Automatic anti-fog lens device, camera module and electronic device

Abstract

The present invention provides an automatic anti-fog lens device, a camera module and an electronic device, comprising a lens barrel; a lens assembly, the lens assembly is arranged in the lens barrel, the lens assembly comprises a first lens, a second lens and a third lens arranged along the optical axis from the object end to the image end; an annular printed circuit board, the annular printed circuit board is arranged between the first lens and the second lens and is in contact with the edge of the first lens, and a heating element and a temperature sensing element are arranged on a side surface of the annular printed circuit board facing the first lens; a flexible circuit board, the flexible circuit board is arranged on the inner wall of the side edge of the lens barrel, and one end of the flexible circuit board is electrically connected to the annular printed circuit board; a control unit, the control unit is electrically connected to the other end of the flexible circuit board. The present invention effectively eliminates the frost and fogging phenomenon in the use of the lens by arranging the heating element and the temperature sensing element.

Description

Technical Field

[0001] The present invention relates to the technical field of lenses, and in particular to an automatic anti-fog lens device, a camera module and an electronic device. Background Art

[0002] When using photography, security, industrial cameras and vehicle-mounted camera modules, frost or fogging on the camera lens surface is often caused by changes in ambient temperature and humidity, which seriously affects the camera imaging quality and even affects the functions of the assisted driving or automatic driving system, thereby causing driving safety problems. Summary of the invention

[0003] In view of the above problems, the present invention solves the lens frost and fogging problems by designing a method that can detect the temperature of the lens group inside the lens body and support electric heating defrosting and defogging in the lens group.

[0004] The present invention provides the following technical solutions:

[0005] A lens device, comprising:

[0006] Lens tube;

[0007] A lens assembly is arranged in the lens barrel, and the lens assembly includes a first lens, a second lens and a third lens arranged along the optical axis from the object end to the image end;

[0008] An annular printed circuit board, the annular printed circuit board is arranged between the first lens and the second lens and is in contact with the edge of the first lens, a heating element and a temperature sensing element are arranged on a surface of the annular printed circuit board facing the first lens, and the temperature sensing element is used to obtain temperature data of the first lens;

[0009] A flexible circuit board, which is arranged on the inner wall of the side of the lens barrel, and one end of the flexible circuit board is electrically connected to the annular printed circuit board, and the other end of the flexible circuit board extends to the outside of the image end of the lens barrel;

[0010] The control unit is electrically connected to the other end of the flexible circuit board and is used to obtain temperature data and control the operation of the heating element; when the obtained temperature data is lower than the preset temperature, the control unit starts the operation of the heating element.

[0011] As a preferred technical solution, an accommodating hole is provided at the edge of the surface on the image end side of the first lens, and the accommodating hole can accommodate the temperature sensing element; an insulating layer is provided at the position corresponding to the accommodating hole on the annular printed circuit board, and the temperature sensing element is arranged on the insulating layer.

[0012] As a preferred technical solution, the first lens is arranged at the object end of the lens barrel, the second lens is arranged close to the first lens, and the third lens is arranged at the image end of the lens barrel.

[0013] As a preferred technical solution, a plurality of optical lenses and a plurality of elastic spacer rings alternately arranged along the optical axis are included between the second lens and the third lens.

[0014] As a preferred technical solution, the heating element is a constantan heating resistor; the temperature sensing element is a negative temperature coefficient thermistor.

[0015] As a preferred technical solution, the heating element and the temperature sensing element are arranged on the surface of the printed circuit board through a surface mounting welding process.

[0016] As a preferred technical solution, the flexible circuit board is interconnected with the stacked layers of the printed circuit board through a multi-layer interconnection process of a soft-hard combination board.

[0017] As a preferred technical solution, it also includes an image sensor printed circuit board; the control unit is arranged on the image sensor printed circuit board, and the control unit is electrically connected to the flexible circuit board through wiring.

[0018] As a preferred technical solution, the control unit includes a field effect transistor switch and a microcontroller.

[0019] As a preferred technical solution, the control unit is used to control the heating of the first lens, the microcontroller transmits the output switching signal to the field effect transistor switch, the field effect transistor switch is turned on, and the power is conducted to the heating element, and the heating element works.

[0020] The present application also provides a camera module, comprising the lens device as described above.

[0021] The present application also provides an electronic device, comprising the lens device as described above.

[0022] The technical solution adopted by the present invention can achieve the beneficial effect: a heating element and a temperature sensing element are arranged inside the lens, and the temperature detection of the lens body and the self-heating defrosting and defogging of the lens body are realized inside the lens, which effectively solves the problem of frost or fogging on the surface of the camera lens caused by changes in ambient temperature and humidity, and eliminates the frost and fogging phenomenon during the use of the lens. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments, which constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions explain the present invention and do not constitute improper limitations on the present invention. In the drawings:

[0024] Figure 1 This is a schematic diagram of the structure of the lens device disclosed in Embodiment 1 of the present invention;

[0025] Figure 2This is a schematic diagram of the structure of the annular printed circuit board disclosed in Embodiment 1 of the present invention;

[0026] Figure 3 This is a schematic diagram of the structure of the lens device disclosed in Example 2 of the present invention.

[0027] Description of reference numerals:

[0028] Lens barrel A; first lens 10; second lens 20; third lens 30; annular printed circuit board B; heating element B1; temperature sensing element B2; flexible circuit board C; elastic spacer ring D; accommodating hole 11. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. In the description of the present invention, it should be noted that the term "or" is usually used in the sense of including "and / or", unless the content clearly indicates otherwise.

[0030] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Example 1

[0033] This embodiment provides a lens device according to Figure 1 ,include:

[0034] Lens tube A;

[0035] The lens assembly is arranged in the lens barrel A, and the lens assembly includes a first lens 10, a second lens 20 and a third lens 30 arranged along the optical axis from the object end to the image end;

[0036] An annular printed circuit board B, the annular printed circuit board B is disposed between the first lens 10 and the second lens 20 and is in contact with the edge of the first lens 10. A heating element B1 and a temperature sensing element B2 are disposed on a surface of the annular printed circuit board B facing the first lens 10. The temperature sensing element B2 is used to obtain temperature data of the first lens 10.

[0037] A flexible circuit board C is arranged on the inner wall of the side of the lens barrel A, and one end of the flexible circuit board C is electrically connected to the annular printed circuit board B, and the other end of the flexible circuit board C extends to the outside of the image end of the lens barrel A;

[0038] The control unit is electrically connected to the other end of the flexible circuit board C and is used to obtain temperature data and control the heating element B1; when the obtained temperature data is lower than the preset temperature, the control unit starts the heating element B1.

[0039] Preferably, the first lens 10 is arranged at the object end of the lens barrel A, the second lens 20 is arranged close to the first lens 10, and the third lens 30 is arranged at the image end of the lens barrel A.

[0040] Preferably, a plurality of optical lenses and a plurality of elastic spacer rings D alternately arranged along the optical axis direction are included between the second lens 20 and the third lens 30 .

[0041] Preferably, the lens is a convex lens, or a concave lens, or a combination of a convex lens and a concave lens.

[0042] There are multiple optical lenses between the second lens 20 and the third lens 30, and the specific number is set according to different lens requirements. An elastic spacer ring D is set between each two adjacent lenses, which can well fix the optical lens in the lens barrel A so that the lens will not tilt or shift due to stress. Among them, the elastic spacer ring D can also be made of non-elastic material, as long as it meets the requirements of fixing the inner lens barrel A.

[0043] Preferably, the heating element B1 is a constantan heating resistor; the temperature sensing element B2 is a negative temperature coefficient thermistor. Among them, the constantan heating resistor is a resistance alloy with copper and nickel as the main components. Constantan has a low resistance temperature coefficient and a wide operating temperature range, generally below 480°C. It also has the advantages of excellent processing performance and good welding performance; the negative temperature coefficient thermistor is also called NTC thermistor, which is a type of sensor resistor whose resistance value decreases as the temperature increases.

[0044] Preferably, the heating element B1 and the temperature sensing element B2 are mounted on the surface of the annular printed circuit board by a surface mount welding process. Figure 2A heating resistor made of constantan is welded on the annular printed circuit board through the surface mount welding (SMT) process, and a negative temperature coefficient thermistor (NTC) is welded as a temperature sensor. The heating element B1 is arranged around the annular printed circuit board, and in the area adjacent to the temperature sensing element B2, the resistance wire of the heating element B1 is connected to the temperature sensing element B2 in a straight line to protect the temperature sensing element B2 from damage.

[0045] Printed circuit boards (PCBs), also known as printed circuit boards B, are providers of electrical connections for electronic components and are represented by PCBs.

[0046] Flexible printed circuit board (FPC), referred to as "flexible board", is a printed circuit board made of flexible insulating substrate (mainly polyimide or polyester film) and has many advantages that rigid printed circuit boards do not have.

[0047] In this embodiment, the annular flexible circuit board C is provided to be interconnected with the printed circuit board B through a multi-layer interconnection process of a soft-hard combination board, wherein the circuit is connected through a PCB through hole.

[0048] Preferably, the control unit is arranged outside the second end A2 of the lens barrel A, and is electrically connected to the flexible circuit board C inside the lens barrel A through wiring.

[0049] Preferably, the control unit includes a field effect transistor switch and a microcontroller.

[0050] The heating element B1 and the temperature sensing element B2 are led out of the lens assembly through the flexible circuit board on the inner wall of the side of the lens barrel A and toward the image end of the lens barrel. The tail of the lens assembly leads out the circuit and is electrically connected to the control unit.

[0051] Temperature detection and automatic heating are implemented on the control unit outside the lens assembly. The control unit is implemented on the ring-shaped printed circuit board B where the image sensor of the camera is located. The temperature of the lens assembly is collected by the negative temperature coefficient thermistor on the ring-shaped printed circuit board B, which is reflected as the resistance value that changes with temperature. Through the voltage divider circuit connection, the resistance value of the thermistor is converted into a voltage value, and the voltage value at both ends of the thermistor that is negatively correlated with the temperature of the lens assembly is collected by the analog-to-digital converter (ADC), converted into a digital signal, and provided to the microcontroller in the control circuit. The microcontroller will determine whether the lens should be heated based on the detected lens assembly temperature data and the written software. If heating is required, the microcontroller will output a switch signal to the field effect transistor (MOSFET) switch, the field effect transistor switch is turned on, and the camera power supply is turned on to the constantan heating resistor on the ring-shaped printed circuit board B, and the lens assembly begins to heat up, and the defrosting and defogging functions are realized by the heating of the lens assembly. The temperature range in which the lens assembly will be heated is determined by the microcontroller software and changes according to the actual debugging situation.

[0052] The reason for frost and fog on the lens surface is that the surface temperature of the outermost lens of the lens group is low and the ambient humidity is high. When the ambient humidity is high and the surface temperature of the outermost lens of the lens group is lower than the condensation temperature, fine water droplets will condense on the outer surface of the outermost lens to form fogging, where the condensation temperature varies in different environments; when the surface temperature of the outermost lens of the lens group is lower than the freezing point, frost will form on the outer surface of the outermost lens. By detecting the temperature of the outermost lens of the lens group inside the lens, it is determined whether the current temperature of the outer surface of the lens reaches the frosting temperature or the fogging temperature. An electric heating device structure is implemented in the lens group. When the temperature of the lens group is too low and defrosting and defoggering is required, the electric heating device structure implemented inside the lens is energized to generate heat, so that the surface temperature of the outermost lens of the lens group rises to a temperature higher than the frosting and fogging temperature, thereby achieving the functional purpose of eliminating frosting and fogging.

[0053] Example 2

[0054] This embodiment 2 provides another lens device, which is different from the embodiment 1 in the placement position of the temperature sensor element B2.

[0055] Preferably, a receiving hole 11 is provided at the edge of the image end surface of the first lens 10. Figure 3 The accommodating hole 11 can accommodate the temperature sensing element B2; a heat insulating layer is provided at a position corresponding to the accommodating hole 11 on the annular printed circuit board B, and the temperature sensing element B2 is arranged on the heat insulating layer, which can more accurately sense whether the outer surface temperature of the first lens 10 reaches the frosting temperature or the fogging temperature.

[0056] Example 3

[0057] This embodiment provides a camera module, including the lens device given in the above embodiments 1-2.

[0058] This embodiment provides an electronic device, including the lens device provided in the above embodiments 1-2.

[0059] The above is a detailed introduction to a lens device, a camera module and an electronic device according to an embodiment of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for a person skilled in the art, according to the idea of ​​the present application, there may be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. An automatic anti-fog lens device, comprising a lens barrel, characterized in that: include: A lens assembly, the lens assembly is arranged in the lens barrel, and the lens assembly includes a first lens, a second lens and a third lens arranged along the optical axis from the object end to the image end; an annular printed circuit board, the annular printed circuit board is arranged between the first lens and the second lens and is in contact with the edge of the first lens, a heating element and a temperature sensing element are arranged on a surface of the annular printed circuit board facing the first lens, and the temperature sensing element is used to obtain temperature data of the first lens; A flexible circuit board, wherein the flexible circuit board is arranged on the inner wall of the side of the lens barrel, and one end of the flexible circuit board is electrically connected to the annular printed circuit board, and the other end of the flexible circuit board extends to the outside of the image end of the lens barrel; A control unit, the control unit is electrically connected to the other end of the flexible circuit board, and is used to obtain the temperature data and control the heating element to work; when the obtained temperature data is lower than a preset temperature, the control unit starts the heating element to work; A receiving hole is provided at the edge of the surface on the image end side of the first lens, and the receiving hole can receive the temperature sensing element; The position of the annular printed circuit board corresponding to the accommodating hole has a heat insulation layer, and the temperature sensing element is arranged on the heat insulation layer; The heating element and the temperature sensing element are arranged on the surface of the annular printed circuit board through a surface mount welding process; a heating resistor made of constantan is welded on the annular printed circuit board through a surface mount welding process, and a negative temperature coefficient thermistor is welded as a temperature sensor, the heating element is arranged around the annular printed circuit board, and in the area adjacent to the temperature sensing element, the resistance wire of the heating element is connected to the temperature sensing element in a straight line.

2. The automatic anti-fog lens device according to claim 1, characterized in that: The first lens is arranged at the object end of the lens barrel, the second lens is arranged close to the first lens, and the third lens is arranged at the image end of the lens barrel.

3. The automatic anti-fog lens device according to claim 1, characterized in that: The heating element is a constantan heating resistor; the temperature sensing element is a negative temperature coefficient thermistor.

4. The automatic anti-fog lens device according to claim 1, characterized in that: The flexible circuit board is interconnected with the stacked layers of the annular printed circuit board through a multi-layer interconnection process of a soft-hard combination board.

5. The automatic anti-fog lens device according to any one of claims 1 to 4, characterized in that: It also includes an image sensor printed circuit board; the control unit is arranged on the image sensor printed circuit board, and the control unit is electrically connected to the flexible circuit board through wiring.

6. The automatic anti-fog lens device according to any one of claims 1 to 4, characterized in that: The control unit includes a field effect transistor switch and a microcontroller.

7. The automatic anti-fog lens device according to claim 6, characterized in that: The control unit is used to control the heating of the first lens. The microcontroller transmits the output switch signal to the field effect transistor switch. The field effect transistor switch is turned on and the power is conducted to the heating element, and the heating element works.

8. A camera module, characterized in that: The invention comprises a lens device as claimed in any one of claims 1 to 7.

9. An electronic device, characterized in that: The invention comprises a lens device as claimed in any one of claims 1 to 7.

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