Drive recorder

Abstract

To provide a drive recorder capable of reducing battery exhaustion while a vehicle is stopped. [Solution] A drive recorder according to an embodiment includes a recording control unit, a power switch, an impact detection unit, and a cutoff circuit. The recording control unit receives power from a battery and performs recording processing. The power switch is provided between the battery and the recording control unit. The impact detection unit outputs a connection signal to connect the power switch when it detects an impact to the vehicle while the vehicle is stopped. The cutoff circuit is provided between the impact detection unit and the power switch, and stops outputting the connection signal to the power switch when the battery voltage falls below a threshold while the vehicle is stopped.

Description

[Technical Field]

[0001] The present invention relates to a drive recorder. [Background technology]

[0002] Conventionally, there is known a drive recorder that receives power from an on-board battery and records captured video when an impact is detected while the vehicle is stopped (power off) (see, for example, Patent Document 1). Patent Document 1 also discloses a technology that detects the voltage of the on-board battery when the power is turned off, and stops the recording process when an impact is detected if the detected voltage is below a threshold, thereby preventing the battery from running out while the vehicle is stopped. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2024-13603 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the conventional technology leaves room for improvement in reducing battery drain while the vehicle is parked. Specifically, even if the battery voltage is above a threshold when the power is off, if the vehicle is left standing for a long time, the battery voltage may drop below the threshold due to natural discharge. In this case, with the conventional technology, because the battery voltage is above the threshold when the power is off, even if the battery voltage is below the threshold when an impact is detected, power is supplied from the battery and recording processing is performed. Therefore, with the conventional technology, there is a risk of the battery draining while the vehicle is parked for a long time.

[0005] The present invention has been made in view of the above, and has an object to provide a drive recorder that can reduce battery drain while the vehicle is stopped. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, the drive recorder according to the present invention comprises a recording control unit, a power switch, an impact detection unit, and a cutoff circuit. The recording control unit receives power from a battery and performs recording processing. The power switch is provided between the battery and the recording control unit. The impact detection unit outputs a connection signal to connect the power switch when it detects an impact to the vehicle while the vehicle is stopped. The cutoff circuit is provided between the impact detection unit and the power switch, and cuts off the output of the connection signal to the power switch when the voltage of the battery falls below a threshold while the vehicle is stopped. [Effects of the Invention]

[0007] According to the present invention, when the battery voltage falls below a threshold while the vehicle is parked, the cutoff circuit cuts off the output of the connection signal to the power switch, thereby cutting off the power supply from the battery. Therefore, when the vehicle is left unused for a long period of time and the battery voltage drops below the threshold, the output of the connection signal is stopped and the power supply is stopped, so that recording processing is not performed when an impact is detected while the vehicle is parked. Therefore, according to the present invention, when the battery voltage drops below the threshold while the vehicle is parked, not supplying power for recording processing can reduce battery death. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a drive recorder according to an embodiment. [Figure 2] FIG. 2 is an explanatory diagram of an example of the operation of the drive recorder. [Figure 3] FIG. 3 is an explanatory diagram of an example of the operation of the drive recorder. [Figure 4] FIG. 4 is an explanatory diagram of an example of the operation of the drive recorder. [Figure 5] FIG. 5 is a diagram showing a blocking circuit according to a modified example. [Figure 6]FIG. 6 is a diagram showing a drive recorder according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a drive recorder according to an embodiment will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the following embodiment.

[0010] First, a configuration example of a drive recorder 1 according to an embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram showing a configuration example of a drive recorder 1 according to an embodiment. In Fig. 1, power supply lines that supply power are indicated by dashed lines, and control lines that transmit control-related signals are indicated by solid lines.

[0011] 1, the drive recorder 1 is connected to a battery 100 and is driven by receiving power supply from the battery 100. The battery 100 is an in-vehicle battery, such as a lead battery or a lithium ion battery.

[0012] The drive recorder 1 includes a recording control unit 2, a power switch 3, an impact detection unit 4, a low-voltage detection circuit 5, a smoothing circuit 6, and a cutoff circuit .

[0013] The recording control unit 2 is driven by power supplied from a battery 100, and controls an imaging unit (not shown) to perform recording processing for recording captured video.

[0014] The power switch 3 is provided between the battery 100 and the recording control unit 2, and connects or disconnects a power supply line connecting the battery 100 and the recording control unit 2. The power switch 3 is configured by a semiconductor switch such as a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), for example.

[0015] The impact detection unit 4 is, for example, a G sensor that detects an impact to the vehicle. The impact detection unit 4 is driven by power supplied from the battery 100 and outputs a connection signal to connect the power switch 3 via a control line.

[0016] The low voltage detection circuit 5 detects whether the voltage of the battery 100 is in a low voltage state. Specifically, the low voltage detection circuit 5 is configured with a comparator, and detects a low voltage state when the voltage of the battery 100 is below a threshold value (reference voltage). When the low voltage detection circuit 5 detects a low voltage state, it outputs a low voltage notification signal to the cutoff circuit 7 via a control line. The reference voltage is, for example, a voltage value corresponding to the power consumed in the recording process when an impact is detected, and a voltage value corresponding to the remaining battery charge at which the battery will run out due to the recording process.

[0017] The smoothing circuit 6 is provided between the low voltage detection circuit 5 and the cutoff circuit 7, and smoothes the low voltage notification signal output from the low voltage detection circuit 5. This allows the smoothing circuit 6 to prevent the cutoff circuit 7 from erroneously operating due to a low voltage notification signal output due to a temporary voltage fluctuation in the battery 100. The smoothing circuit 6 may be configured as a delay circuit that delays the low voltage notification signal by a certain time.

[0018] The cutoff circuit 7 is provided on a control line between the impact detection unit 4 and the power switch 3, and when it receives a low voltage notification signal from the smoothing circuit 6, it cuts off the output of the connection signal output from the impact detection unit 4 to the power switch 3. The cutoff circuit 7 is configured, for example, by a semiconductor switch such as a MOSFET. The cutoff circuit 7 can also be configured by a logic circuit, which will be described in detail later with reference to FIG. 5.

[0019] In the present disclosure, when the voltage of the battery 100 falls below a threshold while the vehicle is stopped, the cutoff circuit 7 cuts off the output of the connection signal to the power switch 3. As a result, when the voltage of the battery 100 is below the threshold, the cutoff circuit 7 can cut off the power switch 3 and stop the supply of power from the battery 100 to the recording control unit 2. In other words, according to the present disclosure, even if an impact is detected while the vehicle is stopped when the voltage of the battery 100 is below the threshold, recording processing can be prevented, thereby reducing the risk of the battery running out.

[0020] 2 to 4, an example of the operation of the drive recorder 1 will be specifically described below, focusing on the operation of the interrupter circuit 7. Figures 2 to 4 are explanatory diagrams of an example of the operation of the drive recorder 1. Figure 2 shows an example of the operation while the ignition (IG) is on, and Figures 3 and 4 show an example of the operation while the IG is off.

[0021] First, an example of operation while the IG is on will be described with reference to Fig. 2. As shown in Fig. 2, while the IG is on, an on signal (High) indicating that the ACC switch is on is input to the power switch 3. This turns on the power switch 3 and connects the power supply line. As a result, the recording control unit 2 receives power supply from the battery 100 and is driven to perform recording processing.

[0022] Next, an example of operation during IG off will be described with reference to Fig. 3 and Fig. 4. Fig. 3 shows a case where the voltage of battery 100 is equal to or higher than threshold value TH, and Fig. 4 shows a case where the voltage of battery 100 is lower than threshold value TH.

[0023] First, an example of operation when the voltage of battery 100 is equal to or higher than threshold value TH will be described with reference to Fig. 3. Prior to describing Fig. 3, the connection state of power switch 3 and cutoff circuit 7 will be described. In Fig. 3, IG is off, so an off signal (Low) indicating that the ACC switch is off is input to power switch 3. That is, in Fig. 3, before step S3, when the power switch 3 is turned on due to impact detection, the power switch 3 is off and cuts off the power supply line.

[0024] 3, since the voltage of the battery 100 is equal to or higher than the threshold value TH, the cutoff circuit 7 is turned on and connects the control line. Specifically, the cutoff circuit 7 is turned on and connects the control line when it receives a normal notification signal (High) from the low voltage detection circuit 5, which indicates that the voltage of the battery 100 is normal.

[0025] Then, with the power switch 3 and the cutoff circuit 7 in the above states, it is assumed that the impact detection unit 4 detects an impact to the vehicle (step S1). When the impact detection unit 4 detects an impact, it outputs a connection signal to the cutoff circuit 7 (step S2). At this time, the cutoff circuit 7 is turned on, so it outputs the connection signal output from the impact detection unit 4 to the power switch 3.

[0026] As a result, the power switch 3 receives the connection signal and changes from off to on (step S3), connecting the power supply line between the battery 100 and the recording control unit 2. As a result, power is supplied from the battery 100 to the recording control unit 2, and the recording control unit 2 starts recording processing (step S4).

[0027] Next, an example of operation when the voltage of the battery 100 is less than the threshold value TH will be described with reference to Fig. 4. In Fig. 4, as in Fig. 3, the IG is off, and therefore the power switch 3 is turned off by receiving an off signal (Low) indicating that the ACC switch is off.

[0028] 4, the voltage of the battery 100 is less than the threshold value TH, so the cutoff circuit 7 is turned off and cuts off the control line. Specifically, the cutoff circuit 7 is turned off and cuts off the control line when it receives a low voltage notification signal (Low) from the low voltage detection circuit 5, which indicates that the battery 100 is in a low voltage state.

[0029] Then, with the power switch 3 and the cutoff circuit 7 in the above states, it is assumed that the impact detection unit 4 detects an impact to the vehicle (step S11). When the impact detection unit 4 detects an impact, it outputs a connection signal to the cutoff circuit 7. At this time, the cutoff circuit 7 is turned off, so it does not output the connection signal output from the impact detection unit 4 to the power switch 3. In other words, the cutoff circuit 7 cuts off the output of the connection signal to the power switch 3.

[0030] As described above, in the present disclosure, when the voltage of the battery 100 is equal to or higher than the threshold value TH while the vehicle is stopped, the cutoff circuit 7 is turned on to output a connection signal to the power switch 3. Then, in the present disclosure, when the voltage of the battery 100 is less than the threshold value TH, the cutoff circuit 7 is turned off to cut off the output of the connection signal to the power switch 3. As a result, even if the vehicle is left standing for a long time and the voltage of the battery 100 drops below the threshold value TH, the power switch 3 is cut off to stop the power supply to the recording control unit 2. In other words, the drive recorder 1 prevents power from being supplied to the recording control unit 2 when the voltage of the battery 100 is less than the threshold value TH while the vehicle is stopped, thereby reducing the risk of the battery running out.

[0031] As described above, the drive recorder 1 according to the embodiment includes the recording control unit 2, the power switch 3, the impact detection unit 4, and the cutoff circuit 7. The recording control unit 2 receives power from the battery 100 and performs recording processing. The power switch 3 is provided between the battery 100 and the recording control unit 2. The impact detection unit 4 outputs a connection signal to connect the power switch 3 when it detects an impact to the vehicle while the vehicle is stopped. The cutoff circuit 7 is provided between the impact detection unit 4 and the power switch 3, and cuts off the output of the connection signal to the power switch 3 when the voltage of the battery 100 falls below a threshold while the vehicle is stopped.

[0032] According to the present disclosure, when the battery voltage falls below a threshold while the vehicle is stopped, the drive recorder 1 can stop the supply of power from the battery 100 by having the cutoff circuit 7 cut off the output of the connection signal to the power switch 3. Therefore, even if the vehicle is left unused for a long period of time and the battery voltage drops below the threshold, the drive recorder 1 can stop the output of the connection signal and stop the power supply, thereby preventing recording processing when an impact is detected while the vehicle is stopped. Therefore, when the battery voltage drops below the threshold while the vehicle is stopped, the drive recorder 1 can reduce battery death by not supplying power for recording processing.

[0033] In the above-described embodiment, the shutoff circuit 7 is configured with a semiconductor switch such as a MOSFET, but the shutoff circuit 7 may also be configured with a logic circuit. The shutoff circuit 7 may also be configured with a logic circuit alone, or may be configured with a logic circuit mounted on an IC (Integrated Circuit). This point will be explained using FIG. 5.

[0034] Fig. 5 is a diagram showing an interruption circuit 7 according to a modified example. As shown in Fig. 5, the interruption circuit 7 is configured by a logic circuit. More specifically, the interruption circuit 7 is an AND circuit.

[0035] Specifically, when a normal communication signal (High) is input from the smoothing circuit 6 and a High connection signal indicating that an impact has been detected is input from the impact detection unit 4, the cutoff circuit 7 outputs a High connection signal to connect the power switch 3.

[0036] On the other hand, when a low signal is input from at least one of the smoothing circuit 6 and the impact detection unit 4, the cutoff circuit 7 outputs a low connection signal that cuts off the power switch 3. In other words, the cutoff circuit 7 cuts off the output of a high connection signal that connects the power switch 3. Specifically, when a low voltage notification signal (low) is input from the smoothing circuit 6 or a low connection signal indicating that no impact has been detected is input from the impact detection unit 4, the cutoff circuit 7 outputs a low connection signal to the power switch 3.

[0037] As described above, in the modified example, when the voltage of the battery 100 is below the threshold value TH while the vehicle is stopped, a low voltage notification signal (Low) is input to the cutoff circuit 7, which cuts off the output of the connection signal. As a result, even if the vehicle is left standing for a long time and the voltage of the battery 100 drops below the threshold value TH, the power switch 3 is cut off and the power supply to the recording control unit 2 is stopped. In other words, when the vehicle is stopped, the drive recorder 1 prevents power from being supplied to the recording control unit 2 when the voltage of the battery 100 is below the threshold value TH, thereby reducing the risk of the battery running out.

[0038] In the above-described embodiment, the cutoff circuit 7 is configured to stop outputting a connection signal to the power switch 3, but it may also stop outputting a start signal for an in-vehicle device that consumes power from the battery 100, in addition to the connection signal. This point will be described with reference to FIG. 6.

[0039] Fig. 6 is a diagram showing a drive recorder 1 according to a modified example. As shown in Fig. 6, the drive recorder 1 is connected to an in-vehicle device 200. The in-vehicle device 200 is, for example, a navigation device or an anti-theft device, and when an impact is detected while the vehicle is stopped, an activation signal is output from the drive recorder 1 and the in-vehicle device 200 is activated. After activation, the in-vehicle device 200 receives power supply from the battery 100 and operates.

[0040] In this modification, the cutoff circuit 7 is provided between the impact detection unit 4 and the in-vehicle device 200, and cuts off the output of the activation signal output from the impact detection unit 4 to the in-vehicle device 200. Specifically, when an impact is detected while the voltage of the battery 100 is below the threshold value TH, the cutoff circuit 7 cuts off the control line between the impact detection unit 4 and the in-vehicle device 200, and therefore can prevent the output of the activation signal to the in-vehicle device 200.

[0041] That is, in the modified example, when the voltage of the battery 100 is less than the threshold value TH, the in-vehicle device 200 is not started even if an impact is detected, thereby reducing the power consumed by the battery 100 for driving the in-vehicle device 200. That is, according to the present disclosure, it is possible to reduce the occurrence of battery exhaustion.

[0042] Further advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. [Explanation of symbols]

[0043] 1. Drive recorder 2 Recording control section 3 Power switch 4 Impact detection unit 5 Low voltage detection circuit 6 Smoothing circuit 7. Breaking Circuit 100 Battery 200 On-vehicle equipment

Claims

1. a recording control unit that receives power from the battery and performs recording processing; a power switch provided between the battery and the recording control unit; an impact detection unit that outputs a connection signal to connect the power switch when an impact to the vehicle is detected while the vehicle is stopped; a cutoff circuit that is provided between the impact detection unit and the power switch and that cuts off output of the connection signal to the power switch when the voltage of the battery falls below a threshold value while the vehicle is stopped; A drive recorder comprising:

2. a low-voltage detection circuit that outputs a low-voltage notification signal to the cutoff circuit when detecting that the voltage of the battery is lower than a threshold; a smoothing circuit provided between the low voltage detection circuit and the cutoff circuit, for smoothing the low voltage notification signal. The drive recorder according to claim 1 .

3. The interruption circuit includes: A switch that connects or disconnects a control line between the impact detection unit and the power switch. The drive recorder according to claim 1 .

4. The interruption circuit includes: a logic circuit to which a low voltage notification signal indicating that the voltage of the battery is lower than a threshold and the connection signal are input; The logic circuit comprises: When the low voltage notification signal is input, the output of the connection signal to the power switch is cut off. The drive recorder according to claim 1 .

5. The impact detection unit When an impact to the vehicle is detected while the vehicle is stopped, a start signal for starting the in-vehicle device is further output. The interruption circuit includes: When the voltage of the battery falls below a threshold while the vehicle is stopped, output of the activation signal to the in-vehicle device is cut off. The drive recorder according to claim 1 .

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