1. Field of the Invention
This invention relates to an antenna device and a radio wave controlled timepiece.
The antenna device used here comprises an antenna including a core and a coil wound around the core, and a structure that functions in cooperation with the antenna in order to improve receiving performance of the antenna.
2. Description of the Related Art
A radio wave controlled wristwatch which receives a radio wave including time information and automatically correct the current time is well known. In the radio wave controlled wristwatch, a small sized antenna is installed in a predetermined position of an inner space of a wristwatch case.
A structure for or improving the receiving sensitivity of a small sized antenna is disclosed in Jpn. Pat. Appln. KOKAI Publication No. 55-91237. In this document, in order to attract more magnetic flux, a sectional area of each one of both end portions is set to be larger than that of a center portion around which a coil is wound in a core of the antenna. And, the antenna having the above described structure constitutes an antenna device.
When the whole wristwatch case is formed of a metal, the appearance of the wristwatch is improved, and the wristwatch looks like a high quality product. However, the metallic wristwatch case functions as a magnetic shield. Thus, in the case where the antenna is installed in an inner space of the metallic wristwatch case, the receiving sensitivity of the antenna may be significantly lowered.
Further, when a magnetic flux generated by the antenna which received a radio wave passes through the metallic wristwatch case, an eddy current may be generated with the wristwatch case. As a result, a loss occurs in the antenna coil and a Q value is lowered, and finally, the receiving sensitivity of the antenna may be significantly lowered.
A structure for preventing occurrence of the eddy current described above in the wristwatch case is disclosed in Jpn. Pat. Appln. KOKAI Publication No. 2005-311715 (and the corresponding U.S. Pat. No. 7,126,548). In this document, a magnetic member for restraining the generation of the eddy current is arranged between the antenna installed in the inner space of the metallic wristwatch case and a surface of the inner space of the wristwatch case. And, the antenna and the magnetic member described above configure the antenna device.
An antenna device according to one aspect of the invention, comprises an antenna which includes an elongated core and a coil wound around a center portion of the core and which receives a radio wave including time information. And, the antenna device further comprises an antenna support member which includes two magnetic portions and a non-magnetic portion supporting the two magnetic portions independently of each other, both end portions of the core of the antenna being magnetically coupled with the two magnetic portions.
A radio wave controlled timepiece according to one aspect of the invention, comprises: a case which includes an inner space having an opening communicated with an outer space; an antenna which is installed in the inner space of the case, which includes an elongated core and a coil wound around a center portion of the core, and which receives a radio wave including time information; a time counting unit which is installed in the inner space of the case and which is configured to count a time; a time display unit which is installed in the inner space of the case, which is visible from the outer space through the opening, which is connected to the time counting unit, and which is configured to display the time; and a time updating unit which is installed in the inner space of the case and which is configured to update the time displayed on the time display unit, on a basis of the time information included in the radio wave received by the antenna. And, the radio wave controlled timepiece further comprises an antenna support member which is installed in the inner space of the case and which includes two magnetic portions and a non-magnetic portion supporting the two magnetic portions independently of each other, both end portions of the core of the antenna being magnetically coupled with the two magnetic portions.
A radio wave controlled timepiece according to another aspect of the invention, comprises: a case which includes an inner space having an opening communicated with an outer space; an antenna which is installed in the inner space of the case, which includes an elongated core and a coil wound around a center portion of the core, and which receives a radio wave including time information; a time counting unit which is installed in the inner space of the case and which is configured to count a time; a time display unit which installed in the inner space of the case, which is visible from the outer space through the opening, which is connected to the time counting unit, and which is configured to display the time; and a time updating unit which is installed in the inner space of the case and which is configured to update the time displayed on the time display unit, on a basis of the time information included in the radio wave received by the antenna. And, the radio wave controlled timepiece further comprises an antenna support member which includes two magnetic portions and a non-magnetic portion supporting the two magnetic portions independently of each other, both end portions of the core of the antenna being magnetically coupled with the two magnetic portions, and the antenna support member configuring the case.
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention, and together with the general description given above and detailed description of the embodiments given below, serve to explain the principles of the invention.
First, referring to
As shown in
Proximal ends of a pair of watch bands 3, 3 for wearing the radio wave controlled wristwatch 100 on a user's wrist are attached at two portions (i.e., 12 o'clock side and 6 o'clock side) positioned in opposite to each other on an outer periphery of the watch case 2. A plurality of input switches SW . . . that cause the timepiece block 1 to perform a variety of functions are further provided on the outer periphery of the watch case 2.
The opening of the inner space in the front surface of the watch case 2 is covered with a watch glass 4, and the watch glass 4 is fixed to the opening. A dial plate 5 is disposed in the inner space immediately beneath the watch glass 4 via a circular frame member RF.
Further in the inner space, a hand moving mechanism 6 and a display panel (a liquid crystal display panel in this embodiment) 7 are disposed just under the dial plate 5. And, the hand moving mechanism 6 is located in the center of the inner space and the display panel 7 is located in the 6 o'clock position of the inner space.
A through hole 5a is formed in the center of the dial plate 5, and three concentric hand moving shafts 6a protruded from the hand moving mechanism 6 are inserted into the through hole 5a. Proximal ends or an hour hand 6H, a minute hand 6M, and a second hand 6S are fixed at the projected ends of three concentric hand moving shafts 6a.
A display window 5b is formed at a 6 o'clock position in the dial plate 5, and a screen of the display panel (the liquid crystal display panel in this embodiment) 7 is exposed in the display window 5b.
As shown in
In this embodiment, the upper housing 8 includes a large recess ranging from the center to the 6 o'clock position and a small recess 8a at the 12 o'clock position. The center of the large recess holds the hand moving mechanism 6, and the 6 o'clock position of the large recess holds the display panel 7. Further, the small recess 8a holds an antenna device 20. An opening for exposing the three concentric hand moving shafts 6a of the hand moving mechanism 6 is formed at the center of the upper housing 8, and another opening for exposing the screen of the display panel 7 is formed at the 6 o'clock position of the upper housing 8.
A circuit board 12 is sandwiched between the upper housing 8 and the lower housing 10. The lower housing 10 holds a battery BT for the hand moving mechanism 6, the display panel 7, and the circuit board 12.
In the inner space of the watch case 2, a housing fixing member 14 is disposed just under the lower housing 10. The housing fixing member 14 is removably fixed by well known fixing means at a position near to the back surface of the watch case 2 on the inner surface of the inner space, so that the ring shaped frame member RF, the dial plate 5, and the upper and lower housings 8 and 10 connected with each other are sandwiched by the watch grass 4 and the housing fixing member 14 in the inner space of the watch case 2.
The opening of the inner space in the back surface of the watch case 2 is covered with a back cover 18 fixed to the back surface via a waterproof ring 16.
Now, a control circuit of the radio wave controlled wristwatch 100 will be explained with reference to
The control circuit is configured on the circuit board 12. The control circuit includes: a CPU (Central Processing Unit) 12a; and a RAM (Random Access Memory) 12b, a ROM (Read Only Memory) 12c, a time counting circuit 12d, and a receiving control circuit 12e, all of which are connected to the CPU (Central Processing Unit) 12a. The control circuit further includes an oscillation circuit 12f connected to the time counting circuit 12d.
The RAM 12b temporarily stores a variety of programs executed by the CPU 12a and data or the like relating to execution of these programs. The ROM 12c stores a variety of programs and data that cause the radio wave controlled wristwatch 100 to execute a variety of functions, in addition to a variety of initializing values and initializing programs.
The receiving control circuit 12e is connected to the antenna device 20. An input portion 12g that includes the plurality of switches SW disposed on the outer periphery of the watch case 2 and a display portion 12h that includes the display panel 7 and the hand moving mechanism 6 are further connected to the CPU 12a.
The time counting circuit 12d counts a our-rent time on a basis of an electrical signal of a predetermined frequency oscillated from the oscillation circuit 12f. Therefore, the time counting circuit 12d and one oscillation circuit 12f configure a time counting unit TCU configured to count the current time.
The CPU 12a controls the display panel 7 and hand moving mechanism 6 of the display portion 12h to display the current time on a basis of current time data from the time counting unit TCU. Therefore the display portion 12h configures a time display unit TDU connected to the time counting unit TCU via the CPU 12a and configured to display a time.
However, the display panel 7 of the display portion 12h can display a variety of information other than the current time on a basis of the program and data that CPU 12a reads out from ROM 12c in response to an input signal from the switches SW of the input portion 12g.
The antenna device 20 is configured to receive a predetermined radio wave that includes standard time information. The receiving control circuit 12e sends to the CPU 12a the standard time information included in the radio wave received by the antenna device 20, and causes the CPU 12a to update the time displayed by the time display unit TDU on a basis of the standard time information. In other words, the receiving control circuit 12e configures a time update unit TRU in cooperation with the CPU 12a.
A detailed functions of the control circuit will be described later.
Now, the antenna device 20 will be described with reference to
The antenna support member 22 includes a non-magnetic portion 22a and two magnetic portions 22b and 22b independent of each other. The non-magnetic portion 22a is positioned between the two magnetic portions 22b and 22b, and supports the two magnetic portions 22b and 22b independently to each other. In detail, the non-magnetic portion 22a is formed of a resin that does not contain magnetic material, and the two magnetic portions 22b and 22b are integrally formed with the non-magnetic portion 22a at its both ends with a resin that contains magnetic material.
An antenna support recess 22c is formed in the antenna support member 22 to extend from one magnetic portion 22b to the other magnetic portion 22b through the non-magnetic portion 22a. The antenna 21 lies in the antenna support recess 22c, whereby both ends a2 of the core 21a of the antenna 21 are in contact with the two magnetic portions 22P) and 22b and are magnetically coupled with the two magnetic portions 22b and 22b.
Now, referring to
The core 21a of the practical antenna device 20 is formed of a magnetic material such as ferrite or amorphous, for example, having high radio wave receiving sensitivity, and includes a center portion a1 having a substantially rectangular cross section and end portions a2 each having a cross section that is slightly larger than that of the center portion a1 and formed integrally with the center portion 1a at each of the both ends thereof.
A non-electrically conductive resin (for example, fluorine resin) having a thickness of about 20 μm to 30 μm is coated on an outer surface of the core 21a, and the coil 21b is wound on the outer surface of the center portion 21a of the core 21 via a coat of the non-electrically conductive resin to have an uniform thickness. The coat of the non-electrically conductive resin may be formed only on the outer surface of the center portion 21a.
The antenna support member 22 includes an upper cover 22U that covers an upper half of the antenna 21 and a lower cover 22 that covers a lower half of the antenna 21.
In the upper cover 22U, an upper housing recess (not shown) in which the upper half of the antenna 21 is to be housed is formed in a contact surface that comes into contact with the lower cover 22L. In the lower cover 22L, a lower housing recess (not shown) in which the lower half of the antenna 21 is to be housed is formed in a contact surface that comes into contact with the upper cover 22U. A flexible board 23 is attached on a lower end surface of the lower cover 22L. Lead lines electrically connected to the terminals of the coil 21b of the antenna 21 are formed on the flexible board 23.
The upper cover 22U and the lower cover 22L are fixed to each other by an adhesive.
An opening 22K is formed at a portion corresponding to the coil 21b of the antenna 21 in each of an upper end surface of the upper cover 22U and the lower end surface of the lower cover 22L, and at a portion corresponding to a part of each of the both ends of the core 21a of the antenna 21 in both of the left and right ends of each of the upper cover 22U and the lower cover 22L. The openings 22K serve to promote external diffusion of heat generated by the antenna 21 and to reduce a height of the antenna support member 22.
Both end portions of each of the upper cover 22U and the lower cover 22L are formed of a synthetic resin that contains magnetic material (for example, 20% by weight to 80% by weight), and configure the magnetic portions 22b. A center portion of each of the upper cover 22U and the lower cover 22L is formed of a synthetic resin that does not contain magnetic material, and configures the non-magnetic portion 22a. In each of the upper cover 22U and the lower cover 22L, the non-magnetic portion 22a is formed integrally with the two magnetic portions 22b positioned at the both ends of the non-magnetic portion 22a, and the non-magnetic portion 22a supports the corresponding two magnetic portions 22b independently to each other.
Therefore, while the antenna 21 is cover with the upper cover 22U and the lower cover 22L as described above, the both end portions 2a of the core 21a of the antenna 21 are in contact with the two magnetic portions 22b of each of the upper cover 22U and the lower cover 22L and are magnetically connected with these magnetic portions 22b.
It is preferable that the magnetic material contained in the synthetic resin that forms the magnetic portion 22b have higher magnetic permeability than that of the core 21a. The magnetic material may have a particle shape or a needle shape.
The magnetic material dispersed in the synthetic resin of the magnetic portion 22b causes the magnetic portion 22b to have magnetic permeability of a predetermined value that is sufficient for converging magnetic flux, and the synthetic resin prevents the lowering of the strength of the magnetic portion 22b.
When the antenna device 20 is placed in a magnetic field of the predetermined radio wave including the time information described previously, the magnetic fluxes of the magnetic field can be caught easily by the magnetic portions 22b each having higher magnetic permeability and larger sectional area than those of the core 21a, and is concentrated at the core 21a, and interlink with the coil 21b. Therefore, much more magnetic flux can be concentrated at the core 21a in comparison with a case in which the magnetic portions 22b are not provided. Thus, in comparison with the case in which the magnetic portions 22b are not provided, it is possible to cause the coil 21b to generate much larger inductive electromotive force. In other words, in comparison with the case in which the magnetic portions 22 are not provided, receiving sensitivity of the antenna device 20 is improved much more remarkably.
In the control circuit shown in
The CPU 12a selectively reads out a plurality of predetermined programs stored in ROM 12c and writes them in RAM 12b in response to a predetermined timing or an operating signal inputted from each of the plurality of switches SW of the input portion 12g, and executes a process based on the selected programs. Then, the CPU sends instructions, data, or the like to a variety of operating portions or circuits connected to the CPU 12a.
The CPU 12a having received the standard time code from the receiving control circuit 12e corrects the current time data sent from the time counting circuit 12d on a basis of the standard time code, and then, controls the display panel 7 and hand moving mechanism 6 of the display portion 12h to display a corrected current time on a basis of the corrected current time data.
As is apparent from the above detailed description, in the radio wave controlled wristwatch 100 according to the first embodiment, the receiving sensitivity of the antenna 21 is greatly amplified by the two magnetic portions 22b of the antenna support member 22 which are in contact with the both end portions of the core 21a of the antenna 21 and which are magnetically coupled with the both end portions. Therefore, even if the watch case 2 is metallic, the antenna 21 can sufficiently receive the standard time radio wave as described above.
Moreover, the two magnetic portions 22b are included in the antenna support member 22 that houses the antenna 21. Thus, the whole size of the antenna device 20 is reduced in comparison with the conventional case in which the both end portions of the core are expanded to improve the receiving sensitivity of the antenna and the antenna is housed in the antenna support member that does not have two magnetic portions. As a result, the radio wave controlled wristwatch 100 can be prevented from being large sized.
Further, the two magnetic portions 22b and the non-magnetic portion 22a in the antenna support member 22 are formed integrally with each other, thus simplifying a structure of the antenna support member 22 and facilitating manufacture of the antenna device 20 and manufacture of the radio wave controlled wristwatch 100 more significantly.
Next, referring to
In each of
In this embodiment, the antenna 21 is directly supported by the upper housing 30, and the upper housing 30 configures an antenna support member for supporting the antenna 21. The upper housing 30 serving as the antenna support member is combined with the antenna 21 to configure the second embodiment of the antenna device 20.
The upper housing 30 serving as the antenna support member includes an antenna housing recess 32 that houses the antenna 21. In the antenna housing recess 32, a center portion which is located near to the coil 21b of the antenna 21 is configured by a non-magnetic portion 30a. In the antenna housing recess 32, both end portions being in contact with the both end portions a2 of the core 21a of the antenna 21 are configured by two magnetic portions 30b. The non-magnetic portion 30a supports the two magnetic portions 30b independently to each other, and is formed integrally with the two magnetic portions 30b. The both end portions a2 of the core 21a of the antenna 21 housed in the antenna housing recess 32 are in contact with the two magnetic portions 30b, and are magnetically coupled with the two magnetic portions 30b. Each of the two magnetic portions 30b is formed of a synthetic resin that contains magnetic material, and the non-magnetic portion 30a is formed of a synthetic resin that does not contain magnetic material. The two magnetic portions 30b and the non-magnetic portion 30a are integrally formed.
Next, referring to
In the practical upper housing 30 (antenna support member) of the antenna device 20 according to the second embodiment, the non-magnetic portion 30a linearly extends from a 12 o'clock position to a 6 o'clock position. The two magnetic portions 30b are formed continuously at both linear side edges of the non-magnetic portion 30a, and each of the two magnetic portions 30b also extends from the 12 o'clock position to the 6 o'clock position.
The antenna housing recess 32 linearly extends from one magnetic portion 30b to the other magnetic portion 30b via the non-magnetic portion 30a at the 12 o'clock position of the upper housing 30. The antenna 21 housed in the antenna housing recess 32 is fixed in the antenna housing recess 32 by an adhesive. The coil 21b on the center portion a1 of the core 21a of the antenna 21 is located near to the non-magnetic portion 30a, and the both end portions a2 of the core 21a are in contact with the two magnetic portions 30b to magnetically connect to the two magnetic portions 30b.
In the center of the non-magnetic portion 30a of the upper housing 30, a hand moving shaft insertion hole 30c is formed into which the three coaxially hand moving shafts 6a of the of the hand moving mechanism 60 (refer to
In the first embodiment described previously, the antenna device 20 is configured by the antenna 21 being combined with the antenna support member 22 independent of the upper housing 8, and the both end portions of the antenna support member 22 configure the two magnetic portions 22b and the center portion thereof configures the non-magnetic portion 22a. In addition, the antenna device 20 configured as described above is further held in the recess 8a of the upper housing 8.
However, in the second embodiment, the antenna 21 is combined with the upper housing 30 serving as the antenna support member and configures the antenna device 20. Therefore, the antenna device 20 according to the second embodiment is much simple in configuration in comparison with the antenna device 20 according to the first embodiment, and a capacity required only for installation of the antenna device 20 (antenna device mounting capacity) is reduced in the inner space of the watch case 2. In addition, the radio wave controlled wristwatch 100 employing the antenna device 20 according to the second embodiment can be downsized more significantly in capacity of the inner space of the watch case 2 (i.e., in whole capacity of the watch case 2) in comparison with the radio wave controlled wristwatch 100 employing the antenna device 20 according to the first embodiment.
Moreover, in the upper housing 30, each of the two magnetic portions 30b, linearly extending from the 12 o'clock position to the 6 o'clock position along the both side edges of the non-magnetic portion 30a that also linearly extends from the 12 o'clock position to the 6 o'clock position, has a much larger sectional area in comparison with each of the two magnetic portions 22 at the both end portions of the antenna support member 22 according to the first embodiment described previously. Therefore, the antenna device 20 according to the second embodiment is much higher in receiving sensitivity than that according to the first embodiment.
[First Modification of the Second Embodiment of the Antenna Device]
Next, referring to
In a configuration of an upper housing 30′ according to the first modification, constituent elements which are the same as those of the upper housing 30 shown in each of
The upper housing 30′ according to the first modification is different from the upper housing 30 in that two magnetic portions 30′b are disposed only at a front surface side of the upper housing 30′ (i.e., at a side facing the dial plate 5 when the upper housing 30′ is housed in the inner space of the watch case 2, as shown in
The capacity of each of the two magnetic portions 30′b of the upper housing 30′ according to the modification is much smaller than that of each of the two magnetic portions 30b or the upper housing 30 described previously. Therefore, the quantity of a synthetic resin containing comparatively expensive magnetic material, which is used in the upper housing 30′, is much smaller than that in the upper housing 30 described previously. Moreover, in the upper housing 30′, the two magnetic portions 30′b are disposed as described above, thereby making it possible to efficiently receive the standard time radio wave entering into the inner space described above from the opening at the front surface side at which the dial plate 5 is disposed in the inner space of the watch case 2.
[Second Modification of the Second Embodiment of the Antenna Device]
Next, referring to
In a configuration of an upper housing 30″ according to the second modification, constituent elements which are the same as those of the upper housing 30 shown in each of
The upper housing 30″ according to the second modification is different from the upper housing 30 according to the first modification in that only both ends in a longitudinal direction of an inner surface of the antenna housing recess 32 are specified by two magnetic portions 30″b and the remaining area of the inner surface of the antenna housing recess 32 is specified by a non-magnetic portion 30″a.
In this modification, the antenna 21 housed in the antenna housing recess 32 is magnetically coupled with the two magnetic portions 30″b by only both ends of the core 21a being in contact with the two magnetic portions 30″b of the upper housing 30″.
The upper housing 30″ according to the second modification and supporting the antenna 21 as described above also serves as the antenna support member and constitutes the antenna device 20 when the upper housing 30″ is combined with the antenna 21.
The capacity of each of the two magnetic portions 30″b of the upper housing 30″ according to this modification is much smaller than that of each of the two magnetic portions 30′b of the upper housing 30′ of the first modification described previously. Therefore, the quantity of a synthetic resin containing a comparatively expensive magnetic material, which is used in the upper housing 30″ of the second modification, can be further reduced in comparison with that in the upper housing 30′ of the first modification described previously. Moreover, receiving efficiency of the standard time radio wave in the upper housings 30″ of the second modification is not so different from that in the upper housing 30′ of the first modification described previously.
Next, referring to
An inner space of the watch case 50 houses constituent elements, excluding the antenna device 20, in the timepiece block 1 accommodated in the inner space of the watch case 2 of the radio wave controlled wristwatch 100 according to the first embodiment shown in
Proximal ends of a pair of watch bands 54 are attached at a 12 o'clock position and a 6 o'clock position on an outer periphery of the watch case 50. Two antenna core support members 56 that support the both end portions a2 of the core 21 of the antenna 21 are disposed at a 12 o'clock position in the inner space of the watch case 50. At the 12 o'clock position, the two antenna core support members 56 are spaced from each other in a direction orthogonal to an imaginary line connecting the 12 o'clock position and the 6 o'clock position with each other along a bottom surface of the inner space of the watch case 50 (i.e., in a direction parallel to an imaginary line connecting a 3 o'clock position and a 9 o'clock position with each other).
In the watch case 50, any portion other than the two antenna core support members 56 described above and the areas surrounding the two antenna core support members 56 is configured as a non-magnetic portion 50a, and the two antenna core support members 56 and the areas surrounding the two antenna core support members 56 are configured as magnetic portions 50b. In the watch case 50, the non-magnetic portion 50a supports the two magnetic portions 50b independently to each other. In more detail, in the present embodiment, the non-magnetic portion 50a is formed of a resin that does not contain magnetic material, and each of the two magnetic portions 50b is formed of a resin that contains magnetic material. The non-magnetic portion 50a and the two magnetic portions 50b are integrally formed to configure the watch case 50.
When the both end portions a2 of the core 21a of the antenna 21 are supported by the two antenna core support members 56 of the watch case 50, the both end portions a2 of the core 21 of the antenna 21 are in contact with the two antenna core support members 56, and are magnetically coupled with the two magnetic portions 50b of the watch case 50.
In other words, in the present embodiment, the watch case 50 is configured as an antenna support member, and the watch case 50 as an antenna support member is combined with the antenna 21 to configure the antenna device 21.
Next, referring to
The configuration of the antenna device 20 according to the present embodiment is similar to that of the antenna device 20 according to the first embodiment shown in
The antenna device 20 according to the third embodiment is different from the simplified antenna device 20 according to the first embodiment in that one portion b1 of each of two magnetic portions 22′b at both sides of a non-magnetic portion 22′a in an antenna support member 22′ is extended along one side of the non-magnetic portion 22′a so that the portions b1 of the two magnetic portions 22′b are in close proximity to each other, and extending ends of the portions b1 are opposed to each other with a slight gap G. In addition, the gap G is embedded with a portion of the non-magnetic portion 22′a.
The portions b1, extended so as to oppose to each other, of the two magnetic portions 22′b form a sub-magnetic path in the antenna support member 22′.
The sub-magnetic path functions as follows. When the antenna device 20 receives the standard time radio wave, magnetic fluxes are generated in a main magnetic path composed of the two magnetic portions 22′b and the core 21a both end portions of which are magnetically coupled with the two magnetic portions 22′b in the antenna device 20. And, when the magnetic fluxes tend to separate from the main magnetic path to a peripheral space thereof, the sub-magnetic path introduces the magnetic flux into itself to prevent the magnetic fluxes from separating from the main magnetic path to the peripheral space thereof. In this situation, the magnetic fluxes generated in the antenna device 20 is prevented from leaking out from the antenna device 20 to the metallic watch case 2, so that it possible to effectively restrain occurrence of an eddy current in the metallic watch case 2 and to restrain the lowering of receiving sensitivity of the antenna device 20.
In the antenna device 20 according to the third embodiment, it is preferable that magnetic permeability of the sub-magnetic path be lower than that of the main magnetic path. This prevents the magnetic fluxes which should pass the main magnetic path of the inside of the coil 21b of the antenna 21 from passing through the sub-magnetic path, and the antenna 21 is surely prevented from lowering its receiving sensitivity.
The antenna device and the radio wave controlled timepiece, both according to the present invention, are not limited to the embodiments and modifications described above. Various modifications and design changes can be made without departing from the spirit of the present invention.
For example, in the embodiments and modifications described above, the both end portions a2 of the core 21a of the antenna 21 are in contact with the two magnetic portions 22b of the antenna support member 22 or the two magnetic portions 22′b of the antenna support member 22′ or the two magnetic portions 30b of the upper housing 30 as the antenna support member or the two magnetic portions 30′b of the upper housing 30′ as the antenna support member or the two magnetic portions 30″b of the upper housing 30″ as the antenna support member or the two antenna core support members 56 of the two magnetic portions 50b of the watch case 50 as the antenna support member, and are magnetically coupled with them.
However, even in a case where the both end portions a2 of the core 21a of the antenna 21 are not directly in contact with the two magnetic portions 22b of the antenna support member 22 or the two magnetic portions 22′b of the antenna support member 22′ or the two magnetic portions 30b of the upper housing 30 as the antenna support member or the two magnetic portions 30′b of the upper housing 30′ as the antenna support member or the two magnetic portions 30″b of the upper housing 30′ as the antenna support member or the two antenna core support members 56 of the two magnetic portions 50b of the watch case 50 as the antenna support member, if magnetic fluxes more than a predetermined quantity can be flow between the both end portions a2 of the core 21a of the antenna 21 and the two magnetic portions with something being interposed therebetween, it can be ca-led that they are magnetically coupled with each other.
Further, as a synthetic resin for forming each of the non-magnetic portion 22a, 22′a, 30a, 30′a, 30″a or 50a, and the magnetic portion 22b, 22′b, 30b, 30′b, 30″b and 50b may be selected from: an epoxy resin; a phenol resin; a melamine resin; a urea resin; an unsaturated polyester resin; a polyimide resin; a furan resin; a polybutadiene-type resin; an ionomer resin; an EEA resin; an AAS resin (ASA resin); an AS resin; an ACS resin; an ethylene vinyl acetate copolymer; an ethylene vinyl alcohol copolymer resin; an ABS resin; a vinyl chloride resin; polyethylene chloride resin; a acetate fiber material resin; a fluorine resin; a polyacetal resin; a polyamide resin 6; a polyamide resin 66; a polyamide resin 11; a polyamide resin 12; a polyarylate resin; a thermoplastic polyurethane elastomer; a liquid crystal polymer; polyether ether ketone; a polysulfone resin; a polyether sulfone resin; high density polyethylene; low density polyethylene; straight-chain low density polyethylene; polyethylene terephthalate; a polycarbonate resin; a polystyrene resin; a polyphenylene ether resin; a polyphenylene sulfide resin; a polybutadiene resin; a polyproprylene resin; a polypropylene resin; a methacrylate resin; and a methylpentene polymer. Among them, an epoxy resin and a phenol resin are preferable from the viewpoints of thermal resistance, dimensional stability, strength, etc.
In the above described embodiments and modifications, the radio wave controlled wristwatches 100 and 200 are described as radio wave controlled timepieces. However, according to the present invention, the radio wave controlled timepiece may be a pocket watch, a wall clock or a table clock.
Further, the magnetic portion 22b, 22′b, 30b, 30′b, 30″b and 50b may be configured, instead of the resin that contains magnetic material, by adhering magnetic material on a surface of a synthetic resin member, or by burying a foil or plate of magnetic material in the synthetic resin member, or by adhering the foil or plate of magnetic material on the surface of the synthetic resin member.
Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.
Number | Date | Country | Kind |
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2006-065307 | Mar 2006 | JP | national |
The present application is a Continuation Application of U.S. application Ser. No. 11/714,386 filed Mar. 6, 2007, now U.S. Pat. No. 7,515,112, which is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2006-065307, filed Mar. 10, 2006, the entire contents of both which are incorporated herein by reference.
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Number | Date | Country | |
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20090161491 A1 | Jun 2009 | US |
Number | Date | Country | |
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Parent | 11714386 | Mar 2007 | US |
Child | 12391190 | US |