WO2024247167A1 - Heating system - Google Patents

Abstract

An infrared imaging device (9) includes, within an imaging range: a person standing in front of a heating device (1); a heating unit (5); and a heated object (3). A thermal image generation unit (11) generates a thermal image from an output signal from the infrared imaging device (9). A person detection unit (12) detects whether a person is present in the thermal image. A person detection area setting unit (18) sets a person detection area (27), which is a region where a person is detected in the thermal image. A sensitivity adjustment unit (26) adjusts the sensitivity of each pixel of the infrared imaging device (9), and the sensitivity of pixels corresponding to the person detection area (27) is set to be higher than that of pixels corresponding to other regions.

Description

Heating System

This disclosure relates to a heating system with a safety device.

Technology has been disclosed that detects the presence/absence of people and their orientation from thermal images acquired by an infrared imaging device (see, for example, Patent Document 1). This information is used for monitoring, crime prevention, autonomous driving, and other purposes, contributing to the realization of a safe and secure society. In equipment that uses high-temperature heat sources, such as in factories or kitchens, there is a demand for improving the safety of heating devices by issuing a warning when a person approaches the heat source or by controlling the temperature of the heat source.

For example, AI-based detection methods are used to detect people on thermal images. On the other hand, safety devices using infrared imaging devices are required to operate independently without connecting to external PCs or servers. Therefore, using a high-performance CPU to operate the AI raises the problem of higher product prices and shorter battery life due to increased power consumption. For this reason, relatively inexpensive microcontroller units (MCUs) with limited performance are often installed. Since the processing power of the MCU is limited, the number of bits of the thermal image input to the MCU needs to be low. For example, an image taken with an infrared camera may be converted into an 8-bit, 256-level grayscale image, and AI-based human detection processing may be performed on the MCU.

Japanese Patent Publication No. 2022-35519

When a high-temperature subject is present within the imaging range of an infrared imaging device, the temperature resolution of 1 digit, which is the unit of digital signals, decreases in thermal images with a reduced number of bits. This causes the difference between the background temperature and the brightness of the person to become extremely small, making it difficult to determine whether a person is present or not on the thermal image.

This disclosure has been made to solve the problems described above, and its purpose is to obtain a heating system that can accurately detect people in a thermal image even when a high-temperature subject is present within the imaging range of the infrared imaging device.

The first heating system according to the present disclosure includes a heating device having a heating section for heating an object to be heated, and a safety device for controlling the heating device, and the safety device includes an infrared imaging device that includes a person standing in front of the heating device, the heating section, and the object to be heated within its imaging range, a thermal image generating section that generates a thermal image from an output signal from the infrared imaging device, a human detection section that detects whether a person is present in the thermal image, a human detection area setting section that sets a human detection area that is an area in the thermal image where a person is detected, and a sensitivity adjustment section that adjusts the sensitivity of each pixel of the infrared imaging device, and the sensitivity adjustment section is characterized in that the sensitivity of the pixels corresponding to the human detection area is set higher than that of pixels corresponding to other areas.

The second heating system according to the present disclosure includes a heating device having a heating section for heating an object to be heated, and a safety device for controlling the heating device, and the safety device includes an infrared imaging device that includes a person standing in front of the heating device, the heating section, and the object to be heated within its imaging range, a thermal image generating section that generates a thermal image from an output signal from the infrared imaging device, a human detection section that detects whether a person is present in the thermal image, and a protective member that is disposed in front of an infrared-transmitting lens of the infrared imaging device and transmits infrared rays, and is characterized in that the thickness of the protective member in an area corresponding to a human detection area, which is an area in the thermal image where a person is detected, is thinner than the thickness of the protective member in an area corresponding to the outside of the human detection area.

The third heating system according to the present disclosure includes a heating device having a heating unit that heats an object to be heated, and a safety device that controls the heating device, and the safety device includes an infrared imaging device that includes a person standing in front of the heating device, the heating unit, and the object to be heated in its imaging range, a thermal image generation unit that generates a thermal image from an output signal of the infrared imaging device, a human detection unit that detects whether a person is present in the thermal image, a human detection area setting unit that sets a human detection area that is an area in the thermal image where a person is detected, and a sensitivity adjustment unit that switches the sensitivity of the entire pixels of the infrared imaging device for each frame of an image continuously captured by the infrared imaging device, and the continuously captured images include a first frame and a second frame in which the sensitivity of the entire pixels is lower than that of the first frame, and the thermal image generation unit generates the thermal image using the first frame for the human detection area and the second frame for other areas.

In the first heating system of the present disclosure, the sensitivity of pixels corresponding to the human detection area is set higher than the sensitivity of pixels corresponding to other areas. This makes it possible to simultaneously display the high-temperature subject and the person on the thermal image using an inexpensive MCU, even if there is a high-temperature subject within the imaging range of the infrared imaging device, and therefore makes it possible to accurately detect the person on the thermal image.

In the second heating system of the present disclosure, the thickness of the protective member in the area corresponding to the human detection area is thinner than the thickness of the protective member in the area corresponding to the outside of the human detection area. This makes it possible to reduce the infrared transmittance in the area corresponding to the outside of the human detection area. Therefore, even if a high-temperature subject is present within the imaging range of the infrared imaging device, it is possible to simultaneously display the high-temperature subject and the person on the thermal image using an inexpensive MCU, thereby making it possible to accurately detect the person on the thermal image.

In the third heating system disclosed herein, the sensitivity of the entire pixels of the infrared imaging device is switched for each frame of continuously captured images, and a thermal image is generated using a first frame with high sensitivity for the human detection area and a second frame with low sensitivity for other areas. As a result, even if a high-temperature subject is present within the imaging range of the infrared imaging device, the high-temperature subject and person 2 can be displayed simultaneously on the thermal image using an inexpensive MCU, making it possible to accurately detect the person on the thermal image.

1 is a side view showing a heating system according to a first embodiment. FIG. 1 is a block diagram showing a heating system according to a first embodiment. 1 is a diagram showing an infrared imaging device according to a first embodiment; FIG. 13 is a flowchart for setting a human detection area and sensitivity. FIG. 13 is a diagram showing an image of sensitivity settings of an infrared imaging device. This is a thermal image taken without adjusting the sensitivity of the human detection area. This is a thermal image taken without adjusting the sensitivity of the human detection area. This is a thermal image taken with the sensitivity of the human detection area adjusted. 13 is a flowchart of human detection. FIG. 11 is a diagram showing an infrared imaging device according to a second embodiment. FIG. 11 is a block diagram showing a heating system according to a second embodiment. 10 is a flowchart showing the operation of a safety device according to a second embodiment. FIG. 13 is a diagram showing a thermal image before offset. FIG. 13 is a diagram showing a thermal image after offset. 13 is a flowchart showing the operation of a safety device according to a third embodiment. FIG. 13 is a diagram showing a part of a safety device according to a fourth embodiment. FIG. 1 shows a first frame with high sensitivity. FIG. 13 shows a second frame with low sensitivity. 13A and 13B are diagrams showing thermal images generated by a thermal image generating unit according to embodiment 5.

The heating system according to the embodiment will be described with reference to the drawings. The same or corresponding components will be given the same reference numerals, and repeated explanations may be omitted.

Embodiment 1.
1 is a side view showing a heating system according to embodiment 1. A heating device 1 is a cooking utensil or the like used by a person 2, and heats an object to be heated 3. A safety device 4 controls the heating device 1.

FIG. 2 is a block diagram showing the heating system according to the first embodiment. The heating section 5 of the heating device 1 heats the object 3 to be heated. The operation section 6 inputs operations from the person 2. The memory section 7 of the heating device 1 stores recipe information such as a heating sequence. The control section 8 controls the heating section 5 according to instructions from the operation section 6 or the recipe information stored in the memory section 7. Examples of recipe information include simmering for 10 minutes after the water temperature reaches 100 degrees, frying for 3 minutes at a frying pan temperature of 160 degrees, etc.

The safety device 4 has an infrared imaging device 9 that captures an image of a subject. The safety device 4 is installed above the heating device 1 at a position and angle such that the imaging range of the infrared imaging device 9 includes the person 2 standing in front of the heating device 1, the heating unit 5, and the object to be heated 3. The control unit 10 controls the infrared imaging device 9.

Thermal image generating unit 11 generates a thermal image from the output signal of infrared imaging device 9 and converts the number of bits. For example, the thermal image generating unit 11 generates an 8-bit grayscale thermal image from a 14-bit digital signal.

The human detection unit 12 detects the presence of a person 2 in the thermal image or the state of the person 2 using various detection methods such as AI. Various deep learning algorithms may be used for these detections. When performing AI processing with an inexpensive MCU, the number of bits of the input image may be limited. For example, an 8-bit grayscale thermal image is generated by extracting the maximum and minimum brightness from the 14-bit brightness data of each pixel to calculate the brightness range, and then dividing this into 256 gradations and allocating the brightness of each pixel.

The temperature calculation unit 13 calculates the temperature of each pixel from the output signal of the infrared imaging device 9 using the sensitivity that has been set above and a conversion formula and coefficients that have been set in advance in the storage unit 14. This allows for highly accurate human detection without compromising the accuracy of the temperature measurement.

The light source 15 is an LED that is mounted on a typical range hood and illuminates the area around the hands of the person 2. The communication unit 16 of the safety device 4 and the communication unit 17 of the heating device 1 transmit and receive data to each other. Note that if recipe information is stored in the memory unit 14 of the safety device 4, the memory unit 7 of the heating device 1 may not be necessary.

The human detection area setting unit 18 sets a human detection area, which is an area in the thermal image where a person 2 is detected. For example, the user operates the operation unit 19 while viewing the thermal image on the display to set the human detection area using the human detection area setting unit 18. Information about the set human detection area is stored in the memory unit 14.

FIG. 3 is a diagram showing an infrared imaging device according to the first embodiment. Infrared light incident on an infrared-transmitting lens 20 is imaged on the light-receiving surface of the infrared imaging device 9. A plurality of detection pixels are arranged in a two-dimensional array on the light-receiving surface of the infrared imaging device 9. The detection pixels are microbolometers, thermopiles, or thermal diodes with a focal plane array (FPA) structure. Each pixel absorbs infrared light and outputs an analog voltage according to its energy. An analog-to-digital converter 21 amplifies the analog signal output from each pixel of the infrared imaging device 9 with an internal analog amplifier and converts it into, for example, a 14-bit digital signal. This digital signal is called luminance. The luminance of each pixel is correlated to temperature according to a predetermined conversion formula to form a thermal image.

The multiple pixels of the infrared imaging device 9 have different sensitivities to the amount of light, output offsets, and their temperature characteristics. For this reason, a reference thermal image is acquired and stored in advance, and a thermal image is obtained by outputting the difference between the reference thermal image and the input signal from the subject. In one example of a method for acquiring a reference thermal image, imaging is performed for a predetermined time with the infrared-transmitting lens 20 covered with the light-shielding member 22. The data captured at this time is averaged for a preset number of frames and stored in the FPN memory 23 as a reference thermal image. The reference thermal image is FPN (fixed pattern noise) data of the light-shielding member 22. The temperature of the light-shielding member 22 is measured by the reference temperature detection unit 24 and stored in the FPN memory 23 as the reference temperature. The light-shielding member 22 is, for example, a mechanical shutter using a black-painted aluminum plate. The reference temperature detection unit 24 is, for example, a temperature IC (Integrated Circuit) attached to the mechanical shutter with thermal conductive tape or the like. Since the output from each pixel is a relative brightness based on a reference thermal image, calculations must be performed using the reference temperature to convert it to absolute temperature. Note that a component with a uniform temperature may be photographed during pre-shipment inspection at the factory of the infrared imaging device, and the thermal image and component temperature at that time may be stored in the FPN memory 23 as the reference thermal image and reference temperature, respectively. In this case, the light shielding member 22 and the reference temperature detection unit 24 are not necessary.

The frame memory 25 records the difference between the reference thermal image recorded in the FPN memory 23 and the output signal of the analog-digital converter 21. By outputting this to the outside, a two-dimensional thermal image can be obtained.

When the temperature of the infrared imaging device 9 changes due to self-heating of the infrared imaging device 9 or the analog-digital converter 21, or changes in the environmental temperature, the temperature of the photographed subject appears to have changed on the thermal image. To correct this, the temperature change of the infrared imaging device 9 can be read by an element temperature detection unit (not shown) installed near the element, and input and recorded in the frame memory 25, and the thermal image can be corrected.

The sensitivity adjustment unit 26 adjusts the gain of the analog amplifier based on the information from the human detection area setting unit 18 to adjust the sensitivity of the corresponding pixel. Alternatively, the sensitivity adjustment unit 26 may adjust the gain of the digital output of the analog-digital converter 21 to adjust the sensitivity of the corresponding pixel. Sensitivity is the amount of change in luminance when the temperature of the subject changes by 1°C. In this embodiment, the sensitivity adjustment unit 26 sets the sensitivity of pixels corresponding to the human detection area, which is the area in the thermal image where a person 2 is detected, higher than that of pixels corresponding to other areas. For example, the sensitivity of pixels in the human detection area is set to 30 digit/K, and the sensitivity of pixels outside the human detection area is set to 10 digit/K, and these are stored in the memory unit 14.

Figure 4 shows a visible image. A heated object 3 is placed on the heating device 1, and a person 2 is standing in front of the heating device 1. Figure 5 is a flowchart for setting the human detection area and sensitivity. The human detection area setting unit 18 sets the human detection area (step S1). Next, the sensitivity adjustment unit 26 changes the sensitivity of the pixels corresponding to the human detection area (step S2). Figure 6 is a diagram showing an image of the sensitivity setting of the infrared imaging device. For example, the sensitivity of the human detection area 27 is increased to 30 digit/K, and the sensitivity of the other areas is left at 10 digit/K.

The thermal image generating unit 11 generates a thermal image using the brightness corrected by the sensitivity. As a result, the brightness of the person 2 photographed within the human detection area 27 is output relatively high, so the difference in brightness with the heat source outside the human detection area 27 is reduced, and the high-temperature subject and the person can be displayed simultaneously on the thermal image.

Figures 7 and 8 are thermal images taken without adjusting the sensitivity of the human detection area. When there is no high-temperature heated object 3, it is possible to detect a person 2, as shown in Figure 7. On the other hand, when there is a high-temperature heated object 3, as shown in Figure 8, there is no difference in brightness between the person 2 and the background temperature, making it difficult to detect the person 2 on the thermal image. Figure 9 is a thermal image taken with the sensitivity of the human detection area adjusted. The high-temperature heated object 3 and the person 2 can be displayed simultaneously on the thermal image.

Figure 10 is a flowchart of human detection. First, the infrared imaging device 9 captures an image of a subject (step S11). Next, the thermal image generation unit 11 generates and outputs a thermal image (step S12). Next, the human detection unit 12 detects whether a person 2 is present in the thermal image (step S13). If a person 2 is not detected or is not present within the human detection area 27, the process returns to step S11. If a person 2 is present within the human detection area 27, an output is made indicating that a person has been detected (step S14). Note that the presence/absence of a person 2 may be determined only within the human detection area 27.

Then, the safety device 4 controls the output of the heating device 1 based on the detection result of the human detection unit 12 and the temperature information calculated by the temperature calculation unit 13. For example, the safety device 4 automatically controls the output of the heating device 1 when the person 2 is not in front of the heating device 1. Specifically, if the output of the heating device 1 is reduced or turned off when the person 2 is not in front of the heating device 1 and the heating device 1 has been on for a predetermined time, it is possible to prevent forgetting to turn it off and reduce energy consumption. Furthermore, when the person 2 is not in front of the heating device 1 and the temperature of the heating device 1 is too high, the safety device 4 reduces or turns off the output of the heating device 1. This makes it possible to prevent abnormal heat generation of the heated object 3, thereby improving the safety of the heating device 1.

Furthermore, when person 2 is in front of heating device 1, safety device 4 prevents automatic control of the output of heating device 1. This allows person 2 to manually control the heat of heating device 1. Furthermore, safety device 4 will not automatically reduce the heat even if person 2 intentionally increases the heat. This prevents person 2's operation from being hindered and convenience from being impaired.

Next, the effects of this embodiment will be explained in comparison with the conventional technology. When human detection using AI is performed with an inexpensive MCU, the number of bits of the input thermal image is limited. When attempting to display a range from high to low temperatures using a thermal image with a small number of bits, the temperature resolution decreases. When a high-temperature heated object 3 is captured, the temperature resolution per count (1 digit) of the digital signal decreases. Therefore, with the conventional technology, there is no difference in brightness between the person 2 and the background temperature, making it difficult to detect the person 2 on the thermal image.

In contrast, in this embodiment, the sensitivity of pixels corresponding to the human detection area 27 is set higher than the sensitivity of pixels corresponding to other areas. As a result, even if a high-temperature subject is present within the imaging range of the infrared imaging device 9, the high-temperature subject and the person can be displayed simultaneously on the thermal image using an inexpensive MCU, making it possible to accurately detect person 2 on the thermal image. In addition, the temperature of the heat source can also be measured at the same time. Furthermore, by setting the human detection area 27 in advance, people who are not approaching the equipment, such as people walking in the aisle, will not be displayed on the thermal image, preventing erroneous detection.

Embodiment 2.
Fig. 11 is a diagram showing an infrared imaging device according to embodiment 2. The difference from embodiment 1 is that there is no sensitivity adjustment unit 26. Fig. 12 is a block diagram showing a heating system according to embodiment 2. The difference from embodiment 1 is that the safety device 4 has an offset setting unit 28. The human detection area setting unit 18 sets the upper limit temperature to be detected as a threshold value. For example, the threshold value is set to 38°C, which is slightly higher than the human body surface temperature. The other configurations are the same as those of embodiment 1.

FIG. 13 is a flowchart showing the operation of the safety device according to the second embodiment. First, the infrared imaging device 9 captures an image (step S21). Next, the temperature calculation unit 13 calculates the temperature of each pixel (step S22). Next, the offset setting unit 28 determines whether there is a pixel outside the human detection area 27 that is hotter than the threshold (step S23). If there is, the offset setting unit 28 performs an offset process to reduce the brightness value output from the infrared imaging device 9 so that the temperature of the pixel becomes the same as the threshold, and outputs the result to the thermal image generation unit 11 (step S24). FIG. 14 is a diagram showing a thermal image before offset. For example, the temperature of the person 2 is 35°C, and the temperature of the heated object 3 is 100°C. FIG. 15 is a diagram showing a thermal image after offset. The temperature of the heated object 3 has been changed to the same temperature as the threshold 38°C.

Then, the thermal image generating unit 11 generates and outputs a thermal image in which the maximum and minimum brightness of the offset-processed data are assigned to a gradation according to the desired number of bits (step S25). Next, the human detection unit 12 detects whether a person 2 is present in the thermal image (step S26). If a person 2 is not detected or is not present within the human detection area 27, the process returns to step S21. If a person 2 is present within the human detection area 27, an output is made indicating that a person has been detected (step S27).

As described above, in this embodiment, if there is a pixel outside the human detection area 27 that is hotter than the threshold, an offset process is performed to reduce the brightness value output from the infrared imaging device 9 so that the temperature of that pixel becomes the same as the threshold. This makes it possible to simultaneously display a high-temperature heat source and a person in a thermal image without providing the infrared imaging device 9 with a mechanism for adjusting pixel sensitivity. Furthermore, because the offset is applied based on the threshold, it is possible to make a person appear the same on the thermal image regardless of the temperature of the heated object. This makes it possible to obtain high detection accuracy. Furthermore, by limiting the human detection area 27, erroneous detection can be suppressed.

Embodiment 3.
In this embodiment, similarly to the second embodiment, there is no sensitivity adjustment unit 26, and the safety device 4 has an offset setting unit 28. The difference from the second embodiment is that the function of the offset setting unit 28 is different as described later, and the human detection area setting unit 18 does not set a threshold value. The other configurations are the same as those of the first and second embodiments.

FIG. 16 is a flowchart showing the operation of the safety device according to the third embodiment. First, steps S21 and S22 are performed in the same manner as in the second embodiment. Next, the offset setting unit 28 determines whether there is a pixel outside the human detection area 27 that is hotter than the maximum temperature of the human detection area 27 (step S31). If there is, the offset setting unit 28 performs an offset process to reduce the brightness value output from the infrared imaging device 9 so that the temperature of the pixel is the same as the maximum temperature of the human detection area 27, and outputs the result to the thermal image generating unit 11 (step S32). For example, if the heated object 3 is 100°C and the maximum temperature of the human detection area 27 is 35.5°C, the temperature of the heated object 3 is changed to 35.5°C. Then, steps S25 to S27 are performed in the same manner as in the second embodiment.

As described above, in this embodiment, if there is a pixel outside the human detection area 27 that is hotter than the maximum temperature of the human detection area 27, an offset process is performed to reduce the brightness value output from the infrared imaging device 9 so that the temperature of that pixel becomes the same as the maximum temperature. This makes it possible to simultaneously display a high-temperature heat source and a person in a thermal image without providing the infrared imaging device 9 with a mechanism for adjusting pixel sensitivity. Furthermore, since there is no need to set a threshold value in advance, this provides greater convenience than the second embodiment. Furthermore, it is possible to prevent the appearance of the person 2 in the thermal image from changing when the body surface temperature of the person 2 drops due to the outside air or rises due to heating by the heating device 1, thereby achieving high human detection accuracy.

The maximum temperature may be determined for each frame, or at regular intervals. Also, if a heat source other than a person is captured in the human detection area 27, the offset may not function properly. Therefore, if a heat source of a predetermined temperature or higher is detected in the human detection area 27, an abnormality may be reported.

Embodiment 4.
17 is a diagram showing a part of a safety device according to embodiment 4. A protective member 29 is disposed in front of the infrared transmitting lens 20 of the infrared imaging device 9 to prevent contamination of the infrared transmitting lens 20 and adjust the sensitivity. The protective member 29 is made of Si, germanium, high density polyethylene (HDPE), or the like that transmits infrared rays. Since the protective member 29 needs to be disposed at a distance that does not affect the imaging performance on the infrared imaging device 9, it is preferable to secure a distance of several centimeters or more between the infrared transmitting lens 20 and the protective member 29.

The thickness of the protective member 29 in the area corresponding to the human detection area 27 is thinner than the thickness of the protective member 29 in the area corresponding to the outside of the human detection area 27. For example, the protective member 29 in the area corresponding to the outside of the human detection area 27 is HDPE with a thickness of 0.5 mm, and the protective member 29 in the area corresponding to the outside of the human detection area 27 is HDPE with a thickness of 0.3 mm. This makes it possible to reduce the infrared transmittance in the area corresponding to the outside of the human detection area 27. Therefore, even if a high-temperature subject is present within the imaging range of the infrared imaging device 9, it is possible to simultaneously display the high-temperature subject and person 2 on the thermal image using an inexpensive MCU, so that person 2 can be accurately detected on the thermal image.

Because the sensitivity can be changed on the hardware side between the human detection area 27 and outside the human detection area 27, there is no need to set the human detection area 27 and thresholds, improving convenience. The protective member 29 for adjusting the sensitivity also serves as the protective member for the module, preventing oil or water droplets from adhering to the infrared-transmitting lens 20 and preventing thermal image capture, improving product reliability.

Embodiment 5.
In the second and third embodiments, the luminance of the high-temperature heat source is set uniformly, so the luminance of the high-temperature subject may saturate and the temperature distribution inside the heat source may not be visible. Therefore, in the present embodiment, the sensitivity adjustment unit 26 switches the sensitivity of the entire pixels of the infrared imaging device 9 for each frame of images continuously captured by the infrared imaging device 9. The continuously captured images have a first frame and a second frame in which the sensitivity of the entire pixels is lower than that of the first frame.

Figure 18 shows a first frame with high sensitivity. The luminance of person 2 is 200 digits. The luminance of both the outer periphery and center of the heated object 3 is saturated at 256 digits. Figure 19 shows a second frame with low sensitivity. The luminance of person 2 is 10 digits. The luminance of the outer periphery of the heated object 3 is 240 digits, and the luminance of the center is 220 digits.

The thermal image generating unit 11 generates a thermal image by using a high-sensitivity first frame for the human detection area 27 and a low-sensitivity second frame for other areas. This makes it possible to display the high-temperature subject and the person 2 simultaneously on the thermal image using an inexpensive MCU, even if there is a high-temperature subject within the imaging range of the infrared imaging device 9, and therefore to accurately detect the person 2 on the thermal image.

FIG. 20 shows a thermal image generated by the thermal image generation unit according to the fifth embodiment. It is possible to simultaneously display the high-temperature heated object 3 and the person 2 on the thermal image without losing information on the temperature distribution of the heated object 3. As a result, in addition to information on the presence/absence and status of the person, it is possible to obtain information on the temperature distribution of the heat source. This makes it possible to improve the controllability of the heating device 1. For example, when cooking on a stove, it is possible to control the heat according to the temperature distribution of ingredients inside a frying pan.

1 Heating device, 2 Person, 3 Heated object, 4 Safety device, 5 Heating unit, 9 Infrared imaging device, 11 Thermal image generation unit, 12 Person detection unit, 13 Temperature calculation unit, 18 Person detection area setting unit, 26 Sensitivity adjustment unit, 27 Person detection area, 28 Offset setting unit, 29 Protective member

Claims (6)

A heating device having a heating unit that heats an object to be heated;
a safety device for controlling the heating device;
The safety device comprises:
an infrared imaging device that captures a person standing in front of the heating device, the heating unit, and the heated object within its imaging range;
a thermal image generating unit that generates a thermal image from an output signal of the infrared imaging device;
a human detection unit that detects whether a human is present in the thermal image;
a human detection area setting unit that sets a human detection area in which a person is detected in the thermal image;
a sensitivity adjustment unit that adjusts the sensitivity of each pixel of the infrared imaging device;
A heating system characterized in that the sensitivity adjustment unit sets a higher sensitivity for pixels corresponding to the human detection area than for pixels corresponding to other areas. The heating system of claim 1, further comprising an offset setting unit that determines whether there is a pixel outside the human detection area that is hotter than the threshold, and if so, reduces the brightness output from the infrared imaging device so that the temperature of the pixel becomes the same as the threshold, and outputs the result to the thermal image generating unit. The heating system of claim 1, further comprising an offset setting unit that determines whether there is a pixel outside the human detection area that is hotter than the maximum temperature of the human detection area, and if so, reduces the brightness output from the infrared imaging device so that the temperature of the pixel becomes the same as the maximum temperature of the human detection area, and outputs the brightness to the thermal image generating unit. A heating device having a heating unit that heats an object to be heated;
a safety device for controlling the heating device;
The safety device comprises:
an infrared imaging device that captures a person standing in front of the heating device, the heating unit, and the heated object within its imaging range;
a thermal image generating unit that generates a thermal image from an output signal of the infrared imaging device;
a human detection unit that detects whether a human is present in the thermal image;
a protective member that is disposed in front of the infrared transmitting lens of the infrared imaging device and transmits infrared rays;
A heating system characterized in that the thickness of the protective member in an area corresponding to a human detection area, which is an area in the thermal image where humans are detected, is thinner than the thickness of the protective member in an area corresponding to the outside of the human detection area. A heating device having a heating unit that heats an object to be heated;
a safety device for controlling the heating device;
The safety device comprises:
an infrared imaging device that captures a person standing in front of the heating device, the heating unit, and the heated object within its imaging range;
a thermal image generating unit that generates a thermal image from an output signal of the infrared imaging device;
a human detection unit that detects whether a human is present in the thermal image;
a human detection area setting unit that sets a human detection area in which a person is detected in the thermal image;
a sensitivity adjustment unit that switches sensitivity of all pixels of the infrared imaging device for each frame of images continuously captured by the infrared imaging device;
the continuously captured images include a first frame and a second frame in which sensitivity of all pixels is lower than that of the first frame;
A heating system characterized in that the thermal image generation unit generates the thermal image using the first frame for the human detection area and the second frame for other areas. the safety device further includes a temperature calculation unit that calculates a temperature of each pixel from an output signal of the infrared imaging device,
A heating system described in any one of claims 1 to 5, characterized in that the safety device controls the output of the heating device based on the detection result of the human detection unit and the temperature information calculated by the temperature calculation unit.

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