JP2013072172A - Communication instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication instrument which is actuated even by a small vibration.SOLUTION: A communication instrument, which consumes electric power of a battery 24 for wireless communication with a communication master only when a vibration sensor 26 accommodated in a case detects a vibration, comprises an arm part 28 which is cantilevered by a fixed object fixed within the case. The vibration sensor 26 is disposed on the arm part 28.

Description

  The present invention relates to a communication device including a vibration sensor that detects vibration.

  In recent years, in automobiles, for the purpose of improving convenience, wireless communication is performed between an electronic key possessed by a user and an in-vehicle device, and door locking / unlocking is permitted on condition that the wireless communication is established. Alternatively, an electronic key system to be executed is mounted. An example of such an electronic key system is disclosed in Patent Document 1. The electronic key system of Patent Document 1 is a so-called smart system in which a radio signal is automatically transmitted and received between the vehicle and the electronic key when the user holding the electronic key approaches the vehicle. The electronic key is driven by the power of the replaceable battery.

  Incidentally, a vibration sensor is mounted on the electronic key of Patent Document 1. The battery power is supplied to each part of the electronic key only when vibration is detected by the vibration sensor. When the power of the battery is supplied to each part of the electronic key, the electronic key is in a state where it can receive a radio signal from the vehicle (standby state), and the power of the battery is not supplied to each part of the electronic key. When the radio signal from the vehicle is not received (non-standby state). Therefore, when the electronic key is not used, for example, when the electronic key is stored indoors, the electronic key is in a non-standby state, and battery consumption is suppressed.

JP 2002-320278 A

  In the case of such an electronic key, a board provided with an electric circuit for performing wireless communication is fixed inside the case. The vibration sensor is also disposed on this substrate. Usually, the case is formed by combining two housings so that a substrate or the like can be easily accommodated therein. Between these two cases, a waterproof member such as rubber is disposed. This waterproof member prevents liquid such as water from entering the inside of the case and adversely affecting the substrate and the like.

  However, many waterproof members are made of an elastic member such as rubber. For this reason, even if the case vibrates, the vibration may be absorbed by the elastic member. Therefore, the vibration of the substrate fixed in the case may be weakened. As a result, the vibration sensor disposed on the substrate may not be able to detect the vibration of the case. Even with an electronic key that is not provided with a waterproof member, if the vibration itself is weak, the vibration sensor may not be able to detect the vibration. As a result, there is a possibility that smart communication cannot be used because power is not supplied from the battery.

  The present invention has been made in view of such a situation, and an object thereof is to provide a communication device that operates even with minute vibrations.

  In order to solve the above problems, the invention of claim 1 is a communication device that consumes power from a power source and performs wireless communication with a communication master only when a vibration sensor housed in the case detects vibration. In the above, the gist is provided with an arm portion that is cantilevered by an inner wall of the case or a fixed object fixed inside the case, and the vibration sensor is provided on the arm portion.

  Vibration is a phenomenon caused by the repeated peaks and valleys of waves transmitted to an object. To detect vibration means to detect the repetition of waves and waves. Therefore, the larger the difference between the peaks and valleys, the easier the detection. According to this configuration, the arm portion that is cantilevered is provided. Therefore, the distal end portion of the arm portion is a free end. When the measurement object vibrates, a wave that causes vibrations is transmitted from the measurement object to the arm portion. The wave transmitted to the arm part enters the free end. This is called an incident wave. It has been found that the incident wave is reflected at the free end, producing a reflected wave. The reflected wave is transmitted to the arm. This phenomenon is called free end reflection. In this free end reflection, when the incident wave incident on the free end is a mountain, the reflected wave reflected at the free end with respect to the incident wave is also a mountain, and when the incident wave is a valley, the reflected wave is also I know it will be a valley. Therefore, the amplitude of the combined wave, which is a combination of the incident wave and the reflected wave that actually vibrate the arm, is larger than the amplitude of the incident wave, that is, the amplitude of the measurement target. For this reason, the vibration sensor provided in the arm part is easy to detect the vibration even when the case vibrates minutely. Thereby, even when the case vibrates slightly, wireless communication can be performed with the communication master.

The gist of the invention according to claim 2 is that, in the communication device according to claim 1, the vibration sensor is provided at a tip portion of the arm portion.
The incident wave to the tip that vibrates the measurement object is reflected at the free end at the tip. Then, the reflected wave reflected at the free end is transmitted from the tip portion toward the measurement object. That is, a combined wave of the incident wave and the reflected wave is generated from the tip portion toward the measurement target. The amplitude where the synthesized wave is generated is larger than the amplitude in the measurement target. The earliest generation of this synthesized wave is at the tip of the arm. For this reason, by providing a vibration sensor at the tip, even if the measurement object vibrates slightly, the vibration can be detected quickly.

  According to a third aspect of the present invention, in the communication device according to the first or second aspect, a substrate is fixed inside the case, and the arm portion is formed by cutting out a part of the substrate. This is the gist.

  According to this configuration, the arm portion can be formed by a simple operation of cutting out the substrate.

  The present invention can provide a communication device that operates even with minute vibrations.

The block diagram which shows the structure of the electronic key system in this embodiment. The top view of the board | substrate in this embodiment. The image figure which shows an incident wave, reflected wave, and these synthetic waves when free end reflection generate | occur | produces at a certain time.

Hereinafter, an embodiment embodying an electronic key system according to the present invention will be described with reference to FIGS.
As shown in FIG. 1, the vehicle 10 is equipped with an electronic key system 1 that executes ID verification using a radio signal communicated with the electronic key 20.

<Vehicle configuration>
The vehicle 10 includes an in-vehicle control unit 11 that controls various in-vehicle devices, an LF transmission unit 12 that is electrically connected to the in-vehicle control unit 11 and transmits a request signal of an LF (Low Frequency) band, and an UHF (Ultra High). And a UHF receiver 13 for receiving a response signal in the (Frequency) band. The vehicle 10 also includes a door lock device 14 and a door handle sensor 15 that are also electrically connected to the in-vehicle controller 11. The door lock device 14 switches between locking and unlocking the door lock. The door handle sensor 15 detects contact of a user with a door handle (not shown).

  The in-vehicle control unit 11 is provided with a nonvolatile memory 11a. An ID code unique to the vehicle 10 is stored in the memory 11a. The in-vehicle controller 11 performs wireless communication with the electronic key 20 through the LF transmitter 12 and the UHF receiver 13. The in-vehicle control unit 11 determines whether or not the electronic key 20 that is communicating corresponds to itself through the transmission / reception of a radio signal performed with the electronic key 20. This determination is made by collating the ID code included in the wireless signal from the electronic key 20 with the ID code stored in the memory 11a. And when it is judged that it corresponds to self, operation of door lock device 14 is permitted. In this state, when contact with the door handle is detected through the door handle sensor 15, the in-vehicle controller 11 executes the operation of the door lock device 14.

<Structure of electronic key>
The electronic key 20 includes an electronic key control unit 21 configured by a computer unit including a CPU or the like. The electronic key control unit 21 is electrically connected to an LF reception unit 22 that receives a radio signal in the LF band and a UHF transmission unit 23 that transmits a radio signal in the UHF band.

  When receiving the request signal, which is an LF band radio signal transmitted from the vehicle 10, the LF receiving unit 22 demodulates the request signal into a pulse signal and outputs the demodulated signal to the electronic key control unit 21.

  The electronic key control unit 21 includes a nonvolatile memory 21a, and an ID code unique to the electronic key 20 is stored in the memory 11a. When the electronic key control unit 21 recognizes the request signal demodulated by the LF receiving unit 22, the electronic key control unit 21 generates a response signal. The response signal includes the ID code stored in the memory 21a. The electronic key control unit 21 outputs the generated response signal to the UHF transmission unit 23. The UHF transmitter 23 modulates the response signal and transmits the modulated response signal as a radio signal in the UHF band.

  The electronic key 20 includes a battery 24, a power supply determination circuit 25, and a vibration sensor 26. The battery 24 is a primary battery that can be replaced. The battery 24 supplies power to each part of the electronic key 20 such as the electronic key control part 21 via the power supply determination circuit 25. The power supply determination circuit 25 monitors the presence or absence of vibration of the electronic key 20 detected by the vibration sensor 26, and determines whether or not the power of the battery 24 is supplied to each part of the electronic key 20 through the monitoring. The power supply determination circuit 25 supplies the power of the battery 24 to each part of the electronic key 20 when the vibration sensor 26 detects vibration, and supplies the power of the battery 24 to each part of the electronic key 20 when the vibration sensor 26 does not detect vibration. Do not supply.

  Each of these components is arranged on a substrate 29 (printed substrate) fixed inside the case of the electronic key 20. More specifically, the substrate 29 includes a substrate body 27 fixed inside the case, and an arm portion 28 formed by cutting out the substrate body 27. As shown in FIG. 2, the arm portion 28 is formed on the side portion of the substrate 29. As shown in FIG. 1, an electronic key control unit 21, an LF reception unit 22, a UHF transmission unit 23, a battery 24, and a power supply determination circuit 25 are provided on the substrate body 27, and a vibration sensor is provided on the distal end portion 28 a of the arm portion 28. 26 are arranged respectively. The arm 28 and the vibration sensor 26 constitute a vibration detection unit 30.

  The distal end portion 28 a of the arm portion 28 is formed wider than the proximal end portion in accordance with the size of the vibration sensor 26. Note that the width from the base end portion to the tip end portion 28a of the arm portion 28 is constant.

  As shown in FIG. 2, the base end portion of the arm portion 28 is a fixed end fixed to the substrate body 27, and the distal end portion is the outside, here, a free end separated from the substrate body 27 and the inner surface of the case. Therefore, when the substrate body 27 (electronic key 20) vibrates, a wave (vibration wave) that causes the vibration is transmitted from the base end portion toward the distal end portion 28a in the arm portion 28. Thereby, the front-end | tip part 28a vibrates. The vibration sensor 26 detects vibration at the tip end portion 28a.

<Operation of electronic key system>
When the user moves while walking with the electronic key 20 held, the vibration of the user accompanying the movement is transmitted to the electronic key 20. The vibration wave that vibrates the electronic key 20 is transmitted to the substrate body 27 fixed inside the case. The vibration wave transmitted to the substrate body 27 is transmitted to the arm portion 28. The vibration wave is transmitted from the proximal end portion toward the distal end portion 28 a in the arm portion 28. The tip 28a is a free end. For this reason, as shown in FIG. 3, the vibration wave incident on the tip portion 28a, that is, the incident wave (indicated by a one-dot chain line in the figure) is reflected at the free end at the tip portion 28a. At the distal end portion 28a, the vibration wave reflected at the free end, that is, the reflected wave (two-dot chain line in the figure) is combined with the incident wave to become a combined wave (solid line in the figure). The synthesized wave vibrates the tip 28a. Here, as shown in FIG. 3, it is known that the reflected wave becomes a mountain when the incident wave is a mountain, and becomes a valley when the incident wave is a valley. Therefore, the amplitude of the synthesized wave is larger than the amplitude of the incident wave. Thereby, the vibration sensor 26 can detect the vibration even when the amplitude of the incident wave is small, that is, even when the substrate body 27 vibrates slightly.

  When the vibration sensor 26 detects vibration, a detection signal indicating that is sent to the power supply determination circuit 25. When the detection signal is input, the power supply determination circuit 25 supplies the power of the battery 24 to each part of the electronic key 20 including the electronic key control part 21. Thereby, the electronic key 20 can receive a request signal from the vehicle 10.

  In this state, when the user approaches the vehicle 10, smart communication is automatically performed between the vehicle 10 and the electronic key 20. When the user touches the door handle sensor 15 provided on the door handle of the vehicle 10 with the smart communication established, the door lock device 14 is activated.

  On the other hand, when the electronic key 20 is placed indoors, it is assumed that smart communication is not performed between the electronic key 20 and the vehicle 10. At this time, the vibration sensor 26 does not detect vibration. Therefore, the vibration sensor 26 does not send a detection signal to the power supply determination circuit 25. That is, the power supply determination circuit 25 does not supply the power of the battery 24 to each part of the electronic key 20. Thereby, power consumption of the battery 24 is suppressed.

As described above in detail, according to the present embodiment, the following effects can be obtained.
(1) The arm portion 28 cantilevered on the substrate body 27 was formed. And the vibration sensor 26 was provided in the front-end | tip part 28a (free end) of the said arm part 28. FIG. The arm 28, the tip 28a, and the vibration sensor 26 constitute a vibration detector 30. A vibration wave when the substrate body 27 vibrates is transmitted to the arm portion 28. This vibration wave is incident on the tip 28a. The incident wave input to the tip portion 28a is reflected at the free end at the tip portion 28a. The reflected wave reflected by the free end is combined with the previous incident wave. This combined composite wave vibrates the tip 28a. In free end reflection, it is known that the reflected wave becomes a mountain when the incident wave is a mountain, and a valley when the incident wave is a valley. Therefore, the amplitude of the synthesized wave is larger than the amplitude of the incident wave. Thereby, the vibration sensor 26 can detect the vibration even when the amplitude of the incident wave is small, that is, even when the substrate body 27 vibrates slightly.

  (2) The vibration detection unit 30 is provided in the electronic key 20 that performs smart communication with the vehicle 10. When the vibration detection unit 30 detects vibration, the electronic key 20 consumes the power of the battery 24 and can perform smart communication with the vehicle 10. Thus, when there is a possibility of smart communication, such as when the user has the electronic key 20, the smart communication can be performed. On the other hand, when the electronic key 20 is placed indoors, it is assumed that smart communication is not performed between the electronic key 20 and the vehicle 10. At this time, the vibration detection unit 30 does not detect vibration. Therefore, the power of the battery 24 is not supplied to each part of the electronic key 20. Thereby, power consumption of the battery 24 is suppressed.

(3) The arm portion 28 is formed integrally with the substrate body 27. Thereby, the structural member accommodated in a case decreases. Accordingly, the number of steps for assembling the electronic key 20 is reduced.
(4) The arm portion 28 was formed at the end portion of the substrate 29. Thereby, the electronic components of the electronic key 20 other than the vibration sensor 26 can be concentrated on one place on the substrate.

In addition, you may change the said embodiment as follows.
In the above embodiment, the vibration sensor 26 is provided at the distal end portion 28 a of the arm portion 28, but it may be provided at the arm portion 28. The arm portion 28 is transmitted with a composite wave in which a vibration wave (incident wave) that vibrates the substrate body 27 and a reflected wave reflected at the free end at the tip portion 28a is transmitted. It becomes larger than the amplitude of the main body 27. Therefore, even if it is a case where it comprises in this way, the effect similar to the said embodiment can be acquired.

  In the above-described embodiment, the arm portion 28 is formed by cutting out the substrate body 27, but it may be anything that is cantilevered by the substrate body 27 or the case. That is, the arm portion 28 may be separate from the substrate body 27. Therefore, the arm portion may be made of a material different from that of the substrate body 27. For example, an elastic member such as a coil spring may be used. Even when configured in this manner, the same effects as those of the above-described embodiment can be obtained.

  In the above embodiment, the arm portion 28 is formed at the end portion of the substrate body 27, but it may not be the end portion. For example, it may be provided at the center of the arm portion 28. Even when configured in this manner, the same effects as those of the above-described embodiment can be obtained.

  -In above-mentioned embodiment, although the electronic key 20 was supposed to perform smart communication between the vehicles 10, it is applicable also to other communication aspects. For example, the present invention can also be applied to what performs so-called wireless communication in which a switch is provided in the electronic key 20 and a radio signal is transmitted with the operation of the switch as a trigger. Even in this case, it is possible to obtain the same effect as the above embodiment.

  In the above embodiment, the battery 24 is a primary battery, but may be a secondary battery or a power storage means such as a capacitor. Even in the case of such a configuration, it is possible to obtain the same effect as the above embodiment.

  In the above embodiment, the vibration sensor 26 detects the vibration of the distal end portion 28a of the arm portion 28, but the detection method is not limited. For example, the detection method includes a displacement method that detects vibration from the displacement of the tip 28a, a speed method that detects vibration from the amount of displacement per time of the tip 28a, an acceleration method that detects vibration from the time derivative of the displacement speed, and the like. There is. Any vibration sensor that employs any of these detection methods can achieve the same effects as those of the above-described embodiment.

  In the above embodiment, the distal end portion 28a of the arm portion 28 is wider than the proximal end portion, but is not necessarily wide. That is, the distal end portion 28a may have a width that is the same as or narrower than the proximal end portion.

  In the above embodiment, an antenna or the like for transmitting / receiving a radio signal to / from the vehicle 10 may be provided in a portion where the substrate body 27 is cut out to form the arm portion 28. If comprised in this way, the notched space can be utilized effectively. As a result, the electronic key 20 can be reduced in size.

  In the above embodiment, the electronic key 20 drives the door lock device by smart communication with the vehicle 10, but may drive other ones. For example, a driving source for traveling such as an engine or a motor may be driven. In addition, when the drive source for driving | running | working of the vehicle 10 is driving, the vibration accompanying the drive of the drive source is transmitted also to a vehicle interior. Therefore, this vibration is also transmitted to the electronic key 20 in the passenger compartment. When the electronic key 20 is placed in the passenger compartment, the vibration of the passenger compartment is directly transmitted, and when the electronic key 20 is held by the user, the vibration of the passenger compartment is transmitted via the user. Therefore, the power of the battery 24 is supplied to each part of the electronic key 20. That is, the electronic key 20 can periodically perform smart communication with the vehicle 10 while the driving source for driving the vehicle 10 is being driven. Accordingly, the vehicle 10 determines whether or not the electronic key 20 is in the vehicle interior using smart communication while the drive source is being driven, and if the electronic key 20 is not in the vehicle interior, transmits an alarm or the like. To notify the user.

  In the above embodiment, the power supply determination circuit 25 supplies the power of the battery 24 to each part of the electronic key 20 only when the vibration sensor 26 detects vibration, but the vibration sensor 26 stops detecting vibration. The power of the battery 24 may be supplied to each part of the electronic key 20 for a predetermined time.

  In the above embodiment, the electronic key 20 is not limited to communicating with the vehicle 10. For example, the house etc. which communicate with the electronic key 20 may be sufficient. In addition to the electronic key, any wireless communication device may be used. Even if comprised in this way, the effect similar to the said embodiment can be acquired.

Next, the technical idea that can be grasped from the above embodiment and other examples will be described below.
(A) The arm portion is formed at an end portion of the substrate.
According to this configuration, the arm portion is formed at the end of the substrate, so that the electronic components of the electronic key other than the vibration sensor can be concentrated on one place on the substrate.

DESCRIPTION OF SYMBOLS 1 ... Electronic key system, 10 ... Vehicle, 11 ... Vehicle-mounted control part, 11a ... Memory, 12 ... LF transmission part, 13 ... UHF receiving part, 14 ... Door lock apparatus, 15 ... Door handle sensor, 20 ... Electronic key, 21 ... Electronic key control unit, 21a ... Memory, 22 ... LF reception unit, 23 ... UHF transmission unit, 24 ... Battery, 25 ... Power supply determination circuit, 26 ... Vibration sensor, 27 ... Substrate body, 28 ... Arm part, 28a ... Tip portion, 29... Substrate, 30.

Claims (3)

In the communication device that consumes the power of the power source and performs wireless communication with the communication master only when the vibration sensor housed in the case detects vibration,
An arm portion that is cantilevered by an inner wall of the case or a fixed object that is fixed inside the case;
The communication device, wherein the vibration sensor is provided in the arm portion. The communication device according to claim 1,
The communication device, wherein the vibration sensor is provided at a distal end portion of the arm portion. The communication device according to claim 1 or 2,
A substrate is fixed inside the case,
The communication device, wherein the arm portion is formed by cutting out a part of the substrate.

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