Real-time clock device, shock logger, and electronic equipment

Abstract

Realization of a real-time clock device that can more accurately determine the occurrence of damage to an object caused by impact. [Solution] The real-time clock device 20 includes a timing circuit 30 that generates time information, a storage circuit 50, a processing circuit 40 that, when it is determined that an impact event has occurred based on the acceleration detected by the acceleration sensor 12, records impact log information based on multiple acceleration data and time information during the impact log retention period in the storage circuit 50, and an interface circuit 60 that outputs the impact log information recorded in the storage circuit 50.

Description

Technical Field

[0001] The present invention relates to a real-time clock device, a shock logger, an electronic device, and the like.

Background Art

[0002] Patent Document 1 discloses a shock detection device. The shock detection device houses a clock, an acceleration sensor, a control unit, a storage unit, a wireless communication unit, a battery, and a housing in a semi-transparent or transparent resin housing. The control unit generates shock data, and the storage unit stores the shock data.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1, acceleration data when the acceleration exceeds a predetermined threshold value is stored in association with the time. However, there is a problem that it is not possible to appropriately determine whether or not the damage boundary has been exceeded based on only one point of acceleration data.

Means for Solving the Problems

[0005] One aspect of the present disclosure relates to a real-time clock device including a timing circuit that generates time information, a storage circuit, a processing circuit that records shock log information based on a plurality of acceleration data and the time information during a shock log holding period in the storage circuit when it is determined that a shock event has occurred based on the acceleration detected by an acceleration sensor, and an interface circuit that outputs the shock log information recorded in the storage circuit.

[0006] Another aspect of this disclosure relates to an impact logger including the real-time clock device described above and the acceleration sensor.

[0007] Another aspect of this disclosure relates to an electronic device that includes the real-time clock device described above, the acceleration sensor, and a processing device for reading the impact log information from the real-time clock device. [Brief explanation of the drawing]

[0008] [Figure 1] An example configuration of the real-time clock device of this embodiment. [Figure 2] A detailed configuration example of the real-time clock device of this embodiment. [Figure 3] An example configuration of the shock logger and electronic equipment according to this embodiment. [Figure 4] An example configuration of the shock logger and electronic equipment according to this embodiment. [Figure 5] An example of an impact logger installation. [Figure 6] An example of an impact logger installation. [Figure 7] A diagram illustrating the method for acquiring impact log information. [Figure 8] An explanatory diagram of an example of a calculation method for velocity change. [Figure 9] Diagram illustrating the damage boundary curve. [Figure 10] A flowchart illustrating an example of the processing in this embodiment. [Figure 11] A flowchart illustrating an example of the processing in this embodiment. [Figure 12] Diagram illustrating various examples of methods for storing acceleration data and time information. [Figure 13] An example of an impact logger in action. [Figure 14] An example of a shock logger in operation. [Figure 15] Detailed configuration example of an accelerometer and detection circuit. [Figure 16] An example of the structure of an impact logger module. [Figure 17] An example of the structure of an impact logger module. [Modes for carrying out the invention]

[0009] The following describes this embodiment. Note that the embodiment described below does not unduly limit the scope of the claims. Furthermore, not all of the configurations described in this embodiment are necessarily essential components.

[0010] 1. Real-time clock device Figure 1 shows an example configuration of the real-time clock device 20 of this embodiment. The real-time clock device 20 is a device that generates time information, for example, through timing processing. The real-time clock device 20 in Figure 1 includes a timing circuit 30, a processing circuit 40, a storage circuit 50, and an interface circuit 60. The real-time clock device 20 is not limited to the configuration in Figure 1, and various modifications can be made, such as omitting some of these components, adding other components, or replacing some components with other components.

[0011] The timing circuit 30 generates time information TM based on a predetermined clock signal. The clock signal is, for example, an oscillating clock signal. For example, the timing circuit 30 performs timing count processing based on a divided clock signal obtained by dividing the clock signal by, for example, a frequency divider circuit, and generates time information TM indicating, for example, the current time through this timing count processing. For example, dividing the clock signal by a frequency divider circuit generates a divided clock signal with a frequency such as 1 Hz or 1 kHz, and time information TM is generated by timing processing based on this divided clock signal. For example, the timing circuit 30 has timing counters for counting seconds, minutes, hours, days, months, and years, and generates time information TM through the count processing of the timing counters. The time information TM may be, for example, the data of the count value of the timing counter itself, or it may be data representing all or part of the year, month, day, hour, minute, and second. The time information TM is then output from the timing circuit 30 to the processing circuit 40. The generated time information TM can also be output externally, for example, via an interface circuit 60.

[0012] The processing circuit 40 is a circuit that performs various arithmetic operations and control operations in the real-time clock device 20. The processing circuit 40 can be realized by, for example, a logic circuit or the like, and specifically, can be realized by a circuit of an ASIC (Application Specific Integrated Circuit) by automatic placement and wiring such as a gate array or the like.

[0013] Then, the processing circuit 40 generates impact log information LG based on the acceleration detected by the acceleration sensor 12. Specifically, when the processing circuit 40 determines that an impact event has occurred, it generates impact log information LG based on a plurality of acceleration data and time information TM during the holding period of the impact log. Then, the processing circuit 40 records the generated impact log information LG in the storage circuit 50. Details of the impact log information LG will be described later. Note that the processing circuit 40 may perform a process of correcting the time information TM from the timing circuit 30 based on a reference signal. The reference signal is, for example, a 1PPS (Pulse Per Second) signal which is a timing standard signal in GPS (GNSS) or the like. Alternatively, a signal based on time synchronization by NTP (Network Time Protocol) or PTP (Precision Time Protocol) or the like may be used as the reference signal.

[0014] The acceleration sensor 12 is, for example, a capacitance-type acceleration sensor using silicon MEMS (Micro Electro Mechanical Systems). Alternatively, the acceleration sensor 12 may be an acceleration sensor using a crystal oscillator, an acceleration sensor using a piezoelectric element, or the like.

[0015] The memory circuit 50 is a circuit that stores information and is implemented by semiconductor memory such as RAM or non-volatile memory. RAM can be, for example, SRAM (Static Random Access Memory) or DRAM (Dynamic Random Access Memory). Non-volatile memory can be any electrically writable ROM, such as EEPROM (Electrically Erasable Programmable Read Only Memory). The memory circuit 50 stores the impact log information LG generated by the processing circuit 40.

[0016] The interface circuit 60 is a circuit for communicating with the outside world. For example, the interface circuit 60 communicates with the external processing unit 100 based on a given communication standard. For example, the interface circuit 60 performs serial communication such as I2C (Inter-Integrated Circuit) or SPI (Serial Peripheral Interface). In the case of serial communication, the real-time clock device 20 has communication terminals such as a serial clock input terminal and serial data input / output terminals. The interface circuit 60 then outputs the impact log information LG recorded in the memory circuit 50. For example, the interface circuit 60 outputs the impact log information LG to the external processing unit 100. The processing unit 100 is, for example, a PC (Personal Computer) or a microcontroller embedded in electronic equipment that collects the impact log information LG.

[0017] Figure 2 shows a detailed configuration example of the real-time clock device 20. In Figure 2, in addition to the components shown in Figure 1, an oscillator 22, an oscillation circuit 24, a power supply voltage selection circuit 26, and a sensor interface circuit 62 are further provided. Note that the real-time clock device 20 is not limited to the configuration shown in Figure 2, and various modifications can be made, such as omitting some of these components, adding other components, or replacing some components with other components. For example, the oscillator 22 may be provided outside the real-time clock device 20, and the acceleration sensor 12 may be provided inside the real-time clock device 20. Also, the configuration may be made without the power supply voltage selection circuit 26.

[0018] The oscillator 22 is an element that generates mechanical vibrations in response to electrical signals. The oscillator 22 can be realized by a vibrating element such as a quartz crystal. For example, the oscillator 22 can be realized by a quartz crystal that vibrates with a thickness shear vibration such as an AT cut or SC cut, a tuning fork type quartz crystal, or a double tuning fork type quartz crystal. In this embodiment, the oscillator 22 can also be realized by various vibrating elements such as vibrating elements other than thickness shear vibration type, tuning fork type or double tuning fork type, or piezoelectric vibrating elements made of materials other than quartz. For example, as the oscillator 22, it is also possible to use a SAW (Surface Acoustic Wave) resonator or a MEMS (Micro Electro Mechanical Systems) oscillator as a silicon oscillator formed using a silicon substrate.

[0019] The oscillation circuit 24 is a circuit that outputs an oscillation clock signal CK. For example, the oscillation circuit 24 generates an oscillation signal by the oscillation operation of the resonator 22 and outputs an oscillation clock signal CK based on the oscillation signal. For example, the oscillation circuit 24 generates a sinusoidal oscillation signal by driving the resonator 22, such as a crystal resonator, with a drive circuit and causing it to oscillate, and outputs a square wave oscillation clock signal CK by shaping the generated oscillation signal with a waveform shaping circuit. The oscillation clock signal CK is, for example, a clock signal with a frequency of 32.768 kHz. However, the frequency of the oscillation clock signal CK is not limited to this and may be a frequency such as 32 kHz. The real-time clock device 20 may also have a clock output terminal that outputs this oscillation clock signal CK.

[0020] The oscillation circuit 24 can be realized, for example, by an oscillation drive circuit electrically connected to one end and the other end of the resonator 22, and passive elements such as capacitors and resistors. The drive circuit can be realized, for example, by a bipolar transistor or a CMOS inverter circuit. The drive circuit is the core circuit of the oscillation circuit 24, and the drive circuit causes the resonator 22 to oscillate by voltage driving or current driving the resonator 22. Various types of oscillation circuits can be used as the oscillation circuit 24, for example, inverter type, Pierce type, Colpitts type, or Hartley type. The oscillation circuit 24 can also include a variable capacitance circuit. By adjusting the capacitance value of this variable capacitance circuit, the oscillation frequency of the oscillation circuit 24 can be adjusted. For example, a temperature compensation circuit can be provided that performs temperature compensation processing based on a temperature detection signal from a temperature sensor (not shown), and by adjusting the capacitance of the variable capacitance circuit based on the temperature compensation result in this temperature compensation circuit, temperature compensation of the oscillation frequency can be achieved. Note that the connection in this embodiment is an electrical connection. An electrical connection is a connection that allows electrical signals to be transmitted, and is a connection that enables the transmission of information by electrical signals. Electrical connections may be made via passive components or the like.

[0021] The sensor interface circuit 62 is a circuit that interfaces with the acceleration sensor 12. The sensor interface circuit 62 receives acceleration data DA from the acceleration sensor 12. It then outputs the received acceleration data DA to the processing circuit 40. For example, a serial communication circuit such as I2C or SPI can be used as the sensor interface circuit 62. In this way, the sensor interface circuit 62 receives acceleration data DA from the acceleration sensor 12 outside the real-time clock device 20 and outputs it to the processing circuit 40, thereby enabling the processing circuit 40 to generate impact log information. Alternatively, the acceleration data DA output by the acceleration sensor 12 may be directly input to the processing circuit 40 without providing such a sensor interface circuit 62.

[0022] The power supply voltage selection circuit 26 is a circuit that selects the internal power supply voltage supplied to the internal circuitry of the real-time clock device 20. For example, the power supply voltage selection circuit 26 selects either the power supply voltage from a battery such as a secondary battery or the power supply voltage from a main power supply via USB or a PC, and supplies it to the internal circuitry of the real-time clock device 20 as the internal power supply voltage. The power supply voltage selection circuit 26 also supplies the power supply voltage from the main power supply to the battery, enabling the battery to be charged. This makes it possible to operate the real-time clock device 20 based on the power supply voltage from the battery even when the main power supply is unavailable.

[0023] Figures 3 and 4 show an example configuration of the shock logger 10 and electronic device 2 of this embodiment. In Figure 3, the shock logger 10 includes an acceleration sensor 12 and a real-time clock device 20. The electronic device 2 includes the shock logger 10 and a processing device 100. That is, the electronic device 2 includes an acceleration sensor 12, a real-time clock device 20 and a processing device 100. The shock log information LG from the real-time clock device 20 is output to an external processing device 100, etc. In this way, a shock logger 10 can be realized in which shock log information LG based on the acceleration detected by the acceleration sensor 12 is recorded in the memory circuit 50 of the real-time clock device 20. The shock logger 10 may also be composed of an acceleration sensor module 80 in which the acceleration sensor 12 is housed in a package and a real-time clock module 82 in which the real-time clock device 20 is housed in a package, as shown in Figure 13, which will be described later. Alternatively, the shock logger 10 may be a shock logger module 8 in which the acceleration sensor 12 and an integrated circuit device 90 in which each circuit of the real-time clock device 20 is provided are housed in a package, as shown in Figure 14, which will be described later.

[0024] In Figure 4, the impact logger 10 includes a battery 19 in addition to an acceleration sensor 12 and a real-time clock device 20. The acceleration sensor 12 and the real-time clock device 20 operate based on the power supply voltage from this battery 19. The battery 19 stores electrical energy chemically or electrically, and can be a primary battery, a secondary battery, or a capacitor, for example. A primary battery could be a small button battery, for example. A secondary battery could be a lithium-ion battery, for example. The capacitor could be an electrolytic capacitor, or a so-called supercapacitor. By providing such a battery 19 in the impact logger 10, the real-time clock device 20 and the acceleration sensor 12 can operate based on the power supply voltage from the battery 19, even without an external power supply. The impact log information LG is then stored in the memory circuit 50 of the real-time clock device 20, and the stored impact log information LG is output to the processing device 100, etc., so that it is possible to determine the occurrence of damage due to impact on the object on which the impact logger 10 is installed.

[0025] Figures 5 and 6 show examples of the installation of the shock logger 10. In Figure 5, the shock logger 10 is mounted on the circuit board 3 of the electronic device 2. Various components such as ICs, resistors, capacitors, and connectors are mounted on the circuit board 3 to realize the functions of the electronic device 2. The electronic device 2 can be various, but examples include printers, projectors, television equipment, cameras, personal computers, displays, game consoles, smartphones, smartwatches, head-mounted displays, or audio equipment. The electronic device 2 is contained in packaging material 1 and transported. The shock logger 10 senses shock information during the logistics process of the electronic device 2, which is the object to be damaged.

[0026] In Figure 6, the shock logger 10 is mounted on a separate circuit board 11 for the shock logger, distinct from the electronic device 2. The electronic device 2 is housed in packaging material 1, and the shock logger 10 is placed inside the packaging material 1. The shock logger 10 senses the shock information applied to the packaging material 1, thereby sensing the shock information applied to the electronic device 2, which is also housed in the packaging material 1.

[0027] The installation location of the impact logger 10 is not limited to inside the packaging material 1. For example, the impact logger 10 may be placed inside an article that is not electronic equipment. Alternatively, the impact logger 10 may be placed inside the cargo compartment of a vehicle, train, ship, or aircraft transporting the article, or it may be mounted inside a container that stores the article during transport.

[0028] Furthermore, if the shock logger 10 is configured to include an acceleration sensor module 80 and a real-time clock module 82, as shown in Figure 13 below, the acceleration sensor module 80 and the real-time clock module 82 are mounted on board 3 in Figure 5 or board 11 in Figure 6. Also, if the shock logger 10 is a shock logger module 8 in which an acceleration sensor 12 and an integrated circuit device 90 are housed in a package, as shown in Figure 14, this shock logger module 8 is mounted on board 3 or board 11.

[0029] As described above, the real-time clock device 20 of this embodiment includes a timing circuit 30 that generates time information, a storage circuit 50, a processing circuit 40, and an interface circuit 60, as shown in Figures 1 and 2. When the processing circuit 40 determines that an impact event has occurred based on the acceleration detected by the acceleration sensor 12, it records impact log information based on multiple acceleration data and time information during the impact log retention period in the storage circuit 50. The interface circuit 60 then outputs the impact log information recorded in the storage circuit 50.

[0030] In this way, when an impact event occurs, impact log information based on multiple acceleration data and time information during the impact log retention period is recorded in the memory circuit 50, and this impact log information can be output externally via the interface circuit 60. The impact log information is based on multiple acceleration data and time information during the impact log retention period. Therefore, by using impact log information based on multiple acceleration data and time information, it becomes possible to more accurately determine whether damage to an object has been caused by an impact when an impact event occurs, compared to when the determination is made based on a single acceleration data.

[0031] For example, as a comparative example of this embodiment, there is an impact logger equipped with an acceleration sensor that records the maximum acceleration and the time when an impact occurs. However, this impact logger can only acquire the maximum acceleration at the time of impact, and it is not possible to determine whether or not an impact belonging to the damage region in the damage boundary curve described later in Figure 9 has been applied.

[0032] Another comparative example of this embodiment is a transport environment recorder equipped with a large-capacity memory that records all acceleration data. However, while a transport environment recorder can determine whether an impact belonging to the damage region on the damage boundary curve has been applied, it requires a large-capacity memory and constant writing of sensor data via a microcontroller. As a result, it consumes a lot of power, and a large-capacity battery is required for long-term recording. Consequently, it faces the challenges of being expensive and large in size.

[0033] In this respect, according to this embodiment, the impact logger 10 that detects impacts can be configured with a real-time clock device 20 and an acceleration sensor 12, enabling lower power consumption, lower costs, and miniaturization. Furthermore, even with such a configuration, it is possible to record maximum acceleration and time information, making it possible to determine whether or not the damage boundary curve has been exceeded, and thus determine whether the object has been damaged. In addition, the number of data recording points can be reduced, making it possible to record impact log information even if the memory capacity of the memory circuit 50 is small.

[0034] Figure 7 is an explanatory diagram of the method for acquiring impact log information in this embodiment. In Figure 7, acceleration thresholds VT1 and VT2 are set. Threshold VT1 is the first threshold, for example, the threshold used to determine the start of impact log retention. Threshold VT2 is the second threshold, for example, the threshold used to determine the end of impact log retention. These thresholds VT1 and VT2 are stored in the memory circuit 50 of the real-time clock device 20. Thresholds VT1 and VT2 can be set to different values ​​for each user of the impact logger 10. For example, the thresholds VT1 and VT2 desired by the user are written to the memory circuit 50 of the real-time clock device 20 using a PC or a writing device.

[0035] In Figure 7, when the acceleration detected by the acceleration sensor 12 exceeds the threshold VT1, the impact log retention period TH begins, and the processing circuit 40 starts recording impact log information. For example, in Figures 5 and 6, the object to be damaged is subjected to various impacts during transport, etc. However, recording all of these impact logs would hinder low power consumption and increase the memory capacity required for the storage circuit 50. For this reason, the threshold VT1 is set to a value at which damage to the object may occur due to impact. When the acceleration detected by the acceleration sensor 12 falls below the threshold VT2, the impact log retention period TH ends, and the processing circuit 40 stops recording impact log information. In other words, in this embodiment, the processing circuit 40 records the impact log information for the retention period TH, from when the acceleration exceeds the threshold VT1 until it falls below the threshold VT2, in the storage circuit 50. Here, the threshold VT2 is smaller than the threshold VT1. In Figure 7, time t is the elapsed time from when the acceleration reaches the maximum acceleration amax until it falls below the threshold VT2. Furthermore, period ta represents the duration during which the impact of the impact event is in effect.

[0036] In this case, as shown in Figure 7, the retention period TH for the impact log is the period that includes the timing when the acceleration reaches its maximum acceleration amax during the impact event. For example, thresholds VT1 and VT2 are set so that the retention period TH includes the timing when the acceleration reaches its maximum acceleration amax. In this way, impact log information based on the maximum acceleration amax can be recorded in the memory circuit 50, and damage determination using a damage boundary curve based on the maximum acceleration amax becomes possible.

[0037] Furthermore, the processing circuit 40 starts recording impact log information when the acceleration exceeds the threshold VT1. For example, the timing when the acceleration exceeds the threshold VT1 becomes the start timing of the impact log retention period TH. In this way, impact log information does not need to be recorded until the acceleration exceeds the threshold VT1, which enables lower power consumption of the real-time clock device 20 and saves memory capacity of the storage circuit 50.

[0038] Furthermore, the processing circuit 40 records impact log information in the storage circuit 50, using the period from when the acceleration exceeds the threshold VT1 until when the acceleration falls below the threshold VT2 as the retention period TH. For example, the processing circuit 40 generates impact log information based on multiple acceleration data detected by the acceleration sensor 12 during the retention period TH and stores it in the storage circuit 50. In this way, the processing circuit 40 can obtain impact log information using acceleration data from the period from when the acceleration exceeds the threshold VT1 until when the acceleration falls below the threshold VT2, and record it in the storage circuit 50. Therefore, by setting the threshold VT2 to a small value, for example, impact log information can be generated and recorded in the storage circuit 50 using acceleration data from the period necessary for more accurate damage determination.

[0039] For example, threshold VT2 is a smaller value than threshold VT1. That is, threshold VT2 is significantly smaller than threshold VT1, for example, close to 0G. Here, G is the acceleration due to gravity, for example, 9.8 m / s². 2For example, the smaller the threshold VT2, the longer the retention period TH for impact logs can be recorded, enabling more accurate damage determination. However, if the threshold VT2 is too small, malfunctions due to noise and other factors may occur. Therefore, the threshold VT2 is determined considering factors such as the noise level in acceleration detection and the detection accuracy of the acceleration sensor 12.

[0040] As will be explained in Figure 11 below, the processing circuit 40 may record impact log information in the storage circuit 50 for a predetermined period of time after the acceleration exceeds the threshold VT1, with the retention period TH being the retention period. For example, the duration of an impact event is a certain length of time. Therefore, if the retention period TH for the impact log is set to the period after the acceleration exceeds the threshold VT1 and the predetermined period of time has elapsed, it becomes possible to obtain impact log information necessary for accurate damage determination.

[0041] Next, an example of damage determination using a damage boundary curve will be explained using Figures 8 and 9. For example, in Figure 8, let t be the time from when the acceleration reaches its maximum acceleration amax until it falls below the threshold VT2. If the threshold VT2 is set to a sufficiently small value, and the acceleration signal waveform in Figure 8 when an impact is applied is considered to be a half-sine wave, then ta, which is the period during which the impact of the impact event acts, can be expressed as ta = 2 × t. The change in velocity corresponds to the area obtained by integrating the acceleration signal waveform. Furthermore, if a half-sine wave is integrated in the range of 0 to π, the area becomes S = 2. The acceleration due to gravity is G = 9.8 m / s². 2 Therefore, the velocity change V obtained by integrating the acceleration signal in the range of 0 to 2 × t can be expressed as shown in equation (1) below.

[0042] V={2×9.8×amax×(2×t)} / π (1)

[0043] Then, using the above-mentioned velocity change V and maximum acceleration amax, it becomes possible to determine damage using a damage boundary curve.

[0044] Figure 9 is an explanatory diagram of the damage boundary curve 9. The damage boundary curve 9 is sometimes abbreviated as DBC. The damage boundary curve 9 shown in Figure 9 is defined in a plane where the horizontal axis is velocity change V and the vertical axis is maximum acceleration amax. Maximum acceleration amax is also called peak acceleration. Of the regions demarcated by the damage boundary curve 9, the region on the side where the maximum acceleration amax and velocity change V are large is the damaged region RD, and the region on the side where the maximum acceleration amax and velocity change V are small is the undamaged region RND. If the maximum acceleration amax and velocity change V belonging to the damaged region RD are applied to an object, the object may be damaged. The damage boundary curve 9 can be determined, for example, by evaluating whether or not an object is damaged after being subjected to an impact.

[0045] Figure 10 is a flowchart illustrating an example of processing in this embodiment. When the acquisition of acceleration data is started, the processing circuit 40 determines whether the acceleration detected by the acceleration sensor 12 is equal to or greater than the threshold VT1 (steps S1, S2). If the acceleration is equal to or greater than the threshold VT1, the processing circuit 40 determines whether the acceleration is equal to or less than the threshold VT2. If the acceleration is not equal to or less than the threshold VT2, it records the acceleration data and time information in the storage circuit 50 (steps S3, S4). That is, the acceleration data and the time information when the acceleration data was detected are associated and stored in the storage circuit 50. On the other hand, if the acceleration is equal to or less than the threshold VT2, the processing circuit 40 records the maximum acceleration data and the time information when the maximum acceleration was detected in the storage circuit 50 (step S5). Furthermore, time information when the acceleration falls below the threshold VT2 is recorded in the memory circuit 50 (step S6). That is, the data of the maximum acceleration amax in Figure 8, the time information tma when the maximum acceleration amax was detected, and the time information ten when the acceleration fell below the threshold VT2 are stored in the memory circuit 50 as impact log information.

[0046] In this way, it becomes possible to determine the time t in Figure 8 and ta = 2 × t from tma and ten. Then, from the maximum acceleration amax and ta = 2 × t, it becomes possible to determine the velocity change V using equation (1) above. Consequently, in the damage boundary curve 9 in Figure 9, it becomes possible to determine whether or not the velocity change V and maximum acceleration amax belonging to the damage region RD have been applied to the object, making it possible to determine the occurrence of damage to the object with less data and simpler processing.

[0047] Figure 11 is a flowchart illustrating another processing example of this embodiment. Steps S11, S12, S14, S15, and S16 in Figure 11 are the same as steps S1, S2, S4, S5, and S6 in Figure 10, and the difference between Figure 11 and Figure 10 is step S13. That is, in step S3 of Figure 10, it is determined whether the acceleration has risen above the threshold VT1 and then fallen below the threshold VT2. In contrast, in step S13 of Figure 11, it is determined whether a predetermined time has elapsed after the acceleration has risen above the threshold VT1. In other words, in Figure 10, the period from when the acceleration rises above the threshold VT1 until it falls below the threshold VT2 is used as the retention period to record impact log information. In contrast, in Figure 11, the period from when the acceleration rises above the threshold VT1 until a predetermined time has elapsed is used as the retention period to record impact log information. For example, if an impact is applied to an object and the acceleration rises above the threshold VT1, it is thought that the acceleration will become 0 after a long time has elapsed. Therefore, by waiting for a predetermined time to elapse, as in step S13, it becomes possible to determine the velocity change V using the calculation method described in Figure 8, and to determine whether or not an impact belonging to the damage region RD has been applied to the object. Once the predetermined time has elapsed, the generation of impact log information using acceleration data will cease, thus enabling lower power consumption and saving of memory capacity in the memory circuit 50.

[0048] 2. Shocking Log Information Next, the details of the impact log information will be explained. Figure 12 shows various examples of impact log information in this embodiment. In B1 of Figure 12, the processing circuit 40 records impact log information in the storage circuit 50, in which multiple acceleration data, a1, a2, a3, etc., and the time information t1, t2, t3, etc., when each acceleration data was detected are associated. For example, acceleration data a1 and the time information t1, when a1 was detected, are recorded in association, and acceleration data a2 and the time information t2, when a2 was detected, are recorded in association. In this way, it becomes possible to more accurately determine whether or not damage has occurred to the object based on multiple acceleration data and the multiple time information corresponding to them. That is, it becomes possible to more accurately determine whether or not damage has occurred than to make a determination based on a single acceleration data and its time information, as in the aforementioned Patent Document 1.

[0049] In this case, as shown in B2 of Figure 12, the processing circuit 40 may further record the maximum acceleration amax data in the storage circuit 50 in addition to the acceleration data and time information in B1. By storing the maximum acceleration amax data in this way, it becomes possible to more reliably determine whether or not an impact that causes damage has been applied to the object. That is, in the damage boundary curve 9 of Figure 9, it is determined whether or not damage has occurred to the object based on whether or not the maximum acceleration amax and the velocity change V belong to the damage region RD. Therefore, by recording the maximum acceleration amax as impact log information, it becomes possible to more reliably determine whether or not an impact that causes damage has been applied to the object. The maximum acceleration amax can be detected by finding the maximum value from the acceleration at the timing before and after it.

[0050] Furthermore, in B3 of Figure 12, the processing circuit 40 records the data of the maximum acceleration amax, the time information tma when the maximum acceleration amax was detected, and the time information ten when the acceleration fell below the threshold VT1 used to determine the end of impact log retention, as impact log information in the storage circuit 50. In this way, based on the data of the maximum acceleration amax and the time information tma and ten, it becomes possible to determine whether an impact that causes damage has been applied to the object with less data and simpler calculations. For example, in Figure 8, the time t from tma to ten can be determined from the time information tma when the maximum acceleration amax occurred and the time information ten when the acceleration fell below the threshold VT1, and the time ta = 2 × t, which is the time when the impact was applied, can be determined. Then, from the maximum acceleration amax and ta = 2 × t, the velocity change V can be determined by equation (1) above, and it can be determined whether the velocity change V and the maximum acceleration amax belonging to the damage region RD have been applied to the object in the damage boundary curve 9 of Figure 9, and the occurrence of damage to the object can be determined.

[0051] Furthermore, in Figure 12, B4, the processing circuit 40 records the data of the maximum acceleration amax and the time information t, which is the time from when the maximum acceleration amax is detected until the acceleration falls below the threshold VT1, as impact log information in the memory circuit 50. In other words, the time t from tma to ten is directly calculated in Figure 8. Even in this way, based on the data of the maximum acceleration amax and the time information t from tma to ten, it becomes possible to determine whether an impact that causes damage has been applied to the object with less data and simpler calculations.

[0052] In this embodiment, the processing circuit 40 may perform damage determination using a damage boundary curve based on multiple acceleration data and time information during the retention period TH in Figure 8, and record the damage determination result information as impact log information in the storage circuit 50. For example, if the maximum acceleration and velocity change belong to the damaged region RD of the damage boundary curve 9 in Figure 9, the processing circuit 40 records damage determination result information indicating that damage has occurred as impact log information in the storage circuit 50. On the other hand, if the maximum acceleration and velocity change belong to the non-damaged region RND, the processing circuit 40 records damage determination result information indicating that no damage has occurred as impact log information in the storage circuit 50. In this way, the damage determination result information performed by the processing circuit 40 of the real-time clock device 20 is stored in the storage circuit 50 as impact log information. Therefore, by simply reading this impact log information from the storage circuit 50, an external processing device 100 or the like can obtain the result of the damage determination using the damage boundary curve.

[0053] In this embodiment, as shown in Figures 3 and 4, the electronic device 2 includes the real-time clock device 20 of this embodiment, an acceleration sensor 12, and a processing device 100 that reads impact log information from the real-time clock device 20. In this way, the impact log information recorded in the memory circuit 50 of the real-time clock device 20 can be used to determine damage to the electronic device 2 during transportation, etc.

[0054] In this embodiment, the processing unit 100 performs damage determination based on the damage boundary curve, using the impact log information. For example, if the maximum acceleration and velocity change belong to the damaged region RD of the damage boundary curve 9 in Figure 9, the processing unit 100 determines that damage has occurred. On the other hand, if the maximum acceleration and velocity change belong to the non-damaged region RND, the processing unit 100 determines that no damage has occurred. In this way, the processing unit 100 can easily determine whether or not damage has occurred in the object being impact-detected by reading the impact log information recorded in the memory circuit 50 of the real-time clock device 20.

[0055] 3. Impact Logger Next, the details of the impact logger 10 of this embodiment will be described. As shown in Figure 3, the impact logger 10 of this embodiment includes a real-time clock device 20 and an acceleration sensor 12. Furthermore, as shown in Figure 4, the impact logger 10 may also include a battery 19.

[0056] In Figure 13, the shock logger 10 is composed of an acceleration sensor module 80 in which the acceleration sensor 12 is housed in a package (first package), and a real-time clock module 82 in which the real-time clock device 20 is housed in a package (second package). In other words, the acceleration sensor 12 and the real-time clock device 20 are housed in separate packages. Specifically, in the acceleration sensor module 80 in Figure 13, the acceleration sensor 12 and the detection circuit 16 for the acceleration sensor 12 are housed in the package. In the real-time clock module 82, the integrated circuit device 90 (described later in Figure 14) and the oscillator 22 are housed in the package. The integrated circuit device 90 is a circuit device that includes the timing circuit 30, processing circuit 40, memory circuit 50, interface circuit 60, etc. for the real-time clock device 20. The package is, for example, a ceramic package, but it may also be a resin package. In this way, the shock logger 10 can be realized with the acceleration sensor module 80 and the real-time clock module 82 housed in separate packages. For example, by mounting an existing acceleration sensor module 80 and a real-time clock module 82 on a circuit board, an impact logger 10 can be realized. Based on the acceleration detected by the acceleration sensor module 80 and the time information measured by the timing circuit 30 of the real-time clock device 20, impact log information can be generated and recorded in the memory circuit 50 of the real-time clock device 20.

[0057] In Figure 14, the shock logger 10 is realized by a shock logger module 8 housed in a package 4, which will be described later in Figures 16 and 17. The package 8 includes an integrated circuit device 90 having a timing circuit 30, a processing circuit 40, a memory circuit 50, and an interface circuit 60, and an acceleration sensor 12. Specifically, in Figure 14, the package 4 houses, for example, the integrated circuit device 90, the acceleration sensor 12, and the oscillator 22. The integrated circuit device 90 also includes an oscillation circuit 24 for causing the oscillator 22 to oscillate, a timing circuit 30, a processing circuit 40, a memory circuit 50, an interface circuit 60, and a detection circuit 16 for the acceleration sensor 12. The package 4, such as a ceramic package, which houses the acceleration sensor 12, the oscillator 22, and the integrated circuit device 90, can be considered as a single component mounted on a printed circuit board, and is extremely compact compared to typical electronic devices that combine multiple components and house them in a casing. For example, the longest side length in the package 4 is 20 mm or less. In this way, by realizing the shock logger 10 using a shock logger module 8 in which an integrated circuit device 90 and an acceleration sensor 12 are housed in a small package 4, it becomes possible to miniaturize and reduce the cost of the shock logger 10 compared to the shock detection device described in Patent Document 1 above.

[0058] Figure 15 shows a detailed configuration example of an acceleration sensor 12 and a detection circuit 16. The acceleration sensor 12 includes an x-axis acceleration sensor element 13, a y-axis acceleration sensor element 14, and a z-axis acceleration sensor element 15. Although this example shows the acceleration sensor 12 as a 3-axis acceleration sensor, the acceleration sensor 12 may be a 1-axis or 2-axis acceleration sensor. The acceleration sensor 12 has a roughly plate-like shape parallel to the xy-plane. In a specific example, the acceleration sensor 12 includes a support substrate having a bottom surface parallel to the xy-plane and a lid joined to the support substrate. The x-axis acceleration sensor element 13, the y-axis acceleration sensor element 14, and the z-axis acceleration sensor element 15 are configured on the support substrate and covered by the lid.

[0059] The x-axis acceleration sensor element 13 includes a comb-shaped fixed electrode fixed to a support substrate, a movable part configured to move relative to the support substrate, and a comb-shaped movable electrode fixed to the movable part. Each tooth of the fixed electrode and each tooth of the movable electrode are arranged to face each other in the x-direction. When acceleration in the x-direction is applied to the x-axis acceleration sensor element 13, the movable part moves in the x-direction, changing the distance between the comb teeth, and thus changing the capacitance between the comb teeth. The detection circuit 16 detects the acceleration in the x-direction as acceleration information SSD by detecting this change in capacitance. The y-axis acceleration sensor element 14 has a similar configuration.

[0060] The z-axis acceleration sensor element 15 includes a comb-shaped fixed electrode fixed to a support substrate, a movable part that can swing on a rotation axis parallel to the xy plane, and a comb-shaped movable electrode fixed to the movable part. Each comb tooth of the fixed electrode and each comb tooth of the movable electrode are arranged to face each other in the x or y direction. When acceleration in the z direction is applied, the movable part swings, changing the overlapping area between the comb teeth, and thus changing the capacitance between the comb teeth. The detection circuit 16 detects this change in capacitance and detects the acceleration in the z direction as acceleration information SSD (acceleration data).

[0061] The detection circuit 16 includes an amplification circuit 17 and an A / D conversion circuit 18. Alternatively, the amplification circuit 17 and the A / D conversion circuit 18 may be provided for each of the x-axis acceleration sensor element 13, the y-axis acceleration sensor element 14, and the z-axis acceleration sensor element 15. Alternatively, the detection circuit 16 may include a selector, which time-divisionally selects the output signals of the x-axis acceleration sensor element 13, the y-axis acceleration sensor element 14, and the z-axis acceleration sensor element 15 and outputs them to the amplification circuit 17.

[0062] The detection circuit 16 includes an amplification circuit 17 and an A / D conversion circuit 18. Here, SQ is assumed to be the output signal of the x-axis accelerometer element 13, but the same applies to the output signals of the y-axis accelerometer element 14 and the z-axis accelerometer element 15. The amplification circuit 17 converts the output signal SQ of the x-axis accelerometer element 13 into a charge-to-voltage (Q / V) conversion and also amplifies it. The A / D conversion circuit 18 converts the output signal of the amplification circuit 17 into a digital signal and outputs the resulting x-axis acceleration as acceleration information SSD. Processing of the output signals of the y-axis accelerometer element 14 and the z-axis accelerometer element 15 is performed in the same manner.

[0063] Figure 17 shows a first structural example of the shock logger module 8. Note that internal wiring and external connection terminals are omitted from the diagram below. Also, the +z direction may be referred to as "up" and the -z direction as "down."

[0064] Package 4 includes a base 5 having a recess and a lid 6 which is a cover for the base 5. The bottom surface SFa of the base 5 is parallel to the xy plane, and the recess of the base 5 opens upward. The integrated circuit device 90, the accelerometer 12, and the oscillator 22 are sealed within package 4 by the lid 6 covering the recess so that its edge joins the edge of the recess of the base 5.

[0065] The recess of the base 5 has a bottom surface SFb and a stepped surface SFc provided above the bottom surface SFb. An integrated circuit device 90 is placed on the bottom surface SFb, and an acceleration sensor 12 is placed on top of it. The integrated circuit device 90 is, for example, a bare chip. The acceleration sensor 12 is, for example, a roughly rectangular parallelepiped. The integrated circuit device 90 and the acceleration sensor 12 are arranged so that their thickness direction is the z direction. The resonator 22 is, for example, a quartz resonator and is configured on a quartz relay substrate 7. The end of the relay substrate 7 is joined to the stepped surface SFc, thereby housing the resonator 22 in the base 5. In a plan view, the resonator 22 may overlap the integrated circuit device 90 and the acceleration sensor 12, or it may overlap only the integrated circuit device 90.

[0066] The integrated circuit device 90 and the acceleration sensor 12 are connected by internal package wiring. Internal package wiring includes bonding wires or wiring provided inside or on the inner surface of the base 5 structure. For example, the integrated circuit device 90 has a pad made of the top layer metal, and the acceleration sensor 12 has terminals for wiring connections. The pad of the integrated circuit device 90 and the terminals of the acceleration sensor 12 may be connected by bonding wires, or they may be connected via the wiring of the base 5. In the latter case, the pad of the integrated circuit device 90 and the terminals of the acceleration sensor 12 may be connected to the wiring of the base 5 by bonding wires or bumps. Similarly, the integrated circuit device 90 and the oscillator 22 are connected by internal package wiring.

[0067] Figure 17 shows a second structural example of the impact logger module 8. In the second structural example of Figure 17, an acceleration sensor 12 is placed on the bottom surface SFb, and an integrated circuit device 90 is placed on top of the acceleration sensor 12. Note that the impact logger module 8 is not limited to the structural examples in Figures 16 and 17. For example, the vibrator 22 may be placed on the bottom surface of the recess of the base 5 at a position that does not overlap with the integrated circuit device 90 in a plan view.

[0068] In the shock logger 10 realized by the shock logger module 8 shown in Figures 16 and 17, the acceleration sensor 12, integrated circuit device 90, and vibrator 22 are housed in a small package 4 that can be mounted on a circuit board. Such a package 4 can be considered as a single component mounted on a printed circuit board or the like, and is extremely small compared to typical electronic devices that combine multiple components and house them in a casing. Therefore, according to this embodiment, it is possible to realize an extremely small shock logger 10.

[0069] As described above, the real-time clock device of this embodiment includes a timing circuit that generates time information and a storage circuit. The real-time clock device also includes a processing circuit that, when it determines that an impact event has occurred based on the acceleration detected by the acceleration sensor, records impact log information based on multiple acceleration data and time information during the impact log retention period in the storage circuit, and an interface circuit that outputs the impact log information recorded in the storage circuit.

[0070] According to this embodiment, when an impact event occurs, impact log information based on multiple acceleration data and time information during the impact log retention period is recorded in the memory circuit, and this impact log information can be output externally via the interface circuit. Since the impact log information is based on multiple acceleration data and time information during the impact log retention period, it becomes possible to determine the occurrence of damage to the object due to impact more accurately compared to when the determination is made based on a single acceleration data.

[0071] In this embodiment, the holding period may also include the timing when the acceleration reaches its maximum during the impact event.

[0072] This allows impact log information based on maximum acceleration to be recorded in the memory circuit, making it possible to determine damage using a damage boundary curve based on maximum acceleration.

[0073] In this embodiment, the processing circuit may also start recording impact log information when the acceleration reaches a first threshold value or higher.

[0074] In this way, impact log information does not need to be recorded until the acceleration exceeds the first threshold, which enables lower power consumption of the real-time clock device and saving memory capacity in the memory circuit.

[0075] In this embodiment, the processing circuit may record impact log information in the storage circuit for a period from when the acceleration exceeds a first threshold until when the acceleration falls below a second threshold, using this period as the retention period.

[0076] In this way, impact log information can be obtained and recorded in the memory circuit using acceleration data from the period after the acceleration exceeds the first threshold until the acceleration falls below the second threshold. Therefore, it becomes possible to obtain impact log information necessary for more accurate damage assessment.

[0077] In this embodiment, the second threshold value may be smaller than the first threshold value.

[0078] A smaller second threshold allows for recording impact logs over a longer retention period, enabling more accurate damage assessment.

[0079] In this embodiment, the processing circuit may record impact log information in the storage circuit for a period of time from when the acceleration exceeds a first threshold until a predetermined time has elapsed, using this period as the retention period.

[0080] In this way, impact log information can be obtained and recorded in the memory circuit using acceleration data from the period after the acceleration exceeds the first threshold until a predetermined time has elapsed. Therefore, it becomes possible to obtain impact log information necessary for more accurate damage assessment.

[0081] In this embodiment, the processing circuit may also record impact log information in the storage circuit, in which each of the multiple acceleration data sets is associated with the time information when each acceleration data set was detected.

[0082] In this way, it becomes possible to more accurately determine whether or not damage has occurred to an object based on multiple acceleration data points and corresponding time information.

[0083] In this embodiment, the processing circuit may also record the maximum acceleration data in a storage circuit.

[0084] By storing data on maximum acceleration in this way, it becomes possible to more reliably determine whether or not an impact that causes damage has been applied to the object.

[0085] In this embodiment, the processing circuit may also record the data of the maximum acceleration, the time information when the maximum acceleration was detected, and the time information when the acceleration fell below a threshold for determining the end of impact log retention in the storage circuit as impact log information.

[0086] This approach makes it possible to determine whether an impact that causes damage has been applied to the object using less data and simpler calculations.

[0087] In this embodiment, the processing circuit may also record the data of the maximum acceleration and the time information from the time the maximum acceleration is detected until the acceleration falls below a threshold for determining the end of impact log retention as impact log information in the storage circuit.

[0088] This approach makes it possible to determine whether an impact that causes damage has been applied to the object using less data and simpler calculations.

[0089] In this embodiment, the processing circuit may perform damage determination using a damage boundary curve based on multiple acceleration data and time information during the retention period, and record the damage determination result information as impact log information in the storage circuit.

[0090] In this way, the damage determination results from the processing circuit of the real-time clock device are stored in the memory circuit as impact log information, and by simply reading this impact log information from the memory circuit, it becomes possible to obtain the damage determination results using the damage boundary curve.

[0091] Furthermore, the impact logger of this embodiment includes the real-time clock device described above and an acceleration sensor.

[0092] In this way, it becomes possible to realize an impact logger in which impact log information based on acceleration detected by an acceleration sensor is recorded in the memory circuit of a real-time clock device.

[0093] Furthermore, this embodiment may include a battery that supplies power to the real-time clock device and the acceleration sensor.

[0094] This allows the real-time clock device and accelerometer to operate based on the power voltage from the battery, even without an external power supply.

[0095] In this embodiment, the real-time clock device may also include a sensor interface circuit that receives acceleration data from an acceleration sensor.

[0096] In this way, the sensor interface circuit receives acceleration data from an external accelerometer of the real-time clock device and outputs it to the processing circuit, enabling the processing circuit to generate impact log information.

[0097] Furthermore, this embodiment may also include a real-time clock module in which a real-time clock device is housed in a package, and an acceleration sensor module in which an acceleration sensor is housed in a package.

[0098] In this way, an impact logger can be realized using an acceleration sensor module and a real-time clock module housed in separate packages.

[0099] Furthermore, this embodiment may include a package that houses an integrated circuit device having a timing circuit, a memory circuit, a processing circuit, and an interface circuit, as well as an acceleration sensor.

[0100] In this way, by realizing an impact logger using an impact logger module in which an integrated circuit device and an acceleration sensor are housed in a package, it becomes possible to miniaturize and reduce the cost of the impact logger.

[0101] Furthermore, the electronic device of this embodiment includes the real-time clock device described above, an acceleration sensor, and a processing device that reads shock log information from the real-time clock device.

[0102] In this way, the impact log information recorded in the memory circuit of the real-time clock device can be used to determine damage to electronic equipment.

[0103] In this embodiment, the processing device may also perform damage determination using a damage boundary curve based on impact log information.

[0104] In this way, the processing unit can easily determine whether or not damage has occurred in the object being impacted by reading the impact log information recorded in the memory circuit of the real-time clock device.

[0105] Although this embodiment has been described in detail above, it will be readily apparent to those skilled in the art that many modifications are possible without substantially departing from the novelty and effects of this disclosure. Therefore, all such modifications are included within the scope of this disclosure. For example, any term that appears at least once in the specification or drawings together with a broader or synonymous term may be replaced with that different term anywhere in the specification or drawings. Furthermore, all combinations of this embodiment and its modifications are also included within the scope of this disclosure. In addition, the configuration and operation of the real-time clock device, shock logger, and electronic equipment are not limited to those described in this embodiment, and various modifications are possible. [Explanation of Symbols]

[0106] 1... Packaging material, 2... Electronic equipment, 3... Circuit board, 4... Package, 5... Base, 6... Lid, 7... Intermediate circuit board, 8... Impact logger module, 9... Damage boundary curve, 10... Impact logger, 11... Circuit board, 12... Accelerometer, 13... x-axis accelerometer element, 14... y-axis accelerometer element, 15... z-axis accelerometer element, 16... Detection circuit, 17... Amplification circuit, 18... A / D conversion circuit, 19... Battery, 20... Real-time clock device, 22... Oscillator, 24... Oscillator circuit, 26... Power supply voltage selection circuit, 30... Timer Path, 40... Processing circuit, 50... Memory circuit, 60... Interface circuit, 62... Sensor interface circuit, 80... Accelerometer module, 82... Real-time clock module, 90... Integrated circuit device, 100... Processing unit, CK... Oscillation clock signal, DA... Acceleration data, LG... Impact log information, RD... Damaged area, RND... Undamaged area, SFab, SFb, SFab... Step surface, SQ... Output signal, TH... Retention period, TM... Time information, V... Velocity change, VT1, VT2... Threshold, amax... Maximum acceleration

Claims

1. A timing circuit that generates time information, Memory circuits and, When it is determined that an impact event has occurred based on the acceleration detected by the acceleration sensor, a processing circuit records impact log information in the storage circuit based on multiple acceleration data during the impact log retention period and the time information. An interface circuit that outputs the impact log information recorded in the memory circuit, A real-time clock device characterized by including [a specific feature].

2. In the real-time clock device described in claim 1, The real-time clock device is characterized in that the holding period is a period that includes the timing at which the acceleration reaches its maximum acceleration in the impact event.

3. In the real-time clock device described in claim 1, The aforementioned processing circuit is A real-time clock device characterized in that it starts recording the impact log information when the acceleration reaches or exceeds a first threshold.

4. In the real-time clock device described in claim 3, The aforementioned processing circuit is A real-time clock device characterized in that the period from when the acceleration becomes equal to or greater than the first threshold until the acceleration becomes equal to or less than the second threshold is defined as the retention period, and the impact log information is recorded in the memory circuit.

5. In the real-time clock device described in claim 4, A real-time clock device characterized in that the second threshold is smaller than the first threshold.

6. In the real-time clock device described in claim 3, The aforementioned processing circuit is A real-time clock device characterized in that the period from when the acceleration becomes equal to or greater than the first threshold until a predetermined time has elapsed is defined as the retention period, and the impact log information is recorded in the memory circuit.

7. In the real-time clock device described in claim 1, The aforementioned processing circuit is A real-time clock device characterized by recording in the memory circuit the impact log information, in which each of the multiple acceleration data sets is associated with the time information when each of the acceleration data sets was detected.

8. In the real-time clock device described in claim 7, The aforementioned processing circuit is A real-time clock device characterized by further recording maximum acceleration data in the memory circuit.

9. In the real-time clock device described in claim 1, The aforementioned processing circuit is A real-time clock device characterized by recording data of the maximum acceleration, the time information when the maximum acceleration was detected, and the time information when the acceleration fell below a threshold for determining the end of impact log retention in the storage circuit as impact log information.

10. In the real-time clock device described in claim 1, The aforementioned processing circuit is A real-time clock device characterized by recording data of the maximum acceleration and time information from the time the maximum acceleration is detected until the acceleration falls below a threshold for determining the end of impact log retention in the storage circuit as impact log information.

11. In the real-time clock device described in claim 1, The aforementioned processing circuit is A real-time clock device characterized by performing damage determination using a damage boundary curve based on a plurality of acceleration data and time information during the retention period, and recording the result information of the damage determination as impact log information in the storage circuit.

12. A real-time clock device according to any one of claims 1 to 11, The acceleration sensor and, An impact logger characterized by including [this feature].

13. In the impact logger described in claim 12, An impact logger characterized by including a battery that supplies power to the real-time clock device and the acceleration sensor.

14. In the impact logger described in claim 12, The real-time clock device is An impact logger characterized by including a sensor interface circuit that receives acceleration data from the acceleration sensor.

15. In the impact logger described in claim 12, The real-time clock device comprises a real-time clock module housed in a package, The acceleration sensor module, which houses the aforementioned acceleration sensor in a package, An impact logger characterized by including [this feature].

16. In the impact logger described in claim 12, An impact logger characterized by including an integrated circuit device having the timing circuit, the memory circuit, the processing circuit, and the interface circuit, and a package that houses the acceleration sensor.

17. A real-time clock device according to any one of claims 1 to 10, The acceleration sensor and, A processing unit that reads the impact log information from the real-time clock device, An electronic device characterized by including [this].

18. In the electronic device described in claim 17, The aforementioned processing apparatus is An electronic device characterized by performing damage determination using a damage boundary curve based on the aforementioned impact log information.

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