Oven, oven with probe, and cooking system

Abstract

An oven includes: a housing provided with a connector to which a temperature detection probe including a thermistor is electrically and mechanically connectable; a voltage divider resistor electrically connected in series with the thermistor to be located on an upper side with respect to the thermistor, between a power supply and a circuit ground in a case where the temperature detection probe is connected to the connector; and a temperature calculation unit configured to calculate a temperature of a detection target with which the temperature detection probe is in contact, on the basis of a voltage between the circuit ground and a connection point between the voltage divider resistor and the thermistor.

Description

CROSS-REFERENCE TO RELATED APPLICATION

[0001] The present application claims priority from Japanese Application JP2024-012940, the content of which is hereby incorporated by reference into this application.BACKGROUND OF THE DISCLOSURE1. Technical Field

[0002] The present disclosure relates to an oven, an oven with a probe, and a cooking system.2. Description of the Related Art

[0003] JP S63-075419 A discloses a meat probe in which a first sensor unit for detecting an internal temperature of a food is provided in a tip portion of a metal rod.SUMMARY OF THE DISCLOSURE

[0004] A heating device to which the meat probe of JP S63-075419 A is connected is provided with a terminal to which a temperature signal from the meat probe is input and a reference potential terminal connected to a line corresponding to a reference potential of the temperature signal. In the heating device of JP S63-075419 A, the temperature signal from the meat probe is pulled down. In general, the reference potential terminal may be grounded for countermeasures against noise and the like. At this time, in a case where a resistance component such as a parasitic resistance is generated between the line of the temperature signal and the earth, the accuracy of the temperature calculation may be decreased.

[0005] The present disclosure has been made in view of the above problems, and an object of the present disclosure is to provide an oven, an oven with a probe, and a cooking system capable of achieving both noise countermeasures and accurate measurement of the temperature of a cooking target.

[0006] An oven according to the present disclosure includes a housing, a voltage divider resistor, and a temperature calculation unit. The housing is provided with a connector to which a temperature detection probe including a thermistor is electrically and mechanically connectable. The voltage divider resistor is electrically connected in series with the thermistor to be located on an upper side with respect to the thermistor, between a power supply and a circuit ground in a case where the temperature detection probe is connected to the connector. The temperature calculation unit calculates a temperature of a detection target with which the temperature detection probe is in contact, on the basis of a voltage between the circuit ground and a connection point between the voltage divider resistor and the thermistor.

[0007] An oven with a probe according to the present disclosure includes the oven and a temperature detection probe. The temperature detection probe is electrically and mechanically connectable to the connector of the oven.

[0008] A cooking system according to the present disclosure includes the oven and a microwave oven. The microwave oven performs wired communication with the oven. A first circuit ground as the circuit ground of the oven is electrically connected to a second circuit ground of the microwave oven. The second circuit ground is electrically connected to the earth.

[0009] According to the present disclosure, it is possible to achieve both noise countermeasures and accurate measurement of the temperature of a cooking target.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 is a diagram illustrating a cooking system according to the present embodiment;

[0011] FIG. 2 is a functional block diagram of the cooking system according to the present embodiment;

[0012] FIG. 3 is an enlarged view of a part of a heating cooking chamber of an oven;

[0013] FIG. 4 is a diagram illustrating a meat probe used in the cooking system according to the present embodiment;

[0014] FIG. 5 is a diagram illustrating a circuit configuration of a temperature detection circuit in which detection processing of a temperature of a cooking target is performed in the cooking system according to the present embodiment; and

[0015] FIG. 6 is a diagram illustrating a comparative example with respect to the temperature detection circuit of the cooking system according to the present embodiment.DETAILED DESCRIPTION

[0016] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that, in the drawings, the same or corresponding portions are denoted by the same reference numerals, and descriptions thereof will not be repeated.

[0017] A cooking system 1 according to the present embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram illustrating the cooking system 1 according to the present embodiment. FIG. 2 is a functional block diagram of the cooking system 1 according to the present embodiment.

[0018] The cooking system 1 includes an oven 10 and a microwave oven 20. The microwave oven 20 is an example of a microwave oven. In the present embodiment, a side of the oven 10 on which an opening and closing door 11D to be described later is disposed is defined as a front side of the oven 10 (cooking system 1), and a side (back surface side) opposite to the front side is defined as a rear side of the oven 10 (cooking system 1). In addition, a right side when the oven 10 (cooking system 1) is viewed from the front side is defined as a right side of the oven 10 (cooking system 1), and a side opposite to the right side is defined as a left side of the oven 10 (cooking system 1). In addition, in a direction orthogonal to a front-rear direction and a left-right direction of the oven 10 (cooking system 1), a side on which a display unit 14 and an operation unit 15 to be described later are arranged is defined as an upper side of the oven 10 (cooking system 1), and a side (bottom side) opposite to the upper side is defined as a lower side of the oven 10 (cooking system 1). Note that these orientations do not limit the orientation of the oven 10 (cooking system 1) of the present disclosure during use.

[0019] In the present embodiment, the oven 10 and the microwave oven 20 are arranged next to each other in an up-down direction. Specifically, the oven 10 is disposed above the microwave oven 20.Oven 10

[0020] The oven 10 includes a heating cooking chamber 11, the opening and closing door 11D, a heating unit 12, a control unit 13, the display unit 14, the operation unit 15, and a housing 16.

[0021] As illustrated in FIG. 1, the housing 16 has, for example, a substantially rectangular parallelepiped shape with a front surface opened. The heating cooking chamber 11 is provided inside the housing 16. A cooking target (not illustrated) is arranged in the heating cooking chamber 11. Typically, the housing 16 is formed of a metal chassis. For example, the heating cooking chamber 11 and the housing 16 are integrally formed. The heating cooking chamber 11 is formed inside the housing 16, and is formed of a member having heat resistance (for example, enamel).

[0022] The opening and closing door 11D is a vertically open opening and closing door. Specifically, the opening and closing door 11D is attached to the housing 16 so as to be rotatable about a horizontal axis with a side of a lower portion on the front side of the housing 16 as the horizontal axis. However, the opening and closing door 11D of the present embodiment is not limited to a vertically open door. For example, a horizontally open opening and closing door that is attached to be rotatable about a vertical axis may be used with a side of a side portion on the left side of the housing 16 as the vertical axis.

[0023] The heating unit 12 heats a cooking target placed in the heating cooking chamber 11. As an example, the heating unit 12 includes a grill heater (not illustrated) and a blower fan (not illustrated). Typically, the grill heaters are located on the upper side and the lower side of the heating cooking chamber 11. Specifically, the grill heater is attached to each of the ceiling of the heating cooking chamber 11 and the bottom surface (floor surface) of the heating cooking chamber 11. The blower fan is disposed on a wall surface on the rear side of the heating cooking chamber 11. The grill heater and the blower fan perform convection cooking on the cooking target. The grill heater performs grill cooking or oven cooking on the cooking target.

[0024] The display unit 14 is disposed on the front surface of the housing 16 and above the opening and closing door 11D. The display unit 14 is a liquid crystal display, an organic EL display, or the like having a function of displaying a screen related to cooking of the cooking target. The operation unit 15 receives a user's operation. Typically, the display unit 14 and the operation unit 15 are integrally formed as a touch panel display. For example, the operation unit 15 is a touch sensor provided on the touch panel display. The touch sensor is, for example, a capacitive touch sensor. The touch sensor receives a touch operation, a slide operation, or the like by the user. When detecting the touch operation or the slide operation, the touch sensor outputs a signal indicating a detection result to the control unit 13. Note that the operation unit 15 may be a physical button, a pressure-sensitive touch panel switch, or the like provided separately from the display unit 14, in addition to the touch sensor provided on the touch panel display.

[0025] The control unit 13 controls the heating unit 12, the display unit 14, and the operation unit 15. Specifically, the control unit 13 includes a processor such as a central processing unit (CPU) or a micro controller unit (MCU). The control unit 13 is mounted and disposed on a control board 13B. The control board 13B is a multilayer board in which a plurality of conductive layers and a plurality of insulating layers are alternately stacked. One or more conductive layers of the plurality of conductive layers form a reference potential layer (signal ground SG1). The signal ground SG1 is an example of a first circuit ground.

[0026] In addition to the control unit 13, a power supply circuit or various circuit elements (not illustrated) are arranged on the control board 13B. For example, a storage unit 13M is arranged on the control board 13B. The storage unit 13M stores various programs, various kinds of data, and the like. Specifically, the storage unit 13M includes a semiconductor memory such as a read only memory (ROM) and a random access memory (RAM), a solid state drive (SSD), or a hard disk drive (HDD). The control unit 13 reads various programs from the storage unit 13M and executes the programs to control the heating unit 12 or control the display on the display unit 14. Note that the storage unit 13M may be provided in the control unit 13 in addition to being provided in the control board 13B separately from the control unit 13. Specifically, the storage unit 13M may be formed as a memory area included in the control unit 13.

[0027] In the present embodiment, the signal ground SG1 of the control board 13B is electrically connected to the housing 16 made of metal having conductivity. In other words, the housing 16 forms a frame ground FG1. That is, the housing 16 and the signal ground SG1 of the control board 13B have the same potential. As a result, it is possible to suppress the occurrence of noise, the occurrence of an error due to disturbance noise, and the like.Microwave Oven 20

[0028] The microwave oven 20 includes a heating cooking chamber 21, a microwave supply unit 22, a control unit 23, a drawer 24, and a housing 26.

[0029] The housing 26 has, for example, a substantially rectangular parallelepiped shape with a front surface opened. The heating cooking chamber 21 is provided inside the housing 26. The heating cooking chamber 21 has a predetermined volume as a space in which the cooking target (not illustrated) can be accommodated. Typically, the housing 26 is formed of a metal chassis.

[0030] The drawer 24 can be drawn out along the front-rear direction with respect to the heating cooking chamber 21. In the present embodiment, a drive mechanism such as a motor that drives the drawer 24 is housed in a space between the bottom wall of the housing 26 and the bottom wall of the heating cooking chamber 21. The drive mechanism switches between a drawn-out state in which the drawer 24 is drawn out from the heating cooking chamber 21 and a pushed-in state in which the drawer 24 is pushed in the heating cooking chamber 21 under the control of the control unit 23 described later. A door capable of opening and closing an opening on the front side of the heating cooking chamber 21 is provided on the front side of the drawer 24. The door opens the opening on the front side of the heating cooking chamber 21 in the drawn-out state, and closes the opening on the front side of the heating cooking chamber 21 in the pushed-in state.

[0031] The microwave supply unit 22 includes a magnetron. The magnetron supplies microwaves to the heating cooking chamber 21 to heat the cooking target placed in the heating cooking chamber 21.

[0032] The control unit 23 controls the microwave supply unit 22 and the drawer 24. Specifically, the control unit 13 includes a processor such as a central processing unit (CPU) or a micro controller unit (MCU). The control unit 23 is mounted and disposed on a control board 23B. The control board 23B is a multilayer board in which a plurality of conductive layers and a plurality of insulating layers are alternately stacked. One or more conductive layers of the plurality of conductive layers form a reference potential layer (signal ground SG2). The signal ground SG2 is an example of a second circuit ground.

[0033] In addition to the control unit 23, a power supply circuit or various circuit elements (not illustrated) are arranged on the control board 23B. For example, a storage unit 23M is arranged on the control board 23B. The storage unit 23M stores various programs, various kinds of data, and the like. Specifically, the storage unit 23M includes a semiconductor memory such as a read only memory (ROM) and a random access memory (RAM), a solid state drive (SSD), or a hard disk drive (HDD). The control unit 23 reads various programs from the storage unit 23M and executes the programs to control the microwave supply unit 22 or controls a drive mechanism for driving the drawer 24. Note that the storage unit 23M may be provided in the control unit 23 in addition to being provided in the control board 23B separately from the control unit 23. Specifically, the storage unit 23M may be formed as a memory area included in the control unit 23.

[0034] In the present embodiment, the signal ground SG2 of the control board 23B is electrically connected to the housing 26 made of metal having conductivity. In other words, the housing 26 forms a frame ground FG2. That is, the housing 26 and the signal ground SG2 of the control board 23B have the same potential.

[0035] In the cooking system 1, the control unit 13 of the oven 10 and the control unit 23 of the microwave oven 20 can communicate with each other. For example, the control unit 13 and the control unit 23 are electrically and mechanically connected to each other via a communication harness. As a result, the signal ground SG1 of the control board 13B and the signal ground SG2 of the control board 23B are electrically connected and have the same potential, and thus, it is possible to transmit and receive signals via the communication harness. As a result, the control unit 13 can control the control unit 23, and can control the microwave supply unit 22 and the drawer 24 via the control unit 23. In addition, the control unit 23 can control the control unit 13, and can control the heating unit 12, the display unit 14, and the operation unit 15 via the control unit 13. That is, the microwave oven 20 performs wired communication with the oven 10. Note that the oven 10 and the microwave oven 20 may communicate with each other by wireless communication in addition to wired communication with each other via a communication harness, for example.

[0036] In addition, in the cooking system 1, the housing 16 of the oven 10 and the housing 26 of the microwave oven 20 are mechanically connected to each other by a conductive metal connection member P1. Specifically, the connection member PI is attached to the lower side on the right side of the housing 16 and the upper side on the right side of the housing 26, and is attached to the lower side on the left side of the housing 16 and the upper side on the left side of the housing 26 (not illustrated in FIG. 1).

[0037] As a result, the housing 16 and the housing 26 are also electrically connected. In other words, the frame ground FG1 of the oven 10 and the frame ground FG2 of the housing 26 are also electrically connected to each other, and the frame ground FG1 and the frame ground FG2 have the same potential. As a result, the signal ground SG1 electrically connected to the frame ground FG1 and the signal ground SG2 electrically connected to the frame ground FG2 have the same potential.

[0038] Typically, the microwave oven 20 is grounded. Specifically, the frame ground FG2 of the microwave oven 20 is grounded to a reference potential GND (earth) via a power cable (not illustrated) or the like. In other words, the frame ground FG2 is electrically connected to the reference potential GND (earth). As a result, the frame ground FG2 and the frame ground FG1, the signal ground SG1, and the signal ground SG2 that are electrically connected to the frame ground FG2 have the same potential as the reference potential GND.

[0039] Next, a meat probe 30 used in the cooking system 1 according to the present embodiment will be described with reference to FIGS. 2 to 4. FIG. 3 is an enlarged view of a part of the heating cooking chamber 11 of the oven 10. FIG. 3 is an enlarged view of a region III indicated by a broken line in FIG. 1. FIG. 4 is a diagram illustrating the meat probe 30 used in the cooking system 1 according to the present embodiment.

[0040] As shown in FIGS. 2 and 3, the cooking system 1 further includes the meat probe 30. Specifically, the meat probe 30 is used together with the oven 10. In other words, the oven 10 and the meat probe 30 constitute an oven with a probe. The meat probe 30 is electrically and mechanically connected to the oven 10. In addition, the meat probe 30 is in contact with the cooking target arranged in the heating cooking chamber 11. The cooking target is an example of a detection target. The meat probe 30 is used to detect a temperature of the cooking target arranged in the heating cooking chamber 11. The meat probe 30 is an example of a temperature detection probe. The detection processing of the temperature of the cooking target using the meat probe 30 will be described later with reference to FIG. 4.

[0041] As illustrated in FIG. 4, the meat probe 30 includes a plug 31, a meter reading body 32, and a cable portion 33. The plug 31 is electrically and mechanically connected to the oven 10. The meter reading body 32 is in contact with the cooking target. The cable portion 33 connects the plug 31 and the meter reading body 32. The meter reading body 32 is made of metal, and has a needle shape.

[0042] On the other hand, as illustrated in FIG. 2, in the housing 16 of the oven 10, a socket 30C to which the meat probe 30 can be electrically and mechanically connected is provided in the heating cooking chamber 11. As an example, the socket 30C is provided on the wall surface on the left side of the heating cooking chamber 11. The plug 31 of the meat probe 30 is inserted into the socket 30C. When the plug 31 is inserted into the socket 30C, the socket 30C and the meat probe 30 are electrically and mechanically connected. The socket 30C is an example of a connector. Note that the relationship between the plug 31 and the socket 30C may be reversed. That is, the plug 31 may be provided in the heating cooking chamber 11, and the meat probe 30 may have the socket 30C. In addition, in the heating cooking chamber 11, a position where the socket 30C is provided is not particularly limited. The socket 30C may be provided on the wall surface on the right side, the wall surface on the rear side, the ceiling, or the floor surface of the heating cooking chamber 11.

[0043] Next, the detection processing of the temperature of the cooking target will be described with reference to FIGS. 3 to 6. FIG. 5 is a diagram illustrating a circuit configuration of a temperature detection circuit in which the detection processing of the temperature of the cooking target is performed in the cooking system 1 according to the present embodiment. FIG. 6 is a diagram illustrating a comparative example with respect to the temperature detection circuit of the cooking system 1 according to the present embodiment.Detection Processing in Cooking System 1

[0044] As illustrated in FIGS. 4 and 5, the meat probe 30 includes the meter reading body 32, and a thermistor TH. Specifically, the thermistor TH is disposed inside the meter reading body 32. An electric resistance value Rth [Ω] of the thermistor TH is changed according to the temperature. The thermistor TH is electrically connected to the plug 31 via the cable portion 33. The plug 31 has a first terminal 31p and a second terminal 31n. For example, the plug 31 has a rod shape. In the plug 31, the first terminal 31p and the second terminal 31n are arranged side by side in the axial direction. The first terminal 31p and the second terminal 31n are insulated from each other. In the present embodiment, the second terminal 31n is located on the distal end side of the plug 31 with respect to the first terminal 31p, but the positions of the first terminal 31p and the second terminal 31n may be reversed.

[0045] One end th1 of the thermistor TH is electrically connected to the first terminal 31p. The other end th2 on a side opposite to the one end th1 of the thermistor TH is electrically connected to the second terminal 31n. In addition, the other end th2 of the thermistor TH is electrically connected to the meter reading body 32. As a result, the heat of the cooking target is easily transferred to the thermistor TH through the meter reading body 32 made of metal having excellent thermal conductivity, and the electric resistance value Rth [Ω] of the thermistor TH easily reflects the temperature of the cooking target.

[0046] On the other hand, in the oven 10, the socket 30C has a first terminal 30p that is

[0047] electrically connected to the first terminal 31p of the plug 31 when the plug 31 is inserted, and a second terminal 30n that is electrically connected to the second terminal 31n of the plug 31 when the plug 31 is inserted. The first terminal 30p is an example of a first connection portion. The second terminal 30n is an example of a second connection portion.

[0048] The first terminal 30p of the socket 30C and the second terminal 30n of the socket 30C are electrically connected to the control unit 13 via pattern wiring of the control board 13B. The control unit 13 has a plurality of input and output terminals (hereinafter, simply referred to as terminals). At least one of the plurality of terminals of the control unit 13 is a reference terminal TV. At least another one of the plurality of terminals of the control unit 13 is a ground terminal TG. At least still another one of the plurality of terminals of the control unit 13 is a voltage input terminal TI.

[0049] The reference terminal TV is electrically connected to a constant voltage power supply circuit (not illustrated). The constant voltage power supply circuit is a power supply arranged on the control board 13B, and generates a reference power supply potential Vdd with respect to the signal ground SG1. The constant voltage power supply circuit is an example of a power supply. The ground terminal TG is electrically connected to the signal ground SG1. The voltage input terminal TI is electrically connected to the first terminal 30p of the socket 30C.

[0050] In addition, a pull-up resistor 41 (electric resistance value R1 [Ω]) is connected between the voltage input terminal TI and the first terminal 30p of the socket 30C and the constant voltage power supply circuit. Specifically, one end r1 of the pull-up resistor 41 is electrically connected to the voltage input terminal TI and the first terminal 30p of the socket 30C. The other end r2 on a side opposite to the one end r1 of the pull-up resistor 41 is electrically connected to the constant voltage power supply circuit.

[0051] In the present embodiment, the second terminal 30n of the socket 30C is electrically connected to the signal ground SG1. As described above, the signal ground SG1 is grounded to the reference potential GND via the housing 16 (frame ground FG1) of the oven 10 and the housing 26 (frame ground FG2) of the microwave oven 20. Accordingly, the second terminal 30n of the socket 30C is electrically connected to the reference potential GND via at least the housing 16. In addition, as illustrated in FIG. 3, since the socket 30C is provided on the wall surface of the heating cooking chamber 11 of the housing 16, the socket 30C and the heating cooking chamber 11 are electrically connected to each other. Specifically, the second terminal 30n of the socket 30C and the heating cooking chamber 11 are electrically connected to each other. In addition, the heating cooking chamber 11 is electrically connected to the housing 16. Accordingly, an indefinite parasitic resistance component 42 (electric resistance value R2 [Ω]) is generated between the second terminal 30n of the socket 30C and the frame ground FG1 (reference potential GND) due to the contact resistance between the socket 30C and the heating cooking chamber 11, the electric resistance of the heating cooking chamber 11, and the like. The electric resistance value R2 of the parasitic resistance component 42 greatly fluctuates particularly depending on the mounting state of the socket 30C or the like.

[0052] When the plug 31 is inserted into the socket 30C, the first terminal 30p of the socket 30C is electrically connected to the one end th1 of the thermistor TH via the first terminal 31p of the plug 31. The second terminal 30n of the socket 30C is electrically connected to the other end th2 of the thermistor TH via the second terminal 31n of the plug 31.

[0053] Thus, the one end th1 of the thermistor TH is electrically connected to the one end r1 of the pull-up resistor 41 and the voltage input terminal TI via the first terminal 31p of the plug 31 and the first terminal 30p of the socket 30C.

[0054] In this manner, when the plug 31 is inserted into the socket 30C, a closed circuit from the constant voltage power supply circuit to the signal ground SG1 through the pull-up resistor 41 and the thermistor TH is formed. At this time, the reference power supply potential Vdd is divided by the pull-up resistor 41 and the thermistor TH. That is, the pull-up resistor 41 is a voltage divider resistor of the reference power supply potential Vdd. As described above, the pull-up resistor 41 is electrically connected in series with the thermistor TH to be located on the upper side with respect to the thermistor TH, between the constant voltage power supply circuit and the signal ground SG1.

[0055] Specifically, when the plug 31 is inserted into the socket 30C, a predetermined voltage (potential difference) based on the reference power supply potential Vdd, the electric resistance value R1 of the pull-up resistor 41, and the electric resistance value Rth of the thermistor TH is applied to the voltage input terminal TI with respect to the signal ground SG1. In other words, a predetermined voltage (potential difference) is generated between the signal ground SG1 and a connection point between the one end r1 of the pull-up resistor 41 and the one end th1 of the thermistor TH.

[0056] The control unit 13 calculates the temperature of the cooking target with which the meat probe 30 is in contact, on the basis of the voltage (potential difference) applied to the voltage input terminal TI. The control unit 13 is an example of a temperature calculation unit. The control unit 13 functions as the temperature calculation unit by reading and executing various programs from the storage unit 13M. For example, the control unit 13 performs A / D conversion of the voltage (potential difference) applied to the voltage input terminal TI into a digital value on the basis of the reference power supply potential Vdd and the signal ground SG1. In the present embodiment, temperature voltage correspondence information indicating a correspondence relationship between the digital value indicating the voltage (potential difference) applied to the voltage input terminal TI and the temperature of the cooking target is stored in advance in the storage unit 13M. The control unit 13 refers to the temperature voltage correspondence information of the storage unit 13M, and acquires a temperature corresponding to the digital value indicating the voltage (potential difference) applied to the voltage input terminal TI.Comparative Example of Temperature Detection Circuit

[0057] As illustrated in FIG. 6, a comparative example with respect to the temperature detection circuit of the cooking system 1 is the same as the temperature detection circuit of the cooking system 1 except that a closed circuit to be formed is different from the temperature detection circuit of the cooking system 1. In other words, the temperature detection circuit of the cooking system 1 and the comparative example are different from each other in the connection relationship between the circuit elements.

[0058] Specifically, the constant voltage power supply circuit and the first terminal 30p of the socket 30C are electrically directly connected without passing through the pull-up resistor 41. On the other hand, the second terminal 30n of socket 30C is electrically connected to the signal ground SG1 via a pull-down resistor 43 (electric resistance value R1 [Ω]). Specifically, one end r1 of the pull-down resistor 43 is electrically connected to the voltage input terminal TI and the second terminal 30n of the socket 30C. The other end r2 of the pull-down resistor 43 is electrically connected to the signal ground SG1. Other connection relationships among the circuit elements are the same as those of the temperature detection circuit in the cooking system 1 illustrated in FIG. 5.

[0059] In the comparative example with respect to the temperature detection circuit of the cooking system 1, the other end th2 of the thermistor TH is electrically connected to the signal ground SG1 via the second terminal 30n of the socket 30C and the pull-down resistor 43. In addition, the signal ground SG1 is electrically connected to the reference potential GND. In addition, similarly to the temperature detection circuit in the cooking system 1 illustrated in FIG. 5, the indefinite parasitic resistance component 42 (electric resistance value R2 [Ω]) is generated between the second terminal 30n (voltage input terminal TI) of socket 30C and the signal ground SG1 (reference potential GND). As a result, a combined resistance component 44 (electric resistance value R0 [Ω]) of the pull-down resistor 43 (electric resistance value R1 [Ω]) and the parasitic resistance component 42 (electric resistance value R2 [Ω]) is generated between the voltage input terminal TI and the ground terminal TG (signal ground SG1). Thus, in the comparative example with respect to the temperature detection circuit of the cooking system 1, a closed circuit from the constant voltage power supply circuit to the signal ground SG1 through the thermistor TH and the combined resistance component 44 is formed. As a result, a voltage (potential difference) based on the reference power supply potential Vdd, the electric resistance value Rth of the thermistor TH, and the electric resistance value R0 of the combined resistance component 44 is applied to the voltage input terminal TI with respect to the signal ground SG1. Since the processing of the control unit 13 in the comparative example is the same as the processing of the control unit 13 in the cooking system 1, the description thereof will be omitted.

[0060] As described above, in the comparative example with respect to the temperature detection circuit of the cooking system 1, the temperature of the detection target is calculated using the combined resistance component 44 of the pull-down resistor 43 and the parasitic resistance component 42. As described above, the electric resistance value R2 [Ω] of the parasitic resistance component 42 is indefinite depending on the mounting state of the socket 30C or the like. Accordingly, in the comparative example of the temperature detection circuit, even in a case where the temperature of the cooking target is a predetermined value, a temperature calculation result fluctuates due to the fluctuation of the electric resistance value R2 of the parasitic resistance component 42.

[0061] On the other hand, as illustrated in FIG. 5, in the temperature detection circuit of the cooking system 1, the other end th2 of the thermistor TH is electrically connected to the signal ground SG1 via the second terminal 30n of the socket 30C. Accordingly, both ends of the parasitic resistance component 42 between the second terminal 30n of the socket 30C and the reference potential GND are electrically short-circuited. As a result, since the electric resistance value R2 [Ω] of the parasitic resistance component 42 is not used to calculate the temperature of the detection target, the temperature calculation result is not affected by the fluctuation of the electric resistance value R2 of the parasitic resistance component 42. Thus, the accuracy of the temperature calculation is improved as compared with the comparative example of the temperature detection circuit illustrated in FIG. 6. In addition, in the oven 10, since the signal ground SG1 and the reference potential GND are electrically connected to each other, it is possible to suppress occurrence of noise, occurrence of an error due to disturbance noise, and the like. Thus, the oven 10 of the present embodiment can achieve both noise countermeasures and accurate measurement of the temperature of the cooking target.

[0062] As illustrated in FIG. 5, in a case where the meat probe 30 is connected to the socket 30C, the meter reading body 32 is electrically connected to the signal ground SG1. As a result, even in a case where the meter reading body 32 of the meat probe 30 comes into contact with the housing 16 (frame ground FG1) or the like, a short circuit of the constant voltage power supply circuit can be suppressed.

[0063] In the present embodiment, the cooking system 1 includes the oven 10 and the microwave oven 20, and the signal ground SG1 of the oven 10 and the signal ground SG2 of the microwave oven 20 are grounded to the reference potential GND via the housings of the oven 10 and the microwave oven 20. However, the cooking system 1 may include only the oven 10, and the signal ground SG1 of the oven 10 may be grounded to the reference potential GND via the housing 16 of the oven 10.

[0064] Note that in the present embodiment, the signal ground SG1 and the frame ground FG1 are electrically connected to each other in the oven 10 alone, but the present disclosure is not limited thereto. In the oven 10 alone, the signal ground SG1 and the frame ground FG1 may be electrically insulated. In this case, the signal ground SG1 of the oven 10 is electrically connected to the signal ground SG2 of the microwave oven 20 by connecting the oven 10 and the microwave oven 20 by a communication harness. In the microwave oven 20, the signal ground SG2 is electrically connected to the frame ground FG2. In addition, the frame ground FG2 of the microwave oven 20 is electrically connected to the reference potential GND (earth) and the frame ground FG1 of the oven 10. Thus, the signal ground SG1 of the oven 10 is electrically connected to the frame ground FG1 and the reference potential GND (earth) via the communication harness and the microwave oven 20.

[0065] The embodiments of the present disclosure have been described above with reference to the drawings. However, the present disclosure is not limited to the embodiments described above, and can be implemented in various aspects without departing from the gist thereof. In addition, the plurality of constituent elements disclosed in the embodiments described above can be appropriately modified. For example, a certain constituent element of all the constituent elements in a certain embodiment may be added to a constituent element of another embodiment, or some constituent elements of all the constituent elements in a certain embodiment may be deleted from the embodiment.

[0066] In addition, the drawings schematically illustrate each constituent element mainly in order to facilitate understanding of the disclosure, and the thickness, length, number, interval, and the like of each illustrated constituent element may be different from the actual ones for convenience of drawing. In addition, the configuration of each constituent element illustrated in the embodiment described above is an example, and is not particularly limited, and it goes without saying that various modifications can be made without substantially departing from the effects of the present disclosure.

[0067] The present disclosure is applicable to the field of heating cookers.

Claims

1. An oven comprising:a housing provided with a connector to which a temperature detection probe including a thermistor is electrically and mechanically connectable;a voltage divider resistor electrically connected in series with the thermistor to be located on an upper side with respect to the thermistor, between a power supply and a circuit ground in a case where the temperature detection probe is connected to the connector; anda temperature calculation unit configured to calculate a temperature of a detection target with which the temperature detection probe is in contact, on the basis of a voltage between the circuit ground and a connection point between the voltage divider resistor and the thermistor.

2. The oven according to claim 1, wherein the circuit ground is electrically connected to the earth.

3. The oven according to claim 1, whereinthe connector hasa first connection portion electrically connected to the voltage divider resistor, anda second connection portion electrically connected to the circuit ground and electrically connected to the earth via the housing, andin a case where the temperature detection probe is connected to the connector,the first connection portion is electrically connected to one end of the thermistor, andthe second connection portion is electrically connected to the other end of the thermistor.

4. The oven according to claim 3, whereinthe temperature detection probe has a meter reading body made of metal, andthe meter reading body is electrically connected to the other end of the thermistor.

5. An oven with a probe comprising:the oven according to claim 1; anda temperature detection probe electrically and mechanically connectable to the connector of the oven.

6. A cooking system comprising:the oven according to claim 1; anda microwave oven configured to perform wired communication with the oven,wherein a first circuit ground as the circuit ground of the oven is electrically connected to a second circuit ground of the microwave oven, andthe second circuit ground is electrically connected to the earth.

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