Camera module heating circuit, camera module and electronic device

Abstract

Embodiments of the present application provide a camera module heating circuit, a camera module and an electronic device, and relate to the technical field of consumer electronics. In the camera module heating circuit, a temperature control module is fixed on a copper plate base, a heating module is integrated inside the copper plate base, a temperature control unit monitors the temperature of the area where the heating module is located in real time, and converts it into a current voltage value. If the current voltage value is not higher than a first voltage reference value, the heating module is automatically controlled to be powered and heated, and the heat is directly conducted to the lens and the image sensor through the copper plate base, thereby ensuring the normal operation of the camera module in a low temperature environment, overcoming the problem that the image sensor responds abnormally, noise increases or fails due to too low temperature, improving the reliability and stability of the camera module, and not relying on the computing power of the main control chip, nor needing software support, avoiding the low temperature failure problem caused by software delay, main control sleep or insufficient computing power of low-end chips.

Description

Technical Field

[0001] This invention relates to the field of consumer electronics technology, and more specifically, to a camera module heating circuit, a camera module, and an electronic device. Background Technology

[0002] In consumer electronics, camera modules have become a core component for human-computer interaction and intelligent sensing. However, when the ambient temperature drops to 0°C or below, significant image quality degradation is commonly observed. This is not due to the failure of a single component, but rather to a multi-physics-field synergistic degradation effect caused by low temperatures. On the one hand, the signal-to-noise ratio of the image sensor decreases sharply with temperature, forcing an increase in gain under low illumination, which leads to the simultaneous amplification of thermal noise and dark current noise, manifesting as dense color noise, enhanced graininess, and severe loss of texture details.

[0003] On the other hand, the optical components in the camera module (such as glass lenses and filters) undergo slight deformation due to thermal expansion and contraction, which disrupts the original precision optical path design and induces optical distortions such as defocusing, reduced resolution, and increased vignetting. The combination of these two factors ultimately results in a deteriorated image quality characterized by high noise, blurred details, and distorted colors.

[0004] Currently, existing technologies for addressing low-temperature issues in camera modules mainly include external polyimide (PI) heating film solutions and microcontroller unit (MCU) digital temperature control solutions. The PI heating film solution requires additional PI heating film, thermally conductive adhesive, and a separate power supply circuit. This makes the thickness and size of the camera module incompatible with the miniaturized structure of existing consumer cameras, and further increases costs due to the added materials and assembly processes.

[0005] MCU digital temperature control solutions rely on the main control chip to perform temperature acquisition and heating logic operations. For low- to mid-range consumer chips with limited computing power, complex software algorithms are required, increasing development costs. Furthermore, the temperature control function completely fails during power outages or when the main control chip is in sleep mode, making it difficult to guarantee the reliability of the camera module. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a camera module heating circuit, a camera module, and an electronic device, which can improve the reliability of the camera module and the image quality under low temperature conditions.

[0007] To achieve the above objectives, the technical solutions adopted in the embodiments of the present invention are as follows: In a first aspect, the present invention provides a camera module heating circuit, including a lens, an image sensor, a temperature control module and a copper plate base. The lens and the image sensor are fixed to one side of the copper plate base, and the temperature control module is fixed to the other side of the copper plate base. The temperature control module includes at least one temperature control unit. At least one heating module is integrated in the copper plate base. The temperature control unit is used to monitor at least one heating module. The heating module conducts heat to the lens and the image sensor through the copper plate base. The temperature control unit is used to output a corresponding current voltage value based on the current temperature of the area where the monitored heating module is located; when it is determined that the current voltage value is not higher than the first voltage reference value, it controls the heating module to be powered on for heating. The copper plate base is used to conduct the heat generated by the heating module to the lens and the image sensor; The temperature control unit is also used to control the heating module to cut off power and stop heating when it is determined that the current voltage value is higher than the first voltage reference value.

[0008] In an optional embodiment, the temperature control unit includes a temperature acquisition circuit and a control circuit, the temperature acquisition circuit and the control circuit are electrically connected, and the control circuit is also electrically connected to a power supply and the heating module; The temperature acquisition circuit is used to output the corresponding current voltage value based on the current temperature of the area where the monitored heating module is located; The control circuit is used to control the power supply to connect to the heating module when it is determined that the current voltage value is not higher than the first voltage reference value, so that the heating module is powered on and heated; and to control the power supply to disconnect from the heating module when it is determined that the current voltage value is higher than the first voltage reference value, so that the heating module is powered off and stops heating.

[0009] In an optional embodiment, the temperature acquisition circuit includes a voltage divider circuit and a low-pass filter circuit, wherein the voltage divider circuit is electrically connected to the low-pass filter circuit. The voltage divider circuit is used to output the corresponding current original voltage value according to the current temperature of the area where the monitored heating module is located; The low-pass filter circuit is used to filter the current original voltage value corresponding to the current temperature to obtain the current voltage value corresponding to the current temperature.

[0010] In an optional embodiment, the voltage divider circuit includes a voltage divider resistor and a thermistor. One end of the voltage divider resistor is electrically connected to a power supply, and the other end of the voltage divider resistor is electrically connected to one end of the thermistor. The other end of the thermistor is grounded. One end of the low-pass filter circuit is electrically connected between the voltage divider resistor and the thermistor. The thermistor is disposed on the heating module monitored by the temperature control unit.

[0011] In an optional embodiment, the control circuit includes a comparator circuit and a switching device. One end of the comparator circuit is electrically connected to the low-pass filter circuit, and the other end of the comparator circuit is electrically connected to the control terminal of the switching device. The first end of the switching device is electrically connected to the power supply, and the second end of the switching device is electrically connected to the heating module. The comparison circuit is configured to output a first control signal to turn on the switching device when it determines that the current voltage value is not higher than the first voltage reference value; and to output a second control signal to turn off the switching device when it determines that the current voltage value is higher than the first voltage reference value.

[0012] In an optional embodiment, the comparison circuit includes a first comparator, a second comparator, an inverter, and an OR gate. The first input terminals of both the first and second comparators are electrically connected to the low-pass filter circuit. The second input terminal of the first comparator is used to receive a second voltage reference value, and the second input terminal of the second comparator is used to receive a first voltage reference value. The second voltage reference value is lower than the first voltage reference value. The output terminal of the first comparator is electrically connected to the first input terminal of the OR gate, the output terminal of the second comparator is electrically connected to the input terminal of the inverter, the output terminal of the inverter is electrically connected to the second input terminal of the OR gate, and the output terminal of the OR gate is electrically connected to the control terminal of the switching device. The first comparator is configured to output a first high level when it determines that the current voltage value is lower than the second voltage reference value, and to output a first low level when it determines that the current voltage value is not lower than the second voltage reference value. The second comparator is configured to output a second low level when it determines that the current voltage is not higher than the first voltage reference value, and to output a second high level when it determines that the current voltage is higher than the first voltage reference value; The inverter is used to output the inverted signal corresponding to the second low level or the second high level; The OR gate is used to output either the first control signal or the second control signal based on the output level of the first comparator and the inverted signal output by the inverter.

[0013] In an optional implementation, the OR gate is used to output the first control signal when the output level of the first comparator is the first high level and the inverted signal output by the inverter is the inverted signal corresponding to the second low level; When the output level of the first comparator is the first low level and the inverted signal output by the inverter is the inverted signal corresponding to the second low level, the first control signal is output. When the output level of the first comparator is the first low level and the inverted signal output by the inverter is the inverted signal corresponding to the second high level, the second control signal is output.

[0014] In an optional implementation, the heating module is a simulated heating resistor or a power resistor; the simulated heating resistor is formed by etching heating traces in sections on the copper plate base, and the impedance on the heating traces is used to simulate a power resistor.

[0015] Secondly, the present invention provides a camera module, including the camera module heating circuit described in any of the foregoing embodiments.

[0016] Thirdly, the present invention provides an electronic device including the camera module described in the foregoing embodiments.

[0017] Compared to existing technologies, the camera module heating circuit, camera module, and electronic device provided in this invention, in the camera module heating circuit, fixes the lens and image sensor on one side of the copper plate base, and adds a temperature control module fixed on the other side. The heating module is integrated inside the copper plate base, and the temperature control unit monitors the temperature of the area where the heating module is located in real time and converts it into a current voltage value. If the current voltage value is not higher than a first voltage reference value, the heating module is automatically powered on for heating. The heat is directly conducted to the lens and image sensor through the copper plate base, thereby ensuring that the camera module can work normally in low-temperature environments. This overcomes the problem of abnormal image sensor response, increased noise, or failure caused by excessively low temperatures, and improves the reliability and stability of the camera module.

[0018] If the current voltage value is higher than the first voltage reference value, the temperature control unit immediately controls the heating module to cut off power and stop heating, preventing local overheating of the camera module and reducing safety hazards such as component damage or even fire caused by continuous temperature rise, thus improving product safety. Simultaneously, the copper plate base can naturally dissipate the heat generated by the camera module at room temperature, serving both heat dissipation and heating functions. The entire temperature control process relies on an analog hardware loop formed by the temperature control unit and the heating module, without relying on the computing power of the main control chip and requiring no software support, avoiding low-temperature failure issues caused by software delays, main control sleep mode, or insufficient computing power of low-end chips.

[0019] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A block diagram of a camera module heating circuit provided in an embodiment of the present invention is shown.

[0022] Figure 2 A block diagram of a heating module in a camera module heating circuit provided in an embodiment of the present invention is shown.

[0023] Figure 3 This diagram shows another block diagram of the camera module heating circuit provided in an embodiment of the present invention.

[0024] Figure 4 A block diagram of a temperature control unit in a camera module heating circuit provided in an embodiment of the present invention is shown.

[0025] Figure 5 This diagram shows another block diagram of the temperature control unit in the camera module heating circuit provided in an embodiment of the present invention. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0027] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0028] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0029] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0030] Please refer to Figure 1 This invention provides a camera module heating circuit 30, which includes a lens 300, an image sensor 400, a temperature control module 500, a copper plate base 600, and a flexible circuit board 700. The lens 300 and the image sensor 400 are fixed to one side of the copper plate base 600, and the temperature control module 500 and the flexible circuit board 700 are fixed to the other side of the copper plate base 600. The temperature control module 500 includes at least one temperature control unit 501, and at least one heating module 601 is integrated within the copper plate base 600. The temperature control unit 501 is used to monitor at least one heating module 601, and the heating module 601 conducts heat to the lens 300 and the image sensor 400 through the copper plate base 600.

[0031] The temperature control unit 501 is used to output the corresponding current voltage value according to the current temperature of the area where the monitored heating module 601 is located; when it is determined that the current voltage value is not higher than the first voltage reference value, it controls the heating module 601 to be powered on and heated; the copper plate base 600 is used to conduct the heat generated by the heating module 601 to the lens 300 and the image sensor 400; the temperature control unit 501 is also used to control the heating module 601 to be powered off and stop heating when it is determined that the current voltage value is higher than the first voltage reference value.

[0032] In this embodiment of the invention, the copper plate base 600 is the physical carrier of the camera module heating circuit 30. The lens 300, image sensor 400, temperature control module 500, and flexible circuit board 700 are all fixed on the copper plate base 600. The main body of the copper plate base 600 is a thermally conductive copper substrate. The base has positioning posts and threaded holes, serving as the sole supporting base for the camera module heating circuit 30, and simultaneously acting as a dual heat-conducting carrier for heat dissipation and heating.

[0033] The image sensor 400 is centrally mounted on the heating module 601 integrated within the copper plate base 600. The back of the image sensor 400 is fully attached to the main body of the copper plate base 600 (i.e., the copper plate), maximizing the heat conduction / heat receiving contact area. The temperature control module 500 consists of multiple temperature control units 501 attached to the other end of the copper plate base 600, which respectively collect the temperature of different areas of the copper plate and control the corresponding heating module 601 to heat or stop heating based on the temperature.

[0034] Both the lens 300 and the image sensor 400 are fixed to the front end of the copper plate base 600. The lens 300 is vertically mounted directly above the image sensor 400. The bottom of the lens 300 bracket is in thermal contact with the copper plate, and the heat from the copper plate is conducted to the lens 300, eliminating the low-temperature deformation of the lens in the lens 300.

[0035] One end of the flexible circuit board 700 is fixed on the copper plate base 600, and the other end extends to the side of the camera module and is electrically connected to the motherboard of the electronic device. This connects the image sensor 400, the temperature control module 500, and the copper plate base 600 to the motherboard of the electronic device, facilitating data transmission and power supply.

[0036] It should be understood that when the temperature inside the camera module heating circuit 30 is high, the copper plate of the copper plate base 600 carries away the heat of the lens 300 and the image sensor 400 to support the heat dissipation of the lens 300 and the image sensor 400 in high-temperature scenarios.

[0037] Given that the copper plate base 600 exhibits different heat conduction paths and uneven heat load distribution in different areas during actual operation, resulting in spatial temperature gradients on its surface, this embodiment of the invention integrates multiple heating modules 601 on the copper plate base 600 to improve temperature control accuracy. For example... Figure 2 As shown. Assume that the copper plate integrates... There are 601 heating modules, and N is greater than 1.

[0038] In one implementation, each heating module 601 can be configured with an independent temperature control unit 501, which can accurately monitor the temperature of the area where the corresponding heating module 601 is located.

[0039] In another embodiment, in adjacent areas with similar temperatures, multiple heating modules 601 are configured with the same temperature control unit 501. The temperature control unit 501 uniformly collects the temperature of representative measuring points and drives all the heating modules 601 under its jurisdiction to heat up synchronously or stop heating. It is assumed that one temperature control unit 501 is configured for multiple heating modules 601 in each row (e.g., heating modules 6011 to N), or one temperature control unit 501 is configured for multiple heating modules 601 in each column (heating module 6011, heating module 601N+1, heating module 6012N+1, heating module 6013N+1). The configuration can be adjusted according to the actual application scenario, and this invention is not limited thereto.

[0040] When the temperature inside the camera module heating circuit 30 is low, the temperature control module 500 monitors the current temperature of the corresponding area through each temperature control unit 501. When the current voltage value corresponding to the current temperature is not higher than the first voltage reference value, the monitoring unit controls the monitoring unit to power on the heat-generating module 601 to generate heat. The heat is transferred to the lens 300 and the image sensor 400 through the copper plate of the copper plate base 600. After heating for a period of time, when the temperature control unit 501 detects that the current voltage value corresponding to the current temperature is higher than the first voltage reference value, it cuts off the power to the monitored heat-generating module 601 to prevent the heat-generating module 601 from continuing to heat up. The first voltage reference value is the voltage value output by the temperature acquisition circuit based on a preset low temperature first threshold (empirical value is 5℃ to 10℃).

[0041] In summary, the camera module heating circuit provided in this embodiment of the invention fixes the lens and image sensor on one side of a copper plate base, and adds a temperature control module fixed on the other side. The copper plate base integrates a heating module, and the temperature control unit monitors the temperature of the area where the heating module is located in real time and converts it into a current voltage value. If the current voltage value is not higher than a first voltage reference value, the heating module is automatically powered on for heating. The heat is directly conducted to the lens and image sensor through the copper plate base, thereby ensuring the camera module operates normally in low-temperature environments. This overcomes the problem of abnormal image sensor response, increased noise, or failure caused by excessively low temperatures, improving the reliability and stability of the camera module.

[0042] If the current voltage value is higher than the first voltage reference value, the temperature control unit immediately controls the heating module to cut off power and stop heating, preventing local overheating of the camera module and reducing safety hazards such as component damage or even fire caused by continuous temperature rise, thus improving product safety. Simultaneously, the copper plate base can naturally dissipate the heat generated by the camera module at room temperature, serving both heat dissipation and heating functions. The entire temperature control process relies on an analog hardware loop formed by the temperature control unit and the heating module, without relying on the computing power of the main control chip and requiring no software support, avoiding low-temperature failure issues caused by software delays, main control sleep mode, or insufficient computing power of low-end chips.

[0043] Alternatively, in one implementation, please refer to Figure 3 The temperature control unit 501 includes a temperature acquisition circuit 502 and a control circuit 503, which are electrically connected. The control circuit 503 is also electrically connected to the power supply 800 and the heating module 601. The temperature regulation process is entirely completed autonomously by the temperature control unit 501. It does not require the main control chip to participate in the calculation, nor does it require the loading and execution of software programs. Even if the electronic device is in a sleep or power-off state, as long as the motherboard still provides basic power, the temperature control unit 501 can continue to work. The temperature acquisition circuit 502 is fixed in the copper plate base 600 to monitor the area where the heating module 601 is located, and can stably sense the temperature changes in the area where the monitored heating module 601 is located.

[0044] The temperature acquisition circuit 502 is used to output the corresponding current voltage value based on the current temperature of the area where the monitored heating module 601 is located. The control circuit 503 is used to connect the power supply to the heating module 601 when it is determined that the current voltage value is not higher than the first voltage reference value, so that the heating module 601 is powered on and heating; and to disconnect the power supply from the heating module 601 when it is determined that the current voltage value is higher than the first voltage reference value, so that the heating module 601 is powered off and stops heating.

[0045] In this embodiment of the invention, the control circuit 503 compares the current voltage value with a first voltage reference value. When it determines that the current voltage value is not higher than the first voltage reference value, it indicates that the temperature of the monitored area has dropped below the set first low-temperature threshold. The control circuit 503 then connects the power supply and the heating module 601, allowing current to flow through the heating module 601 to generate Joule heat. The power supply can be a standard 3.3-volt supply, introduced through the flexible circuit board 700.

[0046] When the current voltage value is determined to be higher than the first voltage reference value, it indicates that the temperature of the monitored area has exceeded the set low temperature first threshold. The lens 300 and the image sensor 400 will not be damaged by low temperature. The control circuit 503 will cut off the power supply path between the power supply and the heating module 601 and stop the heating module 601 from continuing to heat.

[0047] Alternatively, in one implementation, please refer to Figure 4 The temperature acquisition circuit 502 includes a voltage divider circuit 504 and a low-pass filter circuit 505, which are electrically connected. The voltage divider circuit 504 outputs the corresponding current raw voltage value based on the current temperature of the area where the monitored heating module 601 is located; the low-pass filter circuit 505 filters the current raw voltage value corresponding to the current temperature to obtain the current voltage value corresponding to the current temperature.

[0048] In this embodiment of the invention, the temperature acquisition circuit 502 converts the physical temperature into a stable voltage value through a voltage divider circuit 504 and a low-pass filter circuit 505. The voltage divider circuit 504 directly responds to the local temperature change in the area where the heating module 601 is located, which is monitored in the copper plate base 600, and outputs a current original voltage value that decreases as the temperature decreases. Although the current original voltage value can reflect the temperature trend, it contains noise components caused by power fluctuations and transient interference.

[0049] The voltage divider circuit 504 transmits the current original voltage value to the low-pass filter circuit 505. The low-pass filter circuit 505 smooths the current original voltage value, filters out high-frequency interference, and retains the main characteristics of temperature change, thereby outputting a more stable and reproducible current voltage value.

[0050] As can be seen, the temperature acquisition circuit 502 of this embodiment can provide the control circuit 503 with a temperature characterization signal that is highly resistant to interference, timely in response, and highly repeatable without the need for main control intervention.

[0051] Alternatively, in one implementation, please refer to Figure 4 The control circuit 503 includes a comparator circuit 506 and a switching device 507. One end of the comparator circuit 506 is electrically connected to the low-pass filter circuit 505, and the other end of the comparator circuit 506 is electrically connected to the control terminal of the switching device 507. The first terminal of the switching device 507 is electrically connected to the power supply, and the second terminal of the switching device 507 is electrically connected to the heating module 601. The comparator circuit 506 is used to output a first control signal to turn on the switching device 507 when it determines that the current voltage value is not higher than the first voltage reference value; and to output a second control signal to turn off the switching device 507 when it determines that the current voltage value is higher than the first voltage reference value.

[0052] In this embodiment of the invention, the comparator circuit 506 continuously monitors the current voltage value and compares the current voltage value with a first voltage reference value. When it is determined that the current voltage value is not higher than the first voltage reference value, the comparator circuit 506 outputs a first control signal to drive the switching device 507 to connect the power supply and the heating module 601, thereby forming a path between the power supply and the heating module 601, and the heating module 601 begins to work.

[0053] When the current voltage value is determined to be higher than the first voltage reference value, the comparator circuit 506 outputs a second control signal to drive the switching device 507 to disconnect the power supply from the heating module 601, thereby cutting off the power supply path between the power supply and the heating module 601, and the heating module 601 stops heating.

[0054] Alternatively, in one implementation, please refer to Figure 5The voltage divider circuit 504 includes a voltage divider resistor 508 and a thermistor 509. One end of the voltage divider resistor 508 is electrically connected to the power supply, and the other end of the voltage divider resistor 508 is electrically connected to one end of the thermistor 509. The other end of the thermistor 509 is grounded. One end of the low-pass filter circuit 505 is electrically connected between the voltage divider resistor 508 and the thermistor 509. The thermistor 509 is disposed on the heating module 601 monitored by the temperature control unit 501.

[0055] In this embodiment of the invention, the voltage divider circuit 504 consists of a fixed-value voltage divider resistor 508 and a temperature-sensitive thermistor 509 (e.g., a negative temperature coefficient thermistor, or NTC thermistor) connected in series. A power supply is connected to one end of the voltage divider resistor 508, the other end of the voltage divider resistor 508 is connected to one end of the thermistor 509, and the other end of the thermistor 509 is grounded.

[0056] It should be noted that the second voltage reference value is the output voltage value of the temperature acquisition circuit 502 based on a preset second low-temperature threshold (empirical value is 1℃ or 0℃), which is less than the first low-temperature threshold. In order for the comparator circuit 506 to make accurate judgments in the low-temperature range (e.g., 0℃~5℃) between the second and first low-temperature thresholds, the voltage divider resistor 508 selected in the voltage divider circuit 504 cannot be arbitrarily chosen. Instead, it is determined based on the actual temperature and resistance curve of the thermistor 509. This ensures that the output voltage value at the connection point of the two resistors changes as linearly as possible with the temperature, thereby clearly and stably converting the temperature change into a voltage signal that can be reliably identified by the comparator circuit 506, and avoiding the heating module 601 from heating or stopping due to voltage jumps.

[0057] In this way, a voltage value that changes with the resistance of the thermistor 509 will be output at the two resistor connection points. A 1% high-precision NTC thermistor is selected as the core component for temperature sampling and is attached to the heating module 601 monitored by the temperature control unit 501 (i.e., the surface of the heating module 601 corresponding to the heating module 601 on the copper plate). When one temperature control unit 501 monitors one heating module 601, the NTC thermistor is attached to the corresponding heating module 601. When one temperature control unit 501 monitors multiple heating modules 601, the NTC thermistor is attached to one of the heating modules 601, and the temperature of the attached heating module 601 is sampled to control all the heating modules 601 monitored by the temperature control unit 501.

[0058] At low temperatures, the resistance of the NTC thermistor increases sharply, and the voltage drop at the connection point of the two resistors decreases synchronously, converting the temperature of the copper plate partition into an analog voltage signal with a sampling accuracy of ±0.3℃, which meets the low-cost precision temperature measurement requirements of consumer-grade cameras.

[0059] The voltage drop across the two resistor connections represents the current original voltage value, reflecting the real-time temperature of the heating module 601. However, in real-world environments, this original voltage value is susceptible to high-frequency noise, so a low-pass filter circuit 505 is designed. The low-pass filter circuit 505 includes a filter resistor 510 and a filter capacitor 511. One end of the filter resistor is connected between the voltage divider resistor 508 and the thermistor 509, and the other end is electrically connected to one end of the comparator circuit 506. One end of the filter capacitor is connected between the filter resistor and the comparator circuit 506, and the other end is grounded.

[0060] It should be understood that the low-pass filter circuit 505 filters out power supply ripples, instantaneous voltage spikes during copper plate heating, and high-frequency interference from the sensor, outputting a smooth and stable current voltage value. This prevents temperature fluctuations from erroneously triggering the heating module 601 to heat up or stop heating, thereby avoiding the risk of heating lag or overheating caused by misjudgment.

[0061] Alternatively, in one implementation, reference continues to... Figure 5 The comparator circuit 506 includes a first comparator 512, a second comparator 513, an inverter 514, and an OR gate 515. The first input terminal of the first comparator 512 and the first input terminal of the second comparator 513 are both electrically connected to the low-pass filter circuit 505. The second input terminal of the first comparator 512 is used to receive a second voltage reference value, and the second input terminal of the second comparator 513 is used to receive a first voltage reference value. The second voltage reference value is lower than the first voltage reference value. The output terminal of the first comparator 512 is electrically connected to the first input terminal of the OR gate 515, the output terminal of the second comparator 513 is electrically connected to the input terminal of the inverter 514, the output terminal of the inverter 514 is electrically connected to the second input terminal of the OR gate 515, and the output terminal of the OR gate 515 is electrically connected to the control terminal of the switching device 507.

[0062] The first comparator 512 outputs a first high level when it determines that the current voltage value is lower than the second voltage reference value, and outputs a first low level when it determines that the current voltage value is not lower than the second voltage reference value; the second comparator 513 outputs a second low level when it determines that the current voltage is not higher than the first voltage reference value, and outputs a second high level when it determines that the current voltage is higher than the first voltage reference value; the inverter 514 outputs the inverted signal corresponding to the second low level or the second high level; the OR gate 515 outputs a first control signal or a second control signal according to the output level of the first comparator 512 and the inverted signal output by the inverter 514.

[0063] In this embodiment of the invention, the first comparator 512 receives the current voltage value through its first input terminal and the second voltage reference value VREF2 through its second input terminal, and compares the current voltage value with the second voltage reference value VREF2. When the current voltage value is lower than the second voltage reference value VREF2, the first comparator 512 sends a first high level to the first input terminal of the OR gate 515 through its output terminal. When the current voltage value is not lower than the second voltage reference value VREF2, the first comparator 512 sends a first low level to the first input terminal of the OR gate 515 through its output terminal.

[0064] The second comparator 513 receives the current voltage value through its first input terminal and the second voltage reference value VREF1 through its second input terminal, and compares the current voltage value with the first voltage reference value VREF1. When the current voltage value is lower than the first voltage reference value VREF1, the second comparator 513 sends a second low level to the input terminal of the inverter 514 through its output terminal. The inverter 514 flips the second low level and sends the inverted signal of the second low level to the second input terminal of the OR gate 515. When the current voltage value is not lower than the first voltage reference value VREF1, the second comparator 513 sends a second high level to the input terminal of the inverter 514 through its output terminal. The inverter 514 flips the second high level and sends the inverted signal of the second high level to the second input terminal of the OR gate 515.

[0065] In other words, if the inverter 514 receives a high level, then the output inverted signal will be low. If the inverter 514 receives a low level, then the output inverted signal will be high. The OR gate 515 performs an OR operation on the output level of the first comparator 512 and the inverted signal output by the inverter 514, and transmits the output first control signal or second control signal to the control terminal of the switching device 507.

[0066] In one embodiment, the switching device 507 can be a MOSFET power switch, the gate of which is electrically connected to an OR gate 515 to receive a first control signal or a second control signal output by the OR gate 515. The first control signal powers on the heating module 601 to heat up, and the second control signal powers off the heating module 601 to stop heating.

[0067] Optionally, in one embodiment, the OR gate 515 is configured to output a first control signal when the output level of the first comparator 512 is a first high level and the inverted signal output by the inverter 514 is an inverted signal corresponding to a second low level; output a first control signal when the output level of the first comparator 512 is a first low level and the inverted signal output by the inverter 514 is an inverted signal corresponding to a second low level; and output a second control signal when the output level of the first comparator 512 is a first low level and the inverted signal output by the inverter 514 is an inverted signal corresponding to a second high level.

[0068] In this embodiment of the invention, when the current temperature is below the second low-temperature threshold (i.e., the severe low-temperature zone), the current voltage value is below the second voltage reference value, and the output level of the first comparator 512 is a first high level. Since the current voltage value is below the first voltage reference value, the output level of the second comparator 513 is a second low level, and the inverted signal output by the inverter 514 is the inverted signal (i.e., a high level) corresponding to the second low level. After receiving two high levels, the OR gate 515 outputs a first control signal to turn on the switching device 507, allowing the heating module 601 to heat up.

[0069] It should be understood that the image sensor 400 noise and lens 300 deformation problems are most severe in extremely cold environments below 0℃. In extremely cold environments, the temperature of almost all areas where the heat-generating modules 601 are located will be lower than the second low temperature threshold. Almost all heat-generating modules 601 are heated by electricity, and the continuous high-power heating quickly raises the temperature of the camera module, thereby quickly repairing the image quality degradation problem.

[0070] When the current temperature is not lower than the second low-temperature threshold and not higher than the first low-temperature threshold (mild low-temperature zone), and the current voltage value is not lower than the second voltage reference value, the output level of the first comparator 512 is the first low level. When the current voltage value is not higher than the first voltage reference value, the output level of the second comparator 513 is the second low level, and the inverted signal output by the inverter 514 is the inverted signal (i.e., high level) corresponding to the second low level. After receiving a high level, the OR gate 515 outputs the first control signal to turn on the switching device 507, and the heating module 601 heats up.

[0071] Since the temperature inside the camera module has changed from a severely low temperature zone to a slightly low temperature zone, the temperature in the area where some heat-generating modules 601 are located is above the first low-temperature threshold, and no further heating is needed. Only the heat-generating modules 601 whose temperature is below the first low-temperature threshold are continuously heated.

[0072] When the current temperature is higher than the first low-temperature threshold (normal temperature range), the current voltage value is higher than the second voltage reference value, and the output level of the first comparator 512 is a first low level. Since the current voltage value is higher than the first voltage reference value, the output level of the second comparator 513 is a second high level, and the inverted signal output by the inverter 514 is the inverted signal (i.e., low level) corresponding to the second high level. Upon receiving a low level, the OR gate 515 outputs a second control signal to disconnect the switching device 507, and the heating module 601 stops heating.

[0073] Once the camera module's temperature has completely moved out of the low-temperature zone, the heating circuit is cut off to eliminate the safety hazard of overheating and fire. The copper plate base 600 is switched to a heat dissipation substrate, reducing the overall standby power consumption of the device.

[0074] Optionally, in one embodiment, the heating module 601 is a simulated heating resistor or a power resistor; the simulated heating resistor is a power resistor simulated by etching heating traces in sections of the copper base 600 and using the impedance on the heating traces.

[0075] In this embodiment of the invention, if the heating module 601 is a power resistor, multiple power resistors need to be integrated internally during the production of the copper plate, serving as the heating module 601. If the heating module 601 is a simulated heating resistor, heating traces are etched in sections on the copper plate, using the impedance on the traces to simulate the power resistor. Each segment of the heating trace on the copper plate corresponds to a simulated heating resistor. Connecting multiple heating modules 601 in parallel can improve heating capacity, and the heating modules 601 can be deployed according to the actual application scenario.

[0076] This invention provides a camera module 20, which includes a camera module heating circuit 30.

[0077] This invention provides an electronic device 10, which includes a camera module 20. The electronic device 10 can be a mobile phone with a camera, a tablet computer with a camera, a laptop computer with a camera, etc.

[0078] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A heating circuit for a camera module, characterized in that, The device includes a lens, an image sensor, a temperature control module, and a copper plate base. The lens and the image sensor are fixed to one side of the copper plate base, and the temperature control module is fixed to the other side of the copper plate base. The temperature control module includes at least one temperature control unit. At least one heating module is integrated inside the copper plate base. The temperature control unit is used to monitor at least one heating module. The heating module conducts heat to the lens and the image sensor through the copper plate base. The temperature control unit is used to output a corresponding current voltage value based on the current temperature of the area where the monitored heating module is located; when it is determined that the current voltage value is not higher than the first voltage reference value, it controls the heating module to be powered on for heating. The copper plate base is used to conduct the heat generated by the heating module to the lens and the image sensor; The temperature control unit is also used to control the heating module to cut off power and stop heating when it is determined that the current voltage value is higher than the first voltage reference value.

2. The camera module heating circuit according to claim 1, characterized in that, The temperature control unit includes a temperature acquisition circuit and a control circuit, the temperature acquisition circuit and the control circuit are electrically connected, and the control circuit is also electrically connected to the power supply and the heating module; The temperature acquisition circuit is used to output the corresponding current voltage value based on the current temperature of the area where the monitored heating module is located. The control circuit is used to control the power supply to connect to the heating module when it is determined that the current voltage value is not higher than the first voltage reference value, so that the heating module is powered on and heated; and to control the power supply to disconnect from the heating module when it is determined that the current voltage value is higher than the first voltage reference value, so that the heating module is powered off and stops heating.

3. The camera module heating circuit according to claim 2, characterized in that, The temperature acquisition circuit includes a voltage divider circuit and a low-pass filter circuit, and the voltage divider circuit is electrically connected to the low-pass filter circuit. The voltage divider circuit is used to output the corresponding current original voltage value according to the current temperature of the area where the monitored heating module is located; The low-pass filter circuit is used to filter the current original voltage value corresponding to the current temperature to obtain the current voltage value corresponding to the current temperature.

4. The camera module heating circuit according to claim 3, characterized in that, The voltage divider circuit includes a voltage divider resistor and a thermistor. One end of the voltage divider resistor is electrically connected to the power supply, and the other end of the voltage divider resistor is electrically connected to one end of the thermistor. The other end of the thermistor is grounded. One end of the low-pass filter circuit is electrically connected between the voltage divider resistor and the thermistor. The thermistor is located on the heating module monitored by the temperature control unit.

5. The camera module heating circuit according to claim 3, characterized in that, The control circuit includes a comparator circuit and a switching device. One end of the comparator circuit is electrically connected to the low-pass filter circuit, and the other end of the comparator circuit is electrically connected to the control terminal of the switching device. The first end of the switching device is electrically connected to the power supply, and the second end of the switching device is electrically connected to the heating module. The comparison circuit is configured to output a first control signal to turn on the switching device when it determines that the current voltage value is not higher than the first voltage reference value; and to output a second control signal to turn off the switching device when it determines that the current voltage value is higher than the first voltage reference value.

6. The camera module heating circuit according to claim 5, characterized in that, The comparison circuit includes a first comparator, a second comparator, an inverter, and an OR gate. The first input terminals of both the first and second comparators are electrically connected to the low-pass filter circuit. The second input terminal of the first comparator receives a second voltage reference value, and the second input terminal of the second comparator receives a first voltage reference value. The second voltage reference value is lower than the first voltage reference value. The output terminal of the first comparator is electrically connected to the first input terminal of the OR gate, the output terminal of the second comparator is electrically connected to the input terminal of the inverter, the output terminal of the inverter is electrically connected to the second input terminal of the OR gate, and the output terminal of the OR gate is electrically connected to the control terminal of the switching device. The first comparator is configured to output a first high level when it determines that the current voltage value is lower than the second voltage reference value, and to output a first low level when it determines that the current voltage value is not lower than the second voltage reference value. The second comparator is used to output a second low level when it determines that the current voltage is not higher than the first voltage reference value; When it is determined that the current voltage is higher than the first voltage reference value, a second high level is output; The inverter is used to output the inverted signal corresponding to the second low level or the second high level; The OR gate is used to output either the first control signal or the second control signal based on the output level of the first comparator and the inverted signal output by the inverter.

7. The camera module heating circuit according to claim 6, characterized in that, The OR gate is used to output the first control signal when the output level of the first comparator is the first high level and the inverted signal output by the inverter is the inverted signal corresponding to the second low level; When the output level of the first comparator is the first low level and the inverted signal output by the inverter is the inverted signal corresponding to the second low level, the first control signal is output. When the output level of the first comparator is the first low level and the inverted signal output by the inverter is the inverted signal corresponding to the second high level, the second control signal is output.

8. The camera module heating circuit according to any one of claims 1-5, characterized in that, The heating module is a simulated heating resistor or a power resistor; the simulated heating resistor is formed by etching heating traces in sections on the copper plate base, and the impedance of the heating traces is used to simulate the power resistor.

9. A camera module, characterized in that, Includes the camera module heating circuit as described in any one of claims 1-8.

10. An electronic device, characterized in that, Includes the camera module as described in claim 9.

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