Electronic device

To provide an electronic device having an antenna function without having to enlarge the size of the device. The electronic device includes a shielding case, a feeding loop, an operation knob, and an antenna element. The shielding case blocks passage of electromagnetic waves. The feeding loop is a conductor that is disposed annularly along a prescribed plane outside the shielding case and is connected to a radio communication circuit encompassed within the shielding case. The operation knob is configured to be rotatable around a specific axis that passes through an annular ring formed by the feeding loop. The antenna element is an open-loop conductor fixed to the operation knob.

CROSS REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority from Japanese patent application No. 2019-102106, filed on May 31, 2019, the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND

The present disclosure relates to an electronic device.

For electronic devices having functions of transmitting/receiving radio waves, there is a demand for an antenna large enough to perform the functions. On the other hand, there is a demand to downsize the antenna for portable electronic devices as much as possible so as to realize satisfactory handling of the electronic devices. Various proposals are being made to satisfy both of these demands that seem to be mutually contradictory.

For example, a portable small radio equipment disclosed in Unexamined Japanese Patent Application Publication No. H06-125290 has a square-like recessed part provided on a back surface of a radio equipment case and one side of a planar antenna exclusive for reception is rotatably attached to one side of an inside surface of the recessed part, and the antenna is accommodated in the recessed part when the radio equipment is held vertically while talking.

In an electronic device that requires its case to have an electromagnetic shielding property, since a communication circuit disposed inside the case is covered by an electromagnetic wave shield, it is not possible to provide a built-in antenna. However, when the technique disclosed in Unexamined Japanese Patent Application Publication No. H06-125290 is adopted, the back surface of the case of the radio equipment becomes large as a result thereof.

SUMMARY

An electronic device according to an embodiment of the present disclosure includes a shielding case, a feeding loop, an operation knob, and an antenna element. The shielding case blocks passage of electromagnetic waves. The feeding loop is a conductor that is disposed annularly along a prescribed plane outside the shielding case and is connected to a radio communication circuit encompassed within the shielding case. The operation knob is configured to be rotatable around a specific axis that passes through an annular ring formed by the feeding loop. The antenna element is an open-loop conductor fixed to the operation knob.

By this structure, the operation knob that is protruded so as to function as an operation unit can be used as an antenna in the electronic device.

According to an embodiment of the present disclosure, an electronic device having an antenna function in an electronic device having functions of transmitting/receiving radio waves can be provided without having to enlarge the size of the device.

DETAILED DESCRIPTION

For clarifying the explanation, the following description and the drawings are partially omitted and simplified where appropriate. In the respective drawings, the same or corresponding components will be denoted by the same reference numerals, and, for convenience of description, duplicated explanations thereof will be omitted as needed.

Embodiments

Hereinbelow, embodiments of the present disclosure are explained with reference to the drawings.FIG. 1is an outline view of an electronic device according to an embodiment. An electronic device10according to an embodiment of the present disclosure is a transceiver that performs transmission/reception of radio waves. Note that although the electronic device10is referred to as a transceiver, it is not limited thereto and may be any device that performs transmission/reception of radio waves such as a mobile phone, a smartphone, or the like.

Note that for the sake of convenience in explaining the positional relationship of the structural components,FIG. 1is indicated by a right-handed orthogonal coordinate system. Further, in the case where an orthogonal coordinate system is shown inFIG. 2and the subsequent drawings, X-axis, Y-axis, and Z-axis directions thereof are the same as X-axis, Y-axis, and Z-axis directions shown inFIG. 1.

The electronic device10has a configuration in which a cylindrical operation knob11protrudes from a case having a substantially rectangular shape, and a size thereof is a portable size. The electronic device10includes the operation knob11, a transmission button12, a channel selection button13, a display panel14, a speaker unit15, a microphone unit16, and a case17as main components that are visible from the outside. A surface that is on the Y-axis negative side and is parallel to an XZ plane is the front surface of the electronic device10, and a surface that is on the Y-axis positive side and is parallel to the XZ plane is the back surface of the electronic device10. Further, a surface that is on the Z-axis positive side and is parallel to an XY plane is the top surface of the electronic device10, and a surface that is on the Z-axis negative side and is parallel to the XY plane is the bottom surface of the electronic device10. A surface that is on the X-axis positive side and is parallel to the YZ plane is the right side surface of the electronic device10, and a surface that is on the X-axis negative side and is parallel to the YZ plane is the left side surface of the electronic device10.

The operation knob11serves as a power switch for turning on/off the power of the electronic device10and an operation unit for adjusting a volume of a voice output from the speaker. The operation knob11is a cylindrical protrusion that is configured so as to protrude from the top surface of the case17having a substantially rectangular shape, and it is rotatably locked to the top surface of the case17. The operation knob11is formed by molding a dielectric body made of resin or the like, and operations such as on/off of the power, adjustment of a volume of a voice output from the speaker, etc. are performed by the user operating the operation knob11.

The transmission button12is a button that is pressed when transmitting a voice from the electronic device10which is a transceiver. When the user is transmitting his/her voice to a person to whom he/she is talking, the user speaks toward the microphone unit16while pressing the transmission button12.

The channel selection button13is a button for selecting a transmission/reception frequency of a call by performing a prescribed operation. The display panel14is a display for notifying the user of various pieces of information such as the channel number that is selected and the operation state and the remaining amount of the battery of the electronic device10. The speaker unit15is a hole provided in the case17, and outputs a voice of the user from the speaker disposed inside the case17through the hole. The microphone unit16is a hole provided in the case17, and is configured such that an utterance of the user is picked up by a microphone disposed inside the case17.

The case17is a case made of resin and has a substantially rectangular shape. The case17has the operation knob11disposed on the top surface thereof, the display panel14, the channel selection button13, the speaker unit15, and the microphone unit16disposed on the front surface thereof, and the transmission button12disposed on the side surface thereof.

Next, the configuration of the operation knob11and the structure inside the operation knob11are explained with reference toFIGS. 2 and 3.FIG. 3is an exploded perspective view of an antenna part of the electronic device according to the embodiment.

FIG. 2is a sectional diagram of an operation knob part of the electronic device according to the embodiment.FIG. 2is a sectional diagram showing the operation knob11cut out along the YZ plane. As shown in the figures, the electronic device10includes a circuit board18, an encoder19, a feeding loop20, a spacer21, and an antenna element22etc. inside the case17.

The case17is constituted of a resin case171and a shielding case172. The resin case171is a case formed of molded resin. The shielding case172is a metal case structured inside the resin case171.

The shielding case172is an electromagnetic wave shield for suppressing intrusion of the electromagnetic waves present outside the electronic device10into the electronic device10. The shielding case172is formed by press working a metal plate for suppressing predetermined electromagnetic waves from entering the electromagnetic device or is formed by pouring aluminum into a mold. In the embodiment of the present disclosure, the shielding case172has a substantially rectangular shape (a hexahedron) and is configured to encompass various structures such as the radio communication circuit etc. Further, the shielding case172has a recessed part as shown inFIG. 2. The encoder19is fixed to a bottom part of the recessed part formed to the shielding case172. The spacer21is fitted to the recessed part.

The circuit board18is provided with a circuit for the electronic device10to perform various functions. For example, the circuit board18includes a radio communication circuit for performing transmission and reception of a signal. The radio communication circuit of the circuit board18is connected to a coaxial cable201. The encoder19is disposed to the circuit board18.

The encoder19is configured such that volume adjustment is possible by, for example, building in a variable resistor. The encoder19is fixed to the circuit board18and is connected to a circuit of the circuit board18. Further, the encoder19includes a screw unit191and a rotary shaft192.

The screw unit191extends upward from a main body part of the encoder19mounted to the circuit board18and is inserted through the hole provided in the shielding case172and screwed by a bolt23. The encoder19is fixed to the shielding case172by screwing the screw unit191with the bolt23.

The rotary shaft192is a shaft that is disposed coaxially with the screw unit191in a rotatable manner and extends upward from a top part of the screw unit191. The rotary shaft192is fitted to a recessed part110provided to the operation knob11. By this configuration, the operation knob11and the rotary shaft192rotate integrally about an axis A1shown in the figure.

The feeding loop20is a conducting wire disposed annularly and is connected to the radio communication circuit of the circuit board18via the coaxial cable201. As shown inFIG. 3, the feeding loop20is disposed annularly along a plane P1, and a center of the annular ring coincides with the axis A1(the specific axis). One end surface of the feeding loop20is connected to an internal conductor of the coaxial cable201and the other end thereof is connected to an external conductor of the coaxial cable201. The feeding loop20receives a current having a prescribed frequency from the coaxial cable201and runs the received current to the conducting wire that is disposed annularly. Note that while it has been described above that the center of the annular ring of the feeding loop20coincides with the axis A1, it does not necessarily have to coincide with the axis A1.

The feeding loop20is fitted in a groove disposed on the top surface of the spacer21. The coaxial cable201extends downward from a part thereof that is connected to the feeding loop20along the groove provided to the spacer21, passes a cavity173provided in the shielding case172, and is connected to the circuit board18. Note that the axis A1is orthogonal to the plane P1. The plane P1is set so as to be parallel to the top surface of the electronic device10.

The spacer21is disposed on the recessed part provided to the shielding case172and supports the feeding loop20outside the shielding case172. The spacer21is formed of resin. By having the feeding loop20supported at the top surface of the spacer21, the feeding loop20of the electronic device10can be fixed at a desired position outside the shielding case172. Further, by forming the spacer21of soft resin, the electronic device10can suppress intrusion of water and dust into the shielding case172.

The top surface of the spacer21coincides with the plane P1. The plane P1is set above the top surface of the shielding case172. In other words, the plane P1is disposed outside the shielding case172. By setting the plane P1in this manner, it is possible to suppress the effects of the shielding case172on the feeding loop20.

Further, the plane P1is set above an upper edge of the rotary shaft192. The rotary shaft192is formed of a metal such as aluminum. Therefore, by separating the plane P1from the rotary shaft192as described above, it is possible to suppress the effects of the rotary shaft192on the feeding loop20.

The antenna element22is a conductor having an open-loop shape and is formed of copper, gold or the like. As shown inFIG. 3, the antenna element22is a wire material spirally formed along an inclined surface of a cone, the lower part thereof being the bottom surface. The antenna element22includes a first end part221, which is one of the open ends, at the lower side thereof and a second end part222, which is the other open end, at the upper side thereof. The first end part221and the second end part222are not connected to each other by a conductive body, and thus they are in an open-loop state. By this configuration, the antenna element22can receive a magnetic field having a prescribed frequency from the feeding loop20. Accordingly, the antenna element22can function as an antenna of the electronic device10.

Note that the shape of the antenna element22is not limited to a spiral shape as long as it can form an open-loop shape. The shape and the material of the antenna element22are determined according to the frequency of the radio waves used by the electronic device10and the output thereof. Further, the first end part221and the second end part222may be connected to each other via a dielectric body or a capacitor.

As shown inFIG. 2, the operation knob11is configured to be rotatable around the axis A1. The axis A1passes the center of the annular ring formed by the feeding loop20and is orthogonal to the plane P1. Further, the antenna element22is fixed to the inside of the operation knob11. Therefore, even when the operation knob11is rotated, the relative positional relationship between the feeding loop20and the antenna element22does not change. Accordingly, the characteristics of the antenna of the electronic device10do not change even when the operation knob11is operated. Note that the antenna element22may be bonded or press-fitted to the operation knob11or may be fixed to the operation knob11by insert molding when the operation knob11is formed by injection-molding.

The embodiments of the present disclosure have been described above. The electronic device10according to the embodiments has the antenna element22disposed inside the operation knob11. Therefore, there is no need to dispose a whip antenna that protrudes from the case of the electronic device10. Further, with this configuration, the part of the electronic device10that protrudes from the antenna device10can be reduced. Further, the antenna element22fixed to the operation knob11does not come in contact with the feeding loop20. Further, the antenna element22does not wear out or is not deformed even when the operation knob11is rotated. Thus, the electronic device10has a simple and durable structure. According to the embodiments of the present disclosure, an electronic device having an antenna function in an electronic device having functions of transmitting/receiving radio waves can be provided without having to enlarge the size of the device.

Note that the present disclosure is not limited to the embodiments described above and can be modified as appropriate without departing from the gist of the present disclosure. For example, the electronic device described above can be applied to devices that perform reception or transmission of radio waves such as a portable transmitter, a portable receiver, a portable radio, a smartphone, and a mobile phone, in addition to a transceiver.