JP2010216809A - Electronic timepiece with radio information function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make effective use of a component of a radio wave transmitted through a metal case member. <P>SOLUTION: A surface in the shape of a mortar reaching an end of the magnetic core of an antenna mounted inside the case, from the upper end surface of the body of the case are determined, and a route for radio waves is determined along approximately this surface, so that the degree of bending of the cross sectional shape of the case body becomes small, so as not to attenuate the component of the radio wave entering the inside of the case along the gap between the body of the metal case and a metal bezel, or the gap between the body of the metal case and a metal back lid as much as possible, out of the components of the radio wave arriving at the magnetic core of the antenna from the outside of the electronic apparatus. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electronic timepiece with a wireless function. More specifically, the present invention relates to a structure of an electronic timepiece with a wireless function that can provide a highly sensitive radio wave reception by applying an extremely strong radio wave to an antenna.

  As a relatively small electronic device with a wireless function, for example, there are a mobile phone and a so-called radio clock that corrects a display time using a time signal of a wireless station that transmits a standard radio wave. Two conventional examples of radio wave watches which are one of those electronic devices are shown in FIG. 7, FIG. 8 and FIG.

FIG. 7 is a cross-sectional view of a main part of a radio-controlled wristwatch that is the first conventional example. The figure shows the configuration of a watch case that is the exterior of a wristwatch and a standard radio wave receiving antenna disposed in the case. It should be noted that other members built in the case, such as an electronic timepiece movement having a time correction function using radio waves, a power source thereof, a pointer for displaying time, and the like are not shown.

  In FIG. 7, a metal case 2 is a wristwatch case, and a metal bezel 1 is a member for holding the outer periphery of a watch glass 6 covering the upper surface of the time display surface of the watch. It is press-fitted into. The metal back cover 3 is press-fitted to the lower side of the body 2. The magnetic core 4 and the coil 5 are members constituting an antenna for receiving radio waves, and include a magnetic core 4 made of a material having a high magnetic permeability and a coil 5 wound around the magnetic core 4. The other exterior member, the watch glass 6 is non-conductive and non-magnetic, the dial 7 is non-conductive, the dial ring is non-conductive and non-magnetic, and these obstruct the path of radio waves. Consists of no material. The approximate planar arrangement of the antennas 4 and 5 in the watch case is, for example, as shown in FIG. 9 (also used in the explanation of Conventional Example 2 described later).

  In FIG. 9, the radio-controlled timepiece has at least one antenna composed of a magnetic core 4 and a coil 5 inside a metal case 2 and a radio wave 11 outside the case. Further, illustration of other parts is omitted. At this time, the AA cross-sectional view passing through the center of the antenna is FIG. 7 in the conventional example 1 and FIG. 8 in the conventional example 2.

  Radio waves pass through the case member from the outside of the watch and reach the internal antenna. When the radio wave 11 shown in FIG. 9 enters the inside of the case, in the conventional example 1 shown in FIG. 7, most of the metal bezel 1 is bypassed from the upper surface side, and the non-conductive watch glass 6 or dial is used. In addition, the radio wave component 9d that enters through the radio wave 7 is a radio wave path 9c that is a slight gap existing between the metal bezel 1 and the metal body 2 that are materials through which radio waves are difficult to transmit. There is a radio wave component 11e that enters through, and a radio wave component 11f that penetrates through a metal member such as the metal barrel 2 to a small extent.

  However, the contribution of the radio wave component 11e to the radio wave reception sensitivity is usually small. In particular, when the upper surface side of the cross section of the body 2 is greatly in and out as shown in the figure and the radio wave path 9c is bent, the radio wave reaching the magnetic core 4 is very weak and the contribution is further reduced. For this reason, it is considered that the radio wave component that enters the case along the gap between the body 2 and the bezel 1 has not been actively used.

  Next, a conventional example 2 of a radio-controlled wrist watch is cited as Patent Document 1. FIG. 8 is a schematic cross-sectional view of the principal part of the invention described in Patent Document 1, in which the reference numerals of substantially the same members are shown in common with the first conventional example.

JP 2008-203063 A

  As shown in FIG. 8, the watch case of the conventional example 2 includes a synthetic resin bezel 13, a metal case 2, a synthetic resin reinforcing member 12, a metal back cover 3, a non-magnetic body, A non-conductive watch glass 6, a non-magnetic and non-conductive dial 7, and a non-magnetic and non-conductive dial ring 8 are provided, and a magnetic material made of a material having high magnetic permeability is provided inside the case. An antenna including a core 4 and a coil 5 wound around the magnetic core 4 is provided. Further, the inner peripheral surface of the metal barrel 2 is gradually thinned toward the upper side, and a reinforcing member 12 made of a non-metallic material (high-strength synthetic resin) is lined to compensate for a decrease in case strength caused thereby. It is.

  In the electronic watch of Conventional Example 2 shown in FIG. 8, when the radio wave 11 shown in FIG. 9 enters the inside of the case as in Conventional Example 1, the non-metal is used for the bezel 13 and the metal barrel 2 is used. Since the reinforcing member 12 and the bezel 13 that are overlapped with the thin portion are made of non-metal and transmit radio waves well, the radio waves 11g are transmitted from the upper edge of the body 2 to the end of the antenna core 4 of the antenna. Since it arrives straight without detouring, it is considered that many radio waves can be used efficiently. In addition, there is a radio wave component 11h that penetrates and penetrates through a metal member such as the metal barrel 2 although it is very small.

However, from the viewpoint of manufacturing, there is a problem that the reinforcing member 12 is required, and the process of joining the reinforcing member 12 to the case body is increased. From the viewpoint of the design, only the bezel part is made of non-metal. As a result, the quality of the appearance will be impaired. In other words, in the second conventional example, it was possible to improve the reception sensitivity by reducing the number of metal members and configuring the case with members that easily transmit radio waves, but the number of components and the labor of manufacturing are reduced. The sensitivity could not be improved without changing the quality and without losing the sense of quality due to the metal exterior.

  As described above, in Conventional Example 1, there was no viewpoint of effectively utilizing the radio wave component penetrating through the gap between the metal case members. In the conventional example 2, the radio wave component that bypasses the metal case is reduced to increase the radio wave component that directly reaches the antenna. However, the number of members constituting the case, the labor of manufacturing, or the aesthetics are increased. Was sacrificed. The present invention intends to solve these problems by strengthening the radio wave component transmitted through the gaps in the metal case of the electronic device.

  An object of the present invention is to efficiently use radio waves by making radio waves arriving from outside the case reach the internal antenna as much as possible without detouring in an electronic device case with a wireless function composed of a metal barrel and a metal bezel. And providing a case structure in which the sensitivity of reception is improved.

In order to achieve the above object, the electronic timepiece with wireless function of the present invention has the following features.
(1) A watch mechanism with a wireless function inside a watch case including a metal case and a metal bezel that is located above the case and fits with the case and an antenna for receiving radio waves coming from the outside In the electronic device with a wireless function, in which the antenna is obtained by winding a coil around an elongated magnetic core made of a material having high magnetic permeability, the top of the trunk facing the outer lower surface of the bezel Assuming a slotted surface that is a set of straight lines connecting all the points constituting the inner edge of each part and each upper end point of the magnetic core, the upper part of the cylinder located inside the top is , Substantially not above the ground surface.

(2) The bending angle of the shortest path of the radio wave entering along the upper surface of the case from the outside of the watch case toward the upper end point of the magnetic core in the watch case is substantially an obtuse angle.

(3) Further, on the inner side of the inner edge of the top of the cylinder, the upper surface of the cylinder or the lower surface of the bezel has a slope portion substantially along the portion with the steepest slope in the ground surface. thing.

(4) The watch case further includes a metal back cover that fits into the case, and includes all the points constituting the inner edge of the lowermost end of the case facing the outer lower surface of the case cover and the magnetic field. Assuming a second slotted surface that is a set of straight lines connecting the respective lower end points of the core, the lower portion of the body located on the inner side of the lowermost end is the second slotted face. It should not exist substantially below the surface.

(5) Further, the bending angle of the cross section of the case along the radio wave path entering along the lower surface of the case from the outside of the watch case toward the lower end point of the magnetic core in the watch case is not an acute angle. .

(6) Further, an insulating member is disposed on at least a part of the mating surface of the barrel and the bezel.

(7) Further, an insulating member is disposed on at least a part of the mating surface of the body and the back cover.

  Since the present invention employs the above-described configuration, it is possible to easily obtain radio waves with high efficiency even in the case of a combination of a metal barrel and a metal bezel. To demonstrate.

It is sectional drawing which showed Example 1 of this invention. It is sectional drawing which showed the electromagnetic wave path | route in Example 1 of this invention. It is sectional drawing which showed Example 2 of this invention. It is the top view which showed Example 1 and Example 2 of this invention. It is the top view which showed Example 3 of this invention. It is sectional drawing which showed Example 4 of this invention. It is sectional drawing which showed the prior art example 1 of this invention. It is sectional drawing which showed the prior art example 2 of this invention. It is the top view which showed the prior art example 1 and the prior art example 2 of this invention. It is the fragmentary sectional view which expanded a part of FIG.

  The present invention relates to a gap between a metal case body and a metal bezel, or a metal case body, out of radio waves arriving at the antenna magnetic core installed inside the case from the outside of the electronic timepiece. The cross-sectional shape of the case body is minimized so as not to attenuate as much as possible the components of radio waves entering the case along the gap with the metal back cover, and the degree of bending of the cross-sectional shape of the gap is minimized. By so defining, the reception sensitivity of the electronic timepiece with a wireless function is comprehensively increased. Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a cross-sectional view of a main part of a radio-controlled wristwatch that is Embodiment 1 of the present invention, in which the present invention is applied to a round metal shell and a metal bezel. FIG. 10 is an enlarged partial cross-sectional view of a part of the cross-sectional view of FIG. FIG. 2 is a cross-sectional view illustrating a state where radio waves pass through the case in the first embodiment. FIG. 4 is a plan view of the main part of the first embodiment, but shows a schematic plane arrangement of the antennas 4 and 5 inside the case with the watch glass 6 and the dial 7 removed. The plan view of FIG. 4 is also applied to the second embodiment.

In FIG. 1, members having substantially the same role as the above-described conventional example are given the same reference numerals as those in FIGS. 7 and 8, and overlapping explanation is avoided as much as possible. The material of the bezel 1 is, for example, a metal such as Ti, SS, Ag, Au, and BS, and includes materials that have been used for similar parts. The material of the body 2 may be basically the same as the bezel 1 or a different metal. The metal material of the back cover 3 may be the same as or different from the bezel 1 and the body 2. As the material of the magnetic core 4 constituting the antenna, a material having high magnetic permeability such as ferrite or amorphous magnetic material is used. A coil 5 wound around the magnetic core 4 to form an antenna together with the magnetic core 4, a non-magnetic body, a non-conductive watch glass 6 that does not obstruct the path of the radio wave, a non-magnetic body, A non-conductive dial 7 that does not obstruct the path of the light and a non-conductive dial ring 8 that is a non-magnetic material and does not obstruct the path of the radio wave.

Between the metal bezel 1 and the metal cylinder 2, there are innumerable points on the upper edge 4 a located at the upper part of the magnetic core 4 and the inner edge 2 a at the top of the cylinder 2 facing the outer lower surface of the bezel 1. Considering a slotted surface 14 that is a set of connected straight lines, a radio wave path 9a that is substantially parallel to or partially along the slotted surface is assumed.
In addition, a portion of the body 2 is not substantially present above the ground surface 14. (Even if it exists, it is very partial.)

  The portion closer to the outer periphery than the inner edge 2a at the top of the body 2 is surely received by the lower surface of the bezel 1 fixed to the upper surface of the body 2, so that it is not a knife edge, as shown in an enlarged view in FIG. Leave a thin, ring-shaped plane. The portion preferably has a narrow ring width in the horizontal direction for the formation of the radio wave path 9a, and has a width of, for example, 50 to 1000 μm, or 100 to 2000 μm. Therefore, an inner edge and an outer edge exist at the top of the body 2. Further, a thin chamfer with an appropriate dimension may be provided on the outer side along the outer edge.

(Operation when receiving radio waves)
Next, the operation of the first embodiment will be described with reference to FIG. FIG. 2 is a cross-sectional view of the first embodiment, in which a radio wave path that reaches the magnetic core 4 of the internal antenna from the outside of the metal case is indicated by a broken line with an arrow with a symbol. .

In FIG. 2, an external radio wave 11 passes through a metal bezel 1, a metal barrel 2, and a metal back cover 3, and a radio wave component 11 c transmitted to the antenna core 4 and a metal The magnetic wave component 11a that reaches the magnetic core 4 from the dial 7 and bypasses the bezel 1 and the body 2 of the dial, and passes through the radio wave path 9a that is a gap between the metal bezel 1 and the metal body 2 to be magnetized. It is divided into a component 11b (drawn in the assumed form) of the radio wave reaching the core 4. By increasing the strength of the radio wave 11b passing through the radio wave path 9a as much as possible and utilizing this, the overall strength of the radio wave collected by the magnetic core 4 of the antenna is increased and the reception sensitivity is improved.

  In order to use the radio wave 11 from the outside as a function of the radio wave wristwatch and correct the current time, it is necessary to transmit the radio wave from the outside to the antenna composed of the magnetic core 4 and the coil 5 in the watch case. is there. At this time, the arrival points on the antenna of the radio wave components 11a, 11b, and 11c passing through the coil are concentrated on the end points of the magnetic core 4 closest to the radio wave intrusion point. The end point of is important.

Next, a method for selecting the optimum radio wave path 9a in the first embodiment will be described with reference to FIGS.
In FIG. 4, the radio-controlled timepiece includes a metal case 2, a magnetic core 4, and a coil 5, and a radio wave 11 is present outside the case. When the planar shape of the end portion of the magnetic core 4 is square, the upper end point at the distance closest to the circle that becomes the inner edge 2a at the top of the body 2 among the four upper end points existing on the upper surface of the magnetic core 4 Reference numeral 41a is assigned a reference numeral 4a, which is a representative end point. If the planar shape of the end face of the magnetic core 4 is not angular but rounded, the representative upper end point 4a is the inner edge of the top of the body 2 on the upper face near the end of the magnetic core 4. The point closest to the circle 2a or the point closest to the inner peripheral surface of the body 2 is selected. FIG. 1 is a sectional view taken on line AA including the representative upper end point 4a and a point 21a on the inner edge 2a at the shortest distance from the representative upper end point 4a. The cross section passes through the center of the circular body 2.

  Next, a slotted surface 14 is defined. The slot-like surface 14 is constituted by an infinite number of straight lines connecting the upper representative end point 4a and all the points on the circle serving as the inner edge 2a at the top of the case body 2, that is, all the points constituting the inner edge. A conical surface opened upward. (However, when the position of the upper representative end point 4a in the plan view is not at the center of the inner edge 2a as shown in the figure, the axis of the cone is not vertical, but is inclined.) In the present invention, the radio wave path 9a is this slip. The upper surface shape of the body 2 is defined so as to be formed along the main portion of the surface 14 as much as possible.

As described above, as the representative upper end point 4a, the planar position is the point closest to the trunk 2, and the upper surface of the trunk 2 is used to define the slot-like surface. It is difficult to precisely determine the position of the representative end points and the shape of the slotted surface in association with each other. The radio waves that reach the end of the core will have a certain surface density distribution (and the end corners may be denser). The radio wave path is also strictly along a slippery surface. It is because it is thought that there is not. Therefore, the representative end point is simply loosely defined as one point on the surface on the same side of the end portion of the magnetic core (outer portion of the coil 5) as the slip-like surface, and based on that, It would be practical to define the surface. This is because the end of the magnetic core is only a relatively small portion with respect to the whole of the magnetic core 4, so that the representative end point can be selected anywhere on the surface within the range of the magnetic core end on one side. This is because the effects born from the shape and angle will be almost the same. The choice of the representative end point from any of the two end portions of the magnetic core is arbitrary.

  Next, considering the outside of the case from the representative end point (any degree of looseness as defined above), the “field of view” is considered. In the direction where the representative end point 4a is far from the body 2, the field of view is relatively open. In other words, the solid angle that allows the dial 7 to be blocked by the metal case is large. Therefore, since the antenna can catch a relatively large amount of radio wave components entering from the dial side by bypassing the metal case, there are few problems.

On the other hand, in the direction in which the representative end point 4a is close to the cylinder 2, the majority of the visual field has a large solid angle and is blocked by the metal-made cylinder 2. In other words, radio waves entering from this direction are extremely difficult to reach the antenna. Therefore, it is important to provide an effective radio wave path 9a in this direction.

  The cross-sectional surface 14 of the slotted surface represented by a dotted line in FIG. 1 is a cross-section of the steepest portion of the sloped surface having different slopes depending on the location. The cross section of the slotted surface 14 is straight from the top of the body 2 toward the representative upper end point 4a. As a result, it is possible to increase the intensity of radio waves entering from the direction with a narrow viewing angle from the representative upper end point 4a, which is most problematic.

  When the surface along the groove-shaped surface 14 is provided at the upper portion of the cylinder, the surface of the groove-shaped surface defined above may be provided as it is, but it is generally difficult to process a curved surface with a non-uniform slope into the cylinder. . Therefore, if the slope of the other part of the slotted surface provided on the cylinder 2 is matched with the steepest slope shown in FIG. If the conical surface has an axis, the radio wave path 9a in the most important direction is secured, and the field of view of the representative end face 4a is open in other directions, so that there are few problems.

  The metal bezel 1 and the body 2 are fixed by a technique such as press-fitting (sometimes press-fitting with a synthetic resin ring interposed), adhesion or welding. Ideally, the mating surfaces of the two should be along the slot-like surface 14, but actually, as shown in FIG. 1, they are intertwined with each other due to various assembly conditions such as press-fitting into the body of the bezel. It tends to have a cross-sectional shape. However, in that case, it is preferable that the cross section of the body 2 does not protrude above the ground surface 14 and the bezel 1 protrudes downward. The reason for this is that, as shown in FIG. 1, the cross-sectional area of the bezel 1 is relatively smaller than the cross-sectional area of the body 2, so that the inhibition effect on radio waves is less than the inhibition effect of the body 2. Further, when the upper surface of the body 2 is vertically projected above the ground surface 14, the radio wave path 9 a is bent at an acute angle and strongly bent, and the radio wave is easily blocked and attenuated. Is lowered from the bridge-shaped surface 14 as a downwardly facing cylindrical surface, the radio wave path 9a is only bent at an obtuse angle (at most, a right angle at most), and the radio wave is hardly disturbed and has little attenuation.

  Usually, the effect of inhibiting radio waves is stronger in the case body having a larger cross-sectional area or thickness than the metal bezel, and thus the radio wave path 9a that allows the radio waves arriving from the outside of the case to reach the internal antenna is formed in a slit shape. In this case, the sensitivity can be improved by about 10% by making the radio wave reach without making a detour or strong bending as much as possible.

  The turn ring 8 is preferably non-conductive, but may be required to be made of metal for aesthetic purposes such as a watch. Since the cross-section of the facing ring is usually smaller than that of the barrel 2, even if it is a metal, the effect of inhibiting radio waves is much less than that of the barrel 2, and may be negligible.

FIG. 3 is a cross-sectional view of an essential part of a radio-controlled wristwatch that is Embodiment 2 of the present invention. In addition to a round metal shell and a metal bezel, a round metal shell and a metal back cover are shown. The present invention is applied to a radio wave wristwatch having
FIG. 4 is a plan view of the main part of the second embodiment, but shows a schematic planar arrangement of the antennas 4 and 5 inside the case with the watch glass 6 and the dial 7 removed. The plan view of FIG. 4 is used in common with the first embodiment and has already been described.

In FIG. 3, members having substantially the same role as the above-described conventional example and Example 1 are shown in FIG.
The same reference numerals as those in FIG. 7 and FIG. 8 are given to avoid overlapping description as much as possible.

Next, the relationship between the trunk lower part 10 and the trunk 2 and the relation between the trunk lower part 10 and the back cover 3 will be described.
In FIG. 3, a metal case 2 is a wristwatch case, and a metal bezel 1 is a member for holding the outer periphery of a watch glass 6 covering the upper surface of the time display surface of the watch. It is press-fitted into.

  The lower body 10 made of metal is a part of a watch case, and the upper side of the lower body 10 is press-fitted into the lower side of the body 2. Further, the metal back cover 3 is press-fitted into the lower side of the trunk lower part 10. At this time, the material of the trunk lower part 10 may be the same as or different from that of the trunk 2.

Between the metal bezel 1 and the metal cylinder 2, there is a representative upper end point 4a that has been described in the first embodiment, and there is a radio wave path 9a.
Further, between the metal cylinder 2 and the metal cylinder lower part 10, a representative lower end point 4 b located at the lower part of the magnetic core 4 and a point on the inner edge of the top lower part of the cylinder lower part 10 facing the outer upper surface of the back cover 3. Assuming a ground-like surface 15 that is a set of straight lines connecting 2b, there is a substantially parallel radio wave path 9b on the ground-like surface 15. In addition, the portion of the body 2 does not substantially exist below the ground surface 15. (Even if it exists, it is very partial.)

The portion near the outer periphery of the lower portion of the body 2 leaves the upper surface of the body lower portion 10 fixed to the lower surface of the body 2 so as to leave a ring-shaped plane having an appropriate width or a loose inclined surface close to the plane.
Next, a method for selecting the optimum radio wave path 9b in the second embodiment will be described with reference to FIG.
In FIG. 3, like the representative upper end point 4a described in the first embodiment, one of a plurality of end points existing at the end of the lower surface of the magnetic core 4 is defined as a representative lower end point 4b. At this time, the distance between the cylindrical surface of the inner surface of the body 2 and the representative lower end point 4b is the shortest. If the end point is not clear, it is the point on the lower surface of the magnetic core 4 that is closest to the inner surface of the body 2, or the definition is loosened, and the surface on the lower side of the end of the magnetic core 4 (outside of the coil 5) This point is the representative lower end point 4b.

  Next, a slot-like surface 15 is defined. The slot-like surface 15 is a conical surface that is open to the lower side and is composed of an infinite number of straight lines connecting the representative lower end point 4b and all points on the circle that will become the inner edge 2b of the top lower portion of the case body 2. is there. (However, when the position of the representative lower end point 4b in the plan view is not at the center of the inner edge 2b, the axis of the cone is inclined rather than vertical.) In the present invention, the radio wave path 9b is this slip-like surface. The lower surface shape of the trunk | drum 2 is prescribed | regulated so that it may form along the main part of 15 as much as possible.

  When the surface along the groove-like surface 15 is provided at the lower part of the cylinder, it is only necessary to provide the surface defined above as it is, but it is generally difficult to process a curved surface with a non-uniform slope into the cylinder. . Therefore, if the slope of the other part of the slotted surface provided on the cylinder 2 is matched with the steepest slope shown in FIG. If the conical surface has an axis, the radio wave path 9b in the most important direction is secured, and in the other directions, as in the radio wave path 9a on the upper surface side, there is no problem because the field of view of the representative lower end point 4b is open. become.

The metal barrel lower portion 10 and the barrel 2 are fixed by a technique such as press-fitting (sometimes press-fitting with a synthetic resin ring interposed), adhesion, or welding. Ideally, the mating surfaces of the two are along the gap surface 15, but in practice, depending on various conditions in the assembling operation, the cross-sectional shape tends to be intertwined as shown in FIG. 3. However, in that case, it is preferable that the cross section of the cylinder 2 does not protrude below the ground-like surface 15 and the cylinder lower part 10 protrudes upward. The reason is that, as shown in FIG. 3, the cross-sectional area of the trunk lower part 10 is relatively smaller than the cross-sectional area of the trunk 2, so that the inhibition effect on radio waves is less than the inhibition effect of the trunk 2. Also,
When the lower surface of the body 2 is vertically exposed below the ground surface 15, the radio wave path is bent at an acute angle and the radio wave is easily obstructed. When coming out from the surface 15, the radio wave path is only bent at an obtuse angle, and the radio wave is hardly obstructed.

  As a modified example of the second embodiment, on the back cover side of a watch without a bezel or hands, it is considered that the surface of the grooved surface is shallow and the shape of the surface of the grooved surface does not often affect the radio wave intensity. Thus, the member of the trunk lower part 10 is omitted, and the back cover 3 is directly attached to the lower surface of the trunk 2 so that the cross-sectional shape of the lower part of the trunk 2 and the back cover 3 is suppressed to such an extent that the radio wave path 9b does not form an acute angle. It is conceivable that the objective can be achieved approximately. In this case, the mating surface of the outer edge portion of the back cover 3 and the lower surface of the body 2 is allowed to be a flat surface.

  FIG. 5 is a plan view of a radio-controlled wristwatch that is Embodiment 3 of the present invention, in which the present invention is applied to a rectangular metal case and a metal bezel. Similarly to FIG. 4, the timepiece glass 6 and the dial 7 are removed, and a schematic planar arrangement of the antennas 4 and 5 inside the case is shown. The cross-sectional view is the same as FIG. 1 and will not be presented again.

Next, a method for selecting the optimum radio wave path 9a in the third embodiment will be described with reference to FIGS. In FIG. 5, the radio-controlled timepiece has a metal case 2, a magnetic core 4, and a coil 5, and a radio wave 11 is present outside the case. Of the four upper end points existing on the upper surface of the magnetic core 4, the upper end point 41 a at the closest distance to the inner peripheral surface of the body 2 is marked with 4a as a representative end point.
FIG. 1 is a sectional view taken on line AA including the representative upper end point 4a and a point 21a on the inner edge 2a at the shortest distance from the representative upper end point 4a.

  Next, a slotted surface 14 is defined. The slot-like surface 14 is a quadrangular pyramid surface that is open to the upper side and is composed of an infinite number of straight lines connecting the representative upper end point 4a and points on the inner edge 2a at the top of the case 2 of the case. (However, when the position of the representative end point 4a in the plan view is not at the center of the inner edge 2a, the axis of the quadrangular pyramid is not vertical, but is inclined.) In the present invention, the radio wave path 9a is this slip-like surface 14. The upper surface shape of the body 2 is defined so as to be formed along the main portion of the body as much as possible.

  The method for selecting the optimum radio wave path 9b is the same as that in the second embodiment, and the description thereof will be omitted. However, the ground-like surface 15 is a quadrangular pyramid surface opened downward, and the radio wave path 9b is the ground path. The lower surface shape of the body 2 is defined so as to be formed along the main part of the surface 15 as much as possible.

FIG. 6 is a cross-sectional view of an essential part of a radio-controlled wristwatch that is Embodiment 4 of the present invention, in which the present invention is applied to a round metal shell and a metal bezel. Members having substantially the same role as in the first embodiment are given the same reference numerals as those in FIG. 1 to avoid overlapping explanation as much as possible. The difference from the first embodiment is that a magnetic block 16 made of a material having the same or different material as the magnetic core 4 on the upper surface of the end portion of the magnetic core 4 but made of a material having a high magnetic permeability is almost integrated magnetically. This is because the upper end surface of the magnetic core 4 is substantially brought close to the windshield glass 6 side. The magnetic block 16 may be provided at both ends of the magnetic core 4, but only one side thereof is shown in FIG. 6.

The selection method of the bridge-shaped surface, the representative upper end point, and the optimal radio wave path 9a in the fourth embodiment is performed in the same manner as in the first embodiment based on FIG.
The difference is that due to the presence of the magnetic body block 16, the representative upper end point approaches the top side of the body 2, and the slope of the slip-like surface becomes gentler than that of the first embodiment. For this reason, there is an effect that the design and manufacture of the watch case can be made easier.

  Further, as a modification of the present embodiment, the magnetic body block 16 is made of the same material as the magnetic body block 16 or a different material, for example, a wing-shaped member having an enlarged planar surface area at the end, or an end When there is a member whose outer end is warped toward the glass side and the representative upper end point is further brought closer to the glass side, or when the magnetic body block 16 is located below the magnetic core 4 Various cases are conceivable, such as when the magnetic body block 16 exists only on one side of the magnetic core 4.

  As a modification of each embodiment, an insulating member (thin plate, paint, film, etc.) may be provided on the mating surface of the case body and the metal bezel or metal back cover.

  According to the present invention, an electronic timepiece with a metal case with high use efficiency of radio waves can be obtained. Therefore, the industrial applicability is great.

DESCRIPTION OF SYMBOLS 1 Bezel 2 Body 2a Inner edge 2b of the top of the cylinder Inner edge 21a of the lowermost part of the cylinder On the inner edge of the upper part of the cylinder, a point of the shortest distance from the representative upper end point 3 41a Upper end point closest to the inner edge of the top of the trunk 5 Coil 6 Clock glass 7 Dial 8 Dial ring 9a, 9b, 9c Radio wave path 10 Lower trunk 11 Radio waves 11a, 11b, 11c, 11d, 11e, 11f, 11g, 11h Radio wave component 12 Reinforcement material 13 Bezel 14 Slip-like upper side surface 15 Slip-like lower side surface 16 Magnetic block

Claims (7)

  A watch case with a wireless function and an antenna for receiving radio waves coming from outside are accommodated in a watch case including a metal case and a metal bezel that is fitted on the case and is located above the case. In the electronic device in which a coil is wound around an elongated magnetic core made of a material having high magnetic permeability, the antenna constitutes an inner edge of the top of the trunk facing the outer lower surface of the bezel. Assuming a ground-like surface that is a set of straight lines connecting all points and the representative upper end point of the magnetic core, the upper part of the cylinder located inside the top is the ground-like surface. An electronic timepiece with a wireless function, characterized in that the electronic timepiece substantially does not exist on the upper side.   2. The bending angle of the shortest path of a radio wave entering along the upper surface of the case from the outside of the watch case toward the upper end of the magnetic core in the watch case is substantially obtuse. Electronic watch with wireless function as described in 1.   Inside the inner edge of the top of the cylinder, the upper surface of the cylinder or the lower surface of the bezel has a slope portion substantially along the steepest portion of the ground surface. The electronic timepiece with a wireless function according to claim 1 or 2.   The watch case further includes a metal back cover that fits with the case, and all points constituting the inner edge of the lowermost end of the case facing the outer lower surface of the case cover and a representative lower side of the magnetic core Assuming a second ground-like surface that is a set of straight lines connecting the end points, the lower part of the body located inside the lowermost end is more than the second ground-like surface. 4. The electronic timepiece with a wireless function according to claim 1, wherein the electronic timepiece has substantially no lower side.   The bending angle of the cross section of the case along the radio wave path entering along the lower surface of the case from the outside of the watch case toward the lower end point of the magnetic core in the watch case is not an acute angle. Item 5. An electronic timepiece with a wireless function according to Item 4.   6. An electronic timepiece with a wireless function according to claim 1, wherein an insulating member is disposed on at least a part of a mating surface between the case and the bezel.   7. The electronic timepiece with a wireless function according to claim 4, wherein an insulating member is disposed on at least a part of a mating surface between the case and the back cover.

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