected to the second electrode of the first switch and the first electrode of the fourth switch, respectively.

6. The lens heating device according to claim 5, characterized in that, The first switch, the second switch, the third switch, and the fourth switch are metal-oxide-semiconductor field-effect transistors.

7. The lens heating device according to any one of claims 1 to 4, characterized in that, The DC power supply module includes a DC power supply and a DC-DC synchronous boost module electrically connected to the DC power supply.

8. The lens heating device according to claim 7, characterized in that, The DC power supply module further includes a heating function switch disposed between the DC power supply and the DC-DC synchronous boost module, and an ECU module electrically connected to the heating function switch.

9. A vehicle-mounted camera, characterized in that, include: The lens heating device as described in any one of claims 1 to 8; and The lens body, wherein the lens heating device is mounted on the lens body.

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