An indium gallium arsenide infrared temperature measurement detector

Abstract

The utility model discloses an indium gallium arsenide infrared temperature measurement detector relates to infrared temperature measurement technical field, specifically includes: lead, pin, base, this indium gallium arsenide infrared temperature measurement detector still includes: indium gallium arsenide photodiode, indium gallium arsenide photodiode is used for converting infrared signal into current signal, signal processing unit, signal processing unit is used for converting the current signal of output into voltage signal, the casing, the casing is used for protecting indium gallium arsenide photodiode with signal processing unit. Signal processing unit and indium gallium arsenide photodiode are encapsulated in same sealed casing, significantly reduce the volume, shorten the internal lead length, reduce signal transmission loss and external interference, simultaneously need not external operational amplifier circuit, simplify system integration complexity, avoid the problem that peripheral circuit structure is numerous, lead to temperature measurement module volume is bigger, the problem that connecting line is longer, further avoid the problem that signal is interfered.

Description

Technical Field

[0001] This utility model relates to the field of infrared temperature measurement technology, specifically to an indium gallium arsenide infrared temperature detector. Background Technology

[0002] In modern kitchen appliances, especially induction cooking equipment, precise temperature control is crucial for cooking results. Traditional temperature measurement methods, such as thermocouples or thermistors, can provide temperature data, but they are usually slow to respond, have limited accuracy, and are easily affected by environmental factors. In contrast, indium gallium arsenide infrared temperature detectors can achieve non-contact temperature measurement without the obstruction of glass, can detect infrared light in sensitive wavelengths, and are resistant to external interference such as water, water vapor, and cooking fumes.

[0003] The patent (publication number: CN218180123U) discloses an infrared detector, including: a housing, an indium gallium arsenide photodetector unit and a filler, with an opening at the top of the housing; the indium gallium arsenide photodetector unit is disposed inside the housing, and the pins of the indium gallium arsenide photodetector unit are exposed from the bottom of the housing and electrically connected to an external circuit board.

[0004] Patent (Publication No.: CN221102102U) discloses an indium gallium arsenide infrared detector and temperature measurement module, including: an indium gallium arsenide photosensitive unit, a light-transmitting housing, and pins. The indium gallium arsenide photosensitive unit is used to receive infrared rays emitted by a target object and convert them into electrical signals. The housing covers the outer periphery of the indium gallium arsenide photosensitive unit, and at least part of its surface is curved to focus the infrared rays irradiated on the upper surface onto the photosensitive surface of the indium gallium arsenide photosensitive unit. The pins are electrically connected to the indium gallium arsenide photosensitive unit and are exposed from the housing.

[0005] All of the above solutions require the addition of operational amplifiers and external circuitry for current-to-voltage conversion, signal amplification, and other processing to convert the signal into a recognizable signal for the system. This approach results in a complex external circuit structure, a relatively large overall temperature measurement module, and relatively long connecting lines between the external circuits. In some applications, such as induction heating, this can easily lead to signal interference and inaccurate temperature measurements.

[0006] In summary, an indium gallium arsenide infrared thermometer needs to be developed to solve the above problems. Utility Model Content

[0007] To address the shortcomings of existing technologies, the technical solution adopted by this utility model is: an indium gallium arsenide infrared thermometer, specifically comprising:

[0008] The indium gallium arsenide infrared thermometer also includes leads, pins, and a base.

[0009] An indium gallium arsenide (IGaAs) photodiode is used to convert infrared signals into current signals; wherein, the IGaAs photodiode is used to receive infrared radiation emitted by a target object and convert it into a current signal.

[0010] A signal processing unit is provided for converting a current signal into a recognizable voltage signal; wherein the current signal is output from an indium gallium arsenide infrared thermometer.

[0011] A housing for protecting the indium gallium arsenide photodiode and the signal processing unit.

[0012] The leads are typically made of gold wire, but silver, copper, aluminum, and other materials can also be used. Because these materials have extremely low resistivity, they can minimize transmission loss and ensure that the weak current signal generated by the indium gallium arsenide photodiode maintains high fidelity when transmitted to the signal processing unit. This is crucial for maintaining signal integrity and final temperature measurement accuracy. The leads are used to realize the electrical connection between the indium gallium arsenide photodiode and the signal processing unit, and are also used to connect the positive and negative terminals of the power supply and signal lines. They support standard communication protocols such as UART communication and I²C.

[0013] Furthermore, the pins are exposed on the outer surface of the housing or base and are electrically connected to an external circuit board. The pins serve as the electrical interface between the detector's internal circuitry and the external environment, connecting to the application circuit board (such as a PCB) via soldering or other methods. They are responsible for transmitting power, processed signals, and any control signals that may be required.

[0014] Furthermore, the infrared sensitive band of the indium gallium arsenide photodiode is <2.7µm. This band selection enables the detector to effectively sense the peak infrared radiation emitted by an object near room temperature. Simultaneously, this band falls within the transmission range of common silicon-based optical windows such as glass, thus allowing for effective detection even in situations with glass obstructions.

[0015] Furthermore, the signal processing unit is electrically connected to the pins via leads.

[0016] Furthermore, the housing covers the outer surfaces of the indium gallium arsenide photodiode, the signal processing unit, and the leads.

[0017] Furthermore, the housing and the base form a closed-loop sealed space.

[0018] Furthermore, the housing is made of a light-filtering material. Commonly used materials include epoxy resins or engineering plastics with specific formulations. The housing not only provides physical protection and environmental sealing, but its material itself also acts as an optical filter, effectively filtering out visible light and infrared radiation from non-target wavelengths. This ensures that only infrared radiation from the target wavelength reaches the indium gallium arsenide photodiode, reducing background noise interference and improving the signal-to-noise ratio and temperature measurement accuracy.

[0019] Furthermore, the upper surface of the housing is curved. The advantage of the curved design is that it can optimize the focusing of the infrared light path, improve the light signal collection efficiency and detector sensitivity.

[0020] Furthermore, the signal processing unit includes:

[0021] The system comprises an operational amplifier, an MCU unit, and a temperature sensing device. The operational amplifier is electrically connected to the MCU unit and the temperature sensing device via wires. The operational amplifier receives the weak current signal output from the indium gallium arsenide photodiode, amplifies it with low noise and high gain, and typically performs current-to-voltage conversion, outputting an easily processed analog voltage signal. The MCU unit performs digital processing on the signal, including filtering, compensation, and linearization, improving signal quality and temperature measurement accuracy. It has the ability to communicate with microcontrollers or digital systems via interfaces such as UART and I²C. The MCU unit internally includes a comparator circuit and a memory for storing alarm thresholds, which can be fixedly programmed or dynamically configured by external devices via interfaces such as UART and I²C. The temperature sensing device monitors the ambient temperature of key components inside the detector (such as those near the photodiode or signal processing chip) in real time and accurately. This ambient temperature data is an indispensable key parameter for the signal processing unit to perform temperature drift compensation and output the final accurate target temperature value. The signal processing unit uses this data to perform real-time compensation and correction of the photodiode signal.

[0022] Furthermore, the upper surface of the housing is planar. The advantages of a planar design are simple structure, low manufacturing cost, and ease of installation and integration. These two design forms meet the diverse needs of different application scenarios regarding performance, cost, and ease of integration.

[0023] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0024] 1. The signal processing unit and the indium gallium arsenide photodiode are packaged in the same sealed housing, which significantly reduces the size, shortens the internal lead length, reduces signal transmission loss and external interference, and eliminates the need for external operational amplifier circuits, simplifying system integration complexity and avoiding the problems of large temperature measurement module size and long connection lines caused by numerous peripheral circuit structures, further avoiding signal interference problems.

[0025] 2. The MCU unit has a built-in comparator and memory, and sets alarm thresholds. It outputs an alarm signal through a pin, which is received by the external main control system and triggers the alarm device. This design can effectively remind the user that the cooking equipment or the surface of the pot is too hot, preventing the user from leaving the induction cooker during cooking and causing the induction cooker to continue heating, thus further avoiding safety accidents.

[0026] 3. This device offers dual-shell configurations to adapt to different scenarios, namely curved and planar shell designs. The curved shell optimizes the optical path focusing for electromagnetic shielding and is suitable for high-precision, high-interference environments; while the planar shell has a simple structure and low cost, making it suitable for applications that are sensitive to size and cost.

[0027] 4. This device has a built-in MCU unit that integrates real-time temperature compensation algorithms and programmable threshold alarm functions. It directly outputs calibrated temperature data through a digital interface, improving temperature measurement accuracy and system response speed, and avoiding the delay problem of traditional external processing circuits.

[0028] 5. The closed-loop sealing structure of the housing, combined with the lead wires, can effectively resist the corrosion of oil fumes, water vapor and dust, ensuring the long-term stability of the detector under harsh conditions such as humidity and high temperature, and extending its service life. Attached Figure Description

[0029] Figure 1 This is the front view of this utility model;

[0030] Figure 2 This is a cross-sectional plan view of the curved shell of this utility model;

[0031] Figure 3 This is a schematic diagram of the signal processing unit of this utility model;

[0032] Figure 4 This is a cross-sectional plan view of the planar shell of this utility model;

[0033] Figure 5 This is a sectional perspective view of the planar shell of this utility model.

[0034] In the diagram: 41, lead wire; 42, pin; 43, base; 44, indium gallium arsenide photodiode; 45, signal processing unit; 451, operational amplifier; 452, MCU unit; 453, temperature measuring device; 46, housing. Detailed Implementation

[0035] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the present invention to the disclosed forms. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described to better illustrate the principles and practical applications of the present invention, and to enable those skilled in the art to understand the present invention and design various embodiments with various modifications suitable for a particular purpose. Example 1

[0036] Please see Figure 1 - Figure 3This utility model provides a technical solution: an indium gallium arsenide infrared thermometer, specifically comprising:

[0037] The indium gallium arsenide infrared thermometer also includes lead wire 41, pin 42, and base 43.

[0038] An indium gallium arsenide photodiode 44 is used to convert infrared signals into current signals; wherein, the indium gallium arsenide photodiode 44 is used to receive infrared light emitted by a target object and convert it into a current signal.

[0039] The signal processing unit 45 is used to convert the current signal into a recognizable voltage signal; wherein the current signal is output from the indium gallium arsenide infrared thermometer.

[0040] The housing 46 protects the indium gallium arsenide photodiode 44 and the signal processing unit 45. The lead wire 41 is typically made of gold wire, but silver, copper, aluminum, etc., can also be used. Due to the extremely low resistivity of the material, transmission loss is minimized, ensuring that the weak current signal generated by the indium gallium arsenide photodiode 44 maintains high fidelity when transmitted to the signal processing unit 45. This is crucial for maintaining signal integrity and final temperature measurement accuracy. The lead wire 41 is used to achieve electrical connection between the indium gallium arsenide photodiode 44 and the signal processing unit 45, and also to connect the positive and negative terminals of the power supply and signal lines, supporting standard communication protocols such as UART and I²C. Furthermore, the conductivity of gold is not significantly affected by environmental factors such as temperature and humidity, ensuring the reliability of the sensor in complex environments. Its good flexibility, mechanical strength, and corrosion resistance allow it to maintain good wire performance for a long time in humid and oily environments such as kitchens.

[0041] Furthermore, pin 42 is exposed on the outer surface of housing 46 or base 43 and is electrically connected to an external circuit board. Pin 42 is the electrical interface between the internal circuitry of the detector and the external circuitry, and is connected to the application circuit board (such as a PCB) by means of soldering or other methods. It is responsible for transmitting power, processed signals, and possible control signals.

[0042] The infrared sensitive band of the indium gallium arsenide photodiode 44 is <2.7µm. This band selection allows the detector to effectively sense the peak infrared radiation emitted by objects near room temperature. Furthermore, this band falls within the transmission range of common silicon-based optical windows such as glass, enabling effective detection even in environments with glass obstructions. Compared to the infrared sensitive band of thermopile detectors, it has stronger penetrating power and is resistant to external interference such as water, moisture, and oil fumes. The indium gallium arsenide photodiode 44, as a detector chip, is a semiconductor photosensitive device mounted on the inner surface of the base 43.

[0043] The signal processing unit 45 is electrically connected to the pin 42 via the lead 41.

[0044] The housing 46 covers the outer surface of the indium gallium arsenide photodiode 44, the signal processing unit 45, and the lead wire 41.

[0045] The housing 46 and the base 43 form a closed-loop sealed space. The closed-loop sealing structure can effectively isolate external contaminants such as dust and moisture (such as humidity and condensation) from intrusion, prevent corrosion or short circuit of the indium gallium arsenide photodiode 44 and the signal processing unit 45, and significantly improve the long-term reliability of the detector in harsh environments such as humid and dusty conditions.

[0046] The housing 46 is made of a light-filtering material. Commonly used materials include specially formulated epoxy resins or engineering plastics. The housing 46 not only provides physical protection and environmental sealing, but its material itself acts as an optical filter, effectively filtering out visible light and non-target infrared radiation, ensuring that only infrared radiation of the target wavelength reaches the indium gallium arsenide photodiode 44, reducing background noise interference, and improving the signal-to-noise ratio and temperature measurement accuracy. The pigment-doped epoxy resin material can filter out light in the wavelength range below 940nm.

[0047] The upper surface of housing 46 is curved. The advantage of the curved design is that it can optimize the focusing of the infrared light path, improve the light signal collection efficiency and detector sensitivity.

[0048] Signal processing unit 45 includes:

[0049] The system includes an operational amplifier 451, an MCU unit 452, and a temperature measuring device 453. The operational amplifier 451 is electrically connected to the MCU unit 452 and the temperature measuring device 453 via wires. The operational amplifier 451 receives the weak current signal output from the indium gallium arsenide photodiode 44, amplifies it with low noise and high gain, and typically performs current-to-voltage conversion to output an easily processed analog voltage signal. The MCU unit 452 can perform digital processing such as filtering, compensation, and linearization on the signal to improve signal quality and temperature measurement accuracy. It has the ability to communicate with microcontrollers or digital systems through interfaces such as UART and I²C. The MCU unit 452 has a comparator circuit and a memory for storing alarm thresholds. These thresholds can be fixedly programmed or dynamically configured by external devices through interfaces such as UART and I²C. The temperature measuring device 453 monitors the ambient temperature of key parts inside the detector (such as near the photodiode or signal processing chip) in real time and accurately. This ambient temperature data is an indispensable key parameter for the signal processing unit 45 to perform temperature drift compensation and output the final accurate target temperature value. The signal processing unit 45 uses this data to perform real-time compensation and correction of the photodiode signal.

[0050] The working principle is as follows:

[0051] First, the indium gallium arsenide infrared temperature detector is installed inside a cooking appliance such as an induction cooker, while the indium gallium arsenide photodiode 44 is located inside the sensor, facing the cooking area. During the cooking process, the target object, such as a pot or food, emits infrared rays, which are transmitted to the sensor location through the glass panel of the induction cooker or other media.

[0052] The indium gallium arsenide (IGaAs) photodiode 44 serves as the core photosensitive element, with a sensitive wavelength range of <2.7μm, enabling it to effectively detect infrared radiation within this range. When infrared light passes through the filter housing 46 and illuminates the IGaAs photodiode 44, the IGaAs photodiode 44 converts the received infrared light into a corresponding electrical signal. Due to the strong penetrating power of its sensitive infrared wavelength range, high signal quality can be maintained even in environments with glass obstructions or interference factors such as moisture or oil fumes.

[0053] Subsequently, the weak current signal generated by the photodiode is transmitted to the signal processing unit 45 through lead 41. Lead 41, with its extremely low resistivity and excellent corrosion resistance, ensures minimal signal loss during transmission, avoiding signal attenuation due to wire resistance or environmental corrosion (such as oil fumes). The operational amplifier 451 (low-noise design) in the signal processing unit 45 first amplifies the current signal with high gain and completes the current-to-voltage conversion, outputting an analog voltage signal for subsequent processing.

[0054] Next, the amplified analog signal enters the MCU unit 452 for digitization and algorithm processing:

[0055] The MCU's built-in ADC converts analog voltage signals into digital signals, facilitating digital processing.

[0056] Digital signal processing:

[0057] Filtering: Eliminates signal fluctuations caused by circuit noise and environmental interference (such as electromagnetic interference).

[0058] Linearization calibration: The response of the indium gallium arsenide photodiode 44 is not completely linear and needs to be corrected by algorithm to ensure that the output temperature corresponds to the input radiation in a standard manner.

[0059] Temperature compensation: The internal temperature sensing device 453 (such as a thermistor) of the detector monitors the ambient temperature in real time. The MCU corrects the temperature drift error of the photodiode based on this data to ensure that the reading is not affected by its own heat generation or changes in the external temperature.

[0060] Threshold alarm: The MCU internally stores programmable alarm thresholds (such as high temperature warning values), and the MCU unit 452 has a comparator circuit and a memory for storing alarm thresholds, which can compare the measured temperature value with the preset alarm threshold. When the temperature is high, an alarm is issued.

[0061] Finally, the processed temperature data is output to an external system via pin 42:

[0062] The processed temperature data can be transmitted to an external main control system or other display devices through the output interface of the signal processing unit 45 to realize real-time monitoring and display of temperature information. When the measured temperature exceeds the preset alarm threshold, the MCU unit 452 triggers an alarm action and outputs an alarm signal to the external main control system through pin 42. After receiving the alarm signal, the external main control system drives the corresponding alarm devices, such as buzzers and indicator lights, to emit audible and visual alarms, reminding the user to take appropriate measures. The external main control system is the main control board inside the induction cooker, which is responsible for managing and controlling various functions of the induction cooker. It can receive alarm signals from pin 42 of the indium gallium arsenide infrared temperature detector. Based on the received alarm signal, it controls the alarm devices inside the induction cooker to emit audible and visual alarms. When the temperature is high, it can effectively remind the user that the temperature is too high, preventing the user from leaving the area around the induction cooker during cooking and causing the induction cooker to continue heating, which could lead to safety accidents.

[0063] Throughout its operation, the detector's structural design ensures its stability and environmental adaptability:

[0064] Closed-loop sealed housing 46: Prevents dust and moisture from entering, avoids moisture and corrosion of photodiodes and circuits, and reduces the impact of internal airflow disturbance on temperature measurement.

[0065] Curved filter housing 46: Optimizes infrared light collection efficiency, enhances electromagnetic shielding, and reduces external interference.

[0066] Lead wire 41 material + sealing base 43: ensures that the lead wire 41 will not break and the solder joints will not oxidize during long-term use. Example 2

[0067] Please see Figure 1 - Figure 5 This utility model provides a technical solution: an indium gallium arsenide infrared thermometer, wherein the upper surface of the housing 46 is planar. Its main advantages are simple structure, low manufacturing cost, and ease of installation and integration. The two design forms meet the differentiated needs of various application scenarios regarding performance, cost, and ease of integration.

[0068] The working principle is as follows:

[0069] The planar housing 46 reduces costs by simplifying the optical structure while retaining core photoelectric conversion and signal processing capabilities, making it suitable for cost-sensitive scenarios with minimal environmental interference. Its sealed design still ensures basic dust and moisture protection, meeting the needs of conventional applications. In other words, curved and planar housings are the two physical form designs of the housing 46, with the main differences being optical performance (focusing effect) and manufacturing cost.

[0070] Finally, since this detector adopts an integrated filter design with housing 46, meaning housing 46 itself acts as an optical filter, the filtering band of housing 46 will vary depending on the photosensitive wavelength range of the chip, as detailed below:

[0071] 1. When the chip's photosensitive wavelength is <1.8µm, the filter wavelength is <0.94µm;

[0072] 2. When the chip's photosensitive wavelength is <1.8um, the filter wavelength is <0.85um.

[0073] Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. All other embodiments obtained by those skilled in the art and related fields based on the embodiments of this utility model without creative effort should fall within the protection scope of this utility model. Structures, devices, and operating methods not specifically described and explained in this utility model, unless otherwise specified or limited, shall be implemented according to conventional means in the art.

Claims

1. An indium gallium arsenide infrared thermometer, specifically comprising: The indium gallium arsenide infrared thermometer includes a lead wire (41), pins (42), and a base (43), characterized in that it further includes: An indium gallium arsenide photodiode (44) is used to convert infrared signals into current signals; Signal processing unit (45), the signal processing unit (45) is used to convert the output current signal into a voltage signal; Housing (46) for protecting the indium gallium arsenide photodiode (44) and the signal processing unit (45).

2. The indium gallium arsenide infrared thermometer according to claim 1, characterized in that: The pin (42) is exposed from the outer surface of the housing (46) or the base (43) and is electrically connected to an external circuit board.

3. The indium gallium arsenide infrared thermometer according to claim 1, characterized in that: The infrared sensitive band of the indium gallium arsenide photodiode (44) is <2.7um.

4. The indium gallium arsenide infrared thermometer according to claim 1, characterized in that: The signal processing unit (45) is electrically connected to the pin (42) via a lead (41).

5. The indium gallium arsenide infrared thermometer according to claim 1, characterized in that: The housing (46) covers the outer surface of the indium gallium arsenide photodiode (44), the signal processing unit (45), and the lead wire (41).

6. The indium gallium arsenide infrared thermometer according to claim 1, characterized in that: The housing (46) and the base (43) form a closed-loop sealed space.

7. The indium gallium arsenide infrared thermometer according to claim 1, characterized in that: The housing (46) is made of a light-filtering material.

8. The indium gallium arsenide infrared thermometer according to claim 1, characterized in that: The upper surface of the shell (46) is curved.

9. The indium gallium arsenide infrared thermometer according to claim 1, characterized in that: The upper surface of the shell (46) is planar.

Images