TWI876368B - Micro-bolometer sensing circuit and sensing method thereof - Google Patents

Abstract

A micro-bolometer sensing circuit includes a micro-bolometer pixel array, a temperature sensing block, and a thermal imaging sensing block. The micro-bolometer pixel array includes a plurality of micro-bolometer pixels. The micro-bolometer pixel array is configured to sense far-infrared thermal radiation signals. A temperature sensing block is coupled to the micro-bolometer pixel array. The temperature sensing block converts the resistance signal corresponding to at least one of the plurality of micro-bolometer pixels into a first voltage signal. A thermal imaging sensing block is coupled to the micro-bolometer pixel array and to the temperature sensing block. The thermal imaging sensing block converts the resistance signal corresponding to at least one of the plurality of micro-bolometer pixels into a second voltage signal. The thermal imaging sensing block converts the second voltage signal into a corresponding color scale

Description

Microthermal radiation meter sensing circuit and sensing method

The present invention relates to a microthermal radiometer sensing circuit and sensing method, and in particular to a microthermal radiometer sensing circuit and sensing method applied to high pixel array imaging and temperature.

In recent years, the technology of micro-bolometers has been continuously improved. The metal sensing material in the micro-bolometer will change its resistance value due to the change of absorbed radiation heat energy, thereby becoming a thermal imager that can simultaneously measure the temperature and image of the external object to be measured. Generally speaking, in order to obtain high-precision temperature sensing results, a micro-thermal radiometer sensing circuit used in high-pixel array imaging must use a high-resolution analog-to-digital converter (ADC) to accurately measure analog signals. However, the conversion time of a high-resolution analog-to-digital converter (ADC) is long, which affects the frame rate of thermal imaging. If a high-speed analog-to-digital converter (ADC) is used to improve the frame rate, the circuit cost will increase, affecting the overall cost. Therefore, a micro-thermal radiometer sensing circuit used in high-pixel array imaging is needed to improve the frame rate of thermal imaging and enhance the accuracy of temperature sensing.

It should be noted that the contents of the "Prior Art" section are used to help understand the present invention. The contents disclosed in the "Prior Art" section do not mean that the contents have been known to those with ordinary knowledge in the relevant technical field before the present invention is applied.

The present invention provides a micro-thermal radiometer sensing circuit including a micro-thermal radiometer pixel array, a temperature sensing block and a thermal imaging sensing block. The micro-thermal radiometer pixel array includes a plurality of micro-thermal radiometer pixels. The micro-thermal radiometer pixel array is configured to sense far-infrared thermal radiation signals. The temperature sensing block is coupled to the micro-thermal radiometer pixel array. The temperature sensing block converts a resistance value signal corresponding to at least one of the plurality of micro-thermal radiometer pixels into a first voltage signal. The thermal imaging sensing block is coupled to the micro-thermal radiometer pixel array and the temperature sensing block. The thermal imaging sensing block converts the resistance value signal corresponding to at least one of the plurality of micro-thermal radiometer pixels into a second voltage signal. The thermal imaging sensing block converts the second voltage signal into a corresponding color scale.

The present invention provides a sensing method for a microthermal radiation meter sensing circuit. The sensing method includes: initializing a micro-thermal radiometer pixel array and storing parameters; obtaining addressing parameters from a micro-thermal radiometer sensing circuit and performing addressing; sensing a far-infrared thermal radiation signal by the micro-thermal radiometer pixel array, and the micro-thermal radiometer pixel array outputs a resistance value signal corresponding to at least one of a plurality of micro-thermal radiometer pixels to a temperature sensing block to convert the resistance value signal into a first voltage signal; and the micro-thermal radiometer pixel array outputs the resistance value signal to a thermal imaging sensing block to convert the resistance value signal into a second voltage signal, wherein the thermal imaging sensing block converts the second voltage signal into a corresponding color scale.

The micro-thermal radiometer sensing circuit for high-pixel array imaging proposed in the present invention can simultaneously realize high-frame rate thermal imaging and high-precision temperature sensing results, and can be applied to high-pixel high-frame rate thermal imaging devices or high-precision temperature measurement devices, and can also provide a low-cost and high-performance thermal imaging solution.

The present invention provides a microthermal radiometer sensing circuit and sensing method for high pixel array imaging and temperature. To make the above features and advantages of the present invention more obvious and easy to understand, the following is a specific example and a detailed description with the accompanying drawings.

The features of the concepts of the present invention and methods of achieving the features may be more easily understood by reference to the following detailed description of the embodiments and the accompanying drawings. Hereinafter, the embodiments will be described in more detail with reference to the accompanying drawings, in which the same reference numerals refer to the same elements throughout. However, the present invention may be embodied in a variety of different forms and should not be construed as being limited to only the embodiments described herein. Instead, these embodiments are provided as examples so that the present disclosure will be thorough and complete, and will fully convey the various aspects and features of the present invention to those skilled in the art. Therefore, processes, components, and techniques that are not necessary for a complete understanding of the aspects and features of the present invention by those of ordinary skill in the art may not be described.

In the following description, for the purpose of explanation, many specific details are set forth to provide a thorough understanding of various embodiments. However, various embodiments may be practiced without these specific details or with one or more equivalent arrangements. In other cases, well-known structures and devices are shown in block diagram form in order to avoid unnecessary confusion of various embodiments.

The terms used herein are used only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used herein, the singular form "a/an" may also include the plural form unless the context clearly indicates otherwise. It will be further understood that the terms "comprises/comprising", "have/having", "includes/including", when used in this specification, indicate the presence of stated features, wholes, steps, operations, elements and/or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

As used herein, the terms "substantially," "about," "approximately," and similar terms are used as terms of approximation and not as terms of degree, and are intended to take into account the inherent deviations in measured or calculated values that would be recognized by a person of ordinary skill in the art. Taking into account the measurements in question and the errors associated with the measurement of a particular quantity (i.e., the limitations of the measurement system), as used herein, "about" or "approximately" is inclusive of the stated values and means within an acceptable range of deviations from the particular value as determined by a person of ordinary skill in the art. When a certain embodiment can be implemented in different ways, a particular processing order may be performed differently from the order described. For example, two consecutively described circuits or elements may be executed substantially simultaneously or in an order opposite to the order described.

The electronic or electronic devices and/or any other related devices or elements described herein according to embodiments of the present invention may be implemented using any suitable hardware, firmware (e.g., dedicated integrated circuits), software, or a combination of software, firmware, and hardware. For example, the various elements of these devices may be formed on an integrated circuit (IC) chip or on a separate IC chip. In addition, the various elements of these devices may be implemented on a flexible printed circuit film, a tape carrier package (TCP), a printed circuit board (PCB), or formed on a substrate. In addition, the various elements of these devices may be processes or threads that run on one or more processors in one or more computing devices, execute computer program instructions, and interact with other system elements to perform the various functions described herein. The computer program instructions are stored in a memory that can be implemented in a computing device using a standard memory device such as random access memory (RAM). The computer program instructions may also be stored in other non-transitory computer-readable media such as a CD-ROM, a flash memory drive, or the like. In addition, those skilled in the art will recognize that the functionality of various computing devices may be combined or integrated into a single computing device, or that the functionality of a particular computing device may be distributed among one or more other computing devices without departing from the spirit and scope of the exemplary embodiments of the present invention.

Based on the material properties and micro-electromechanical structures (MEMS), the resistance value of the microthermal radiometer is relatively high. Depending on the material, the resistance value ranges from 10 ³ (K) ohms to 10 ⁶ (M) ohms. For relatively high resistance values, if you want to obtain better temperature sensing results, you must use a longer sensing time to achieve it. However, this will affect the frame rate of thermal imaging, and the impact is particularly serious for the sensing circuit of the microthermal radiometer array with high pixels (high density).

Please refer to FIG. 1 , which is a system block diagram of a microthermal radiation meter sensing circuit according to an embodiment of the present invention.

In one embodiment, the micro-bolometer sensing circuit 100 includes a micro-bolometer pixel array 102, a temperature sensing block 104, and a thermal imaging sensing block 106. The micro-bolometer pixel array 102 includes a plurality of micro-bolometer pixels. The micro-bolometer pixel array 102 can be used to sense far-infrared thermal radiation signals. The temperature sensing block 104 is coupled to the micro-bolometer pixel array 102, and the temperature sensing block 104 can convert a resistance value signal corresponding to at least one pixel of the plurality of micro-bolometer pixels into a first voltage signal. In some embodiments, the temperature sensing block 104 may convert the received resistance value signal into a corresponding temperature value to output as a first voltage signal. In some embodiments, when the resistance value signal received by the temperature sensing block 104 has a linear relationship with the temperature, the temperature sensing block 104 may also directly output the resistance value signal as the first voltage signal, or output the first voltage signal after adjusting the resistance value signal for appropriate offset. The thermal imaging sensing block 106 is coupled to the microthermal radiometer pixel array 102 and the temperature sensing block 104. The thermal imaging sensing block 106 converts the resistance value signal corresponding to all or part of the pixels of the plurality of microthermal radiometer pixels 102 into a second voltage signal. In some embodiments, the thermal imaging sensing block 106 may output the converted second voltage signal. In some embodiments, the thermal imaging sensing block 106 converts the second voltage signal into a corresponding color scale and then outputs it.

In one embodiment, the microthermal radiometer pixel array 102 is a thermal sensing element that can be used to sense far-infrared thermal radiation with a wavelength of about 8 to 14 micrometers (μm). The thermal sensing element is realized by combining a material film having a response characteristic to radiation with a wavelength of about 8 to 14 μm through micro-electromechanical technology and semiconductor process technology. In other words, the microthermal radiometer sensing circuit 100 is a resistive thermal sensing element.

Please refer to FIG. 2 , which is a detailed system block diagram of a microthermal radiation meter sensing circuit according to an embodiment of the present invention.

In one embodiment, the micro-thermal radiometer sensing circuit 200 includes a micro-thermal radiometer pixel array 102, a temperature sensing block 104, a thermal imaging sensing block 106, a signal processing block (Analog Signal Pre-processing circuit block) 108, a pixel addressing circuit (Row Addressing circuit) 110, and control and parameter blocks (Control & Parameters circuit blocks) 112A, 112B. The micro-thermal radiometer pixel array 102 includes a plurality of micro-thermal radiometer pixels. The microthermal radiometer pixel array 102 can be used to sense far infrared thermal radiation signals, and the microthermal radiometer pixel array 102 is coupled to the analog signal processing block 108, the control and parameter block 112A, and the pixel addressing circuit 110. The temperature sensing block 104 is coupled to the analog signal processing block 108 and the control and parameter block 112A, and the temperature sensing block 104 can receive the third voltage signal V3 from the signal processing block 108, and convert the third voltage signal V3 (analog signal) into the first voltage signal V1 (digital signal). In some embodiments, the temperature sensing block 104 can convert the received resistance value signal into a corresponding temperature value for output. In some embodiments, when the resistance value signal received by the temperature sensing block 104 has a linear relationship with the temperature, the temperature sensing block 104 can also directly output the resistance value signal, or output it after adjusting the resistance value signal for appropriate offset. The thermal imaging sensing block 106 is coupled to the signal processing block 108 and the control and parameter block 112B of the analog front end. The thermal imaging sensing block 106 can receive the third voltage signal V3 from the signal processing block 108, and convert the third voltage signal V3 (analog signal) into a second voltage signal V2 (digital signal). In some embodiments, the thermal imaging sensing block 106 can output the converted second voltage signal. In some embodiments, the thermal imaging sensing block 106 converts the second voltage signal V2 into a corresponding color scale and then outputs it.

In one embodiment, the control and parameter block 112 can be used to control the operation process, timing control, parameter setting, etc. of the microthermal radiometer high pixel array imaging system, so that the microthermal radiometer high pixel array imaging system can be fully executed according to the operation process designed by the system developer. The control and parameter block 112 is coupled to the microthermal radiometer pixel row addressing circuit 110 to issue control signals and instructions to the microthermal radiometer pixel row addressing circuit 110 so that it can correctly address and switch the microthermal radiometer pixel array 102. The control and parameter block 112 is also coupled to the analog front-end signal processing block 108 to send control signals and instructions to the analog signal front-end signal processing block 108, and transmits operation parameters at the same time, so that after setting the parameter adjustment, the analog signal front-end processing operation flow is completed according to the steps. The control and parameter block 112 is also coupled to the thermal imaging sensing block 106 to send control signals and instructions to the thermal imaging sensing block 106, and sequentially complete the analog signal measurement of the microthermal radiometer pixel, and output the sensing result to the back-end processing system. The control and parameter block 112 is also coupled to the temperature sensing block 104 to issue control signals and instructions to the temperature sensing block 104, sequentially complete the analog signal measurement operation of the microthermal radiometer pixel, and calculate the corresponding temperature value and output the temperature result to the back-end processing system. In some embodiments, the control and parameter block 112 can be designed as a single circuit block. In some embodiments, the control and parameter block 112 can be designed as multiple circuit blocks to independently drive and control, for example, the temperature sensing block 104 and the thermal imaging sensing block 106.

Please refer to Figures 3 to 6. Figure 3 is a schematic diagram of a microthermal pyrometer pixel array according to an embodiment of the present invention. Figure 4 is a side view of a microthermal pyrometer pixel array according to an embodiment of the present invention. Figure 5 is an operation schematic diagram of a pixel horizontal addressing circuit according to an embodiment of the present invention. Figure 6 is a system block schematic diagram of a microthermal pyrometer pixel array according to an embodiment of the present invention.

In one embodiment, the micro-radiometer pixel array 102 includes a plurality of micro-radiometer pixels 1022, a reference pixel 1024, and a pixel channel switch circuit 1026. The micro-radiometer pixel 1022 can be used to sense far-infrared thermal radiation signals with a wavelength of 8-14 μm. The reference pixel 1024 can be used to sense the background thermal response of the micro-radiometer pixel array 102 to compensate and correct the thermal radiation sensing offset of the micro-radiometer pixel array. 6 , the pixel channel switch circuit 1026 is connected between the pixel PXL and the microthermal radiation meter sensing circuit 602, wherein each pixel PXL has two electrodes located at opposite ends, each electrode is respectively configured with at least one switch circuit 1026A, 1026B, and is connected to the sensing circuit microthermal radiation meter sensing circuit 602 through the switch circuits 1026A, 1026B.

3 and 4 , in one embodiment, the microthermal radiometer pixel 1022 is located in the center of the entire area of the microthermal radiometer pixel array 102, and the reference pixel array 1024 is located on both sides of the microthermal radiometer pixel array 102. The pixel channel switch circuit 1026 is located below the microthermal radiometer pixel 1022 and the reference pixel 1024 through semiconductor process technology. Each pixel includes a set of pixel channel switch circuits 1026.

4 and 5 , in one embodiment, the sensing scanning method of the microthermal radiometer pixel array 102 is to address a row of microthermal radiometer pixels 1022 as a microthermal radiometer pixel group for one sensing. Each microthermal radiometer pixel row includes a row of microthermal radiometer pixels 1022 and all reference pixels 1024 in the row. In each sensing process, a whole row of microthermal radiometer pixels 1022 and all reference pixels 1024 in the row are measured at the same time. The pixel channel switch circuit 1026 of all pixels in the addressed row of microthermal radiometer pixels 1022 connects all pixels in the row to the microthermal radiometer sensing circuit 602 to perform a sensing operation of the microthermal radiometer pixels 1022. The sensing operation of the entire microthermal radiometer pixel array 102 is completed by operating the sequential scanning process through the control circuit (not shown) in the control and parameter block.

Please refer to FIG. 2 and FIG. 7 , FIG. 7 is a schematic diagram of signal conversion of a signal processing block according to an embodiment of the present invention.

In one embodiment, the analog front-end processing block 108 is an analog circuit combination that converts the resistance signal (or resistance value) of the microthermal radiometer pixel into a measurable voltage signal. The input of the analog front-end processing block 108 is an addressed column of pixels of the microthermal radiometer pixel array, and the analog front-end processing block 108 outputs a third voltage V3 to the temperature sensing block 104 and the thermal imaging sensing block 106.

Please refer to Figures 8, 9A and 9B. Figure 8 is a system block diagram of a signal processing block according to an embodiment of the present invention. Figure 9A is a schematic diagram of a drive and bias circuit according to an embodiment of the present invention. Figure 9B is a schematic diagram of multiple sets of drive and bias circuits according to an embodiment of the present invention.

In one embodiment, the analog front-end processing block 108 includes a driving and biasing circuit 1082, a reference voltage source 1084, and an analog signal amplifier 1086. Two ends of the reference voltage source 1084 are coupled to the driving and biasing circuit 1082 and the analog signal amplifier 1086, respectively.

9A , in one embodiment, the driving and biasing circuit 1082 includes a driving circuit 1082B and a biasing circuit 1082A, which functions to provide driving power to the microthermal irradiance meter pixel array 102, and converts the resistance signal of the microthermal irradiance meter pixel into a voltage signal through the biasing circuit 1082A. The pixels of the microthermal irradiance meter pixel array 102 are connected to the signal processing block 108 of the analog signal front end through the pixel channel switching circuits 1026A and 1026B. First, the biasing circuit 1082A of the driving and biasing circuit 1082 is introduced. The bias circuit 1082A has two bias resistors RU and RD, and the pixels of the microthermal irradiometer pixel array 102 are connected between the two bias resistors RU and RD via the pixel channel switch circuit 1026. The upper bias resistor RU is connected to a driving voltage source (Driving), and the other end is connected to the output end of one of the pixel channel switch circuits 1026A of the pixels of the microthermal irradiometer pixel array 102. The lower bias resistor RD is connected to the output end of another pixel channel switch circuit 1026B of the pixels of the microthermal irradiometer pixel array 102, and the other end of the lower bias resistor RD is connected to the ground point of the driving and bias circuit 1082.

In one embodiment, the driving voltage source is a DC power source. For example, it can be a DC voltage source or a DC current source. The driving voltage source provides electrical energy through the upper bias resistor RU, the pixel of the microthermal pyrometer pixel array 102, the lower bias resistor RD, and the ground point of the driving and biasing circuit 1082 to establish a bias voltage for each element in the loop. The structure of the driving and biasing circuit 1082 is composed of a combination of several basic units (basic structures), and one basic unit only processes the signal of one pixel of the microthermal pyrometer pixel array 102. N pixels of the microthermal pyrometer pixel array 102 are processed at a time, and N sets of basic units of the driving and biasing circuit 1082 are arranged accordingly to form a complete driving and biasing circuit 1082.

In one embodiment, the electrode point where the upper bias resistor RU is connected to the pixel of the microthermal radiometer pixel array 102 can convert the resistance signal of the pixel of the microthermal radiometer pixel array 102 into a measurable voltage signal, and guide the voltage signal to the output electrode of the driving and biasing circuit 1082 through the electrode point as the output signal of the driving and biasing circuit 1082.

In one embodiment, the electrical characteristics of each pixel of the microthermal radiometer pixel array vary due to the production process of the semiconductor process, which affects the consistency of the sensing result. This can be adjusted to the same numerical range through signal offset processing. In one embodiment, the reference voltage source 1084 is a power source for providing a signal offset processing voltage, and can obtain a corresponding reference voltage according to the electrical characteristics of different pixels through the initialization calibration process of the microthermal radiometer sensing system, and can apply a corresponding reference voltage according to the initialization calibration results of different pixels during the microthermal radiometer pixel array sensing process to obtain a sensing result with a consistent numerical range.

Please refer to Figures 10A and 10B. Figure 10A is a system block diagram of a reference voltage source according to an embodiment of the present invention. Figure 10B is a block diagram of multiple reference voltage sources according to an embodiment of the present invention.

In one embodiment, the reference voltage source 1084 outputs a corresponding voltage according to the electrical characteristics of each microthermal irradiometer pixel. The reference voltage source 1084 has a function of adjusting the voltage, so a digital-to-analog converter (DAC) is a suitable circuit for the reference voltage source 1084. The basic structure of the reference voltage source 1084 includes a digital-to-analog converter circuit DAC, a control block 114, and a data buffer 116. The input end of the digital-to-analog converter DAC is a data bus connected to the output data bus of the data buffer 116. The control signal electrode of the digital-to-analog converter DAC is connected to the control block 114. The input ends of the data buffer 116 and the control block 114 are connected to the control and parameter block 112 to receive control signals and parameters from the control and parameter block. The digital-to-analog converter DAC outputs a corresponding analog voltage or turns off the circuit according to the value from the data buffer 116 and the control signal state of the control block 114.

In one embodiment, the initialization calibration process of the microthermal pyrometer sensing system is to obtain the reference voltage value of each microthermal pyrometer pixel and store it in the pixel reference voltage data buffer (Reference Sources Buffers) 118 of the control and parameter block 112. The pixel reference voltage data buffer 118 can be any memory type made based on semiconductor technology, such as: SRAM, digital buffer, etc. The micro-thermal pyrometer sensing system operation process addresses the micro-thermal pyrometer pixel array 102, and writes the corresponding pixel address into the control register 120 of the control and parameter block 112. The control register 120 outputs the pixel index IDX connected to the pixel reference voltage data buffer 118. The pixel reference voltage data buffer 118 outputs the digital-to-analog converter DAC setting value corresponding to the reference voltage of the micro-thermal pyrometer pixel according to the content of the pixel index IDX, and is connected to the data buffer 116 of the reference voltage source 1084.

In one embodiment, the control register 120 of the control and parameter block 112 outputs a DAC control signal and is connected to the control block 114 of the reference voltage source 1084. The control block 114 directs the signal of the data buffer 116 to the digital-to-analog converter DAC and starts the digital-to-analog converter DAC, so that the digital-to-analog converter (DAC) outputs a corresponding voltage as a reference voltage for the microthermal radiometer pixel, and outputs the reference voltage of the microthermal radiometer pixel to the next-stage analog signal amplifier circuit (Amplifiers).

In one embodiment, the structure of the reference voltage source 1084 is composed of a plurality of basic structures, and one basic structure processes the signal of only one pixel of the microthermal pyrometer pixel array 102. When processing N pixels of the microthermal pyrometer pixel array 102 at a time, N sets of basic structures of the reference voltage source are correspondingly arranged to form a complete reference voltage source 1084. In the present invention, N is a positive integer.

Please refer to FIG. 11A and FIG. 11B . FIG. 11A is a system block diagram of a signal amplifier circuit according to an embodiment of the present invention. FIG. 11B is a system block diagram of multiple signal amplifier circuits according to an embodiment of the present invention.

In one embodiment, the resistance value of the microthermal radiometer pixel is large, and the conduction current of the microthermal radiometer pixel during sensing is relatively small. Therefore, the analog voltage value after being processed by the drive and bias circuit 1082 is relatively small. The small voltage signal must be amplified in time by the analog signal amplifier circuit 1086 before it can be provided to the analog-to-digital converter ADC for conversion to obtain a recognizable digital result.

In one embodiment, the analog signal amplifier circuit 1086 includes a unity gain buffer 132 and a programmable gain amplifier (PGA) 134. The structure of the analog signal amplifier circuit 1086 is composed of a plurality of basic structures. One basic structure processes the signal of only one pixel of the microthermal pyrometer pixel array 102. The basic structures of processing N pixels of the microthermal pyrometer pixel array 102 at a time and setting N sets of analog signal amplifier circuits accordingly can be combined into a complete analog signal amplifier circuit 1086.

In one embodiment, the positive input of the programmable gain amplifier 134 is the voltage output by the driving and biasing circuit 1082, and the negative input is the reference voltage output by the reference voltage source 1084. After the signal is amplified by the programmable gain amplifier 134, a voltage that can be converted by the analog-to-digital converter ADC can be obtained. The positive input electrode of the programmable gain amplifier 134 is connected to the output electrode of the driving and biasing circuit 1082, and the negative input electrode is connected to the output electrode of the reference voltage source 1084. On the other hand, the output electrode of the programmable gain amplifier 134 is connected to the positive input electrode of the voltage follower (unity gain buffer) 132.

In one embodiment, the programmable gain amplifier 134 is a programmable dual-end input amplifier, and its amplification gain value can be controlled by the hardware circuit or program of the microthermal radiation meter sensing system. Its output voltage can be expressed as: V _O = (V _p – V _n ) × Gain. Wherein, V _O is the output voltage, V _p is the positive input voltage, V _n is the negative input voltage, and Gain represents the amplification gain.

In one embodiment, the programmable gain amplifier 134 may also add an input voltage offset value (V _offset ) to a desired range, so that the output voltage can be expressed as: V _O = (V _p – V _n ) × Gain + V _offset . Wherein, V _O is the output voltage, V _p is the positive input voltage, V _n is the negative input voltage, Gain represents the amplification gain, and V _offset is the offset reference voltage.

In one embodiment, the output electrode of the voltage follower 132 is the output terminal OUT of the analog signal amplifier circuit 1086, wherein the output terminal OUT of the amplifier circuit 1086 is connected to the thermal imaging sensing block 106 and the temperature sensing block 104. The voltage follower 132 has the function of signal filtering and (or) signal isolation. Through the characteristics of the operational amplifier (OP-amp), the output signal of the programmable gain amplifier 134 is not affected by the structure, impedance difference or signal change of the next stage circuit, so that the output signal of the programmable gain amplifier 134 can be stably and losslessly output to the next stage circuit.

Please refer to Figures 12A and 12B. Figure 12A is a system block diagram of a thermal imaging sensing block according to an embodiment of the present invention. Figure 12B is a schematic diagram of multiple circuit blocks inside a thermal imaging sensing block according to an embodiment of the present invention. Please refer to Figures 13A and 13B. Figure 13A is a system block diagram of a sample-and-hold circuit according to an embodiment of the present invention. Figure 13B is a system block diagram of multiple sample-and-hold circuits according to an embodiment of the present invention.

In one embodiment, the thermal imaging sensing block 106 can convert the analog voltage signal converted from the resistance signal of the microthermal radiometer pixel into a digital signal for post-processing and imaging. The thermal imaging sensing block 106 includes a sample and hold circuit 1062, an analog to digital converter 1064, and a digital data buffer 1066.

In one embodiment, the function of the sample-hold circuit 1062 is to sample and hold the input analog voltage to prevent the signals of the front and rear sections from affecting each other during the operation time. The input end of the sample-hold circuit 1062 is coupled to the output end OUT of the signal processing block 108 of the front end of the analog signal, and the output end of the sample-hold circuit 1062 is connected to the input end of the analog-to-digital converter 1064. The sample-hold circuit 1062 has a control electrode connected to the control and parameter block to receive the control signal SC1 of the microthermal radiation meter sensing system. The circuit composition of the sample-hold circuit 1062 includes at least one switching element SW (for example: field effect transistor (FET)), an input capacitor C as a charge storage medium, and an operational amplifier (OP-amp) 136. The input terminal of the sample-hold circuit 1062 is the input electrode of the switch element SW, the output electrode of the switch element SW is connected to the positive electrode of the capacitor C, the negative electrode of the capacitor C is grounded, and the electrode of the switch element SW connected to the capacitor C is connected to the positive input electrode of the operational amplifier 136. The negative input electrode of the operational amplifier 136 is connected to the output electrode of the operational amplifier 136 to form a voltage follower circuit, and the output electrode of the operational amplifier 136 is the output electrode OUT1 of the sample-hold circuit 1062.

In one embodiment, the structure of the sample-and-hold circuit 1062 is a combination of several basic structures, and one basic structure only processes the signal of one pixel of the microthermal pyrometer pixel array 102. When processing N pixels of the microthermal pyrometer pixel array 102 at a time, N sets of basic structures of the sample-and-hold circuit are correspondingly set to form a complete sample-and-hold circuit 1062.

When the switch element SW is in the closed state, the front-end input voltage passes through the switch element SW and is connected to the positive input electrode of the capacitor C and the positive input electrode of the operational amplifier 136. The charge flows into the capacitor C. The timing is controlled by the switch element SW. The charge establishes a voltage at the same level as the input voltage in the capacitor C. The operational amplifier 136 outputs an analog voltage signal identical to the positive input electrode of the capacitor C.

When the switch element SW is in an open state, the front-end input signal is disconnected from the capacitor C and the operational amplifier 136 by the switch element SW. The capacitor C stores charge, builds voltage and stops changing. This voltage is connected to the positive input electrode of the operational amplifier 136, and the operational amplifier 136 outputs an analog voltage signal that is the same as the positive input electrode of the capacitor. Through the periodic closing and opening control of the switch element SW, the sampling and holding function of the signal can be realized, so that the front-end circuit signal can be transferred to the back-end circuit, and the signals of the front-end and back-end circuits do not interfere with each other. Before the switch element SW is closed-circuit controlled, the charge inside the capacitor C must be reset to zero, and then closed-circuit control is performed, so that the analog signal is established from zero for each switch control, so that the analog signals of each cycle are not distorted and do not affect each other.

In one embodiment, the analog-to-digital converter 1064 converts the input analog voltage into digital data. The analog-to-digital converter 1064 converts the analog voltage sampled by the microthermal radiometer pixel into digital data as a data source for thermal imaging data processing and display. The main purpose of the analog-to-digital converter 1064 of the thermal imaging sensing block 106 is to convert the resistor signal (analog signal) of the microthermal radiometer pixel into a digital signal for thermal imaging, so the resolution of the analog-to-digital converter 1064 is based on a format that conforms to thermal imaging. The thermal imaging format is mainly displayed in 256 levels of color (0~255 levels or grayscale), showing the sensing size of each micro-thermal radiometer pixel within the visible range, that is, the infrared radiation sensing measurement, which also corresponds to the temperature of each pixel in the visible range. Since it is only necessary to distinguish the high and low surface temperatures of objects within the visible range, it is not necessary to display high-precision temperature values. Therefore, the resolution of the analog-to-digital converter 1064 of the thermal imaging sensing block 106 is 8~10 bits. For example, the formats displayed by the thermal imaging sensing block 106 include but are not limited to Ice Fire, Fusion, Rainbow, Globow, Sepia, Color, Rain and Wheel 6. It is particularly noted that the analog-to-digital converter 1064 is an analog-to-digital converter that operates at a high speed and has a relatively low resolution.

In one embodiment, the digital data buffer 1066 is a digital data storage device for storing the digital data output by the analog-to-digital converter 1064, and then outputting the digital data to the back-end system for thermal imaging data processing and display. The relevant description of the digital data buffer 1066 has been recorded in the previous text and will not be repeated here.

In one embodiment, the structures of the analog-to-digital converter 1064 and the digital data buffer 1066 are each composed of a combination of several basic structures. One basic structure processes the signal of only one pixel of the microthermal pyrometer pixel array. The basic structures of processing N pixels of the microthermal pyrometer pixel array at a time and setting N sets of sample-and-hold circuits accordingly can be combined to form a complete analog-to-digital converter 1064 and digital data buffer 1066.

Please refer to Figures 13A, 13B and 14. Figure 14 is an operation timing diagram of a sample-and-hold circuit according to an embodiment of the present invention.

In one embodiment, the operation timing of the sample-hold circuit is divided into three stages. First, when the sample-hold circuit is turned on (ON), the capacitor C starts to charge, and the pixel signal gradually increases. When the sample-hold circuit is turned off (OFF), the capacitor C maintains the source charge, and the analog and digital converters start to convert the pixel signal into a digital signal. When the sample-hold circuit is reset (reset), the capacitor C starts to discharge the charge to zero. As time increases, the three stages are cycled continuously.

Please refer to Figure 15A and Figure 15B. Figure 15A is a system block diagram of a temperature sensing block according to an embodiment of the present invention. Figure 15B is a system diagram of a channel multiplexer in a temperature sensing block according to an embodiment of the present invention.

In one embodiment, the temperature sensing block 104 converts the analog voltage signal converted from the resistance signal of the microthermal radiometer pixel into a digital signal for subsequent digital processing and temperature calculation. The temperature sensing block 104 includes a sample-and-hold circuit 1042, a channel multiplexer MUX, an analog-to-digital converter 1044, and a digital data buffer 1046.

In one embodiment, the function of the sample-hold circuit 1042 is to sample and hold the input analog voltage to prevent the signals of the front and back sections from affecting each other during operation. The input end of the sample-hold circuit 1042 is coupled to the output end OUT of the signal processing block 108 of the front section of the analog signal, and the output end of the sample-hold circuit 1042 is connected to the input end of the channel multiplexer MUX. The sample-hold circuit 1042 has a control electrode connected to the control and parameter block 112 to receive the control signal SC2 of the microthermal radiation meter sensing system. Among them, other relevant descriptions about the sample-hold circuit 1042 have been recorded in the previous text and will not be repeated here.

In one embodiment, the function of the channel multiplexer 172 is to select a specific channel from a plurality of input analog voltage channels and output the analog voltage to a subsequent circuit. The channel multiplexer 172 has a plurality of analog signal input electrodes and at least one analog signal output electrode. Through a decoder circuit (decoder) 164, it receives an external coded signal and decodes the external coded signal into a channel address to switch the addressed input channel to an output channel. The input end of the channel multiplexer 172 is connected to each output end of the sample-hold circuit 1042, and the output end of the channel multiplexer 172 is connected to the input end of the analog-to-digital converter 1044. The channel multiplexer 172 has a control electrode coupled to the control and parameter block 112 to receive the control signal SC2 of the microthermal radiometer sensing system and address a plurality of input channels to switch to the output end.

15B , in one embodiment, the channel multiplexer MUX has a plurality of analog switch circuits 162, the number of which is the same as the number of channels of the sample-hold circuit 1042. Each analog switch circuit 162 includes an analog switch SW, and each analog switch SW has an input electrode coupled to the corresponding sample-hold circuit 1042. The output electrodes of all the analog switches SW are coupled to each other.

In one embodiment, the initial state of the analog switch SW is an open circuit state. Each analog switch SW has a control signal SC3 connected to the output end of the decoding circuit. When the analog switch receives the start signal, it switches to a closed circuit state.

In one embodiment, the input end of the decoding circuit 164 is connected to the control and parameter block 112, and receives the channel addressing signal from the microthermal radiation meter sensing system. The decoding circuit 164 decodes the input signal and outputs the obtained addressing result to the corresponding analog switch SW to control its closed circuit state.

In one embodiment, the function of the analog-to-digital converter 1044 is to convert the input analog voltage into digital data. The analog-to-digital converter 1044 converts the analog voltage sampled by the microthermal radiation meter pixel into digital data (which can be a voltage or current signal, which is not limited here) as a data source for thermal radiation temperature calculation. The digital data buffer 1046 is a digital data storage device for storing the digital data output by the analog-to-digital converter 1044, and then outputs it to the back-end system for thermal radiation temperature calculation. It is particularly noted that the analog-to-digital converter 1044 is an analog-to-digital converter that operates at a relatively low speed and has a relatively high resolution.

In one embodiment, the temperature sensing block 104 includes an analog-to-digital converter 1044 and a digital data buffer 1046, which processes the signal of an addressed pixel of the micro-thermal radiometer pixel array 102, and processes the sensing signal of one pixel of the micro-thermal radiometer pixel array 102 at a time. Since the main purpose of the analog-to-digital converter 1044 of the temperature sensing block 104 is to convert the resistance signal of the micro-thermal radiometer pixel into a digital signal, the resolution of the analog-to-digital converter 1044 meets the resolution specification of the thermal radiation temperature. It is particularly noted that the resolution of thermal radiation temperature is required to be higher than the resolution of thermal imaging (8~10 bits), so the resolution of the analog-to-digital converter 1044 of the temperature sensing block 104 is approximately 16~24 bits.

Please refer to FIG. 16 , which is a system block diagram of an integrated microthermal radiation meter sensing circuit according to an embodiment of the present invention.

In one embodiment, the micro-thermal radiometer pixel array 102 is addressed by the micro-thermal radiometer pixel row addressing circuit 110, and the addressing unit is one row at a time. One row has N pixels. The control and parameter blocks 112A and 112B receive the control and parameters of the micro-thermal radiometer sensing circuit to transmit the sensed signal to each micro-thermal radiometer pixel block for parameter setting and operation control. The analog signal front-end signal processing block 108 has N sets of driving and biasing circuits 1082, N sets of reference voltage sources 1084, and N sets of analog signal amplification circuits 1086.

The thermal imaging sensing block 106 includes N sets of sample-and-hold circuits 1062, N sets of analog-to-digital converters 1064, wherein the analog-to-digital converters 1064 have a resolution of approximately 8 to 10 bits, and N sets of digital data buffers 1066.

The temperature sensing block 104 includes N sets of sample-and-hold circuits 1042, a set of channel multiplexers 1048, a set of analog-to-digital converters 1046, wherein the analog-to-digital converters 1046 have a resolution of approximately 16-24 bits, and a set of digital data buffers 1046.

In one embodiment, the number of pixel temperature sensing blocks 104 and/or the number of circuits (S) of the temperature sensing block 104 may be increased according to user requirements, for example, n = 5. The addressing unit of the microthermal radiometer pixel array 102 is n pixels in one row.

The analog signal front-end signal processing block 108 includes n sets of driving and biasing circuits 1082, n sets of reference voltage sources 1084, and n sets of analog signal amplifying circuits 1086.

The thermal imaging sensing block 106 includes n sets of sample-and-hold circuits 1062, n sets of analog-to-digital converters 1064, and n sets of digital data buffers 1066.

The temperature sensing block 104 includes n sets of sample-and-hold circuits 1042, S sets of channel multiplexers 1048, S sets of analog-to-digital converters 1044, and S sets of digital data buffers 1046, where S is a positive integer.

Please refer to FIG. 17 , which is a system block diagram of an integrated microthermal radiation meter sensing circuit according to an embodiment of the present invention.

In one embodiment, in order to reduce circuit cost, the number of circuits in the microthermal pyrometer sensing circuit can be reduced. The addressing unit of the microthermal pyrometer pixel array 102 is n pixels in one row.

The analog signal front-end signal processing block 108 includes n/m sets of driving and biasing circuits 1082, a set of channel multiplexers 172 , n/m sets of reference voltage sources 1084, and n/m sets of analog signal amplifying circuits 1086, where m is a factor of n.

The thermal imaging sensing block 106 includes n/m sets of sample-and-hold circuits 1062 , n/m sets of analog-to-digital converters 1064 , and n/m sets of digital data buffers 1066 .

The temperature sensing block 104 includes n/m sets of sample-and-hold circuits 1042, a set of channel multiplexers 1048, a set of analog-to-digital converters 1044, and a set of digital data buffers 1046.

In one embodiment, the number of pixel temperature sensing blocks 104 and/or the number of circuits (S) of the temperature sensing block 104 may be increased according to user requirements, for example, n = 5. The addressing unit of the microthermal radiometer pixel array 102 is n pixels in one row.

The analog signal front-end signal processing block 108 includes n/m sets of driving and biasing circuits 1082, a set of channel multiplexers 172 , n/m sets of reference voltage sources 1084, and n/m sets of analog signal amplifying circuits 1086, where m is a factor of n.

The thermal imaging sensing block 106 includes n/m sets of sample-and-hold circuits 1062 , n/m sets of analog-to-digital converters 1064 , and n/m sets of digital data buffers 1066 .

The temperature sensing block 104 includes n/m sets of sample-and-hold circuits 1042, S sets of channel multiplexers 1048, S sets of analog-to-digital converters 1044, and S sets of digital data buffers 1046, where S is a positive integer.

Please refer to Figures 18A-18C, which are system flow charts of an integrated microthermal radiometer sensing method according to an embodiment of the present invention.

In one embodiment, the system flow chart of the microthermal irradiometer sensing method includes steps S1802 to S1856. In step S1802, the microthermal irradiometer sensing circuit performs pixel and environmental parameter initialization and parameter storage. In step S1804, the control and parameter block obtains the addressing parameter from the sensing system. In step S1806, the control and parameter block performs row addressing. In step S1808, the pixel channel switch circuit connects all pixels of the addressed row to the signal processing block of the analog signal front end. In step S1810, the drive and bias circuit drives and biases the pixels of the microthermal pyrometer pixel array and establishes a voltage. In step S1812, the control and parameter block obtains the reference voltage parameter from the microthermal pyrometer pixel sensing circuit (system). In step S1814, the control and parameter block sets the reference voltage source. In step S1816, the analog signal amplifier circuit performs a signal amplification operation. In step S1818, the analog signal amplifier circuit outputs the voltage to the thermal imaging sensing block. In step S1820, the control and parameter block controls the sample and hold circuit and performs voltage sampling. In step S1822, the control and parameter block controls the sample-and-hold circuit and performs voltage holding. In step S1824, the analog-to-digital converter converts the analog voltage into digital data. In step S1826, the analog-to-digital converter outputs the digital data to the digital data buffer. In step S1828, the digital data buffer outputs the digital data (voltage or current signal) to the external sensing system (not shown). In step S1830, the sensing system processes the data and converts it into color gradation values. In step S1832, the sensing system outputs the color gradation values to the display. In step S1834, the display performs thermal imaging display.

On the other hand, in step S1836, the analog signal amplifier circuit outputs the voltage to the temperature sensing block. In step S1838, the control and parameter block controls the sample and hold circuit to perform voltage sampling. In step S1840, the control and parameter block controls the sample and hold circuit to perform voltage holding. In step S1842, the control and parameter block controls the channel multiplexer to perform channel addressing. In step S1844, the channel multiplexer decodes the channel address. In step S1846, the channel multiplexer connects the addressed channel to the analog-to-digital converter. In step S1848, the analog-to-digital converter converts the analog voltage into digital data. In step S1850, the analog-to-digital converter outputs digital data to the digital data buffer. In step S1852, the digital data buffer outputs digital data to the sensing system. In step S1854, the sensing system processes the data and converts it into a thermal radiation temperature value. In step S1856, the sensing system outputs the thermal radiation temperature value to the back-end processing system. It is particularly noted that point A and point B represent the connection points of flow charts 18A-18C.

In some embodiments, the temperature sensing block includes a low-speed, high-precision analog-to-digital converter. The thermal imaging sensing block includes a high-speed, low-precision analog-to-digital converter.

In some embodiments, the microthermal radiometer sensing circuit further includes a signal processing block. The signal processing block includes a plurality of analog circuits. The signal processing block is coupled to the microthermal radiometer pixel array, the temperature sensing block, and the thermal imaging sensing block. The signal processing block converts a resistance value signal corresponding to an addressed row of pixels in the microthermal radiometer pixel array into a plurality of third voltage signals, wherein the temperature sensing block and the thermal imaging sensing block receive the plurality of third voltage signals and convert the plurality of third voltage signals into a high-resolution first voltage signal and a low-resolution second voltage signal.

In some embodiments, the signal processing block includes a driving bias circuit. The driving bias circuit includes: a driving circuit that provides a driving power supply to the microthermal radiometer pixel array; and a bias circuit coupled to the driving circuit, wherein the bias circuit converts a resistance value signal corresponding to at least one of the plurality of microthermal radiometer pixels into a voltage signal; a reference voltage source coupled to the driving bias circuit, wherein the reference voltage source provides a corresponding reference voltage according to initialization calibration results of the plurality of microthermal radiometer pixels; and a signal amplification circuit coupled to the reference voltage source, wherein the signal amplification circuit converts the voltage signal into a third voltage signal, wherein the signal amplification circuit includes a programmable gain amplifier.

In some embodiments, the signal processing block further includes a channel multiplexer. The channel multiplexer is coupled to the microthermal pyrometer pixel array and is configured to sequentially process pixel sensing signals of different blocks in the microthermal pyrometer pixel array.

In some embodiments, the bias circuit includes a first bias resistor (upper bias resistor RU), one end of which is coupled to a driving power source, and the other end of which is coupled to a first switching circuit; and a second bias resistor (lower bias resistor RD), one end of which is coupled to a ground terminal, and the other end of which is coupled to a second switching circuit, wherein at least one of the plurality of microthermal pyrometer pixels is coupled to a bias resistor and the second bias resistor.

In some embodiments, the first voltage signal is a digital thermal radiation temperature signal. The second voltage signal is a digital thermal imaging signal. The resolution of the first voltage signal is higher than that of the second voltage signal. The analog-to-digital converter in the thermal imaging sensing block is used to sense the second voltage signal at a higher sensing speed than the analog-to-digital converter in the temperature sensing block senses the first voltage signal.

In some embodiments, a sensing method of a microthermal radiometer sensing circuit includes initializing a microthermal radiometer pixel array and storing parameters; obtaining addressing parameters from the microthermal radiometer sensing circuit and performing addressing; sensing a far-infrared thermal radiation signal by the microthermal radiometer pixel array, and the microthermal radiometer pixel array outputs a resistance value signal corresponding to at least one of a plurality of microthermal radiometer pixels to a temperature sensing block to convert the resistance value signal into a first voltage signal. In some embodiments, the temperature sensing block can convert the received resistance value signal into a corresponding temperature value to output as a first voltage signal. In some embodiments, when the resistance value signal received by the temperature sensing block has a linear relationship with the temperature, the temperature sensing block can directly output the resistance value signal as a first voltage signal, or output the first voltage signal after adjusting the resistance value signal for appropriate offset; and the microthermal radiometer pixel array outputs the resistance value signal to the thermal imaging sensing block to convert the resistance value signal into a second voltage signal, wherein in some embodiments, the thermal imaging sensing block 106 can output the converted second voltage signal. In some embodiments, the thermal imaging sensing block converts the second voltage signal into a corresponding color scale and then outputs it.

In some embodiments, the signal processing block is further based on a channel multiplexer to sequentially process the pixel sensing signals of different blocks in the microthermal radiometer pixel array.

The microthermal radiometer sensing circuit for high pixel array imaging proposed by the present invention can simultaneously realize high frame rate thermal imaging and high precision temperature sensing results, and can be applied to high pixel and high frame rate thermal imaging devices or high precision (high resolution) temperature measurement devices, and can also provide a low-cost and high-performance thermal imaging solution.

Although the present invention has been disclosed as above by the embodiments, they are not intended to limit the present invention. Any person with ordinary knowledge in the relevant technical field can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be defined by the scope of the attached patent application.

100, 200, 602: Micro-radiometer sensing circuit 102: Micro-radiometer pixel array 1022, PXL: Pixel 1024: Reference pixel 1026, 1026A, 1026B: Switching circuit 104: Temperature sensing block 1042, 1062: Sample and hold circuit 1044, 1064: Analog-to-digital converter 1046, 1066: Digital data buffer 106: Thermal imaging sensing block 108: Signal processing block 1082: Drive and bias circuit 1082A: Bias circuit 1082 B: Drive circuit 1084: Reference voltage source 1086: Signal amplifier circuit 110: Addressing circuit 112, 112A, 112B: Control and parameter block 114: Control block 116: Data buffer 118: Reference voltage data buffer 120: Control register 132: Voltage follower 134: Programmable gain amplifier 136: Operational amplifier 164: Decoding circuit 172, MUX: Multiplexer C: Capacitor DAC: Digital to Analog Converter IDX: Pixel index OUT: Output terminal OUT1: Output electrode RU, RD: Resistors SC1, SC2, SC3: Signal SW: Switching element S1802~S1856: Steps V1~V3: Voltage

FIG. 1 is a system block diagram of a microthermal radiometer sensing circuit according to an embodiment of the present invention. FIG. 2 is a detailed system block diagram of a microthermal radiometer sensing circuit according to an embodiment of the present invention. FIG. 3 is a schematic diagram of a microthermal radiometer pixel array according to an embodiment of the present invention. FIG. 4 is a side view of a microthermal radiometer pixel array according to an embodiment of the present invention. FIG. 5 is an operation diagram of a pixel horizontal addressing circuit according to an embodiment of the present invention. FIG. 6 is a system block diagram of a microthermal radiometer pixel array according to an embodiment of the present invention. FIG. 7 is a signal conversion diagram of a signal processing block according to an embodiment of the present invention. Figure 8 is a system block diagram of a signal processing block according to an embodiment of the present invention. Figure 9A is a schematic diagram of a drive and bias circuit according to an embodiment of the present invention. Figure 9B is a schematic diagram of multiple sets of drive and bias circuits according to an embodiment of the present invention. Figure 10A is a system block diagram of a reference voltage source according to an embodiment of the present invention. Figure 10B is a block diagram of multiple sets of reference voltage sources according to an embodiment of the present invention. Figure 11A is a system block diagram of a signal amplifier circuit according to an embodiment of the present invention. Figure 11B is a system block diagram of multiple sets of signal amplifier circuits according to an embodiment of the present invention. FIG. 12A is a system block diagram of a thermal imaging sensing block according to an embodiment of the present invention. FIG. 12B is a system block diagram of multiple groups of circuit blocks inside a thermal imaging sensing block according to an embodiment of the present invention. FIG. 13A is a system block diagram of a sample-and-hold circuit according to an embodiment of the present invention. FIG. 13B is a system block diagram of multiple groups of sample-and-hold circuits according to an embodiment of the present invention. FIG. 14 is an operation timing diagram of a sample-and-hold circuit according to an embodiment of the present invention. FIG. 15A is a system block diagram of a temperature sensing block according to an embodiment of the present invention. FIG. 15B is a system diagram of a channel multiplexer in a temperature sensing block according to an embodiment of the present invention. FIG. 16 is a system block diagram of an integrated microthermal radiometer sensing circuit according to an embodiment of the present invention. FIG. 17 is a system block diagram of an integrated microthermal radiometer sensing circuit according to an embodiment of the present invention. FIG. 18A-18C are system flow charts of an integrated microthermal radiometer sensing method according to an embodiment of the present invention.

100: Microthermal radiometer sensing circuit 102: Microthermal radiometer pixel array 104: Temperature sensing block 106: Thermal imaging sensing block

Claims (18)

A micro-thermal radiometer sensing circuit comprises: a micro-thermal radiometer pixel array, comprising a plurality of micro-thermal radiometer pixels, wherein the micro-thermal radiometer pixel array is configured to sense far-infrared thermal radiation signals; a temperature sensing block, coupled to the micro-thermal radiometer pixel array, wherein the temperature sensing block converts a resistance value signal corresponding to at least one of the plurality of micro-thermal radiometer pixels into a first voltage signal; a thermal imaging sensing block, coupled to the micro-thermal radiometer pixel array and the temperature sensing block, wherein the thermal imaging sensing block converts a resistance value signal corresponding to at least one of the plurality of micro-thermal radiometer pixels into a second voltage signal, wherein The thermal imaging sensing block converts the second voltage signal into a corresponding color scale; and a signal processing block, including a plurality of analog circuits, wherein the signal processing block is coupled to the microthermal radiometer pixel array, the temperature sensing block and the thermal imaging sensing block, and the signal processing block converts the resistance value signal corresponding to an addressed row of pixels in the microthermal radiometer pixel array into a plurality of third voltage signals, wherein the temperature sensing block and the thermal imaging sensing block receive the plurality of third voltage signals and convert the plurality of third voltage signals into the first voltage signal with high resolution and the second voltage signal with low resolution. A microthermal radiometer sensing circuit as described in claim 1, wherein the temperature sensing block includes a low-speed, high-precision analog-to-digital converter. A microthermal radiometer sensing circuit as described in claim 2, wherein the thermal imaging sensing block includes a high-speed, low-precision analog-to-digital converter. The microthermal irradiance sensing circuit as described in claim 1, wherein the signal processing block includes: a driving bias circuit, including: a driving circuit, providing a driving power supply to the microthermal irradiance pixel array; and a bias circuit, coupled to the driving circuit, wherein the bias circuit converts a resistance value signal corresponding to at least one of the plurality of microthermal irradiance pixels into a voltage signal; A reference voltage source coupled to the driving bias circuit, wherein the reference voltage source provides a corresponding reference voltage according to the initialization correction results of the plurality of microthermal radiometer pixels; and a signal amplification circuit coupled to the reference voltage source, wherein the signal amplification circuit converts the voltage signal into the third voltage signal, wherein the signal amplification circuit includes a programmable gain amplifier. The microthermal radiometer sensing circuit as described in claim 4, wherein the signal processing block further includes: a multiplexer coupled to the microthermal radiometer pixel array, configured to sequentially process pixel sensing signals of different blocks in the microthermal radiometer pixel array. A microthermal radiation meter sensing circuit as described in claim 4, wherein the bias circuit comprises: a first bias resistor, one end of which is coupled to a driving power source, and the other end of which is coupled to a first switching circuit; and a second bias resistor, one end of which is coupled to a ground terminal, and the other end of which is coupled to a second switching circuit, wherein at least one of the plurality of microthermal radiation meter pixels is coupled to the first bias resistor and the second bias resistor. A microthermal radiation meter sensing circuit as described in claim 1, wherein the first voltage signal is a digital thermal radiation temperature signal. A microthermal radiometer sensing circuit as described in claim 7, wherein the second voltage signal is a digital thermal imaging signal. A microthermal radiation meter sensing circuit as described in claim 8, wherein the resolution of the first voltage signal is higher than that of the second voltage signal. A sensing method for a microthermal radiometer sensing circuit includes: initializing a microthermal radiometer pixel array and storing parameters; obtaining addressing parameters from the microthermal radiometer sensing circuit and performing addressing; sensing a far-infrared thermal radiation signal by the microthermal radiometer pixel array, and the microthermal radiometer pixel array outputs a resistance value signal corresponding to at least one of a plurality of microthermal radiometer pixels to a temperature sensing block to convert the resistance value signal into a first voltage signal; the microthermal radiometer pixel array outputs the resistance value signal to a thermal imaging sensing block. The resistance value signal is converted into a second voltage signal, wherein the thermal imaging sensing block converts the second voltage signal into a corresponding color scale; and the resistance value signal corresponding to a row of pixels addressed in the microthermal radiometer pixel array is converted into a plurality of third voltage signals by a signal processing block including a plurality of analog circuits, wherein the temperature sensing block and the thermal imaging sensing block receive the plurality of third voltage signals and convert the plurality of third voltage signals into the first voltage signal with high resolution and the second voltage signal with low resolution. The sensing method as described in claim 10, wherein the temperature sensing block includes a low-speed high-precision analog-to-digital converter. The sensing method as described in claim 11, wherein the thermal imaging sensing block includes a high-speed, low-precision analog-to-digital converter. The sensing method as described in claim 10, wherein the signal processing block includes: a driving bias circuit, including: a driving circuit, providing a driving power supply to the microthermal radiation meter pixel array; and a bias circuit, wherein the bias circuit converts the resistance value signal corresponding to at least one of the plurality of microthermal radiation meter pixels into a voltage signal; a reference voltage source, wherein the reference voltage source provides a corresponding reference voltage according to the initialization correction results of the plurality of microthermal radiation meter pixels; and a signal amplification circuit, wherein the signal amplification circuit converts the voltage signal into the third voltage signal, wherein the signal amplification circuit includes a programmable gain amplifier. As described in claim 13, the signal processing block is further based on a multiplexer to sequentially process the pixel sensing signals of different blocks in the microthermal radiometer pixel array. The sensing method as described in claim 13, wherein the bias circuit comprises: a first bias resistor, one end of which is coupled to a driving power source, and the other end of which is coupled to a first switching circuit; and a second bias resistor, one end of which is coupled to a ground terminal, and the other end of which is coupled to a second switching circuit, wherein at least one of the plurality of microthermal pyrometer pixels is coupled to the first bias resistor and the second bias resistor. The sensing method as described in claim 10, wherein the first voltage signal is a digital thermal radiation temperature signal. The sensing method as described in claim 16, wherein the second voltage signal is a digital thermal imaging signal. As described in claim 17, the sensing method, wherein the sensing speed of the analog-to-digital converter of the thermal imaging sensing block sensing the second voltage signal is higher than the sensing speed of the analog-to-digital converter of the temperature sensing block sensing the first voltage signal.