JP2010093416A - Mobile device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mobile device capable of suppressing the influence of a metal member on radio waves transmitted from the mobile device, while being provided with a belt-like metal member. <P>SOLUTION: The length in the longitudinal direction of decoration metals 8, 8, 10 and 10 is set, such that the decoration metals 8, 8, 10 and 10 do not resonate, when receiving the radio waves having the wavelength regarding the same as the length in the longitudinal direction of the decoration metals 8, 8, 10 and 10. In harmonics having the frequency which is an integral multiple of the fundamental waves of transmission radio waves generated by an electronic key 2, one having the wavelength of comparable length in the longitudinal direction of the electronic key 2, in particular, is prevented from resonating with the decoration metals 8, 8, 10 and 10, and the output strength of the harmonic is prevented from resulting in marked increase. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a portable device that performs predetermined wireless communication with a specific communication target.

  Conventionally, as shown in Patent Document 1, for example, a door lock is locked and unlocked by transmitting and receiving an identification code through a predetermined wireless communication with a communication control device provided in a vehicle, a house, or the like. An electronic key is used. A circuit board is accommodated in the case of the electronic key. On the circuit board, a control circuit in which an identification code corresponding to the communication control device is stored and a transmission antenna for performing wireless communication with the communication control device are mounted. The control circuit transmits the identification code to the communication control device through the transmission antenna. The communication control device determines whether or not the identification code included in the radio wave transmitted from the transmission antenna of the electronic key matches the identification code stored in the communication key. Unlock.

The electronic key is detachably provided with an emergency key that can be attached to a key cylinder provided on the door in order to manually lock and unlock the door lock. In addition, in this type of electronic key, the appearance of the electronic key is used in order to favor the possession of the electronic key while ensuring the wireless communication performance that allows normal wireless communication with the communication control device. It is also desirable to ensure the appearance of For example, a decoration or the like is applied to the surface of the case of the electronic key to give the electronic key a high design. As an example of the decoration, for example, in order to give a high-class feeling, there is a case where a glittering design as seen in a metal product is given.
JP 2002-322841 A

  By the way, usually, for example, a key plate of an emergency key or a decoration of a glitter design uses a metal such as aluminum or iron. Generally, when the length of a metal member provided in the vicinity of an antenna matches the half wavelength of a radio wave received by the metal member, the metal member resonates with the radio wave. On the other hand, a radio wave having a frequency of several hundred MHz, that is, a radio wave having a wavelength of several m to several tens cm is used as a radio wave transmitted from the electronic key to the communication control device. Therefore, it is considered that a metal member provided in an electronic key set to a size of several centimeters from the viewpoint of portability is usually resonated by a radio wave having a wavelength of several meters to several tens of centimeters transmitted from the electronic key. hard.

  However, among many harmonics having a frequency that is an integral multiple of the fundamental wave of the radio wave transmitted from the electronic key, the half wavelength is the same as the length of the metal member provided on the electronic key. There is something. Therefore, the harmonics and the metal member may resonate and the output intensity of the harmonics of the transmission radio wave may increase. For this reason, there is a possibility that the output intensity of the harmonics of the transmission radio wave cannot satisfy the regulations such as the Radio Law.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a portable device including a band-shaped metal member that can suppress the influence of the metal member on radio waves transmitted from the portable device. Is to provide a machine.

  According to the invention described in claim 1, a case made of a non-conductive material, a transmission antenna that is provided inside the case and transmits a unique identification code of itself to a communication target, and the transmission antenna In a portable device that operates a specific device corresponding to the communication target on the condition that the identification code matches on the communication target side. Of the harmonics having a resonance frequency that is an integral multiple of the fundamental wave of the transmission radio wave transmitted from the transmission antenna, the half wavelength thereof is approximately the same as the length of the case along the longitudinal direction of the metal member. The gist is that the length of the metal member is set so as not to coincide with the harmonic frequency.

  Usually, the output intensity of harmonics having a frequency that is an integral multiple of the fundamental wave of a transmitted radio wave tends to decrease as the order increases. Therefore, in order to satisfy laws and regulations such as the Radio Law, there is a problem of harmonics whose half wavelength is approximately the same as the length of the case along the longitudinal direction of the metal member. According to the present invention, the resonance frequency of the metal member has a half-wavelength of the harmonics having a frequency that is an integral multiple of the fundamental wave of the transmission radio wave transmitted from the transmission antenna. The length of the metal member was set so that it did not coincide with the frequency of the harmonics that was comparable to the length. For this reason, it can prevent that the harmonic which has a half wavelength comparable as the length of a case resonates with a metal member, and the output intensity of the harmonic of a portable machine increases significantly. Therefore, in the portable device provided with the metal member, the influence of the metal member on the radio wave transmitted from the portable device can be suppressed. In addition, since the length of the whole metal member can be changed easily, the influence of the metal member on the radio wave transmitted from the portable device can be easily suppressed.

  According to a second aspect of the present invention, the resonance frequency of the metal member is such that the frequency of one harmonic wave of the transmission radio wave transmitted from the transmission antenna and one higher or lower harmonic wave than the harmonic wave. The gist is that the length of the metal member in the longitudinal direction is set so as to be a value between the wave frequencies.

  According to this invention, it can suppress suitably that a metal member resonates with the harmonic which has a wavelength comparable as the length of the longitudinal direction of the said metal member. Therefore, it can prevent that the output intensity of the harmonic of a portable machine increases significantly.

  According to a third aspect of the present invention, the metal member is a decorative metal provided on the surface of the case, and is provided on the surface of the case and has a band shape whose length is set according to the decoration on the case. The gist of the present invention is to include a decorative portion and an extending portion provided at an end of the decorative portion and extending inward of the case.

  According to the present invention, even when a decorative metal is provided on the design surface of the case so as to satisfy the design of the appearance of the portable device, in the harmonic having a frequency that is an integral multiple of the fundamental wave of the transmission radio wave emitted by the portable device. In particular, it is possible to prevent an object having a wavelength comparable to the length of the decoration part from resonating with the decoration metal and greatly increasing the output intensity of the harmonics of the portable device. In addition, by changing the length of the extending portion, it is possible to change the length of the entire metal member without affecting the appearance of the portable device. For this reason, the resonance frequency of the metal member has the same half-wavelength as the length of the case along the longitudinal direction of the metal member, of harmonics having a frequency that is an integral multiple of the fundamental wave of the transmission radio wave transmitted from the transmission antenna. It becomes easy to set the length of the metal member so as not to coincide with the frequency of the higher harmonic.

  According to a fourth aspect of the present invention, the metal member is a mechanical key for manually operating a specific device corresponding to the communication target, and is attached to the specific device and has a length corresponding to the device. The gist of the invention is to include a belt-shaped mounting portion to be set and an extending portion provided at an end portion of the mounting portion and extending in the surface direction of the mounting portion.

  According to the present invention, even when a mechanical key for manually operating a specific device corresponding to a communication target is provided in a portable device, a harmonic having a frequency that is an integral multiple of the fundamental wave of a transmission radio wave emitted by the portable device. It is possible to prevent a wave having a wavelength comparable to the length in the longitudinal direction of the mounting portion from resonating with the mechanical key and greatly increasing the output intensity of the harmonics of the portable device. Further, by changing the length of the extending portion, the entire length of the metal member can be changed without affecting the length of the mounting portion. For this reason, the resonance frequency of the metal member has the same half-wavelength as the length of the case along the longitudinal direction of the metal member, of harmonics having a frequency that is an integral multiple of the fundamental wave of the transmission radio wave transmitted from the transmission antenna. It becomes easy to set the length of the metal member so as not to coincide with the frequency of the higher harmonic.

  The gist of the invention described in claim 5 is that the metal member is provided inside the case, and is provided in an annular shape and has an open loop shape divided in the circumferential direction.

  In general, when there is a metal near the antenna, radio waves transmitted from the antenna during wireless communication with the communication target are affected by the metal. Accordingly, a metal member is provided in the portable device, and this metal member is effectively used as a transmission antenna in wireless communication with a communication target, and the output intensity of the fundamental wave of the transmission radio wave transmitted from the portable device is improved. The applicant has come to mind. According to the present invention, as described above, it is possible to prevent a harmonic having a half wavelength comparable to the length of the case from resonating with the metal member and greatly increasing the output intensity of the harmonic of the portable device. be able to. For this reason, it is possible to improve only the output intensity of the fundamental wave while suppressing an increase in the output intensity of the harmonics of the transmission radio wave transmitted from the portable device.

  ADVANTAGE OF THE INVENTION According to this invention, in the portable machine provided with the strip | belt-shaped metal member, the portable machine which can suppress the influence of the metal member with respect to the electromagnetic wave transmitted from a portable machine can be provided.

Hereinafter, an embodiment in which the present invention is embodied in an electronic key used for opening and closing a door lock in an electronic key system of a vehicle will be described with reference to the drawings.
<Outline of electronic key system>
As shown in FIG. 1, the electronic key system 1 includes an electronic key 2 as a portable device and a locking / unlocking control device 3 as a communication target mounted on a vehicle. When the user has the electronic key 2 and approaches a predetermined area (communication area) of the vehicle, the electronic key 2 receives the request signal Sr transmitted from the locking / unlocking control device 3. This request signal Sr is a signal for requesting the electronic key 2 to transmit the ID code. When receiving the request signal Sr, the electronic key 2 transmits an ID signal Si including its own ID code stored in advance. When receiving the ID signal Si transmitted from the electronic key 2, the locking / unlocking control device 3 collates the ID code on the electronic key 2 side included in the ID signal Si with the vehicle-side ID code stored in advance. The door lock is unlocked on condition that both ID codes match. On the other hand, when the user holds the electronic key 2 and moves away from the predetermined area away from the vehicle, the locking / unlocking control device 3 cannot receive the ID signal Si transmitted from the electronic key 2. The locking / unlocking control device 3 locks the door of the vehicle on condition that the ID signal Si on the electronic key 2 side cannot be received. Thus, the door is locked and unlocked without the user touching the vehicle.

<Electronic key>
As shown in FIG. 2, the case 4 of the electronic key 2 is made of a non-conductive material such as resin, and is formed in a flat shape that forms a rectangle in plan view (as viewed from above in FIG. 2). As shown in FIG. 3, the case 4 is composed of an upper case 5 and a lower case 6 each formed in a box shape having an opening, and an internal storage formed when these openings are assembled in a state of abutting each other. A circuit board 7 is accommodated in the space 4a. Various electronic components for performing predetermined wireless communication and the like with the vehicle (more precisely, the locking / unlocking control device 3) are mounted on the circuit board 7.

  Step portions 5b and 5b are recessed in the respective portions along the two long sides at the edge of the surface 5a of the upper case 5. The step portions 5 b and 5 b are formed in a linear shape extending along the longitudinal direction of the upper case 5. In addition, accommodation recesses 5c and 5c extending along the thickness direction of the upper case 5 are respectively provided at both ends of the step portions 5b and 5b and along the short side of the upper case 5. Decorative metals 8 and 8 are attached to the step portions 5b and 5b and the housing recesses 5c and 5c, respectively, for giving the electronic key 2 a high-class feeling, that is, a lustrous design as seen in precious metal products. . Each of the decorative metals 8 and 8 is made of, for example, a metal material such as aluminum or iron, and the surface thereof is plated for producing glitter.

  As shown in FIG. 3, each of the decorative metals 8, 8 is formed in a substantially rectangular plate shape corresponding to the stepped portions 5 b, 5 b and is arranged on the surface 5 a of the upper case 5, An extending portion 8b provided at both ends of the decorative portion 8a and extending inward (downward in FIG. 3) along the side surface of the upper case 5 is provided. The decoration part 8a of each decoration metal 8 is arrange | positioned at corresponding step part 5b, 5b, and the extension part 8b is arrange | positioned at accommodation recessed part 5c, 5c. As shown in FIG. 4A, the length of the decorative portion 8 a of each decorative metal 8, 8 is set to be the same length as the length L of the case 4. The thickness of the decorative portion 8 a of each decorative metal 8, 8 is set to be flush with the surface 5 a of the upper case 5 by being attached to the step portions 5 b, 5 b of the upper case 5. Further, the length and thickness of the extended portions 8b of the decorative metals 8 and 8 are flush with the side surface of the upper case 5 (the side surface 4d of the case 4) by being attached to the corresponding accommodating recesses 5c and 5c. It is set to be.

  In addition, between the stepped portions 5b and 5b of the surface 5a of the upper case 5, a lock switch 5d operated when the door lock of the vehicle is locked by a button operation with the electronic key 2, and a button with the electronic key 2 are also used. An unlock switch 5e that is operated when unlocking the door lock of the vehicle by operation is provided.

  As shown in FIG. 3, step portions 6 b and 6 b are recessed in the portions along the two long sides at the edge of the surface 6 a of the lower case 6, similar to the upper case 5. The step portions 6 b and 6 b are formed in a straight line extending along the longitudinal direction of the lower case 6. In addition, housing recesses 6c and 6c extending along the thickness direction of the lower case 6 are respectively provided at both ends of the step portions 6b and 6b and along the short side of the lower case 6. Decorated metals 10 and 10 for attaching the electronic key 2 with a high-class feeling, that is, a brilliant design as found in noble metal products, are attached to the respective step portions 6b and 6b and 6c and 6c. Each of the decorative metals 10 and 10 is formed of a metal material such as aluminum or iron, for example, like the decorative metals 8 and 8, and the surface thereof is plated for producing glitter.

  As shown in FIG. 3, each of the decorative metals 10 and 10 is formed in a substantially rectangular plate shape corresponding to the stepped portions 6b and 6b, and the decorative portions 10a and 10a disposed on the surface 6a of the lower case 6, Extending portions 10b and 10b provided at both ends of the decorative portions 10a and 10a and extending inwardly (upward in FIG. 3) along the side surface of the lower case 6 are provided. The decorative portions 10a and 10a of the decorative metals 10 and 10 are disposed in the corresponding step portions 6b and 6b, and the extended portions 10b and 10b are disposed in the accommodating recesses 6c and 6c. As shown in FIG. 4A, the lengths of the decorative portions 10 a and 10 a of the decorative metals 10 and 10 are set to be the same as the length L of the case 4. The thicknesses of the decorative metals 10 and 10 are set to be flush with the surface 6a of the lower case 6 by being attached to the step portions 6b and 6b of the lower case 6, respectively. Further, the lengths and thicknesses of the extending portions 10b and 10b of the decorative metals 10 and 10 are the same as the side surface of the lower case 6 (the side surface 4d of the case 4) by being attached to the corresponding accommodating recesses 6c and 6c. It is set to be.

  In the present embodiment, the resonance frequency of the decorative metals 8, 8, 10, 10 is one higher harmonic frequency of the transmission radio wave transmitted from the transmission antenna 11 and one higher order than the harmonic wave, or The length of the entire decorative metal 8, 8, 10, 10 is set so as to be a value between the frequencies of the lower harmonics. Specifically, by changing the lengths of the extending portions 8b, 8b, 10b, 10b provided at both ends of the decorative portions 8a, 8a, 10a, 10a, the decorative portions 8a, 8a, 10a, 10a The length of the entire decorative metal 8, 8, 10, 10 is set to an appropriate value without changing the length.

  As shown in FIGS. 4A and 4B, the decorative metals 8, 8, 10, and 10 are completely overlapped when viewed from the surfaces 5a and 6a of the case 4 (the upper case 5 and the lower case 6). Has been placed. The decorative metals 8, 8, 10, and 10 correspond to metal members. The electronic key 2 of this embodiment includes a surface 5a of the upper case 5 provided with an upper side decorative metal (hereinafter referred to as a decorative metal) 8 and a lower side decorative metal (hereinafter referred to as a decorative metal). The surface 6a of the lower case 6 provided with 10 is a design surface. Since the case 4 is formed in a flat shape as described above, the areas of the surfaces 5a and 6a of the case 4 (upper case 5 and lower case 6), which are surfaces orthogonal to the thickness direction of the case 4, are as follows. The area of the four side surfaces 4d along the thickness direction of the case 4 is larger.

  As shown in FIG. 3, the circuit board 7 is formed in a rectangular flat plate shape. A transmission antenna 11, a reception circuit (not shown), a control circuit (not shown), and a transmission circuit (not shown) are mounted on a surface 7 a on the upper case 5 side of the circuit board 7. A receiving antenna (not shown) and a power circuit (not shown) are mounted on the side surface 7b. The receiving circuit receives the request signal Sr (see FIG. 1) transmitted from the locking / unlocking control device 3 as a radio wave having a predetermined frequency via a receiving antenna. Then, the receiving circuit demodulates the received request signal Sr into a pulse signal, and sends the demodulated request signal Sr to the control circuit. In order to respond to the demodulated request signal Sr, the control circuit sends an ID signal Si (see FIG. 1) including its own ID code stored in advance to the transmission circuit. The transmission circuit modulates the ID signal into a radio wave having a predetermined frequency (433 MHz) and transmits it through the transmission antenna 11. In addition, when the control circuit detects that the lock switch 5d is pushed, the lock request includes its own ID code and a lock request for setting the door lock of the unlocked vehicle to the locked state. A signal Sa (see FIG. 1) is sent to the transmission circuit, and the transmission circuit transmits the lock request signal Sa via the transmission antenna 11. In addition, when the control circuit detects that the unlock switch 5e has been pushed, it puts its own unique ID code and an unlocking request for unlocking the door lock of the locked vehicle. An unlock request signal Sb (see FIG. 1) is sent to the transmission circuit, and the transmission circuit transmits the unlock request signal Sb via the transmission antenna 11.

  As shown in FIG. 4A and FIG. 4B, the transmission antenna 11 is a pattern antenna formed by printing and forming a metal plate as an antenna line (antenna pattern) directly on the circuit board 7. The transmission antenna 11 is provided on one end side in the longitudinal direction of the circuit board 7 (the lower end side in FIGS. 4A and 4B). The circuit board 7 is between the two decorative metals 8, 8, 10, 10 when viewed from the surface 5a, 6a side of the case 4 and is at one end side in the longitudinal direction of the case 4 (see FIGS. In b), it is accommodated in the case 4 so that the transmission antenna 11 is disposed on the lower side. Further, the circuit board 7 is arranged so that the entire transmission antenna 11 does not overlap the decorative metals 8, 8, 10, 10 when viewed from the front surfaces 5 a, 6 a of the case 4. Since the case 4 is formed in a flat shape as described above, the areas of the surfaces 5a and 6a of the case 4 (upper case 5 and lower case 6), which are surfaces orthogonal to the thickness direction of the case 4, are as follows. The area of the side surface 4d which is a surface along the thickness direction of the case 4 is larger. For this reason, it is easy to arrange the transmitting antenna 11 at a position where the entire portion does not overlap with the decorative metals 8, 8, 10, 10 when viewed from the surface 5 a, 6 a side of the case 4.

  By the way, generally, when there is a metal near the transmission antenna, the metal and the transmission antenna are magnetically coupled when radio waves are transmitted from the transmission antenna. For this reason, in radio communication with the locking / unlocking control device 3, the radio wave transmitted from the transmission antenna 11 is affected by the decorative metals 8, 8, 10, 10, and the transmission radio wave transmitted from the electronic key 2 The output intensity changes.

  Here, with reference to FIG. 5, a change in output intensity due to a difference in frequency of radio waves transmitted from an electronic key provided with a metal member will be considered. FIG. 5 shows the output intensity of the radio wave with respect to the frequency of the radio wave transmitted from the electronic key 2 in which the decorative metals 8, 8, 10, and 10 are provided on the surfaces 5 a and 6 a of the case 4 as in the present embodiment. Is a graph showing the result of simulation by the inventor. Note that the length of the case 4 of the electronic key 2 is assumed to be 6 cm, and in this simulation, the length of the decorative metal 8, 8, 10, 10 in the longitudinal direction is the length of the surface 5a, 6a of the case 4. The same 6 cm is set. That is, the result of this simulation is a case where the lengths of the decorative metals 8, 8, 10, 10 are set according to the length of the surfaces 5a, 6a of the case 4, and the electronic key according to the present embodiment. In this example, the extended portions 8b, 8b, 10b, and 10b are omitted from the two decorative metals 8, 8, 10, and 10. In the graph of FIG. 5, the horizontal axis indicates the frequency of the radio wave transmitted from the transmission antenna 11 of the electronic key 2, and the vertical axis indicates the output intensity of the transmission radio wave. In FIG. 5, the output intensity of the electronic key 2 provided with the decorative metals 8, 8, 10, and 10 as shown in the present embodiment is indicated by ●, and the output intensity in the case of the circuit board 7 alone is indicated by ▲. Is shown.

  As shown in FIG. 5, when the frequency of the transmission radio wave is 1 GHz or less, the output intensity of the electronic key 2 provided with the decorative metals 8, 8, 10, 10 is about the same as that of the circuit board 7 alone. It becomes. On the other hand, when the frequency of the transmission radio wave is 2.5 GHz to 2.3 GHz, in other words, when the half wavelength of the transmission radio wave is about 6 cm, the electronic key 2 provided with the decorative metals 8, 8, 10, and 10 is provided. The output intensity increases significantly as compared with the case of the circuit board 7 alone. That is, when the lengths of the decorative metals 8, 8, 10, 10 provided on the electronic key 2 and the half-waves of the radio waves received by the decorative metals 8, 8, 10, 10 are approximately the same, the electronic key 2 The output intensity of the transmitted radio wave increases.

  The output intensity of the electronic key 2 provided with the decorative metals 8, 8, 10, and 10 has a peak in the vicinity where the frequency of the transmission radio wave is 1.7 GHz and 3.9 GHz. That is, the decorative metals 8, 8, 10, and 10 resonate with radio waves having frequencies of 1.7 GHz and 3.9 GHz. In the present embodiment, a radio wave having a frequency of 433 MHz is transmitted from the transmission antenna 11. For this reason, when the length of the decorative metals 8, 8, 10, 10 is set to the same length as the length L of the case 4 (in this case, 6 cm), the decorative metals 8, 8 provided on the electronic key 2 are used. , 10 and 10 receive a radio wave having substantially the same frequency as the harmonic wave of the radio wave transmitted from the transmission antenna 11, the output intensity of the harmonic wave of the transmission radio wave of the electronic key 2 increases.

  Normally, the output intensity of the harmonics of the transmitted radio waves tends to decrease as the order increases. Therefore, in order to satisfy laws and regulations such as the Radio Law, harmonics having a wavelength comparable to the length L of the case 4 is a problem.

  As described above, in the present embodiment, the resonant frequency of the decorative metals 8, 8, 10, and 10 is one harmonic frequency of the transmission radio wave transmitted from the transmission antenna 11 and 1 higher than the harmonic frequency. The lengths of the decorative metals 8, 8, 10, and 10 are set so as to be a value between the frequencies of higher and lower harmonics. Therefore, among the harmonics having a frequency that is an integral multiple of the fundamental wave of the transmission radio wave of the electronic key 2, the half wavelength of the decorative metal 8, 8, 10, 10 is about the same as the length of the case 4. Does not match the harmonic frequency. For this reason, harmonics having a half wavelength comparable to the length of the case 4 resonate with the decorative metals 8, 8, 10, and 10, and the output intensity of the harmonics of the electronic key 2 is greatly increased. Can be prevented. Therefore, in the electronic key 2 provided with the decorative metals 8, 8, 10, 10, the influence of the decorative metals 8, 8, 10, 10 on the radio wave transmitted from the electronic key 2 can be suppressed.

  Moreover, in this Embodiment, extension part 8b, 8b, 10b, 10b is provided in the both ends of the decoration part 8a, 8a, 10a, 10a of each decoration metal 8,8,10,10. For this reason, by changing the length of the extended portions 8b, 8b, 10b, 10b, the decorative metals 8, 8, 10 are not affected without affecting the length of the decorative portions 8a, 8a, 10a, 10a. , 10 can be easily changed. Therefore, even when the decorative metals 8, 8, 10, 10 are provided on the design surface of the case 4 so as to satisfy the design of the external appearance of the electronic key 2, the decorative metal 8, It is easy to set the length of the entire decorative metal 8, 8, 10, 10 so that the influence of 8, 10, 10 is suppressed.

Next, the operational effects of the above embodiment will be described below.
(1) Among the harmonics in which the resonant frequency of the decorative metals 8, 8, 10, 10 has a frequency that is an integral multiple of the fundamental wave of the transmission radio wave transmitted from the transmitting antenna 11, the half wavelength is the decorative metal 8 The lengths of the decorative metals 8, 8, 10, and 10 are set so as not to coincide with the harmonic frequency that is the same as the length of the case 4 along the longitudinal direction of. For this reason, harmonics having a half wavelength comparable to the length of the case 4 resonate with the decorative metals 8, 8, 10, and 10, and the output intensity of the harmonics of the electronic key 2 is greatly increased. Can be prevented. Therefore, in the electronic key 2 provided with the decorative metals 8, 8, 10, 10, the influence of the decorative metals 8, 8, 10, 10 on the radio wave transmitted from the electronic key 2 can be suppressed. In addition, since the length of the decoration metal 8, 8, 10, 10 whole can be changed easily, the influence of the decoration metal 8, 8, 10, 10 on the radio wave transmitted from the electronic key 2 is easy. Can be suppressed.

  (2) The resonance frequency of the decorative metal 8, 8, 10, 10 is between the frequency of one harmonic of the transmission radio wave and the frequency of one higher or lower harmonic than the harmonic. The length in the longitudinal direction of the decorative metals 8, 8, 10, and 10 was set so that For this reason, it suppresses suitably that the decoration metal 8, 8, 10, 10 will resonate with the harmonic which has a wavelength comparable as the length of the longitudinal direction of the said decoration metal 8, 8, 10, 10. be able to. Therefore, it is possible to prevent the harmonic output intensity of the electronic key 2 from increasing significantly.

  (3) By changing the length of the extending portions 8b, 8b, 10b, 10b, the overall length of the decorative metals 8, 8, 10, 10 is changed without affecting the appearance of the electronic key 2. be able to. For this reason, among the harmonics having the resonance frequency of the decorative metals 8, 8, 10, 10 having an integer multiple of the fundamental wave of the transmission radio wave transmitted from the transmission antenna 11, the half wavelength is the decorative metal 8. It is easy to set the lengths of the decorative metals 8, 8, 10, and 10 so that they do not coincide with the harmonic frequency that is comparable to the length of the case 4 along the longitudinal direction of It becomes.

In addition, you may change this Embodiment as follows.
-In above-mentioned embodiment, although extended part 8b, 8b, 10b, 10b was provided in the both ends of the decoration part 8a, 8a, 10a, 10a of the decoration metal 8, 8, 10, 10, for example, FIG. As shown to a) and (b), you may provide the extension part 21b only in the end of the decoration part 21a of each decoration metal 21. As shown in FIG.

  In the above embodiment, the end portions of the extended portions 8b, 8b, 10b, and 10b of the decorative metals 8, 8, 10, and 10 are provided along the side surface 4d of the case 4. For example, FIG. And as shown to (b), you may further extend the edge part 21c of extension part 8b, 8b, 10b, 10b in the direction along surface 5a, 6a. In this case, for example, as shown in FIGS. 7A and 7B, the end 21c of the extended portion 21b is a surface on which the decorative portion 21a is disposed (in this case, the surface 5a of the upper case 5). It may be arranged on a different surface (in this case, the surface 6a of the lower case 6).

  In the above embodiment, the decorative metals 8, 8, 10, and 10 are provided on the surfaces 5a and 6a of the upper case 5 and the lower case 6, but only one of them (in this case, the upper case 5 only) is provided with the decorative metal. 8, 8, 10, and 10 may be provided.

  -In above-mentioned embodiment, although extended part 8b, 8b, 10b, 10b of the decoration metal 8, 8, 10, 10 was arrange | positioned in the site | part along the short side of case 4, for example, Fig.8 (a) and As shown in (b), the extending portion 21 d may be arranged at a site along the long side of the case 4.

  In the above embodiment, the linear decorative metal 8, 8, 10, 10 is provided on the electronic key 2 as the metal member. However, as shown in FIG. 9A, the case 4 is viewed from the surface 5a side. A decorative metal 30 formed in a substantially L shape may be provided on the electronic key 2. Further, as shown in FIG. 9B, a decorative metal 31 formed in a substantially U shape when viewed from the surface 5 a side of the case 4 may be provided on the electronic key 2.

  In the above-described embodiment, the electronic key 2 provided with the decorative metals 8, 8, 10, and 10 is embodied as the metal member, but the embodiment is not limited thereto. For example, as shown in FIGS. 10A and 10B, the electronic key 2a is provided with a mechanical key 40 for manually operating a specific device corresponding to a communication target as a metal member. Also good. The case 41 of the electronic key 2 a is provided with a key accommodating portion 42 that opens on one side surface of the case 41. The mechanical key 40 is formed in a substantially L shape, and when manually locking and unlocking the door lock, the key groove portion 40a inserted into the corresponding key cylinder and the extending portion extending in the surface direction of the key groove portion 40a Gripping portion 40b. In this case, the portion where the key groove 40c is formed in the key groove portion 40a of the mechanical key 40 corresponds to the mounting portion. Then, the length of the key groove portion 40a is changed by changing the distance L1 between the key groove 40c and the grip portion 40b, or the length of the grip portion 40b as shown by a two-dot chain line in FIG. The length of the entire mechanical key 40 is set to an appropriate value by changing the length L2.

  Further, for example, as shown in FIG. 11, the electronic key 2 b in which the metal member 50 is provided inside the case 4 may be embodied. The metal member 50 is provided in an annular shape and has an open loop shape divided in the circumferential direction. According to this configuration, the metal member 50 is effectively used as a transmission antenna in wireless communication with the locking / unlocking control device 3, and the output intensity of the fundamental wave of the transmission radio wave transmitted from the electronic key 2b is improved. On the other hand, harmonics of the transmission radio wave are prevented from resonating with the metal member 50. For this reason, it is possible to improve only the output intensity of the fundamental wave while suppressing an increase in the output intensity of the harmonics of the transmission radio wave transmitted from the electronic key 2b.

In the above embodiment, the transmission antenna 11 is arranged so as not to overlap the decorative metals 8, 8, 10, 10, but may be arranged so that a part of the transmission antenna 11 overlaps.
In the above embodiment, the case 4 is formed in a flat shape that forms a rectangle in a plan view, but is not limited to such a mode, and may be formed, for example, in a triangle or a circle in a plan view. Moreover, in the said embodiment, although the case 4 was formed in flat shape, you may form a case in a cube shape, for example.

In the embodiment described above, the side surfaces (surfaces 5a and 6a) orthogonal to the thickness direction of the case 4 are used as design surfaces, but the side surfaces 4d along the thickness direction of the case 4 may be used as design surfaces.
In the above embodiment, the lock switch 5d and the unlock switch 5e are provided on the electronic key 2, and the door lock can be locked and unlocked by these operations, but may be omitted.

In the above embodiment, a transponder may be mounted on the electronic key 2, and ID verification may be performed between the transponder and the locking / unlocking control device 3.
In the above embodiment, the door lock of the vehicle as the corresponding device is unlocked and unlocked by wireless communication between the electronic key 2 and the locking / unlocking control device 3, but the electronic key 2 and the engine control are controlled. The start of the engine as a corresponding device may be permitted by wireless communication with the device.

  In the above embodiment, the electronic key system 1 of the vehicle is embodied as an electronic key used for opening and closing the door lock, but may be embodied as an electronic key system such as a house.

The schematic block diagram of the electronic key system of a vehicle. The perspective view which shows the external appearance shape of an electronic key. The perspective view which shows the case structure of an electronic key. (A) is the top view which looked at the electronic key from the front side, (b) is the top view which looked at the electronic key from the back side. The graph which illustrates the simulation result by an inventor about the relationship between the frequency of the electromagnetic wave transmitted from an electronic key, and output intensity. (A) is a perspective view which shows the external appearance of the electronic key of another example, (b) is a side view of an electronic key. (A) is a perspective view which shows the external appearance of the electronic key of another example, (b) is a side view of an electronic key. (A) is a perspective view which shows the external appearance of the electronic key of another example, (b) is a side view of an electronic key. (A) is a top view of the electronic key of another example, (b) is a top view of the electronic key of another example. (A) is a perspective view which shows the external appearance shape of the electronic key of another example in which the mechanical key was provided as a metal member, (b) is a top view of a mechanical key. The top view of the electronic key of another example.

Explanation of symbols

  2 ... Electronic key as portable device, 4,41 ... Case, 5a, 6a ... Surface, 8, 10, 21, 30, 31 ... Decorated metal as metal member, 8a, 10a, 21a ... Decoration part, 8b , 10b, 21b, 21d ... extended portion, 11 ... transmitting antenna, 40 ... mechanical key, 40a ... key groove portion as mounting portion, 40b ... gripping portion as extended portion, 50 ... metal member, L ... length.

Claims (5)

A case made of a non-conductive material, a transmission antenna that is provided inside the case and transmits a unique identification code of itself to a communication target wirelessly, and a band-shaped metal member provided separately from the transmission antenna A portable device that operates a specific device corresponding to the communication target on condition that the identification code matches on the communication target side,
Among the harmonics having a resonance frequency of the metal member that is an integer multiple of the fundamental wave of the transmission radio wave transmitted from the transmission antenna, the half wavelength is the length of the case along the longitudinal direction of the metal member. A portable device in which the length of the metal member is set so as not to coincide with a harmonic frequency that is comparable.   The resonance frequency of the metal member is a value between the frequency of one higher harmonic wave of the transmission radio wave transmitted from the transmission antenna and the frequency of one higher or lower harmonic wave than the higher harmonic wave. The portable device according to claim 1, wherein the length of the metal member in the longitudinal direction is set.   The metal member is a decorative metal provided on the surface of the case, and is provided on the surface of the case and has a strip-shaped decorative portion whose length is set according to the decoration on the case, and the decorative The portable device according to claim 1, further comprising an extending portion provided at an end portion of the portion and extending inward of the case.   The metal member is a mechanical key for manually operating a specific device corresponding to the communication target, and is attached to the specific device and a band-shaped mounting portion whose length is set according to the device; The portable device according to claim 1, further comprising an extending portion provided at an end portion of the mounting portion and extending in a surface direction of the mounting portion.   3. The portable device according to claim 1, wherein the metal member has an open loop shape provided inside the case, provided in an annular shape and divided in a circumferential direction thereof.

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