JP7570097B2 - Systems and programs - Google Patents

Description

The present invention relates to, for example, systems and programs.

One example of a system for correcting the time on the internal clock of a drive recorder is the invention disclosed in Patent Document 1. In Patent Document 1, with regard to an invention relating to a vehicle video recording device such as a drive recorder and an in-vehicle system including the vehicle video recording device (paragraph [0001], etc.), paragraph [0054] states that "The drive recorder 1 further includes, within the main body 10, an internal clock 33... and a control unit 36," and paragraph [0065] states that "The control unit 36, which acquires the reference date and time data sent at a predetermined timing from the navigation device 2, corrects and calibrates the internal clock 33."

Patent No. 5704425

For example, retroactively altering information that identifies the time when data was already recorded can be considered a type of tampering with the time of the recording, and may not be desirable. On the other hand, if the time is not synchronized, the recording time will be recorded based on an incorrect clock, and it may not be possible to correctly identify the time at which the location in the captured image was passed, which may cause problems. For this reason, technology is needed for recording information that can identify the time when data was recorded.

The above-mentioned problems are described as being independent, and the present invention does not necessarily have to solve all of the problems described. The purpose of the invention of this application is not limited to this, and the applicant intends to obtain rights to configurations that aim to obtain effects from parts of the configuration disclosed in this specification and drawings, etc., through divisional applications, amendments, etc. For example, this specification discloses a problem in which the phrase "can be" in this specification is read as "the problem is". The problems are described as being independent, and the applicant intends to obtain rights to the configuration for solving this problem alone through divisional applications, amendments, etc. Even if the problem is implicitly understood from the description in the specification, the applicant intends to include part of the configuration described in this specification in the scope of the patent claim by amendment or divisional application. Problems that combine these independent problems are also disclosed.

(1) Provided is a system having a recording device for recording data, the system being equipped with a function for acquiring from a clock unit a first time for identifying the time when the data was recorded, a function for acquiring information for adjusting the time of the clock unit to a second time, and a function for controlling, when the information is acquired while the data is being recorded, not to adjust the time, but to record the difference between the first time and the second time in association with the data. In this way, since the clock unit is not adjusted while the data is being recorded, the continuity of the time indicated by the clock unit is ensured, and time jumps can be prevented. For example, when control such as data recording is being performed based on the clock unit, if the time is adjusted during the control, the time that is the reference for the control will jump discontinuously, but the occurrence of such an event can be prevented.

(2) The control function may record the first time in addition to the difference in association with the data, and may leave the first time recorded before the time adjustment stored even after the time adjustment. In this way, the time when the data was recorded can be found based on the difference. In addition, since the recorded first time is stored as is, the data is not altered, and the actual time when the data was recorded can be identified.

(3) It is preferable to have a function of calculating a third time indicating the time when the data was recorded based on the first time and the difference recorded in association with the data, and outputting the data based on the calculated third time. In this way, even if the time on the clock unit is out of sync, it is possible to identify the time when the data was recorded based on the first time and the difference, and output the data.

(4) The data may include an image and may have a function for displaying the third time together with the image. In this way, a person viewing the image can visually understand the time when the image was recorded.

(5) The display function may include a function for selectively displaying the third time and the first time together with the image. In this way, a person viewing the image can visually grasp, with respect to the time when the image was recorded, the time measured by the clock unit and the time calculated from the difference and the time used for time adjustment.

(6) The display function may be such that the displayed time is either the third time or the first time. In this way, a person viewing the video can visually ascertain whether the time displayed is the time measured by the clock unit or the time calculated from the difference and the time used for time adjustment, with respect to the time when the video was recorded.

(7) It is advisable to obtain the information for adjusting the time in a manner that does not use an environment that is accessible to unspecified persons. This increases the communication security of the system, and can, for example, minimize the occurrence of information leaks.

(8) When the control function acquires information for adjusting the time while the data is being recorded, it is preferable that the time adjustment is performed after the recording of the data is stopped. In this way, even if the time for adjusting the time is acquired while the data is being recorded, it is possible to prevent the information specifying the time of recording of the data from becoming discontinuous. In addition, after the recording of the data is stopped and then started, the recording is preferably performed based on the time with high accuracy after the time adjustment.

(9) The information for adjusting the time can be obtained from a plurality of different sources, and the control function can be configured to preferentially adopt information for adjusting the time from a predetermined source with a high priority when the information for adjusting the time is obtained while the data is being recorded. In this way, by making it possible to obtain information for adjusting the time from a plurality of different sources and prioritizing sources with a high priority, it is possible to more easily ensure the accuracy of the time measured by the clock unit. For example, a time closer to the correct time can be obtained.

(10) The recording device operates by receiving power from the vehicle, and the control function preferably performs the time adjustment when the engine of the vehicle is stopped and the recording of the data stops. In this way, by adjusting the time when the engine is stopped, the time is corrected to the time after the time adjustment when the engine is started next time, which is advantageous. It is possible to adjust the time when the engine is started next time, but since it is sometimes desirable to start recording data as quickly as possible when starting, it is advantageous to adjust the time when the engine is stopped and there is plenty of time.

(11) The recording devices may include a first recording device and a second recording device. When the first recording device acquires information for adjusting the time, it transmits information for adjusting the time to the fourth time determined based on the acquired information to the second recording device, and the second recording device records the difference between the fourth time and the first time acquired by itself based on the information for adjusting the time acquired from the first recording device. In this way, the first recording device that has acquired the time for adjusting the time can transmit it to the second recording device.

(12) The recording device may be a third recording device, and the second recording device may transmit information for adjusting the time to the fifth time based on information for adjusting the time to the fourth time to the third recording device, and the third recording device may record the difference between the fifth time and the first time acquired by itself based on information for adjusting the time acquired from the second recording device. In this way, the third recording device may adjust the time using the time acquired from the second recording device, so that multiple recording devices may transmit the time for time adjustment one after another as if in a chain.

(13) The first recording device records video footage of the vehicle's surroundings and has a GPS receiving function, and the second recording device records video footage of the interior of the vehicle, and the first recording device determines the fourth time based on the second time acquired based on a signal received by the GPS receiving function. In this way, even if the second recording device does not have a GPS receiving function or cannot use it, it can record information identifying the time when data was recorded based on the time for time adjustment determined based on the GPS receiving function of the first recording device. For example, it can identify and display videos recorded at the same time by multiple recording devices based on the correct time.

(14) The first recording device may generate information for adjusting the time to the fourth time, taking into account the time that has elapsed since acquiring information for adjusting the time to the second time. In this way, the time for time adjustment can be transmitted to recording devices that cannot obtain the time for time adjustment themselves, such as a GPS receiving function, or to recording devices that cannot directly access the source of the time for time adjustment. The process of generating the time taking into account the time elapsed may, for example, measure the elapsed time since reception and add it to the time for time adjustment received by the device itself. Alternatively, the time for time adjustment may be generated from the difference between the time of the clock unit at the time of transmission and the time at which the clock unit received the signal, since the elapsed time has advanced from the time of reception at the time of transmission, without measuring the elapsed time.

(15) The recording devices include a fourth recording device and a fifth recording device, the fourth recording device is capable of communicating with an external device, the fourth recording device transfers a data transmission request received from the external device to the fifth recording device, the fifth recording device transmits the recorded data corresponding to the data transmission request acquired from the fourth recording device to the fourth recording device, and the fourth recording device transfers the data acquired from the fifth recording device to the external device. In this way, even if the fifth recording device does not communicate with the external device, the data recorded by the fifth recording device can be transmitted to the external device via the fourth recording device. The transmission request may, for example, specify the time of recording, and the correct time data may be sent using the difference. For security reasons, it is preferable to communicate with the external device using closed communication, for example.

(16) Provide a system for recording data, which has a function of controlling the recording of a difference between a first time measured by a clock unit for identifying the time when the data was recorded and a second time that is more accurate than the first time, in association with the data. In this way, it is possible to provide a technology for recording information for identifying the time when the data was recorded.

(17) It is preferable to provide a program for causing a computer to realize the functions of any one of the systems (1) to (16).

The above-mentioned system may consist of one device or multiple devices.

The inventions (1) to (16) above can be combined in any way. For example, at least a portion of the configuration of at least one of the inventions (2) and after may be added to all or a portion of the configuration of the invention shown in (1). In particular, it is preferable to add at least a portion of the configuration of at least one of the inventions (2) and after to the invention shown in (1). The applicant intends to obtain patent rights, design rights, etc. for those including these configurations by filing amendments, divisional applications, or applications for conversion to design registration applications, etc.

The present invention can provide a technology for recording information to identify the time when data was recorded. It also has at least one of the following effects, for example. In a system in which recording control is based on a clock unit, the time on which control is based can be controlled without discontinuous jumps during recording, ensuring continuity. In addition, by adjusting the time at an appropriate timing, the system can subsequently operate based on the time after the adjustment. This is advantageous because the time when the data was recorded is not altered.

The effects of the invention of this application are not limited to this, and effects achieved from the configuration parts disclosed in this specification and drawings, etc. are also disclosed, and it is our intention to obtain rights to the configuration that achieves said effects through divisional applications, amendments, etc. For example, in this specification, the phrase "can..." is a description that clearly indicates the effect achieved, and there are also parts that show the effect even without the phrase "can...". Also, there are effects that can be understood from the configuration even without such a description.

1 is a block diagram showing a preferred embodiment of a system according to the present invention; 13 is a flowchart showing a time correction process. FIG. 13 is a diagram for explaining the operation of setting the time. FIG. 13 is a diagram showing an example of a display of a captured image. FIG. FIG.

Below, an embodiment of the present invention will be described with reference to the drawings. These drawings are used to explain the technical features that may be adopted by the present invention. The configurations and shapes of the devices described are merely illustrative examples, and the present invention should not be interpreted as being limited thereto. Various changes, modifications, and improvements may be made based on the knowledge of those skilled in the art without departing from the scope of the present invention. In the following description, labeling using numbers such as 1st (first), 2nd (second), etc. is intended to identify each element, and does not define the number of elements.

[How the idea for the present invention came about]
The inventor has found a new problem with regard to the alteration of a recording file recorded based on a time-displaced internal clock in a recording device such as a drive recorder equipped with a time adjustment function, and the accompanying problem of admissibility as evidence. For example, if the time is adjusted during recording, the recording time will change discontinuously in the middle, and the continuity of the recording time will not be ensured. For example, if the recording time is recorded in each frame that constitutes the recorded data, the recording time will jump and become discontinuous before and after the time adjustment. Furthermore, altering the recording time in the middle of the recording is a kind of falsification, and for example, the evidential admissibility of the recorded data may be reduced.

On the other hand, if the time is not synchronized, the recording time will be based on an incorrect clock, and it will not be possible to correctly determine the hour, minute, and second at which the person passed the location in the footage. This may reduce the evidentiary value of footage taken before the time was synchronized.

In addition to the above issues, there may be other cases where it is undesirable to subsequently modify information that identifies the time when data in an already recorded file was recorded. The following embodiment is one example of an embodiment for solving such issues.

[Basic configuration of one embodiment of the system]
1 shows a preferred embodiment of the system. The system 1 of this embodiment includes a drive recorder 2, which is one aspect of a recording device, and a device 3 that can communicate with the drive recorder 2 and provide the time.

The communication between the drive recorder 2 and the device 3 may be, for example, wireless communication, wired communication, or a combination of these, and in particular, wireless communication. In the case of wireless communication, for example, wireless communication may be performed in an environment connected to a wireless LAN or LTE. The drive recorder 2 and the device 3 may be used in a limited closed space such as a vehicle, an office, or a business establishment, and it is desirable to perform the communication in an environment connected to a line that is somewhat secure. In this embodiment, the secure line may be a line that allows communication in a more secure environment than a public line such as the Internet. In this embodiment, the secure line may be a communication line that restricts the persons who can communicate with each other by virtual (logical) or physical means. The secure line may be, for example, a line that restricts the persons who can communicate by a method using authentication information such as an ID or a password, and such a line may be Wi-Fi (for example, Wi-Fi with a password) or other wireless LAN (Local Area Network). Such a wireless LAN may not require a pay-per-use communication fee based on the amount of communication, or may be cheaper than a public line. The secure line may be, for example, a VPN (Virtual Private Network), which is a virtual network constructed via a public line of a telecommunications carrier (for example, a line of the LTE (Long Term Evolution) system). The secure line may be a dedicated line (for example, a wired communication path) or a network (closed network, also called a closed network) that is physically isolated from the public line. In this way, it is desirable for the drive recorder 2 to communicate with the device 3 by a method that does not use an environment accessible to unspecified persons (for example, a communication device). In this way, it is desirable from the viewpoint of communication security, such as preventing access to the drive recorder 2 by a third party.

The device 3 has a function of providing the drive recorder 2 with a time (an example of a second time) that specifies the time after the time adjustment as information for time adjustment. Time adjustment is a process of correcting the time measured by the clock. By adjusting the time, the time difference of the time measured by the clock becomes small (preferably becomes zero). In this embodiment, the time adjustment is a process of correcting the time measured by the clock by regarding the time given from the outside as the correct time. In this embodiment, the time provided by the device 3 is treated as correct time information in the system 1. If the time provided by the device 3 indicates a standard time such as Japan Standard Time in Japan, the accuracy of the time after the time adjustment of the drive recorder 2 is improved. The device 3 may have a clock that measures the current time of, for example, a PCAPP, a smartphone APP, a server APP, a mobile communication base station, etc., and may have a function of providing the time obtained from the clock to the drive recorder 2 by superimposing it on a command, for example. The server APP should be a server other than an NTP server that can be accessed by the general public. When a communication device connects to an NTP server, it is necessary to connect to the Internet line, which is a public line, and this may cause security problems. In contrast, using a server APP other than an NTP server is desirable from the viewpoint of communication security. Furthermore, the device 3 may be, for example, a drive recorder or other in-vehicle device.

In this embodiment, the drive recorder 2 is a device that is later installed in a vehicle. Examples of vehicles include private cars and commercial cars, and vehicle types include passenger cars, buses, trucks, and special vehicles such as forklifts. Vehicles are not limited to automobiles, and include various types of vehicles such as public transportation vehicles such as trains, monorails, and linear motor cars. Vehicles other than vehicles may also be used, such as ships and airplanes.

The drive recorder 2 includes a camera 11, a microphone 12, an abnormality detection sensor 13, a GPS module 14, an operation button 15, a control unit 16, a temporary storage memory 17, a monitor 18, a speaker 19, a memory card slot 20, a first internal clock 22, a power supply unit 23, a first communication unit 24, and the like. The camera 11 captures a predetermined area, such as the front of the vehicle. The microphone 12 collects, for example, surrounding sounds. The microphone 12 collects, for example, the voices of people in the vehicle and other sounds generated in the vehicle cabin, and impact sounds when an object collides with the vehicle. The abnormality detection sensor 13 is, for example, an acceleration sensor or a six-axis sensor (integrated with three-axis acceleration and three-axis angular velocity), and detects the state of the vehicle, such as the impact applied to the vehicle, the acceleration of the vehicle, and the inclination of the vehicle. The control unit 16 estimates that an accident (collision) has occurred when the detection value of the abnormality detection sensor 13 exceeds a threshold value or shows a predetermined temporal change indicating, for example, the occurrence of an impact. In addition to accident occurrences, the control unit 16 can also be used to detect driving conditions such as sudden braking, sudden steering, sudden acceleration, and sudden braking, and record the history of these conditions.

The GPS module 14 receives a GPS signal based on positioning. The control unit 16 determines the current position from the received GPS signal, and sends the position information (longitude, latitude) of the determined current position to the control unit 16. The GPS module 14 also obtains date and time information based on the received GPS signal, and sends it to the control unit 16. The date and time information obtainable from the GPS signal includes the current time, so the control unit 16 can use this to set the time of the first internal clock 22.

The operation button 15 is a button that issues various instructions to the control unit 16, and has a function for issuing an instruction to start recording, for example. When this operation button 15 is pressed, the control unit 16 may perform event recording, which starts recording the video captured by the camera 11 and the sound collected by the microphone 12. The operation button 15 may also have a function for issuing an instruction to stop recording. The instruction to start recording and the instruction to stop recording may be different buttons for issuing the respective instructions, but it is preferable that they are issued by different operations on the same button. This is advantageous because it reduces the number of buttons installed and makes it possible to miniaturize the drive recorder 2.

The temporary storage memory 17 is, for example, a RAM that temporarily stores video data captured by the camera 11. The control unit 16 constantly stores video data captured at least a certain amount of time in the past. Since the storage capacity is finite, the control unit 16 deletes old video data according to a certain criterion. The certain criterion may be, for example, video data stored a certain amount of time ago or when the memory capacity for storage reaches a certain amount. In this embodiment, the temporary storage memory 17 may be, for example, a ring buffer.

The monitor 18 is a display unit that displays images. The control unit 16 displays, for example, video data captured by the camera 11 on the monitor 18 in real time. The speaker 19 outputs sound. The control unit 16 outputs a specified sound from the speaker 19 during a specified recording, alarm, operation, etc. The control unit 16 uses the speaker 19 to notify, for example, the operation sound of the operation button 15 and various messages (guides, alarms, etc.).

The memory card slot 20 is capable of inserting and removing, for example, a micro SD card 21. When the micro SD card 21 is inserted, the control unit 16 reads and writes data from and to the micro SD card 21. The micro SD card 21 is a storage medium on which data such as video is recorded by the drive recorder 2. The micro SD card 21 is an external storage means that is insertable and removable from the memory card slot 20, but an internal storage means (e.g., a hard disk or EEPROM) of the drive recorder 2 or other storage means may be used instead of or in combination with the micro SD card 21. However, in terms of protecting the data stored in the storage means, it is desirable for the drive recorder 2 to be able to access a system that can record data without using an environment that is accessible to an unspecified number of people (e.g., a cloud computing environment).

The first internal clock 22 is a clock unit that provides a time (an example of a first time) that is the reference time for control operations in the drive recorder 2. The first internal clock 22 measures a time (current time) for identifying the time when data was recorded in the drive recorder 2. In this embodiment, the time measured by the first internal clock 22 includes date and time information. In this embodiment, the first internal clock 22 is a real-time clock driven by a crystal oscillator.

The power supply unit 23 supplies power to each part of the drive recorder 2. The power supply unit 23 is connected to the vehicle (vehicle battery) and, for example, receives power from the vehicle while the vehicle is operating after the engine is turned on, and, for example, steps down the voltage to a predetermined voltage value to supply the power supply voltage to the devices and the like equipped in the drive recorder 2, thereby providing power for operation to each part. The power supply unit 23 also has a storage means such as a secondary battery, and has a function of charging during operation and supplying power for keeping the drive recorder 2 in the ON state for a predetermined time even after the engine is turned off. Note that instead of or in addition to the secondary battery of the power supply unit 23, a storage means such as a supercapacitor or a capacitor may be used as a storage means for storing electric charge inside. Also, an environment may be created in which the drive recorder 2 can operate for a certain period of time by power supply from an external source.

The control unit 16 is a microcomputer equipped with a CPU, ROM, RAM, non-volatile memory, I/O, etc., and executes a predetermined process based on information input from the various input devices (camera 11, microphone 12, abnormality detection sensor 13, GPS module 14, operation button 15, temporary storage memory 17, memory card slot 20, etc.) and outputs predetermined information using output devices (temporary storage memory 17, monitor 18, speaker 19, memory card slot 20, etc.). The functions of the drive recorder 2 are stored in the EEPROM of the control unit 16 as a program executed by the computer in the control unit 16, and are realized by the computer in the control unit 16 executing this program. The functions realized by the computer through the program in the control unit 16 include a function to perform various controls in the drive recorder 2. The control unit 16 has, for example, a function to record data such as video (recording function), a function to output data, a function to display an image (video), and a time adjustment function to adjust the time of the first internal clock 22.

The control unit 16 is a circuit for realizing the basic functions of the drive recorder 2, and stores the image data captured by the camera 11 as an image file in the temporary storage memory 17, and stores the captured image file in a non-volatile memory based on a detection signal from the abnormality detection sensor 13 or the pressing of the operation button 15. In this embodiment, a micro SD card 21 attached to the memory card slot 20 is used as the non-volatile memory. By removing the micro SD card 21 and attaching it to a memory card reader connected to a personal computer, data can be imported into the personal computer and the image file can be played using a viewer installed on the personal computer. In addition, the recorded images, etc. can be transmitted by data transmission via wired communication or wireless communication, rather than being taken out by removing the micro SD card 21 as described above. In order to perform wired communication, the main body of the drive recorder 2 can be provided with a connector, USB, etc. for connecting a communication cable.

The function of recording this video data (recording function) will now be described in more detail. The camera 11, for example, constantly captures images of the surroundings of the vehicle. The control unit 16 stores the video data captured by the camera 11 in a temporary storage memory 17 such as a ring buffer. The images stored in this temporary storage memory 17 are updated successively to the latest images, and past video data is retained for a set period of time.

For example, when the output value of the abnormality detection sensor 13 for an impact occurring during an accident, sudden braking, or sudden steering exceeds a threshold value or shows a predetermined change over time, the control unit 16 reads out video data for a certain period of time before the impact was detected from the temporary storage memory 17 and stores it in a non-volatile memory, for example, the microSD card 21, and records the video captured by the camera 11 after the threshold value is exceeded on the microSD card 21 directly or via the temporary storage memory 17. As a result, video for a predetermined period of time before and after the impact is saved in the microSD card 21, which is a non-volatile memory. At this time, the control unit 16 also records the surrounding sounds collected by the microphone 12 in association with the video data. The control unit 16 also temporarily stores this recording in the temporary storage memory 17, and when storing the video data on the microSD card 21, the recorded audio data is also stored on the microSD card 21.

The control unit 16 creates and records one file for each specified unit time as the video data to be recorded. Thus, one file contains multiple frames acquired at a specified frame rate. The frames are managed in chronological order in the order they were recorded, and are output and played back in that order. Audio data collected at the same time is also stored in this file.

Furthermore, when the control unit 16 stores data such as video in the temporary memory 17 and the micro SD card 21, the control unit 16 associates and stores the time (an example of the first time) indicating the recording time of the data acquired from the first internal clock 22. The time indicating the recording time of the data may be associated with each frame, for example, or the recording time may be recorded for the entire file. In addition, the control unit 16 may record, as the associated data, not only the time based on the first internal clock 22, but also, for example, the time based on the GPS signal detected and output by the GPS module 14. In the drive recorder 2, when the GPS signal cannot be received, for example, immediately after the power is turned on or in a tunnel, the time based on the GPS signal cannot be acquired. In such a case, the control unit 16 may leave the storage area for the time based on the GPS signal blank or record information indicating that the signal cannot be received. Furthermore, the information that the control unit 16 associates and stores with the video data is not limited to time as described above, but may include, for example, position information based on GPS, the output value of the sensor, and the time when the sensor output value exceeds a threshold value. For example, the sensor output value should be recorded if it exceeds a threshold value, and not recorded if it does not exceed the threshold value.

The storage of data in the micro SD card 21 in the drive recorder 2 is not limited to the one triggered by the detection signal of the abnormality detection sensor 13 as described above. The control unit 16 may have a function of triggering the pressing of the operation button 15, for example. In this way, when a situation occurs that the user wants to record, video recording can be performed. Furthermore, recording in the micro SD card 21 is not limited to an event recording mode that is performed when an accident based on the output of the abnormality detection sensor 13 occurs or when a recording start condition is satisfied, such as pressing the operation button 15, but may have a continuous recording mode that records in the micro SD card 21 from when the drive recorder 2 is turned on until it is turned off. When the continuous recording mode is provided, the control unit 16 may record the recording destination of the video data output from the camera 11 and the audio data output from the microphone 12 directly in the micro SD card 21, not in the temporary storage memory 17. By recording directly in the micro SD card 21 in this way, the process of writing once in the temporary storage memory 17 is unnecessary, which is preferable. Furthermore, when video data, etc. is written directly to the micro SD card 21, and the device has a continuous recording mode and an event recording mode, when the control unit 16 meets the event recording start condition, it is preferable that the control unit 16 use the data recorded as continuous recording for the past section data from the time the condition was met. In addition, in the event recording, the control unit 16 may record the data as a file separate from the file for continuous recording, for example.

For example, when the operation button 15 is operated to instruct the camera to stop recording while the camera is operating in the continuous recording mode, the control unit 16 stops recording to the micro SD card 21. When the operation button 15 is operated to instruct the camera to stop recording while the camera is operating in the event recording mode, the control unit 16 stops recording to the temporary storage memory 17, etc. Even when the continuous recording mode is not operating and only the event recording mode is operating, the control unit 16 performs a process of constantly recording a certain amount of video, etc., in the temporary storage memory 17, etc., in an overwrite manner, etc., in order to record video before the event occurs. When the operation button 15 is operated to instruct the camera to stop recording, the control unit 16 stops recording as described above, since it is not necessary to store and hold a certain amount of video, etc., in order to record video before the event occurs. This recording stop is performed, for example, when the camera is inserting or removing the micro SD card, setting the mode, or when the user does not want to record.

The first communication unit 24 is for communicating with the device. The first communication unit 24 has a function for communicating using a predetermined communication method, such as wireless LAN or LTE. The first communication unit 24 connects to the second communication unit 34 according to a predetermined procedure, and transmits and receives data and commands.

In this embodiment, the device 3 includes a control unit 31, a second internal clock 32, a power supply unit 33, a second communication unit 34, and the like. The second communication unit 34 is accessed by the first communication unit 24 to establish communication, and transmits and receives data and commands to and from the first communication unit 24. The second internal clock 32 is more accurate than the first internal clock 22 of the drive recorder 2, and provides a time obtained, for example, based on a GPS reception function. High accuracy means that the second internal clock 32 has a smaller time deviation from the original time (standard time in this embodiment) than the first internal clock 22. Although not shown, the device 3 may have a function of acquiring time using a GPS module or the like and adjusting the time based on the time. The power supply unit 33 has a function of receiving power from, for example, a commercial power source, and supplying a power supply voltage by reducing the voltage to a predetermined voltage value, for example, to operate the device. In this way, the device 3 receives power from a commercial power source and operates constantly.

[Time adjustment function]
The time obtained based on the GPS signal acquired by the GPS module 14 is accurate. However, the GPS module 14 may not be able to receive the GPS signal immediately after startup or in a place where radio waves cannot reach, such as a tunnel. In this case, accurate time cannot be obtained based on the GPS signal. For example, when the GPS module 14 operates in a continuous recording mode, it cannot receive the GPS signal at the start of recording. In this way, there are cases where control cannot be performed based on the time obtained using the GPS signal, and the control unit 16 obtains the time from the first internal clock 22 and performs control based on that time.

A drive recorder may be installed inside the passenger compartment of a vehicle. The temperature inside the passenger compartment can become high, for example, when the vehicle is parked under the blazing sun in summer, and low, similar to the temperature outside the vehicle, when the vehicle is parked in winter. The temperature can change significantly even within a day, as the air conditioner adjusts the temperature to a comfortable level for the driver while the vehicle is in the vehicle. In addition, if the drive recorder 2 is mounted on a forklift, the range of temperature change can be expected to increase and the time lag can become large if the forklift goes in and out of a freezer, for example. For example, after entering a freezer at -30 degrees, the temperature difference can exceed 60 degrees when it is taken outside in midsummer (30 degrees or higher). As a result, the time on the vehicle's internal clock can easily become out of sync.

In this embodiment, the first internal clock 22 is driven by a quartz oscillator, and the accuracy of a quartz oscillator may decrease due to temperature changes, causing it to deviate from the correct time over time. Therefore, it is preferable for the drive recorder 2 to adjust the time of the first internal clock 22, which serves as the control reference, at an appropriate timing and correct it to the correct time. Also, as described above, the recording time is associated with the video file and recorded based on the time of the first internal clock 22. For example, it is preferable to adjust the time of the first internal clock 22 in order to improve the evidentiary value of the video, such as the hour, minute, and second at which the video was taken.

Therefore, in this embodiment, the control unit 16 of the drive recorder 2 has a function of adjusting the time based on the time of the second internal clock 32 provided from the device 3. As shown in FIG. 2, the control unit 16 acquires the time of the second internal clock 32 from the device 3 with which communication has been established (S1). For example, when the drive recorder 2 is in a power-on state, it establishes communication with the device 3 at an appropriate timing, and the control unit 16 of the drive recorder 2 sends a request to the control unit 31 of the device 3 to send the time of the second internal clock 32, and in response, the control unit 31 transmits the time of the second internal clock 32 by superimposing it on the command. The control unit 16 acquires the time from the received command.

The control unit 16 determines whether or not recording is in progress (S2). If video data or the like is being recorded to the temporary storage memory 17 and/or the micro SD card 21 (Yes in S2), the control unit 16 compares the time obtained from the device 3 with the time of the first internal clock 22, and determines the difference, which is the time discrepancy (S3).

The control unit 16 records the obtained difference in association with the data being recorded (S4). The difference may be entered, for example, in a frame or in the history of the video file. While the control unit 16 records the obtained difference in this way, it does not adjust the time of the first internal clock 22. The drive recorder 2 also creates and records video files in short time units, such as one minute or several minutes. Therefore, the control unit 16 also records the obtained difference in association with the data being recorded of the video file created thereafter. As will be described later, the control unit 16 adjusts the time of the first internal clock 22 at an appropriate timing. Therefore, the control unit 16 also records the difference in association with the data being recorded of the video file created thereafter, as described above, until the time adjustment is performed.

In addition, during recording in this manner, the control unit 16 associates the difference with the video files that are created one after another and stores them. For this reason, the difference calculated in processing step S3 may be stored by the control unit 16, for example, and the stored difference may also be associated with and stored in the data that is subsequently recorded.

On the other hand, when the time is acquired from the device 3, if video data or the like is not being recorded in the temporary storage memory 17 and/or the micro SD card 21 (No in S2), the control unit 16 adjusts the time of the first internal clock 22 based on the acquired time (S5).

The control unit 16 records video data, etc., in units of time. Therefore, if, as shown in FIG. 3(b), the time T4' is acquired when the time on the first internal clock 22 is T4 during a recording operation, and the time on the first internal clock 22 is corrected to T4' and then the time on the first internal clock 22 is switched so that it counts up to T5', T6', ... based on the corrected T4', the recorded time will be discontinuous.

In contrast, in this embodiment, as shown in FIG. 3(a), even if the control unit 16 acquires time T4' (an example of the first time) during recording, it simply records the obtained difference Δt, does not adjust the time of the first internal clock 22, and advances the time in the same time increments as T4, T5, T6, .... This ensures the continuity of the times recorded in association with the video data, such as T4, T5, T6, ....

It is preferable that the control unit 16 holds the difference as a fixed value. It is preferable that the difference indicates the difference between the most recently acquired time and the time measured by the first internal clock 22 at that time. The control unit 16 also counts up the time of the first internal clock 22 as time passes. Therefore, the time after a predetermined time has passed can be found by adding/subtracting the difference to the counted up time.

Furthermore, when the control unit 16 obtains the time from the device 3 after recording starts and adjusts the time of the first internal clock 22, there may be a lack of continuity between the time just before the time adjustment and the time after the time adjustment. For example, when the control unit 16 records the recording time in each frame that constitutes the recorded data, the recording time jumps and becomes discontinuous before and after the time adjustment. In this case, the time adjustment causes the data to be rewritten. This is a type of tampering, and there is a possibility that the evidentiary value of the recorded data will be reduced. For example, there is a possibility that the evidentiary value of the vehicle's travel route and the dates and times when it was at each location will be reduced based on the recorded file.

*Time adjustment based on difference Δt The control unit 16 adjusts the time of the first internal clock 22 when the drive recorder 2 is powered off. For example, when the vehicle engine is turned off, for example, when the power supply from the vehicle battery to the drive recorder 2 is stopped due to ACCOFF, the control unit 16 performs a predetermined end process and then turns off the power of the main body. As described above, since the power supply unit 23 includes a storage means such as a secondary battery, it is possible to continuously supply power voltage to each internal device for a predetermined time even if the supply from the external power source is cut off. Therefore, the control unit 16 performs various end processes such as recording various data to the micro SD card 21 while the power is being continuously supplied. At this time, the control unit 16 performs time adjustment based on the difference Δt to correct the current time Tn (an example of the first time) of the first internal clock 22 to the correct time Tn' (=Tn-Δt) after the recording process is stopped due to the power OFF process.

In this way, when the drive recorder 2 is powered off when no recording is being performed, the first internal clock 22 is adjusted, so that the next time the drive recorder 2 is powered on, recording processing and various other controls are performed based on the correct time after the time adjustment.

Furthermore, in this embodiment, while the control unit 16 adjusts the time on the first internal clock 22, data that has already been recorded is left as it is without correcting the time indicating when that data was recorded. In this way, the time recorded in the video file is not corrected, so the data is not altered, which may increase the evidential value of the data. Also, since the video file records the difference in association with the data, even if the time on the first internal clock 22 is out of sync, the correct time indicating when the data was recorded can be found later. Then, when the time on the first internal clock 22 is adjusted, the difference is set to zero.

As described above, the time is adjusted when the power is turned OFF, but if the control unit 16 cannot change the time when the power is turned OFF, it is preferable to correct it when the power is next turned ON. For example, the control unit 16 adjusts the time of the first internal clock 22 based on the stored difference at an appropriate timing when the startup process associated with the power being turned ON is performed. Since recording is performed at least after the startup process is completed, it is also possible to adjust the time based on the difference and the time measured by the first internal clock 22 at startup, even before recording begins. Therefore, the recording time of the video file performed after the power is turned ON will be recorded based on the time after the time has been adjusted, and various controls also operate based on the time after the time has been adjusted.

The difference used to adjust the time when the power is turned on may be recorded, for example, in association with a video file and the difference may be read from there, but the difference may also be stored in a non-volatile memory such as the micro SD card 21 and read from there for use.

In addition, the time of the first internal clock 22 is not limited to being adjusted when the power is turned off or when the drive recorder 2 is started up as described above. For example, even when the drive recorder 2 is powered on, the control unit 16 may have a function of adjusting the time of the first internal clock 22 when not recording. For example, the control unit 16 may adjust the time when recording is stopped while the drive recorder 2 is powered on. Recording may be stopped, for example, by a user's operation or when the control unit 16 judges it. An operation to instruct the stop of recording is performed, for example, when the micro SD card 21 is replaced. The control unit 16 may adjust the time when the micro SD card 21 is removed from the drive recorder 2. When a recording period is set by a timer, the control unit 16 may stop recording and adjust the time when the recording period ends. In this way, the time can be adjusted to the correct time while the drive recorder 2 is powered on, so that the correct recording time can be recorded in subsequent recordings. Since recording is stopped, there are no continuity issues with the recorded video file.

The control unit 16 keeps the difference associated with the video file before the time was adjusted and does not correct the recorded time. Then, because the time on the first internal clock 22 becomes the correct time as a result of the time adjustment, it is preferable to invalidate the difference before the time adjustment for the video file after the time adjustment. To invalidate the difference, the control unit 16 may, for example, clear (delete) the difference, associate an invalidation flag with the difference (set an invalid flag), or set the difference to zero. By invalidating the difference, it is possible to know which differences are not necessary for future time adjustment.

[Acquisition of time for time adjustment]
In the above embodiment, the drive recorder 2 communicates with the device 3 and obtains the time of the second internal clock 32 of the device 3, but for example, the GPS module 14 may receive a GPS signal and use the time obtained from the signal. GPS signals are also highly secure as they are not susceptible to eavesdropping. In this way, communication with the device 3 is not required, making time adjustment easier and more preferable in terms of security.

The GPS module 14 starts positioning a predetermined time or more after the drive recorder 2 is powered on. However, the drive recorder 2 often starts recording before this positioning is performed. Therefore, when the GPS module 14 determines its position and acquires the time after recording starts, the control unit 16 calculates the difference between the time of the first internal clock 22 based on the acquired time, and records the calculated difference in association with the video file.

The time for time adjustment may be a time manually input by the user to the drive recorder 2. Such a time can be input at any timing while the drive recorder 2 is powered on. In the system 1, this manually input time is also treated as correct time information. For example, the user registers the current time in the drive recorder 2 while checking the correct time with a GPS clock or the like. The control unit 16 compares the input time for time adjustment with the time of the first internal clock 22 to obtain the difference. When the time for time adjustment is manually registered, it is common to immediately adjust the time of the first internal clock 22. However, in this embodiment, the control unit 16 does not immediately adjust the time, but instead obtains and records the difference between the time of the first internal clock 22 at that time and the input time for time adjustment.

The drive recorder 2 can obtain the time for time adjustment from different sources, and when the time is obtained during recording, the difference is calculated and the time source (GPS/LTE/server/manual input by the user, etc.) is recorded. When multiple correct times are obtained during recording, the control unit 16 may use the difference calculated based on the source with the highest predetermined priority, rather than the first received time. The priority may be determined, for example, based on the level of accuracy. By setting the priority higher for a source that provides a time that is more consistent or more likely to match the standard time, the accuracy of the time after time adjustment is improved. The priority may be determined before the drive recorder 2 is shipped, or may be determined after the product is shipped by user settings or other methods.

The timing for acquiring the time for time adjustment may be any timing while the drive recorder 2 is powered on, but may be performed, for example, every time the power is turned on. For example, when the power is turned on and the system starts up, the system communicates with the device 3 to acquire the time held by the second internal clock 32, or acquires the correct time information obtained by positioning the GPS module 14, and stores and holds the difference with the time of the first internal clock 22. The first internal clock 22 may then be adjusted when recording ends, such as when the power is turned off. The control unit 16 may acquire the time for time adjustment, for example, at a predetermined interval. The timing for acquiring the time is determined, for example, before the drive recorder 2 is shipped, taking into account the magnitude of the time difference that occurs in the first internal clock 22.

[Video file playback function]
As described above, the video file stored in the micro SD card 21 can be played back by the drive recorder 2 or an external playback device. The playback device is, for example, a personal computer. In this case, the video file is recorded in the personal computer and can be played back by, for example, a viewer installed in the personal computer. The drive recorder 2 or the external playback device (hereinafter referred to as "playback device, etc.") has a function of playing back video based on the recorded video file and simultaneously displaying the time indicating when the video was recorded. The time may be displayed on a time display section 51 superimposed on an image 50 of a captured frame as shown in FIG. 4, for example.

The playback device etc. may have a function of selecting between the time based on an internal clock (e.g., the first internal clock 22 or the internal clock of the playback device) and the time based on a GPS signal, and displaying it on the time display unit 51. The selection may be made by a user's instruction, but the playback device etc. may be configured to give priority to the time based on the GPS signal and display it on the time display unit 51 if the time is stored in association with the GPS signal.

When the playback device, etc., has the function of displaying multiple types of time in this way, it is preferable that the playback device, etc., has a function of displaying so that it is clear which time is currently being displayed. Displaying so that it is clear may take various forms, such as changing the display color or arranging information 52 indicating the type, such as icons, marks, or characters, in close proximity. The type indicating information 52 should display the corresponding information for each, but the playback device, etc. may display only one type, and when it does not display it, it may be understood that it is the other type. Furthermore, when the time is recorded based on the first internal clock 22 and the time is continuous, the playback device, etc., may also correct and display the time that is past the time when the time for time adjustment was determined. Note that when displaying the time after time adjustment, it is not essential to display it in a way that makes it clear that it is the time after time adjustment.

The time based on the internal clock may be the time of the internal clock, but may also be a time calculated based on the recorded time of the first internal clock 22 and the difference Δt (an example of a third time). In this way, even when the playback device etc. cannot receive a GPS signal, the correct time can be displayed, and the user can know the correct time from the display. The playback device etc. should display in such a way that it is clear which of these times is being displayed. Displaying in such a way that it is clear may be the same as the method described above.

[Other forms of recording system]
The recording system is not limited to a drive recorder 2 installed in a vehicle, but may be, for example, a system that records the operating status of a vehicle for operational management, a surveillance system that records the operating status of machines in a factory, etc., or a surveillance system that records images captured by surveillance cameras installed in various locations.

In the above embodiment, the data to be recorded is an example of application to a drive recorder, and therefore an example of recording video files captured by a camera, etc. has been described, but the present invention is not limited to this, and may be applied to a recording device for various types of time-series data, such as the location history of a vehicle or device, changes in the location and acceleration of a vehicle or device, the operating state of a vehicle or device (e.g., driving state), and sensor values detected by a sensor that represent the state of a vehicle or device.

The number of recording devices such as drive recorder 2 that record data is not limited to one, and multiple devices may be installed in the system. In such a system, each recording device may be connected to device 3 and acquire the time from device 3, but it is preferable to send and receive the time between recording devices to synchronize the time.

*One form of a system with multiple recording devices In the case of multiple installations, it is preferable to use a drive recorder mounted at an appropriate position of the vehicle, such as a front and rear camera. For example, a system is provided with a first drive recorder 2a equipped with a camera 11 that captures the front of the vehicle, a second drive recorder 2b equipped with a camera 11 that captures the rear of the vehicle, and a third drive recorder 2c equipped with a camera 11 that captures the interior of the vehicle. The first drive recorder 2a is attached, for example, to the windshield of the vehicle 60, the second drive recorder 2b is attached, for example, to the rear glass of the vehicle, and the third drive recorder 2c is attached, for example, to the ceiling of the vehicle interior, and each captures images of a predetermined capture area and records them on the micro SD card 21. Each drive recorder is also provided with a first internal clock 22, and records the time of the first internal clock 22 of the own device in association with the video file.

For example, the third drive recorder 2c installed in the vehicle's cabin may have a harder time receiving GPS signals than other drive recorders. Also, the third drive recorder 2c may not have a GPS module installed, for example. In a system configured in this way, the first drive recorder 2a and/or the second drive recorder 2b may be the time source for synchronizing the time on the third drive recorder 2c.

For example, the first drive recorder 2a and the second drive recorder 2b (an example of a first recording device) are connected to the communication unit 24 of the third drive recorder 2c (an example of a second recording device) via the communication unit 24 mounted on each of them, and are configured to be able to communicate wirelessly. The control unit 16 of the third drive recorder 2c then establishes communication with the first drive recorder 2a or the second drive recorder 2b at an appropriate timing, and transmits a transmission request for the time to be adjusted to the drive recorder with which communication has been established. The control unit of the drive recorder that receives the transmission request transmits the time, for example, by superimposing the time acquired by the GPS module 14 of its own device as information for time adjustment, and a time (an example of a fourth time) that specifies the time after time adjustment on a command and transmitting it to the control unit 16 of the third drive recorder 2c. Then, the control unit 16 of the third drive recorder 2c calculates the difference between this time and the time measured by the first internal clock 22 of its own device based on the acquired time for time adjustment, and records it in association with the video file. The control unit 16 then adjusts the time of the first internal clock 22 at an appropriate timing, such as when the power is turned off.

The control units 16 of the first drive recorder 2a and the second drive recorder 2b may also synchronize the first internal clock 22 based on the time acquired by the GPS module 14 of their own device using the method already described.

In the above example, the first drive recorder 2a and the second drive recorder 2b transmit the time based on the GPS signal received by the GPS module 14 to the third drive recorder 2c. However, for example, by storing and holding the difference as described above, the time (an example of the fourth time) may be obtained using the difference held by the device itself from the time of the first internal clock 22 of the device itself, and transmitted to the third drive recorder 2c. In this way, the time can be transmitted even in a situation where the GPS module 14 cannot determine the position when a transmission request is received from the third drive recorder 2c and cannot obtain the time based on the GPS signal.

In this embodiment, the three drive recorders are time-aligned based on the time of the GPS signal, so even if there is a time discrepancy between the internal clocks of each drive recorder, video files recorded at the same time in each drive recorder can be associated based on the difference data.

In the embodiment described above, both the first drive recorder 2a and the second drive recorder 2b are equipped with a GPS module, but for example, the second drive recorder 2b may also be of a type that does not have a GPS module, and the time of the second drive recorder 2b may also be set based on the time acquired from the first drive recorder 2a. In this way, the times of the three drive recorders are corrected based on the time acquired by the same GPS module, which makes it easier to achieve synchronization.

*Another form of system with multiple recording devices (recording system installed on trains)
As shown in FIG. 6, for example, there is a recording system equipped with various types of monitoring camera devices at predetermined positions of train cars. The monitoring cameras include, for example, a first monitoring camera device 61 installed outside the leading car, and a plurality of second monitoring camera devices 62 installed at the entrance and exit of the car, at the fluorescent lamp on the ceiling of the car, near the coupling section, etc. In both the first monitoring camera device 61 and the second monitoring camera device 62, a control unit 65 operates based on the time of an internal clock 66 (an example of a clock for identifying the time of data recording), and records a video file obtained by shooting with the camera 63 of the device in a recording medium such as an SD card 64. The video data is formed into one video file in a predetermined time unit, and is continuously recorded while the car is in operation. Furthermore, the first monitoring camera device 61 and the second monitoring camera device 62 are equipped with a communication unit 67, and are configured to enable communication between the monitoring camera devices by a predetermined communication method such as Wi-Fi. Furthermore, in this embodiment, the first monitoring camera device 61 has a built-in GPS module 68, and is capable of acquiring location information and time information from a received GPS signal.

The SD card 64 is placed at the back of the device body, which is covered with multiple layers, and can be removed by removing the multiple lids and covers using a screwdriver, key, etc. Furthermore, the communication unit 67 is designed to communicate via a secure line. This increases security and minimizes the risk of recorded video, etc., leaking to the outside.

As in the above-mentioned embodiments, the control unit 65 of the first surveillance camera device 61 calculates the difference between the time acquired by the GPS module 68 and the time of the internal clock 66 based on the time acquired by the GPS module 68, stores the difference in association with the video file, and adjusts the time of the internal clock 66 while recording is stopped or at other appropriate times. In other words, while the train is running, if the time of the internal clock is changed, the continuity of the recorded video file will be lost, so for example, it is preferable to record continuously at least from the starting station to the terminal station without adjusting the time of the internal clock 66, and more preferably not to adjust the time until the train leaves the depot and returns. During this time, the time of the internal clock 66 is not adjusted, but by recording the difference, the correct recording time of the recorded video file can be obtained. The time can be acquired, for example, once during a series of recordings, for example immediately after startup.

Because it is difficult to receive GPS signals inside a vehicle, in this embodiment, the time is set based on the time obtained by the GPS signal from the first surveillance camera device 61. For this reason, the second surveillance camera device 62 does not need to be equipped with a GPS module.

The first monitoring camera device 61 may transmit the time acquired by the first monitoring camera device 61 to each of the second monitoring camera devices 62, but in this embodiment, the first monitoring camera device 61 (an example of a first recording device) transmits a time (an example of a fifth time) that specifies the time after time adjustment to one or some of the second monitoring camera devices 62 (an example of a second recording device) as information for time adjustment, and the other second monitoring camera devices 62 (an example of a third recording device) are configured to acquire this time from the second monitoring camera device 62 that received it, for example. In this way, for example, when the number of second monitoring camera devices 62 installed increases, the communication load of the first monitoring camera device 61 can be suppressed from increasing. In addition, the first monitoring camera device 61 is installed outside the leading car and away from the second monitoring camera device 62, while the multiple second monitoring camera devices 62 may be installed in a relatively limited and narrow space, such as within the same car. In such a case, the first surveillance camera device 61 may transmit the time to another specified second surveillance camera device 62 using, for example, LTE as a first communication method, and the time may be transmitted between the second surveillance camera devices 62 in a sequential chain-like manner using, for example, Wi-Fi as a second communication method.

In addition, for example, some surveillance cameras installed under fluorescent lights are equipped with LTE communication capabilities, so the second surveillance camera device 62 installed under the fluorescent light can obtain the time from the first surveillance camera device 61, and the second surveillance camera device 62 installed under the fluorescent light can transmit the time using Wi-Fi as a second communication method to the second surveillance camera device 62 that does not have LTE communication capabilities as a first communication method.

The second surveillance camera device 62 that receives the time may obtain and record the difference, and when sending to another second surveillance camera device 62, may add the elapsed time from reception to transmission to obtain the time for time adjustment (an example of the fourth time) and transmit it. In this embodiment, the time of the internal clock 66 is not adjusted immediately after reception, so it is not necessary to immediately transmit it to another surveillance camera device. In this case, instead of adding the elapsed time, the time may be obtained by adding or subtracting the difference to the current time of the internal clock 66, and transmitted as the time for time adjustment. In this way, the internal clocks of multiple surveillance camera devices can be synchronized. The method of transmitting the time is not limited to Wi-Fi, and may be any method that can transmit the time electrically, radio waves, or visually, such as LTE, GPS, wired communication LAN, UART, or video analysis.

In this embodiment, based on the time acquired by the first surveillance camera device 61, the multiple second surveillance camera devices 62 perform time correction processing such as calculating and recording the difference and adjusting the time, so that when playing back images captured by multiple surveillance camera devices, it is possible to synchronize the time by outputting or identifying images captured at the same time.

In addition, the first surveillance camera device 61 (an example of a fourth recording device) and the second surveillance camera device 62 (an example of a fifth recording device) may have a function to transmit video at a specific time in response to an instruction to obtain video (an example of data) at that time. In this way, even when the train is running, the recorded video can be transmitted to the outside based on a request from outside the recording system, for example, and the recorded video can be checked. In such a case, the video corresponding to the specific time can be read and transmitted by taking into account the difference in the recording time based on the internal clock 66 recorded on the SD card. In this way, video at the correct time can be transmitted.

In addition, since the instruction to acquire the video at the specified time may be sent from a remote location, a surveillance camera device equipped with, for example, an LTE communication function as a first communication method receives the acquisition instruction and transfers the video at the corresponding time. Furthermore, the surveillance camera device equipped with the LTE communication function may be equipped with a function to send a transfer request to another surveillance camera device not equipped with the said function to transmit video at the same time, and the other surveillance camera device may transmit video at the requested time to the surveillance camera device equipped with the said LTE communication function. The surveillance camera device that has acquired the video may transfer the video at the specified time using LTE communication. LTE communication may be replaced with other communication methods (e.g., 4G, 5G).

Furthermore, the instruction to acquire video at a specified time may be issued to all surveillance camera devices or to a specific surveillance camera device, and a surveillance camera device having, for example, an LTE communication function as a first communication method that receives an instruction to acquire video for a specific surveillance camera device may have the function of sending a request to the specific surveillance camera to transmit video at the same time using, for example, Wi-Fi as a second communication method, and transferring the received video when a response is received.

The information for time adjustment is not limited to a time that specifies the time after time adjustment (e.g., a time obtained from device 3 or input by a user), but may also indicate the amount of correction to the time during time adjustment. For example, device 3 calculates a correction amount from the difference between the time measured by the first internal clock 22 of drive recorder 2 and the time measured by the second internal clock 32, and provides this to drive recorder 2. The control unit 16 of drive recorder 2 applies this correction amount to the time measured by the first internal clock 22 (e.g., by adding or subtracting) to adjust the time of the first internal clock 22.

The device 3 that provides correct time information is not limited to the above, and can be applied to various devices, such as base stations for mobile communications such as mobile phones. Such base stations have the function of receiving GPS signals and holding accurate current time information based on the GPS signals. A communication module (e.g., an LTE module) that communicates with the base station has the function of acquiring correct time information based on the GPS held by the base station when it is triggered by connection to the base station. When the drive recorder 2 enters an area where communication with a base station is possible, it connects to the base station (more specifically, connects wirelessly). This connection is usually realized automatically without any explicit human instruction, such as an operation to instruct the connection. In addition, the communication module has the function of allowing the time information acquired by the communication module to be accessed from the outside and referred to.

Therefore, a communication module that communicates with a base station is installed in a recording device such as a drive recorder or a surveillance camera. The control unit of the recording device can then use the time information acquired when the communication module connects to the base station to perform the above-mentioned time correction process. The communication module installed in the recording device can be installed, for example, inside the main body case of the recording device, or it can be a separate type that is provided separately from the main body case.

When a recording device or the like is mounted on a moving object such as a vehicle, the base station to which the communication module is connected changes as the vehicle or the like moves. After the communication module is turned on, it acquires correct time information when it first connects to any base station and establishes communication, and thereafter, even if the base station to which it connects changes, it does not acquire new time information until the power is turned off. Therefore, even if the base station to which it connects changes as the vehicle moves, it does not acquire time information each time. The control unit 16 performs processing such as obtaining and storing difference data based on the correct time information acquired after the power is turned on. Then, once this processing is performed after the power is turned on, it is not performed until the power is turned off. This is based on the knowledge that it is sufficient to perform correction processing when the power is turned on and the first connection is made to a base station, but the correction processing may be performed by connecting to a base station on another occasion while the power is on. In the above-mentioned modified example, the device 3 is a base station, but for example, the communication module may be regarded as the device 3.

The scope of the present invention is not limited to the configurations explicitly described in the specification, but includes combinations of various aspects of the present invention disclosed in this specification. The configurations of the present invention that are sought to be patented are specified in the attached claims, but it is our intention to include configurations disclosed in this specification in the claims in the future, even if they are not currently specified in the claims.

The present invention is not limited to the configurations described in the above-mentioned embodiments. The components of each of the above-mentioned embodiments and variations may be arbitrarily selected and combined. Any components of each of the embodiments and variations may be arbitrarily combined with any components described in the means for solving the invention or any components that embody any components described in the means for solving the invention. We intend to acquire rights to these as well through amendments to this application or divisional applications, etc. Even if there is a description such as "in the case of" or "when", this is not intended to describe a configuration that is limited to that case or time. We also disclose configurations that are not in these cases or times, and we intend to acquire rights to them. Furthermore, the parts that are described in order are not limited to this order. We also disclose configurations in which some parts are deleted or the order is changed, and we intend to acquire rights to them.

In addition, by converting to a design registration application, it is intended to obtain rights to the overall design or partial design. The drawings show the entire device in solid lines, but they include not only the overall design but also partial designs claimed for a portion of the device. For example, it is not only a drawing that includes a portion of the device as a partial design, but also a drawing that includes a portion of the device as a partial design regardless of the portion. A portion of the device may be a portion of the device, or a portion of that portion. It is intended to obtain rights to not only the overall design, but also partial designs in which any portion of the solid line portion of the drawing is shown as a broken line portion. In addition, the modules, materials, parts, etc. inside the device's casing, all of which are shown in the drawings, are subject to trade independently, and it is intended to obtain rights to them by converting to a design registration application in the same way.

1: System 2: Drive recorder 2a: First drive recorder 2b: Second drive recorder 2c: Third drive recorder 3: Equipment 11: Camera 14: GPS module 15: Operation button 16: Control unit 17: Temporary storage memory 18: Monitor 19: Speaker 20: Memory card slot 21: Micro SD card 22: First internal clock 23: Power supply unit 24: First communication unit 31: Control unit 32: Second internal clock 33: Power supply unit 33: Internal clock 34: Second communication unit 36: Control unit 41: GPS receiver 42: Internal clock 50: Image 51: Time display unit 60: Vehicle 61: First surveillance camera device 62: Second surveillance camera device 63: Camera 64: SD card 65: Control unit 66: Internal clock 67: Communication unit 68: GPS module

Claims (7)

A system including a recording device that records data generated or acquired in real time in association with a first time acquired from an internal clock ,
The recording device includes a first recording device and a second recording device provided in a vehicle ,
The first recording device is
a function of acquiring information for adjusting the time of the internal clock of the device to the second time;
a function of performing control such that, when the information is acquired during recording of the data, the time adjustment is not performed, and a difference between the first time and the second time is recorded in association with the data;
when information for adjusting the time is acquired, transmitting information for adjusting the time to a fourth time determined based on the acquired information to the second recording device;
The second recording device is
The time setting device has a function of recording a difference between the fourth time and the first time acquired by the device itself, based on information for performing the time setting acquired from the first recording device.
system. The recording device provided in the vehicle includes a third recording device,
The second recording device is
a function of transmitting information for setting the time to a fifth time to the third recording device based on information for setting the time to the fourth time,
The third recording device is
The device has a function of recording a difference between the fifth time and the first time acquired by the device itself, based on information for performing the time adjustment acquired from the second recording device.
The system of claim 1 . The first recording device records an image of the surroundings of the vehicle and has a GPS receiving function;
The second recording device has a function of recording an image captured inside the vehicle,
The first recording device has a function of determining the fourth time based on the second time acquired based on a signal received by the GPS receiving function.
3. A system according to claim 1 or 2. The first recording device has a function of generating information for setting the time to the fourth time by taking into account the elapsed time since the acquisition of information for setting the time to the second time.
A system according to any one of claims 1 to 3. A system including a recording device provided in a vehicle, the recording device correlating data generated or acquired in real time with a first time acquired from an internal clock, and recording the data,
The recording device includes:
a function of acquiring information for adjusting the time of the internal clock to a second time;
a function of controlling the time adjustment based on the acquired information so that the first time recorded before the time adjustment is kept stored even after the time adjustment based on the acquired information, and when the information is acquired while the data is being recorded, the time adjustment is not performed and a difference between the first time and the second time is recorded in association with the data;
the data comprises an image;
The recording device or the playback device is
a function of calculating a third time indicating a time when the data was recorded based on the first time and the difference recorded in association with the data, and outputting the data based on the calculated third time;
a function of displaying the third time or the first time selected according to a predetermined condition together with the image;
A system comprising: The function of displaying is
The system according to claim 5 , wherein the displayed time is displayed so as to indicate whether it is the third time or the first time. 7. A program for causing a computer to realize the functions of the first recording device according to claim 1.

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