Detecting device, sensor device, and detection method

Abstract

A detecting device according to the present disclosure comprises an acquiring unit and a detecting unit. The acquiring unit acquires, from a first sensor including a plurality of first elements having a characteristic that changes in accordance with temperature and the time exposed to the temperature, first sensor information relating to a first element of which the characteristic has changed. The acquiring unit acquires, from a second sensor including a plurality of second elements having a characteristic that changes in accordance with temperature and exposure time, the ease with which the characteristic of the second sensor changes with respect to temperature and exposure time being different from that of the first sensor, second sensor information relating to a second element of which the characteristic has changed. The detecting unit detects at least one of the temperature around the first and second sensors and the exposure time in accordance with the first and second sensor information.

Description

Detection device, sensor device, and detection method

[0001] The present disclosure relates to a detection device, a sensor device, and a detection method.

[0002] For example, electronic devices such as computers and cameras have multiple electronic components densely packed together. Therefore, heat generated by each electronic component during operation can cause malfunctions in the electronic device. Even when the electronic device is not in operation, malfunctions can occur due to rechargeable batteries that heat up during charging or exposure to high temperatures, such as inside a car in summer.

[0003] For this reason, many electronic devices are equipped with temperature sensors that detect the temperature of electronic components, etc. In addition to temperature sensors, electronic devices may also be equipped with various other sensors, such as timers that detect predetermined times.

[0004] Japanese Patent Application Laid-Open No. 2004-96073

[0005] For example, the main power of an electronic device may not always be on when it is necessary to detect the temperature, such as during charging. If a power source is required to drive the sensor, the electronic device may use, for example, a backup power source to detect the temperature when the main power of the electronic device is not on. In this case, without a backup power source, it is not possible to detect the temperature of the electronic device when the main power is not on.

[0006] It is desirable to be able to detect not only the state of an electronic device when it is powered on, but also the state when it is off (for example, temperature and exposure time to that temperature). In other words, it is desirable to be able to detect the state using a sensor that does not require a power source (i.e., does not require a backup power source).

[0007] Therefore, the present disclosure provides a detection device, a sensor device, and a detection method that can detect the surrounding state using a sensor that does not require a power source.

[0008] It should be noted that the above problem or object is merely one of multiple problems or objects that can be solved or achieved by multiple embodiments disclosed in this specification.

[0009] The detection device of the present disclosure includes an acquisition unit and a detection unit. The acquisition unit acquires, from a first sensor having a plurality of first elements whose characteristics change depending on temperature and exposure time, first sensor information relating to the first elements whose characteristics have changed. The acquisition unit acquires, from a second sensor having a plurality of second elements whose characteristics change depending on the temperature and the exposure time, second sensor information relating to the second elements whose characteristics have changed depending on the temperature and the exposure time, the second sensor having a different susceptibility to changes in the characteristics depending on the temperature and the exposure time than the first sensor. The detection unit detects at least one of the temperature around the first and second sensors and the exposure time according to the first and second sensor information.

[0010] FIG. 1 is a diagram illustrating an example of a schematic configuration of an information processing device according to a first embodiment of the present disclosure. FIG. 2 is a block diagram illustrating an example of a configuration of a sensor unit according to the first embodiment of the present disclosure. FIG. 3 is a graph illustrating an example of characteristics of a first sensor and a second sensor according to the first embodiment of the present disclosure. FIG. 4 is a diagram illustrating an example of a first table according to the first embodiment of the present disclosure. FIG. 5 is a diagram illustrating an example of a second table according to the first embodiment of the present disclosure. FIG. 6 is a flowchart illustrating an example of the flow of a detection process according to the first embodiment of the present disclosure. FIG. 7 is a block diagram illustrating an example of a configuration of a sensor unit according to a first modified example of the first embodiment of the present disclosure. FIG. 8 is a block diagram illustrating an example of a configuration of an information processing device according to a second modified example of the first embodiment of the present disclosure. FIG. 9 is a diagram illustrating an example of a schematic configuration of an information processing device according to a second embodiment of the present disclosure. FIG. 10 is a block diagram illustrating an example of a configuration of a sensor unit according to the second embodiment of the present disclosure. FIG. 11 is a graph for explaining an example of calculation of temperature and exposure time according to the second embodiment of the present disclosure. FIG. 12 is a flowchart illustrating an example of the flow of a detection process according to the second embodiment of the present disclosure.

[0011] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In this specification and drawings, components having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted.

[0012] Furthermore, in this specification and drawings, multiple components having substantially the same functional configuration may be distinguished by adding different letters or numbers after the same reference numeral. For example, multiple components having substantially the same functional configuration may be distinguished as necessary, such as first sensors 1411_1 and 1411_2. However, if there is no need to particularly distinguish between multiple components having substantially the same functional configuration, only the same reference numeral may be used. For example, if there is no need to particularly distinguish between first sensors 1411_1 and 1411_2, they will simply be referred to as first sensor 1411.

[0013] Furthermore, although specific values ​​are sometimes used in the present specification and drawings, these values ​​are merely examples and other values ​​may also be applied.

[0014] One or more embodiments (including examples, modifications, and application examples) described below can be implemented independently. However, at least a portion of the embodiments described below may be implemented in appropriate combination with at least a portion of another embodiment. These embodiments may include novel features that are different from each other. Therefore, these embodiments may contribute to solving different purposes or problems and may produce different effects from each other.

[0015] 1 is a diagram illustrating an example of a schematic configuration of an information processing device 10 according to a first embodiment of the present disclosure. The information processing device 10 is, for example, an electronic device such as a personal computer (PC), a tablet terminal, a smartphone, a camera, etc. The information processing device 10 may be of any type as long as it is equipped with a sensor device (details of which will be described later) that measures at least one of the temperature around a measurement target and the exposure time of the measurement target to that temperature.

[0016] The information processing device 10 shown in FIG. 1 includes a communication unit 110, a storage unit 120, a control unit 130, and a sensor unit 140 (an example of a sensor device).

[0017] (Communication Unit 110) The communication unit 110 is a communication interface for communicating with other communication devices. The communication unit 110 may be a network interface or a device connection interface. The communication unit 110 may be a LAN (Local Area Network) interface such as a NIC (Network Interface Card), or a Universal Serial Bus (USB) interface configured by a USB host controller or a USB port. The communication unit 110 may be a wired interface or a wireless interface. The communication unit 110 is controlled by the control unit 130.

[0018] (Storage Unit 120) The storage unit 120 is a readable and writable storage device such as a dynamic random access memory (DRAM), a static random access memory (SRAM), a flash memory, or a hard disk.

[0019] (Control Unit 130) The control unit 130 is a controller that controls each unit of the information processing device 10. The control unit 130 may be realized by a processor such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit). In particular, the control unit 130 may be realized by a processor executing various programs stored in an internal storage device of the information processing device 10 using a RAM (Random Access Memory) or the like as a work area. The control unit 130 may be realized by an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). The control unit 130 may also be realized by a GPU (Graphics Processing Unit). A CPU, an MPU, an ASIC, an FPGA, and a GPU can all be considered controllers. The control unit 130 may be composed of multiple physically separated objects. For example, the control unit 130 may be composed of multiple semiconductor chips.

[0020] (Sensor Unit 140) The sensor unit 140 detects at least one of the ambient temperature of the measurement target and the time (exposure time) that the measurement target is exposed to that temperature. Examples of the measurement target of the sensor unit 140 include electronic components (e.g., ICs (Integrated Circuits) and rechargeable batteries) mounted on the information processing device 10.

[0021] 2 is a block diagram showing an example configuration of the sensor unit 140 according to the first embodiment of the present disclosure. The sensor unit 140 shown in FIG. 2 includes a first sensor 1411, a second sensor 1412, an acquisition circuit 142, a determination circuit 143, a storage 144, and an initialization circuit 145.

[0022] (First Sensor 1411) The first sensor 1411 has a plurality of first elements (not shown) whose characteristics (e.g., "1" or "0") change depending on the temperature and the exposure time to the temperature. Examples of the first elements include magnetic tunnel junction elements (MTJ). For example, the first elements may be magnetoresistive random access memories (MRAMs).

[0023] The first element is not limited to an MRAM, and the first sensor 1411 may be any element that is sensitive to temperature, that is, an element whose characteristics change depending on the temperature and the exposure time to that temperature.

[0024] The first sensor 1411 may be a nonvolatile memory having a temperature-sensitive memristor as a first element. Examples of temperature-sensitive memristors include, in addition to MRAM, resistive random access memory (ReRAM) and phase-change memory (PCM).

[0025] An initial value (bit value) is written to the first sensor 1411 by an initialization circuit 145, which will be described later. That is, each first element of the first sensor 1411 is controlled by the initialization circuit 145 so that it has specific characteristics as an initial state.

[0026] The initial states of the first elements may be the same or different from each other, and the initial values ​​of the first elements may be "0" or "1."

[0027] The characteristic ("0" or "1") of each first element of the first sensor 1411 is inverted depending on the temperature and exposure time. The number of inverted first elements changes depending on the ambient temperature and exposure time of the first sensor 1411. Hereinafter, the ratio of the number of first elements that are inverted (changed) depending on the ambient temperature and exposure time to the total number of first elements included in the first sensor 1411 will be referred to as the inversion rate of the first sensor 1411 (an example of the first rate of change, the first inversion rate F １ (also referred to as "Synopsis of the Japanese Language")

[0028] Here, the first sensor 1411 is configured with a nonvolatile memory whose characteristics change depending on the temperature. Therefore, the first sensor 1411 can maintain specific characteristics (initial values) when power is not supplied to the first sensor 1411. Furthermore, the characteristics of the first sensor 1411 change depending on the ambient temperature and exposure time when power is not supplied.

[0029] (Second sensor 1412) The second sensor 1412 has a plurality of second elements (not shown) whose characteristics (e.g., "1" or "0") change depending on the temperature and the exposure time at this temperature. The second elements are the same as the first elements except that the second elements differ in how easily their characteristics change depending on the temperature and the exposure time at this temperature (sensitivity to temperature).

[0030] Therefore, the second sensor 1412 has the same characteristics as the first sensor 1411, except for its sensitivity to temperature.

[0031] For example, when the first element and the second element are MTJs, the temperature sensitivities of the first element and the second element can be made different by making the size of the magnetic layer, for example, the diameter of the magnetic layer, different between the first element and the second element.

[0032] An initial value (bit value) is written to the second sensor 1412 by an initialization circuit 145, which will be described later. That is, each second element of the second sensor 1412 is controlled by the initialization circuit 145 so that it has specific characteristics as an initial state.

[0033] The initial states of the second elements may be the same or different. The initial value of the second element may be "0" or "1." The initial value of the second sensor 1412 may be the same as or different from the initial value of the first sensor 1411.

[0034] The characteristic ("0" or "1") of each second element of the second sensor 1412 is inverted depending on the temperature and exposure time. The number of inverted second elements changes depending on the ambient temperature and exposure time of the second sensor 1412. Hereinafter, the ratio of the number of second elements inverted (changed) depending on the ambient temperature and exposure time to the total number of second elements included in the second sensor 1412 will be referred to as the inversion rate of the second sensor 1412 (an example of the second rate of change, the second inversion rate F ２ (also referred to as "Synopsis of the Japanese Language")

[0035] Here, the second sensor 1412 is configured with a nonvolatile memory whose characteristics change depending on the temperature. Therefore, the second sensor 1412 can maintain specific characteristics (initial values) when no power is supplied to the second sensor 1412. Furthermore, the characteristics of the second sensor 1412 change depending on the ambient temperature and exposure time when no power is supplied.

[0036] (Acquisition Circuit 142 ) The acquisition circuit 142 acquires first sensor information from the first sensor 1411 and second sensor information from the second sensor 1412 .

[0037] The first sensor information includes information about the first elements whose characteristics have changed, specifically, the first sensor information includes a bit value ("0" or "1") for each first element.

[0038] The second sensor information includes information about the second elements whose characteristics have changed, specifically, the second sensor information includes a bit value ("0" or "1") for each second element.

[0039] The acquisition circuit 142 outputs the first sensor information and the second sensor information to the determination circuit 143 .

[0040] (Storage 144) The storage 144 is a readable and writable storage device such as a DRAM, an SRAM, a flash memory, or a hard disk. The storage 144 stores the initial values ​​of the first sensor 1411 and the second sensor 1412. The storage 144 also stores the determination result (for example, at least one of the temperature and the exposure time) by the determination circuit 143.

[0041] (Initialization Circuit 145) The initialization circuit 145 initializes the first sensor 1411 and the second sensor 1412, for example, in accordance with an instruction from the determination circuit 143. The initialization circuit 145 is, for example, an example of a processing unit.

[0042] The initialization circuit 145 holds an initial value, i.e., commands a specific characteristic, for each first element of the first sensor 1411. The initialization circuit 145 holds an initial value, i.e., commands a specific characteristic, for each second element of the second sensor 1412.

[0043] For example, the determination circuit 143 instructs the initialization circuit 145 to initialize the first sensor 1411 after the acquisition circuit 142 acquires the first sensor information. Also, the determination circuit 143 instructs the initialization circuit 145 to initialize the second sensor 1412 after the acquisition circuit 142 acquires the second sensor information.

[0044] Alternatively, after detecting (determining) the temperature and exposure time, the determination circuit 143 may instruct the initialization circuit 145 to initialize the first sensor 1411 and the second sensor 1412. Note that the timing at which the initialization circuit 145 initializes the first sensor 1411 and the second sensor 1412 is not limited to the above example. For example, the initialization of the first sensor 1411 and the second sensor 1412 may be performed at various timings, such as at a timing instructed by the control unit 130.

[0045] (Determination Circuit 143) The determination circuit 143 detects at least one of the temperatures of the first sensor 1411 and the second sensor 1412, in other words, the ambient temperature of the measurement object, and the exposure time, based on the first sensor information and the second sensor information acquired by the acquisition circuit 142. The determination circuit 143 is, for example, an example of a detection unit. Note that, hereinafter, it is assumed that the determination circuit 143 detects both the temperature and the exposure time.

[0046] The determination circuit 143 determines a first reversal rate F based on the first sensor information. １ The determination circuit 143 calculates the second reversal rate F based on the second sensor information. ２ The determination circuit 143 calculates the first reversal rate F １and the second reversal rate F ２ The temperature and exposure time are detected according to the

[0047] FIG. 3 is a graph showing an example of the characteristics of the first sensor 1411 and the second sensor 1412 according to the first embodiment of the present disclosure.

[0048] FIG. 3A shows the first reversal rate F １ 10 is a graph showing the relationship between the temperature and exposure time (Time) for each temperature.

[0049] In FIG. 3A, the a １ Gaa １ = 61, b １ Ga b １ = 340, thermal stability Δ when temperature T = 0 (temperature is 0 degrees) １、Ｔ＝０ But, Δ １、Ｔ＝０ A graph is shown for the case where = 76.

[0050] Here, the thermal stability Δ at temperature T １ is expressed by the following formula (1): The first reversal rate F １ The cumulative reversal rate is expressed by the following formula (2).

[0051]

[0052] In addition, a １ is a value according to the first element. １ is a value determined depending on the material properties of the first element. ０ represents the spin torque.

[0053] FIG. 3B shows the second reversal rate F ２ 10 is a graph showing the relationship between the temperature and exposure time (Time) for each temperature.

[0054] In FIG. 3B, the a ２ Gaa ２ = 64, b ２ Ga b ２ = 340, thermal stability Δ when temperature T = 0 (temperature is 0 degrees) ２、Ｔ＝０ But, Δ ２、Ｔ＝０ A graph is shown for the case where .gtoreq.80.

[0055] Here, the thermal stability Δ at temperature T ２ is expressed by the following formula (3): The second reversal rate F ２ The cumulative reversal rate is expressed by the following formula (4).

[0056]

[0057] In addition, a ２ is a value according to the second element. ２ is a value determined depending on the material properties of the second element. Here, it is assumed that the first element and the second element are made of the same material. That is, b １ and the second element b ２ is the same.

[0058] As shown in FIG. 3, the first reversal rate F １ and the second reversal rate F ２ changes depending on the temperature and exposure time. The way in which this changes (the slope (gradient) in FIGS. 3A and 3B) differs between the first sensor 1411 and the second sensor 1412.

[0059] Here, the determination circuit 143 cannot detect both the temperature and the exposure time using only one of the first sensor 1411 and the second sensor 1412. This is because the reversal rate F changes depending on both the temperature and the exposure time.

[0060] Therefore, as shown in FIG. 3A, even if the first reversal rate F1 is a predetermined value (1.00E-1 in FIG. 3A), there are multiple combinations of temperature and exposure time.

[0061] In this way, the determination circuit 143 determines the first reversal rate F １ or the second reversal rate F ２ The temperature and exposure time cannot be detected by either one alone.

[0062] However, the determination circuit 143 can detect the temperature and exposure time by using both the first sensor 1411 and the second sensor 1412. For example, as shown in FIGS. 3(a) and 3(b), even at the same temperature and exposure time, the first reversal rate F １ and the second reversal rate F２ is different.

[0063] Therefore, the first reversal rate F １ Even if the second reversal rate F ２ Depending on the value of , the determination circuit 143 can uniquely detect the temperature and exposure time.

[0064] In this way, the determination circuit 143 detects the temperature and exposure time by utilizing the gradient of the reversal rate F of the first sensor 1411 and the second sensor 1412. The determination circuit 143 detects the temperature and exposure time by combining the first sensor 1411 and the second sensor 1412 which have different thermal stabilities Δ.

[0065] In the following, the first reversal rate F １ or the second reversal rate F ２ Two examples of the method for detecting the temperature and exposure time using the method will be described below.

[0066] (First Detection Method) In the first detection method, the determination circuit 143 determines the first reversal rate F １ and the second reversal rate F ２ The temperature and exposure time are detected using a function (calculation formula) with the following parameters.

[0067] For example, by solving simultaneous equations of the temperature T and the exposure time t for the above-mentioned equations (1) to (4), the solutions of the following equations (5) and (6) can be obtained.

[0068]

[0069] In addition, a １ , a ２ , b １ and b ２ is known as described above. The determination circuit 143 calculates the first reversal rate F １ and the second reversal rate F ２ The determination circuit 143 detects the temperature T by substituting the first inversion rate F １ and the second reversal rate F ２ The exposure time t is detected by substituting

[0070] In this way, the determination circuit 143 calculates the reversal rate F (cumulative reversal rate) using simultaneous equations for two variables (temperature T and exposure time t).

[0071] As shown in FIG. 2, the determination circuit 143 outputs the detected temperature T and exposure time t to the control unit 130 and the storage 144 .

[0072] (Second Detection Method) In the second detection method, the determination circuit 143 detects the temperature T and the exposure time t using a table. For example, the determination circuit 143 detects the first reversal rate F １ and the second reversal rate F ２ The temperature T is detected using a first table showing the temperature T according to the combination of

[0073] The first table is assumed to be created in advance based on, for example, the above-mentioned formulas (1) to (4) or experiments, etc. The first table is stored, for example, in the storage 144. The determination circuit 143 obtains the first table from the storage 144 when detecting the temperature T.

[0074] 4 is a diagram illustrating an example of a first table according to the first embodiment of the present disclosure. In the first table of FIG. 4, a first reversal rate F １ and the second reversal rate F ２ The temperature T corresponding to the combination of

[0075] The determination circuit 143 determines the first reversal rate F １ and the second reversal rate F ２ The temperature T is determined from the second table based on the combination of the first and second inversion rates F. By using the first table, the determination circuit 143 determines the temperature T based on the first inversion rate F. １ and the second reversal rate F ２ It can be uniquely determined from the combination of

[0076] Furthermore, for example, the determination circuit 143 determines the first reversal rate F １ and the second reversal rate F ２ The temperature T is detected using a second table showing the exposure time t according to the combination of

[0077] The second table is assumed to be created in advance based on, for example, the above-mentioned formulas (1) to (4) or experiments, etc. The second table is stored, for example, in the storage 144. The determination circuit 143 obtains the second table from the storage 144 when detecting the exposure time t.

[0078] 5 is a diagram illustrating an example of a second table according to the first embodiment of the present disclosure. In the second table of FIG. 5, the first reversal rate F １ and the second reversal rate F ２ The exposure time t according to the combination of

[0079] The determination circuit 143 determines the first reversal rate F １ and the second reversal rate F ２ By using the second table, the determination circuit 143 determines the temperature T based on the combination of the exposure time t and the first reversal rate F. １ and the second reversal rate F ２ It can be uniquely determined from the combination of

[0080] As described above, the first sensor 1411 and the second sensor 1412 maintain their initial values ​​when power is not supplied to them. Furthermore, when power is not supplied to the first sensor 1411 and the second sensor 1412, their initial values ​​are inverted depending on the ambient temperature and exposure time. The determination circuit 143 detects the temperature and exposure time depending on the inversion rate F at which the initial values ​​are inverted.

[0081] This allows the determination circuit 143 to detect the temperature and exposure time during the period when power is not being supplied to the sensor unit 140 after power is supplied to the sensor unit 140. In this way, the sensor unit 140 can measure the ambient temperature and exposure time of the measurement object regardless of whether power is being supplied or not.

[0082] More specifically, the judgment circuit 143 can detect the highest temperature and the exposure time to this temperature between the time when the initial values ​​are set in the first and second sensors 1411 and 1412 and the time when the first and second sensor information is read out.

[0083] (Detection Process) Fig. 6 is a flowchart showing an example of the flow of the detection process according to the first embodiment of the present disclosure. The detection process in Fig. 6 is executed by the sensor unit 140 in response to an instruction from the control unit 130, for example. Alternatively, the detection process may be executed at a predetermined cycle, or may be executed in response to a trigger other than an instruction from the control unit 130. For example, the sensor unit 140 may execute the detection process when power is supplied to the sensor unit 140.

[0084] 6, the sensor unit 140 acquires first sensor information from the first sensor 1411 (step S101), and second sensor information from the second sensor 1412 (step S102).

[0085] Next, the sensor unit 140 detects at least one of the temperature and the exposure time according to the first sensor information and the second sensor information (step S103).

[0086] For example, the sensor unit 140 calculates a first reversal rate F1 based on the first sensor information. The sensor unit 140 calculates a second reversal rate F2 based on the second sensor information. The sensor unit 140 detects at least one of the temperature and the exposure time according to a combination of the first reversal rate F1 and the second reversal rate F2.

[0087] The sensor unit 140 initializes the first sensor 1411 and the second sensor 1412 (step S104), and ends the process.

[0088] As described above, the sensor unit 140 according to the first embodiment includes the first and second sensors 1411 and 1412 whose initial characteristics are inverted depending on the temperature and exposure time when no power is supplied. The sensor unit 140 detects the temperature and exposure time using information about the inverted characteristics (e.g., inversion rate).

[0089] This allows the sensor unit 140 to detect the ambient temperature and exposure time of the object to be measured even during periods when power is not being supplied to the sensor unit 140, i.e., regardless of whether power is being supplied or not.

[0090] <1-1. Modifications> (First Modification) In the first embodiment described above, the determination circuit 143 issues an initialization instruction to the initialization circuit 145. However, the initialization instruction may be issued by a device other than the determination circuit 143, for example, the control unit 130.

[0091] Fig. 7 is a block diagram showing an example configuration of a sensor unit 140 according to a first modified example of the first embodiment of the present disclosure. The sensor unit 140 shown in Fig. 7 has the same configuration as the sensor unit 140 shown in Fig. 2, except that an initialization circuit 145 receives instructions from the control unit 130.

[0092] The initialization circuit 145 initializes the first sensor 1411 and the second sensor 1412 in accordance with an instruction from the control unit 130 .

[0093] For example, the control unit 130 instructs the initialization circuit 145 to perform initialization when it receives a notification of the detection result from the determination circuit 143. Alternatively, the control unit 130 may instruct the initialization circuit 145 to perform initialization in response to a predetermined trigger, such as when a predetermined application is started or when the processing load of the information processing device 10 exceeds a certain level.

[0094] When the control unit 130 issues an initialization instruction, the sensor unit 140 can detect the temperature and exposure time according to the state of a layer higher than the sensor unit 140, such as the state of the information processing device 10, for example.

[0095] (Second Modification) In the first embodiment described above, the sensor unit 140 detects the temperature and exposure time, and initializes the first and second sensors 1411 and 1412. However, these processes may be performed by a device other than the determination circuit 143, for example, the control unit 130.

[0096] 8 is a block diagram showing an example of the configuration of the information processing device 10 according to the second modified example of the first embodiment of the present disclosure, in which the communication unit 110 is omitted from the illustration.

[0097] The sensor unit 140 shown in Fig. 8 includes a first sensor 1411, a second sensor 1412, and an acquisition circuit 142. The sensor unit 140 shown in Fig. 8 is the same as the sensor unit 140 shown in Fig. 2 except that it does not include the determination circuit 143, the storage 144, and the initialization circuit 145.

[0098] 8 includes a determination unit 131 and an initialization unit 132. The determination unit 131 operates in the same manner as the determination circuit 143 in FIG. 2. The initialization unit 132 operates in the same manner as the initialization circuit 145 in FIG. 2.

[0099] 8 functions in the same manner as the storage 144. Specifically, the storage 120 stores the initial values ​​(initial states of the first elements and the second elements) of the first sensor 1411 and the second sensor 1412. The storage 120 also stores the determination results (temperature and exposure time) of the determination unit 131.

[0100] In this way, part of the processing performed by the sensor unit 140 in the first embodiment may be performed by the control unit 130. Alternatively, part of the processing performed by the sensor unit 140 in the first embodiment may be performed by an external device other than the information processing device 10.

[0101] In addition, although the control unit 130 detects both the temperature and exposure time and initializes the sensor here, the control unit 130 may perform either one of these functions. For example, the control unit 130 may detect the temperature and exposure time, and the sensor unit 140 may perform the initialization.

[0102] Although the storage unit 120 stores both the initial values ​​and the determination results of the sensors, the storage unit 120 may store only one of them. For example, the storage unit 120 may store the determination results, and the internal storage (storage 144) of the sensor unit 140 may store the initial values.

[0103] In the first embodiment described above, the sensor unit 140 has two sensors (first sensor 1411 and second sensor 1412), but the number of sensors is not limited to two and may be three or more.

[0104] For example, the sensor unit 140 may include a third sensor having a different temperature sensitivity from the first sensor 1411 and the second sensor 1412 .

[0105] Alternatively, the sensor unit 140 may include a plurality of first sensors 1411 and a plurality of second sensors 1412 .

[0106] When the sensor unit 140 includes a plurality of first sensors 1411, the determination circuit 143 determines a plurality of first reversal rates F from a plurality of pieces of first sensor information acquired from the plurality of first sensors 1411. １ The determination circuit 143 calculates the first reversal rate F １ The temperature and exposure time are determined using, for example, the average value of

[0107] When the sensor unit 140 includes a plurality of second sensors 1412, the determination circuit 143 determines a plurality of second reversal rates F from a plurality of pieces of second sensor information acquired from the plurality of second sensors 1412. ２ The determination circuit 143 calculates a plurality of second reversal rates F ２ The temperature and exposure time are determined using, for example, the average value of

[0108] 9 is a diagram illustrating an example of a schematic configuration of an information processing device 10A according to a second embodiment of the present disclosure. The information processing device 10A illustrated in Fig. 9 has the same configuration as the information processing device 10 in Fig. 1, except that it includes a sensor unit 140A instead of the sensor unit 140.

[0109] 10 is a block diagram showing an example configuration of the sensor unit 140A according to the second embodiment of the present disclosure. The sensor unit 140A shown in Fig. 10 includes a plurality of first sensors 1411_1, 1411_2..., a plurality of second sensors 1412_1, 1412_2..., and a plurality of third sensors 1413_1, 1413_2....

[0110] Although the number of each sensor is described as three here, the number of each sensor is not limited to three and may be two or less or four or more. Also, the number of each sensor may be different.

[0111] The sensor unit 140A also includes an acquisition circuit 142A, a determination circuit 143A, a storage 144A, and an initialization circuit 145A.

[0112] (Third sensor 1413) The third sensor 1413 has a plurality of third elements (not shown) whose characteristics (for example, "1" or "0") change depending on the temperature and the exposure time of the third element. The third elements are the same as the first and second elements except that the ease with which the characteristics change depending on the temperature and the exposure time of the third element (sensitivity to temperature) differs.

[0113] Therefore, the third sensor 1413 has the same characteristics as the first sensor 1411 and the second sensor 1412, except that the third sensor 1413 has a different sensitivity to temperature.

[0114] For example, if the first to third elements are MTJs, the temperature sensitivities of the first to third elements can be made different by making the size of the magnetic layer, for example, the diameter of the magnetic layer, different for each of the first to third elements.

[0115] An initialization circuit 145A (to be described later) writes an initial value (bit value) to the third sensor 1413. That is, each third element of the third sensor 1413 is controlled by the initialization circuit 145A so as to have specific characteristics as an initial state.

[0116] The initial states of the third elements may be the same or different from each other. The initial value of the third element may be "0" or "1." The initial value of the third sensor 1413 may be the same as or different from the initial values ​​of the first sensor 1411 and the second sensor 1412.

[0117] The characteristic ("0" or "1") of each third element of the third sensor 1413 is inverted depending on the temperature and exposure time. The number of inverted third elements changes depending on the ambient temperature and exposure time of the third sensor 1413. Hereinafter, the ratio of the number of third elements inverted depending on the ambient temperature and exposure time to the total number of third elements included in the third sensor 1413 will be referred to as the inversion rate of the third sensor 1413 (third inversion rate F ３) is called.

[0118] Here, the third sensor 1413 is configured with a nonvolatile memory whose characteristics change depending on the temperature. Therefore, the third sensor 1413 can maintain specific characteristics (initial values) when power is not supplied to the third sensor 1413. Furthermore, the characteristics of the third sensor 1413 change depending on the ambient temperature and exposure time when power is not supplied.

[0119] (Acquisition Circuit 142A) The acquisition circuit 142A acquires first sensor information from each of the first sensors 1411_1 to 1411_3. The acquisition circuit 142A acquires second sensor information from each of the second sensors 1412_1 to 1412_3. The acquisition circuit 142A acquires third sensor information from each of the third sensors 1413_1 to 1413_3.

[0120] The first sensor information includes information about the first elements whose characteristics have changed, specifically, the first sensor information includes a bit value ("0" or "1") for each first element.

[0121] The second sensor information includes information about the second elements whose characteristics have changed, specifically, the second sensor information includes a bit value ("0" or "1") for each second element.

[0122] The third sensor information includes information about the third elements whose characteristics have changed, specifically, the third sensor information includes a bit value ("0" or "1") for each third element.

[0123] The acquisition circuit 142A outputs the first to third sensor information to the determination circuit 143A.

[0124] (Storage 144A) The storage 144A is a readable and writable storage device such as a DRAM, an SRAM, a flash memory, or a hard disk. The storage 144A stores the initial values ​​of the first to third sensors 1411 to 1413. The storage 144A also stores the determination results (for example, at least one of the temperature and the exposure time) by the determination circuit 143A.

[0125] (Initialization Circuit 145A) The initialization circuit 145A initializes the first to third sensors 1411 to 1413 in accordance with, for example, an instruction from the determination circuit 143A. The initialization circuit 145A is, for example, an example of a processing unit.

[0126] The initialization circuit 145A holds an initial value, i.e., commands a specific characteristic, for each first element of the first sensor 1411. The initialization circuit 145A holds an initial value, i.e., commands a specific characteristic, for each second element of the second sensor 1412. The initialization circuit 145A holds an initial value, i.e., commands a specific characteristic, for each third element of the third sensor 1413.

[0127] For example, the determination circuit 143A instructs the initialization circuit 145A to initialize the first sensor 1411 after the acquisition circuit 142A acquires the first sensor information. Furthermore, for example, the determination circuit 143A instructs the initialization circuit 145A to initialize the second sensor 1412 after the acquisition circuit 142A acquires the second sensor information. For example, the determination circuit 143A instructs the initialization circuit 145A to initialize the third sensor 1413 after the acquisition circuit 142A acquires the third sensor information.

[0128] Alternatively, the determination circuit 143A may instruct the initialization circuit 145A to initialize the first to third sensors 1411 to 1413 after detecting (determining) the temperature and exposure time. The timing at which the initialization circuit 145A initializes the first to third sensors 1411 to 1413 is not limited to the example described above. For example, the initialization of the first to third sensors 1411 to 1413 may be performed at various times, such as at times instructed by the control unit 130.

[0129] Furthermore, as in the first modified example described above, the control unit 130 may directly instruct the initialization circuit 145A to execute initialization.

[0130] (Determination Circuit 143A) The determination circuit 143A detects at least one of the ambient temperature of the measurement target and the exposure time based on the first to third sensor information acquired by the acquisition circuit 142A. The determination circuit 143A is, for example, an example of a detection unit. In the following, it is assumed that the determination circuit 143A detects both the temperature and the exposure time.

[0131] The determination circuit 143A determines a plurality of first reversal rates F based on the plurality of first sensor information. １ Hereinafter, the first reversal rate F calculated based on the first sensor information of the first sensor 1411_1 will be referred to as １ is the first reversal rate F １１ The first reversal rate F calculated based on the first sensor information of the first sensor 1411_2 is written as １ is the first reversal rate F １２ The first reversal rate F calculated based on the first sensor information of the first sensor 1411_3 is written as follows: １ is the first reversal rate F １３ It is written as follows.

[0132] The determination circuit 143A determines a plurality of second reversal rates F based on the plurality of second sensor information. ２ Hereinafter, the second reversal rate F calculated based on the second sensor information of the second sensor 1412_1 is ２ The second reversal rate F ２１ The second reversal rate F calculated based on the second sensor information of the second sensor 1412_2 is written as ２ The second reversal rate F ２２ The second reversal rate F2 calculated based on the second sensor information of the second sensor 1412_3 is written as follows: ２ The second reversal rate F ２３ It is written as follows.

[0133] The determination circuit 143A determines a plurality of third reversal rates F based on the plurality of third sensor information. ３ Hereinafter, the third reversal rate F calculated based on the third sensor information of the third sensor 1413_1 will be referred to as ３ The third reversal rate F ３１ The third reversal rate F calculated based on the third sensor information of the third sensor 1413_2 is written as follows: ３The third reversal rate F ３２ The third reversal rate F calculated based on the third sensor information of the third sensor 1413_3 is written as follows: ３ The third reversal rate F ３３ It is written as follows.

[0134] The determination circuit 143A determines the first reversal rate F １１ ~F １３ , the second reversal rate F ２１ ~F ２３ , and a third reversal rate F ３１ ~F ３３ The temperature and exposure time are detected using

[0135] As described above using equations (1) and (3), the thermal stability Δ ｉ is expressed by the following formula (7): As described above using formulas (2) and (4), the i-th reversal rate F ｉ is expressed by the following equation (8).

[0136]

[0137] As mentioned above, a ｉ is a value according to the i-th element of the i-th sensor 141i. b is a value determined according to the material characteristics of the i-th element of the i-th sensor 141i. Here, it is assumed that the materials of the i-th elements are all the same. Also, τ ０ represents the spin torque.

[0138] Based on equations (7) and (8), the following equation (9) is derived.

[0139]

[0140] Equation (9) is y = In(-In(1-F ｉ )), x = a ｉ Hereinafter, (T-b) / (T+273) is set as the slope α, and In(t / τ ０ ) is the intercept β, the temperature T and the exposure time t are expressed by the following equations (10) and (11).

[0141]

[0142] The slope α and intercept β are determined by the variable y = In(-In(1-F ｉ )), x = a ｉ It can be obtained by calculating a regression line from the set (plot) of In(-In(1-F ｉ )) is the i-th reversal rate F ｉ The i-th calculated value y ｉ Also, a ｉ is the i-th element value x corresponding to the i-th element included in the i-th sensor 141i. ｉ (a ｉ ) is also written as

[0143] Here, the determination circuit 143A calculates the slope α and the intercept β by calculating a regression line, but the determination circuit 143A may calculate the slope α and the intercept β by a method other than the method of calculating a regression line. For example, the determination circuit 143A may calculate the slope α and the intercept β by using an approximate curve (approximate straight line).

[0144] 11 is a graph for explaining an example of calculation of the temperature T and the exposure time t according to the second embodiment of the present disclosure. ｉ and the i-th element value x ｉ (a ｉ ) relationship is shown.

[0145] In the example of FIG. 11, the first element value a １ Haa １ = 58, the second element value a of the second sensor 1412 ２ Haa ２ =61, the third element value a of the third sensor 1413 ３ Haa ３ = 64.

[0146] Note that b in equation (7) is the same for all of the first to third sensors 1411 to 1413, i.e., b = 340. In other words, the first to third elements included in the first to third sensors 1411 to 1413 are all made of the same material.

[0147] In FIG. 11, the measurement object is exposed to a temperature of T=120 (degrees) for a time period of t=9.9*10 ４ (seconds) The calculated value y of the i-th exposure ｉ=In(-In(1-F ｉ )) are shown.

[0148] As described above, the sensor unit 140A includes a plurality of i-th sensors 141i. The i-th element value a of each i-th sensor 141i is ｉ (design value) are all the same value. Therefore, theoretically, the multiple i-th reversal rates F ｉ１ ~F ｉ３ should have the same value, but in reality, multiple i-th reversal rates F ｉ１ ~F ｉ３ can have different values.

[0149] This is the actual i-th element value a of each i-th sensor 141i. ｉ This is because the i-th element value a of each i-th sensor 141i varies. ｉ If there is a variation of σ=0.3 in the (manufactured value), the i-th calculated value y ｉ varies as shown in the graph of FIG.

[0150] Therefore, the determination circuit 143A determines the i-th calculated value y ｉ =In(-In(1-F ｉ The determination circuit 143A calculates the i-th element value a ｉ (design value) and the i-th calculated value y ｉ A regression line is calculated from the above, and the slope α and intercept β of the regression line are calculated.

[0151] 11, the slope α is −0.5402 and the intercept β is 31.204. When the determination circuit 143A calculates the temperature T and the exposure time t from the equations (10) and (11) using the slope α and the intercept β, the temperature T is 125° C. and the exposure time t is 3.6*10° C. ４ (seconds).

[0152] 11 are values ​​used in the simulation or calculated by the simulation. For example, when the i-th element is exposed to a temperature T of 120°C for a time t of 9.9*10°C, ４ (seconds) and whether the value is inverted, i.e., the i-th inversion rate F ｉIn other words, the temperature calculated by the determination circuit 143A is T=125 (degrees), and the exposure time is t=3.6*10 ４ (seconds) also varies depending on the random number.

[0153] Here, the determination circuit 143A theoretically determines the first calculated value y １ and the first element value a １ and a second calculated value y ２ and the second element value a ２ If there is one set of α and β, the slope α and the intercept β can be calculated.

[0154] That is, if the sensor unit 140A has one first sensor 1411 and one second sensor 1412, the determination circuit 143A can theoretically detect the temperature T and the exposure time t.

[0155] In order for the determination circuit 143A to detect the temperature T and the exposure time t with higher accuracy, it is desirable that the sensor unit 140A includes many i-th sensors 141i with different temperature sensitivities (i is a large number).

[0156] Furthermore, in order for the judgment circuit 143A to detect the temperature T and exposure time t with higher accuracy, it is desirable that the sensor unit 140A has a larger number of i-th sensors 141i (where j is the number of i-th sensors 141i_j, the number j is large).

[0157] However, as the number of j i-th sensors 141 i_j increases, the area of ​​the sensor unit 140A increases. Therefore, it is desirable that the number of j i-th sensors 141 i_j (the values ​​of i and j) be determined appropriately depending on the accuracy required of the sensor unit 140A and the area of ​​the sensor unit 140A.

[0158] (Detection Process) Fig. 12 is a flowchart showing an example of the flow of the detection process according to the second embodiment of the present disclosure. The detection process in Fig. 12 is executed by the sensor unit 140A in response to an instruction from the control unit 130, for example. Alternatively, the detection process may be executed at a predetermined cycle, or may be executed in response to a trigger other than an instruction from the control unit 130. For example, the sensor unit 140A may execute the detection process when power is supplied to the sensor unit 140A.

[0159] As shown in FIG. 12, the sensor unit 140A acquires first sensor information from each of the first sensors 1411_1 to 1411_3 (step S201).

[0160] The sensor unit 140A acquires second sensor information from each of the second sensors 1412_1 to 1412_3 (step S202).

[0161] The sensor unit 140A acquires third sensor information from each of the third sensors 1413_1 to 1413_3 (step S203).

[0162] Next, the sensor unit 140A calculates a regression line from each piece of sensor information (step S204). Specifically, the sensor unit 140A calculates the i-th reversal rate F ｉ The sensor unit 140A calculates the i-th reversal rate F ｉ to the i-th calculated value y ｉ The sensor unit 140A calculates the i-th calculated value y ｉ and the i element value a ｉ Calculate the regression line from

[0163] The sensor unit 140A detects at least one of the temperature T and the exposure time t using the calculated regression line (step S205). The sensor unit 140A calculates the slope α and intercept β of the regression line, and detects at least one of the temperature T and the exposure time t using the slope α and intercept β.

[0164] The sensor unit 140A initializes all the sensors (the first sensors 1411_1 to 1411_3, the second sensors 1412_1 to 1412_3, and the third sensors 1413_1 to 1413_3) (step S206), and ends the process.

[0165] As described above, the sensor unit 140A according to the second embodiment detects a plurality of i-th reversal rates F ｉ By obtaining a regression line using the above equation, the temperature T and exposure time t can be detected.

[0166] This allows the sensor unit 140A to detect the ambient temperature T of the object to be measured and the exposure time t even during periods when power is not being supplied to the sensor unit 140, i.e., regardless of whether power is being supplied or not.

[0167] In this embodiment, as in the modified example of the first embodiment described above, some of the processing of the sensor unit 140A (for example, the processing of the judgment circuit 143A and the initialization circuit 145A) may be performed by the control unit 130 or an external device.

[0168] <<3. Summary>> Although the embodiments of the present disclosure have been described above, the technical scope of the present disclosure is not limited to the above-described embodiments, and various modifications are possible without departing from the gist of the present disclosure. Furthermore, components of the embodiments and modifications may be combined as appropriate.

[0169] Furthermore, the effects of each embodiment described in this specification are merely examples and are not intended to be limiting, and other effects may also be obtained.

[0170] The present disclosure may also be configured as follows: (1) A detection device including: an acquisition unit that acquires, from a first sensor having a plurality of first elements whose characteristics change depending on temperature and exposure time when exposed to the temperature, first sensor information relating to the first elements whose characteristics have changed; and an acquisition unit that acquires, from a second sensor having a plurality of second elements whose characteristics change depending on the temperature and the exposure time, second sensor information relating to the second elements whose characteristics have changed depending on the temperature and the exposure time, the second sensor having a different tendency for the characteristics to change depending on the temperature and the exposure time than the first sensor; and a detection unit that detects at least one of the temperature around the first and second sensors and the exposure time according to the first and second sensor information. (2) The detection device according to (1), wherein the detection unit calculates, based on the first sensor information, a first rate of change indicating a proportion of the first elements whose characteristics have changed among the plurality of first elements included in the first sensor, and calculates, based on the second sensor information, a second rate of change indicating a proportion of the second elements whose characteristics have changed among the plurality of second elements included in the second sensor. (3) The detection device according to (2), wherein the detection unit detects at least one of the temperature and the exposure time according to a combination of the first rate of change and the second rate of change. (4) The detection device according to (2) or (3), wherein the detection unit detects at least one of the temperature and the exposure time using a function or a table having the first rate of change and the second rate of change as parameters. (5) The detection device according to (2), further comprising a calculation unit that calculates a first calculated value from the first rate of change and a second calculated value from the second rate of change, wherein the detection unit detects at least one of the temperature and the exposure time using the first calculated value and the second calculated value. (6) The detection device according to (5), wherein the detection unit detects at least one of the temperature and the exposure time using a first element value corresponding to the first element included in the first sensor, a second element value corresponding to the second element included in the second sensor, the first calculated value, and the second calculated value.(7) The detection device according to any one of (1) to (6), wherein the acquisition unit acquires the first sensor information from each of the plurality of first sensors. (8) The detection device according to any one of (1) to (7), wherein the acquisition unit acquires the second sensor information from each of the plurality of second sensors. (9) The detection device according to any one of (1) to (8), further comprising a processing unit that initializes the first sensor so that the first element has the specific characteristic. (10) The detection device according to any one of (1) to (9), further comprising a processing unit that initializes the second sensor so that the second element has the specific characteristic. (11) The detection device according to any one of (1) to (10), wherein the first element and the second element are memristors that are sensitive to temperature. (12) The detection device according to any one of (1) to (11), wherein the acquisition unit has a plurality of third elements whose characteristics change depending on the temperature and the exposure time, and acquires third sensor information about the third elements whose characteristics have changed from third sensors whose susceptibility to change depending on the temperature and the exposure time differs from that of the first sensor and the second sensor. (13) The detection device according to (12), wherein the acquisition unit acquires the third sensor information from each of the plurality of third sensors. (14) The detection device according to (12) or (13), further comprising a processing unit that initializes the third sensor so that the third element has the specific characteristic. (15) The detection device according to any one of (12) to (14), wherein the third element is a memristor that is sensitive to temperature.(16) A sensor device comprising: a first sensor having a plurality of first elements whose characteristics change depending on temperature and exposure time at the temperature; a second sensor having a plurality of second elements whose characteristics change depending on the temperature and exposure time, the second sensor having a different tendency for the characteristics to change depending on the temperature and exposure time than the first sensor; an acquisition unit that acquires first sensor information on the first elements whose characteristics have changed from the first sensor and second sensor information on the second elements whose characteristics have changed from the second sensor; and a detection unit that detects at least one of the temperature around the first and second sensors and the exposure time according to the first and second sensor information. (17) A detection method including: acquiring, from a first sensor having a plurality of first elements whose characteristics change depending on temperature and exposure time exposed to the temperature, first sensor information about the first elements whose characteristics have changed; acquiring, from a second sensor having a plurality of second elements whose characteristics change depending on the temperature and the exposure time, second sensor information about the second elements whose characteristics have changed depending on the temperature and the exposure time, the second sensor having a different tendency for the characteristics to change depending on the temperature and the exposure time than the first sensor; and detecting at least one of the temperature around the first and second sensors and the exposure time according to the first and second sensor information.

[0171] 10, 10A Information processing device 110 Communication unit 120 Storage unit 130 Control unit 131 Determination unit 132 Initialization unit 140, 140A Sensor unit 142, 142A Acquisition circuit 143, 143A Determination circuit 144, 144A Storage 145, 145A Initialization circuit 1411 First sensor 1412 Second sensor 1413 Third sensor

Claims

1. A detection device comprising: an acquisition unit that acquires, from a first sensor having a plurality of first elements whose characteristics change depending on temperature and exposure time when exposed to the temperature, first sensor information relating to the first elements whose characteristics have changed; and an acquisition unit that acquires, from a second sensor having a plurality of second elements whose characteristics change depending on the temperature and exposure time and whose susceptibility to changes in characteristics due to the temperature and exposure time differs from that of the first sensor, second sensor information relating to the second elements whose characteristics have changed; and a detection unit that detects at least one of the temperature around the first and second sensors and the exposure time depending on the first and second sensor information.

2. The detection device described in claim 1, wherein the detection unit calculates, based on the first sensor information, a first rate of change indicating the proportion of the first elements whose characteristics have changed among the multiple first elements possessed by the first sensor, and calculates, based on the second sensor information, a second rate of change indicating the proportion of the second elements whose characteristics have changed among the multiple second elements possessed by the second sensor.

3. The detection device according to claim 2, wherein the detection unit detects at least one of the temperature and the exposure time in accordance with a combination of the first rate of change and the second rate of change.

4. The detection device according to claim 2, wherein the detection unit detects at least one of the temperature and the exposure time using a function or table with the first rate of change and the second rate of change as parameters.

5. The detection device according to claim 2, further comprising a calculation unit that calculates a first calculated value from the first rate of change and a second calculated value from the second rate of change, wherein the detection unit detects at least one of the temperature and the exposure time using the first calculated value and the second calculated value.

6. The detection device according to claim 5, wherein the detection unit detects at least one of the temperature and the exposure time using a first element value corresponding to the first element included in the first sensor, a second element value corresponding to the second element included in the second sensor, the first calculated value, and the second calculated value.

7. The detection device according to claim 1, wherein the acquisition unit acquires the first sensor information from each of a plurality of the first sensors.

8. The detection device according to claim 1, wherein the acquisition unit acquires the second sensor information from each of a plurality of the second sensors.

9. The detection device of claim 1, further comprising a processing unit that initializes said first sensor so that said first element has a particular said characteristic.

10. The detection device of claim 1, further comprising a processing unit that initializes said second sensor so that said second element has said particular characteristic.

11. The sensing device of claim 1, wherein the first element and the second element are temperature-sensitive memristors.

12. The detection device described in claim 1, wherein the acquisition unit has a plurality of third elements whose characteristics change depending on the temperature and the exposure time, and acquires third sensor information regarding the third elements whose characteristics have changed from third sensors whose susceptibility to change depending on the temperature and the exposure time is different from that of the first sensor and the second sensor.

13. The detection device according to claim 12, wherein the acquisition unit acquires the third sensor information from each of a plurality of the third sensors.

14. The detection device of claim 12, further comprising a processing unit that initializes said third sensor so that said third element has said particular characteristic.

15. The sensing device of claim 12, wherein the third element is a temperature-sensitive memristor.

16. A sensor device comprising: a first sensor having a plurality of first elements whose characteristics change depending on temperature and exposure time at said temperature; a second sensor having a plurality of second elements whose characteristics change depending on said temperature and exposure time, said second sensor having a different tendency for said characteristics to change depending on said temperature and exposure time than said first sensor; an acquisition unit that acquires first sensor information from said first sensor relating to said first elements whose characteristics have changed, and acquires second sensor information from said second sensor relating to said second elements whose characteristics have changed; and a detection unit that detects at least one of the temperature around said first and second sensors and the exposure time according to said first and second sensor information.

17. A detection method comprising: acquiring, from a first sensor having a plurality of first elements whose characteristics change in response to temperature and exposure time at said temperature, first sensor information relating to the first elements whose characteristics have changed; acquiring, from a second sensor having a plurality of second elements whose characteristics change in response to said temperature and exposure time, second sensor information relating to the second elements whose characteristics have changed in response to said temperature and exposure time, the second sensor having a different susceptibility to changes in the characteristics due to said temperature and exposure time than said first sensor; and detecting at least one of the temperature and the exposure time around the first and second sensors in response to the first and second sensor information.

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