Patent Description:
<CIT> (hereinafter also referred to as Patent Literature <NUM>) discloses a smart key system for an automobile. The smart key system disclosed in Patent Literature <NUM> includes an on-vehicle device and a portable device capable of wirelessly communicating with the on-vehicle device. In the on-vehicle device disclosed in Patent Literature <NUM>, the larger the strength of the noise signals contained in a radio signal received from the portable device is, the more the strength of the radio signal transmitted to the portable device is increased.

In the smart key system disclosed in Patent Literature <NUM>, there is a case where as the radio signal transmitted from the on-vehicle device is increased, a resin case of the on-vehicle device and a resin panel through which the on-vehicle device is fixed to and held by the body of the vehicle are electrostatically charged. When the resin case of the on-vehicle device and the resin panel through which the on-vehicle device is fixed to and held by the body of the vehicle are electrostatically charged, the strength of the noise signals contained in the radio signal received from the portable device is increased, so that the strength of the radio signal transmitted from the on-vehicle device is further increased and hence the resin case and the resin panel are electrostatically charged even further.

When the amount of electrostatic charging in the resin case and the resin panel increases, the vehicle may not exhibit its normal traveling performance due to the increased amount of electrostatic charging.

The present disclosure has been made in order to solve the above-described problem, and an object thereof is to provide a smart key system for an automobile capable of preventing or reducing the deterioration of the performance of the vehicle (i.e., the automobile) which would otherwise be caused by electrostatic charging of a resin case of an on-vehicle device and a resin panel through which the on-vehicle device is fixed to and held by the body of the automobile.

A first exemplary aspect is a smart key system for an automobile, including: an on-vehicle device configured to transmit and receive a radio signal to and from an electronic key; and a resin panel through which the on-vehicle device is fixed to and held by a body of the automobile, in which
the on-vehicle device includes:.

By the above-described configuration, it is possible to prevent or reduce the deterioration of the performance of the vehicle (i.e., the automobile) which would otherwise be caused by electrostatic charging of a resin case of an on-vehicle device and electrostatic charging of a resin panel through which the on-vehicle device is fixed to and held by the body of the vehicle.

In an aspect, in the smart key system for an automobile, the control unit may increase a strength of the search signal when a strength of the response signal received by the receiver is equal to or smaller than a predetermined strength, when a strength of a noise signal contained in the response signal is equal to or larger than the predetermined strength, or when the strength of the response signal is equal to or smaller than a predetermined strength and the strength of the noise signal is equal to larger than the predetermined strength.

In the case where the control unit controls the search signal as described above, the resin case and the resin panel are electrostatically charged more easily, so that the present disclosure is particularly effective.

In an aspect, in the smart key system for an automobile, at least one of the resin case and the resin panel, and the body of the automobile electrically connected to a negative electrode of an auxiliary battery may be connected to a ground, so that electrostatic charging may be removed from them.

By the above-described configuration, electrostatic charging can be efficiently removed from the resin case, the resin panel, or both of them.

In an aspect, in the smart key system for an automobile, at least one of the resin case and the resin panel, and the body of the automobile including an electrostatic-charging removing device may be connected to a ground, so that electrostatic charging may be removed from them.

Even by the above-described configuration, electrostatic charging can be efficiently removed from the resin case, the resin panel, or both of them.

In an aspect, in the smart key system for an automobile, at least one of the resin case and the resin panel may include a surfactant layer for the removal of the electrostatic charging on an exterior surface thereof.

In an aspect, in the smart key system for an automobile, at least one of the resin case and the resin panel may include an elastic film containing a surfactant for the removal of the electrostatic charging on an exterior surface thereof.

In an aspect, in the smart key system for an automobile, at least one of the resin case and the resin panel may include an elastic mesh sheet containing a surfactant for the removal of the electrostatic charging on an exterior surface thereof.

According to the present disclosure, it is possible to provide a smart key system for an automobile capable of preventing or reducing the deterioration of the performance of the vehicle (i.e., the automobile) which would otherwise be caused by electrostatic charging of a resin case of an on-vehicle device and electrostatic charging of a resin panel through which the on-vehicle device is fixed to and held by the body of the vehicle.

The above and other objects, features and advantages of the present disclosure will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not to be considered as limiting the present disclosure.

<FIG> is a block diagram showing a configuration of a key system for an automobile according to related art.

A key system <NUM> for an automobile according to the related art enables a user carrying an electronic key to carry out predetermined operations and thereby to use various functions provided in the automobile.

Examples of combinations of predetermined operations and functions provided in automobiles include unlocking of a door of an automobile by depressing a button provided on the door, and starting-up of an engine by depressing an engine start button.

The key system <NUM> for the automobile according to the related art includes an on-vehicle device <NUM> and an electronic key <NUM>.

The on-vehicle device <NUM> includes a transmitter <NUM>, a receiver <NUM>, an input unit <NUM>, a control unit <NUM>, and a resin case <NUM>.

The transmitter <NUM> transmits a search signal, which is a radio signal, to the electronic key <NUM> under the control of the control unit <NUM>. The receiver <NUM> receives a response signal transmitted from the electronic key <NUM> in response to the search signal.

Upon receiving the response signal, the receiver <NUM> outputs authentication information contained in the response signal to the control unit <NUM>.

The input unit <NUM> is, for example, a door unlock button or an engine start button, and is a device on which a user performs a predetermined operation. When the predetermined operation is performed on the input unit <NUM> by the user, the input unit <NUM> notifies the control unit <NUM> that the predetermined operation has been performed thereon.

When the control unit <NUM> is notified, by the input unit <NUM>, that the user has performed the predetermined operation, the control unit <NUM> controls the transmitter <NUM>, and thereby makes (e.g., instructs) the transmitter <NUM> transmit a search signal.

Further, when the control unit <NUM> acquires, from the input unit <NUM>, the authentication information contained in the response signal transmitted from the electronic key <NUM>, the control unit <NUM> determines whether or not the acquired authentication information is the same as authentication information that is registered in advance. When the authentication information is the same as the one registered in advance, the control unit <NUM> notifies the control apparatus, which controls a predetermined function, that a function corresponding to the predetermined operation performed by the user should be carried out.

Note that when the strength of the response signal received from the electronic key <NUM> is equal to or smaller than a predetermined strength, when the strength of a noise signal contained in the response signal is equal to or larger than a predetermined strength, or when the strength of the response signal is equal to or smaller than the predetermined strength and the strength of the noise signal is equal to larger than the predetermined strength, the control unit <NUM> does not perform the determination and instead controls the transmitter <NUM> so that the transmitter <NUM> transmits a search signal having a strength higher than that of the previous search signal.

Further, the control unit <NUM> includes, for example, an arithmetic unit such as a CPU (Central Processing Unit) (not shown), and a storage unit such as a RAM (Random Access Memory) and a ROM (Read Only Memory) in which programs and data for controlling the on-vehicle device <NUM> are stored. That is, the control unit <NUM> has functions as a computer and controls the on-vehicle device <NUM> based on the aforementioned program.

The resin case <NUM> is a case made of resin that houses therein the transmitter <NUM>, the receiver <NUM>, the input unit <NUM>, and the control unit <NUM>. The resin case <NUM> is fixed to and held by the vehicle (i.e., the automobile), for example, through a resin panel provided in the body of the vehicle.

<FIG> is a schematic cross-sectional diagram showing a resin case and a resin panel in the case where the input unit <NUM> is an engine start button.

A resin panel <NUM> is a resin panel provided in front of the driver's seat inside the vehicle, and a hole in which an on-vehicle device <NUM> is fitted (i.e., inserted) is formed.

The resin case <NUM> is fitted (i.e., inserted) into the hole of the resin panel <NUM>, so that resin case <NUM> is fixed to and held by the body of the vehicle.

A cable <NUM> is a cable for connecting the control unit <NUM> of the on-vehicle device <NUM> to an ECU (Engine Control Unit) of the engine. The control unit <NUM> requests the ECU of the engine to start up the engine through the cable <NUM>.

The electronic key <NUM> includes a receiver <NUM>, a transmitter <NUM>, and a control unit <NUM>.

When the receiver <NUM> receives a search signal from the on-vehicle device <NUM>, the receiver <NUM> notifies the control unit <NUM> of the reception of the search signal.

The transmitter <NUM> transmits a response signal, which is a radio signal, to the on-vehicle device <NUM> under the control of the control unit <NUM>.

Upon receiving the information indicating the reception of the search signal from the receiver <NUM>, the control unit <NUM> controls the transmitter <NUM> and thereby makes (e.g., instructs) the transmitter <NUM> transmit a response signal containing authentication information. Note that the control unit <NUM> determines the strength of the response signal based on the strength of the received search signal. Specifically, the control unit <NUM> controls the transmitter <NUM> in such a manner that the higher the strength of the search signal is, the stronger response signal the transmitter <NUM> transmits.

Further, the control unit <NUM> includes, for example, an arithmetic unit such as a CPU (Central Processing Unit) (not shown), and a storage unit such as a RAM (Random Access Memory) and a ROM (Read Only Memory) in which programs and data for controlling the electronic key <NUM> are stored. That is, the control unit <NUM> has functions as a computer and controls the electronic key <NUM> based on the aforementioned program.

As described above, when the strength of the response signal received from the electronic key <NUM> is equal to or smaller than a predetermined strength, when the strength of a noise signal contained in the response signal is equal to or larger than a predetermined strength, or when the strength of the response signal is equal to or smaller than the predetermined strength and the strength of the noise signal is equal to larger than the predetermined strength, the on-vehicle device <NUM> transmits a search signal having a higher strength. The higher the strength of the search signal is, the stronger response signal the electronic key <NUM> transmits. By the above-described configuration, the on-vehicle device <NUM> can receive a response signal having an appropriate strength.

However, in the key system <NUM> for an automobile according to the related art, there are cases where as the strength of the search signal increases, the resin case <NUM> and the resin panel <NUM> are electrostatically charged. The electrostatic charging of the resin case <NUM> and the resin panel <NUM> causes noise signals in the response signal received by the on-vehicle device <NUM>, and hence causes a further increase in the strength of the search signal and resulting larger electrostatic charging of the resin case <NUM> and the resin panel <NUM>.

As a result of diligent study, the inventors have found that electrostatic charging of the resin case <NUM> and the resin panel <NUM> causes the processing speed of the control apparatus of the vehicle to decrease, so that the performance of the vehicle is impaired.

As a result of further study, the inventors have found that it is possible to prevent or reduce the deterioration of the performance of the vehicle by removing electrostatic charging of the resin case and the resin panel.

Therefore, in a first embodiment, at least one of the resin case and the resin panel, and the body of the vehicle electrically connected to a negative electrode of an auxiliary battery are connected to the ground, so that electrostatic charging is removed from either or both of the resin case and the resin panel.

Further, in a second embodiment, at least one of the resin case and the resin panel includes an electrostatic-charging removing surfactant layer on an exterior surface thereof, so that electrostatic charging is removed from at least one of the resin case and the resin panel by the electrostatic-charging removing surfactant layer.

<FIG> is a block diagram showing a configuration of a key system for an automobile according to a first embodiment.

A key system <NUM> for an automobile according to the first embodiment enables a user carrying an electronic key to carry out predetermined operations and thereby to use various functions provided in the automobile.

Examples of combinations of predetermined operations and functions provided in automobiles include unlocking of a door of the automobile by depressing a button provided on the door and starting-up of an engine by depressing an engine start button.

The key system <NUM> for the automobile according to the first embodiment includes an on-vehicle device <NUM>, an electronic key <NUM>, and a resin panel <NUM>.

The input unit <NUM> is, for example, a door unlock button or an engine start button, and is a device that receives a predetermined operation from a user. Upon receiving the predetermined operation from the user, the input unit <NUM> notifies the control unit <NUM> of the reception of the predetermined operation.

The resin case <NUM> is a case made of resin that houses therein the transmitter <NUM>, the receiver <NUM>, the input unit <NUM>, and the control unit <NUM>. The resin case <NUM> is fixed to and held by the vehicle (i.e., the automobile) through the resin panel <NUM>.

The resin case <NUM> is electrostatically charged as the strength of the search signal transmitted from the transmitter <NUM> increases.

Upon receiving the information indicating the reception of the search signal from the receiver <NUM>, the control unit <NUM> controls the transmitter <NUM> and thereby makes (e.g., instructs) the transmitter <NUM> transmit a response signal containing authentication information. Note that the control unit <NUM> determines the strength of the response signal based on the strength of the received search signal. Specifically, the control unit <NUM> controls the transmitter <NUM> so that the higher the strength of the search signal is, the stronger response signal the transmitter <NUM> transmits.

The resin panel <NUM> is a panel made of resin through which the on-vehicle device <NUM> is fixed to and held by the body of the vehicle. For example, when the input unit <NUM> is an engine start button, the resin panel <NUM> is a resin panel provided in front of the driver's seat inside the vehicle, and a hole in which the on-vehicle device <NUM> is fitted (i.e., inserted) is formed.

The resin panel <NUM> is electrostatically charged as the strength of the search signal transmitted from the transmitter <NUM> increases.

In the smart key system for an automobile according to the first embodiment, at least one of the resin case <NUM> and the resin panel <NUM>, and the body of the automobile electrically connected to a negative electrode of an auxiliary battery are connected to the ground.

The auxiliary battery has a function of removing electrostatic charging from the body of the automobile, so that, by the above-described configuration, electrostatic charging is removed from either or both of the resin case <NUM> and the resin panel <NUM>. As a result, it is possible to prevent or reduce the deterioration of the performance of the vehicle (i.e., the automobile) which would otherwise be caused by electrostatic charging of the resin case <NUM> and the resin panel <NUM>.

In the smart key system for the automobile according to this embodiment, at least one of the resin case <NUM> and the resin panel <NUM>, and the body of the automobile including an electrostatic-charging removing device may be connected to the ground. The electrostatic-charging removing device is preferably disposed, for example, in a metal frame such as a body frame, a brake pedal mounting frame, and a steering column frame. Further, at least one of the resin case <NUM> and the resin panel <NUM> is preferably connected directly to the ground, i.e., directly connected to the metal frame in which the electrostatic-charging removing device is disposed. Examples of the electrostatic-charging removing device include air ionization self-discharging type aluminum foil adhesive tape or the like.

As described above, in the smart key system for the automobile according to the first embodiment, electrostatic charging is removed from either or both of the electrostatically-charged resin case <NUM> and the resin panel <NUM> through the connection between the body of the vehicle and the ground. By the above-described configuration, the key system for the automobile according to the first embodiment can prevent or reduce the deterioration of the performance of the vehicle (i.e., the automobile).

A smart key system for an automobile according to a second embodiment has a configuration similar to that of the key system for an automobile according to the first embodiment.

In the first embodiment, electrostatic charging is removed from at least one of the electrostatically-charged resin case <NUM> and the resin panel <NUM> through the connection between the body of the automobile and the ground. In contrast to this, in the second embodiment, electrostatic charging is removed from at least one of the electrostatically-charged resin case <NUM> and the resin panel <NUM> by an electrostatic-charging removing surfactant layer provided on the surface thereof.

At least one of the resin case <NUM> and the resin panel <NUM> according to this embodiment includes an electrostatic-charging removing surfactant layer on the exterior surface thereof.

The electrostatic-charging removing surfactant layer may be formed by, for example, spraying an electrostatic-charging removing surfactant on the exterior surfaces of the resin case <NUM> and/or the resin panel <NUM>.

As the electrostatic-charging removing surfactant, a cationic surfactant, an anionic surfactant, an amphoteric ion-based surfactant, a non-ionic surfactant, or a mixture thereof may be used. Among them, the cationic surfactant is particularly preferred because of its high electrostatic-charging removing property.

The electrostatic-charging removing surfactant contains a hydrophilic group, so that it has a high affinity with water molecules. Therefore, the surface of the electrostatic-charging removing surfactant layer is strongly bound to water molecules. Since water molecules bonded to the electrostatic-charging removing surfactant remove static electricity, the electrostatic charging of the resin case <NUM> and the resin panel <NUM> are removed by the electrostatic-charging removing surfactant layer.

In the smart key system for an automobile according to this embodiment, at least one of the resin case and the resin panel may include an elastic film containing an electrostatic-charging removing surfactant on the exterior surface thereof. Note that in the case where the resin case and the resin panel include an elastic film containing an electrostatic-charging removing surfactant, they may or may not include an electrostatic-charging removing surfactant layer.

Further, in the smart key system for an automobile according to this embodiment, at least one of the resin case and the resin panel may include an elastic mesh sheet containing an electrostatic-charging removing surfactant on the exterior surface thereof. Note that in the case where the resin case and the resin panel include an elastic mesh sheet containing an electrostatic-charging removing surfactant, they may or may not include an electrostatic-charging removing surfactant layer.

<FIG> is a schematic cross-sectional diagram showing an example of a resin case and a resin panel including an elastic mesh sheet containing an electrostatic-charging removing surfactant on the exterior surface thereof, and is a schematic cross-sectional diagram in the case where the input unit <NUM> is an engine start button. It should be noted that an elastic mesh sheet <NUM> is an elastic mesh sheet containing an electrostatic-charging removing surfactant, and a cable <NUM> is a cable for connecting the control unit <NUM> of the on-vehicle device <NUM> to an ECU of an engine.

Further, <FIG> is a figure showing an example of a resin case and a resin panel including an elastic mesh sheet containing an electrostatic-charging removing surfactant on the exterior surface thereof, and is a figure in the case where the input unit <NUM> is an engine start button.

Even by the above-described configuration, electrostatic charging of the resin case <NUM> and the resin panel <NUM> can be removed.

As described above, in the smart key system for an automobile according to the second embodiment, electrostatic charging is removed from at least one of the resin case <NUM> and the resin panel <NUM> by the electrostatic-charging removing surfactant layer provided on the exterior surface of at least one of the resin case <NUM> and the resin panel <NUM>. By the above-described configuration, the smart key system for an automobile according to the second embodiment can prevent or reduce the deterioration of the performance of the vehicle (i.e., the automobile).

Claim 1:
A smart key system for an automobile, comprising: an on-vehicle device (<NUM>) configured to transmit and receive a radio signal to and from an electronic key (<NUM>); and a resin panel (<NUM>) through which the on-vehicle device is fixed to and held by a body of the automobile, wherein
the on-vehicle device (<NUM>) comprises:
a transmitter (<NUM>) configured to transmit a search signal to the electronic key (<NUM>);
a receiver (<NUM>) configured to receive a response signal transmitted from the electronic key (<NUM>) in response to the search signal;
a control unit (<NUM>) configured to control at least the transmission of the search signal; and
a resin case (<NUM>) configured to house therein the transmitter (<NUM>), the receiver (<NUM>), and the control unit (<NUM>), and
wherein the smart key system is configured such that electrostatic charging generated by the search signal transmitted from the transmitter is removed from either or both of the resin case (<NUM>) and the resin panel (<NUM>).