Electronic clock

Abstract

It ensures stable electrical conductivity even for components that are repeatedly opened and closed. [Solution] The electronic device, a clock 100, comprises metal parts such as metal buttons 7 and metal button pipes 75, which are externally mounted on a case 1; a diaphragm 42, which is a metal plate provided inside the back side of the case 1 and functions as a GND; and an internal terminal plate 9 that connects the metal parts such as metal buttons 7 and metal button pipes 75 to the diaphragm 42, which is the metal plate. The internal terminal plate 9 is sandwiched between the case 1 and the diaphragm 42, which is the metal plate.

Description

Technical Field

[0001] The present invention relates to an electronic device and an electronic timepiece. Background Art

[0002] Conventionally, a configuration is known that achieves conduction between various members and GND on the back cover side via a terminal plate having spring properties. For example, Patent Document 1 describes a structure in which a back cover conduction spring for conducting to the back cover is integrally formed on a circuit pressing plate that presses a circuit board functioning as a ground plate, and the circuit board is conducted to the back cover via the back cover conduction spring. Prior Art Documents Patent Documents

[0003] Patent Document 1 Japanese Unexamined Patent Publication No. 2020-12842 Summary of the Invention Problems to be Solved by the Invention

[0004] However, the back cover is a part that is opened and closed relatively frequently for battery replacement, maintenance, and the like. Therefore, when a configuration is adopted in which conduction is achieved by bringing a spring terminal plate or the like into contact with the back cover, the portion in contact with the back cover gradually wears as the back cover is repeatedly opened and closed, which may reduce the function as a spring.

[0005] If the function as a spring decreases, it becomes difficult to stably bring the terminal plate into contact with a member such as the back cover that functions as GND, which may cause variation in contact resistance values.

[0006] The present invention is made to solve these problems, and an object of the present invention is to provide an electronic device and an electronic timepiece that can achieve stable conduction even with respect to a member that is repeatedly opened and closed. Means for Solving the Problems

[0007] To solve the aforementioned problems, the electronic device according to the present invention is Metal parts enclosed in the case, A metal plate provided inside the back side of the case, which functions as a GND, The case comprises an internal terminal plate provided inside the case for connecting the metal parts to the metal plate, The internal terminal plate is characterized by being sandwiched between the case and the metal plate. [Effects of the Invention]

[0008] According to the present invention, stable electrical conductivity can be achieved even for members that are repeatedly opened and closed. [Brief explanation of the drawing]

[0009] [Figure 1] This is an exploded perspective view of the main parts of the clock according to this embodiment. [Figure 2] Figure 1 is a front view of the clock. [Figure 3] This is a cross-sectional view of the main part of the clock along line III-III in Figure 2. [Figure 4] This is a cross-sectional view of the main part of the clock along the IV-IV line in Figure 2. [Figure 5] This is a side view of the clock as seen from the direction of arrow V in Figure 2. [Figure 6] This is a side view of the clock as seen from the direction of arrow VI in Figure 2. [Figure 7] (a) is a cross-sectional view of the main part along the line VIIa-VIIa in Figure 5, and (b) is a cross-sectional view of the main part along the line VIIb-VIIb in Figure 6. [Figure 8] (a) is a perspective view of the metal bezel in the embodiment. (b) is an exploded perspective view of the main parts of the metal button portion according to the embodiment. (c) is a perspective view of the metal button pipe shown in (b). (d) is a perspective view of the external terminal plate in the embodiment. [Figure 9] This is an enlarged cross-sectional view of section IX, enclosed by the dashed line in Figure 3. [Figure 10] It is an enlarged cross-sectional view of a portion X surrounded by an alternate long and short dash line in FIG. 7(a), wherein (a) shows a state where no load is applied to the metal bezel, and (b) shows a state where a load is applied to the metal bezel. [Figure 11] It is a plan view of the back cover member according to the embodiment. [Figure 12] It is an exploded perspective view of essential parts of the back cover member shown in FIG. 11. [Figure 13] It is a perspective view of essential parts of the piezoelectric sound generating unit according to the embodiment. [Figure 14] It is an essential-part cross-sectional view taken along line XIV-XIV of the back cover member in FIG. 11. [Figure 15] It is a perspective view of the internal terminal plate according to the embodiment. [Figure 16] It is an enlarged cross-sectional view of a portion XVI surrounded by an alternate long and short dash line in FIG. 4. [Figure 17] It is an enlarged cross-sectional view of essential parts in a modified example of the timepiece shown in FIG. 2, and is an enlarged cross-sectional view showing an example in which an internal terminal plate according to a modified example is applied to the same portion as that shown in FIG. 16. MODE FOR CARRYING OUT THE INVENTION

[0010] An embodiment of an electronic device (electronic timepiece) according to the present invention will be described with reference to the drawings. In the present embodiment, a case where the electronic device (electronic timepiece) is a wristwatch worn on a user's wrist (hereinafter simply referred to as "timepiece 100") will be described as an example. It should be noted that various technically preferable limitations for carrying out the present invention are added to the embodiments described below, but the scope of the present invention is not limited to the following embodiments and illustrated examples.

[0011] [Configuration] FIG. 1 is an exploded perspective view of essential parts of a timepiece that is an electronic device (electronic timepiece) according to the present embodiment, and FIG. 2 is a front view of essential parts of the timepiece shown in FIG. 1. FIG. 3 is an essential-part cross-sectional view taken along line III-III of the timepiece in FIG. 2, and FIG. 4 is an essential-part cross-sectional view taken along line IV-IV of the timepiece in FIG. 2. Further, FIG. 5 is a side view of the 9 o'clock side of the timepiece as viewed from the direction of arrow V in FIG. 2, and FIG. 6 is a side view of the 3 o'clock side of the timepiece as viewed from the direction of arrow VI in FIG. 2.

[0012] As shown in FIG. 1, a timepiece 100, which is an electronic device (electronic timepiece) according to the present embodiment, includes a case 1. The case 1 of the present embodiment is formed into a hollow short column shape with open upper and lower ends, and the internal hollow portion constitutes a storage space for storing various components. The case 1 is formed of a relatively hard synthetic resin such as engineering plastic or super engineering plastic, for example. Note that the material for forming the case 1 is not limited to those exemplified herein.

[0013] On the outer side surface of the case 1, a pair of band attachment portions 11 to which an unillustrated band is attached are provided at the 12 o'clock position and 6 o'clock position of the analog timepiece. Further, as will be described later, the timepiece 100 of the present embodiment is provided with metal buttons 7 at the 2 o'clock position, 4 o'clock position, 8 o'clock position, 9 o'clock position, and 10 o'clock position of the analog timepiece. A through hole 17 through which a shaft portion 72 of the metal button 7 described later is inserted is formed at a position corresponding to the metal button 7 on the outer side surface of the case 1.

[0014] As shown in FIGS. 3 and 4, the opening portion on the front side of the case 1 (the viewing side of the timepiece, the upper side in FIGS. 3 and 4) is closed by a windshield member 14. The windshield member 14 is a transparent member (cover member) formed of, for example, a glass material or a transparent resin material, and is fixed to the case 1 by, for example, adhesion. A transparent or semi-transparent solar panel 15 is superimposed on the windshield member 14, and is provided integrally with the windshield member 14 by, for example, adhesive fixation (see FIGS. 3 and 4). Note that the shape, arrangement position, and the like of the solar panel 15 are not limited to the illustrated example.

[0015] The opening on the back side of case 1 (the non-visible side in the watch, the lower side in Figures 3 and 4) is closed by the case back member 3. The case back member 3 may be integrally formed with case 1. The case back member 3 is made of a hard resin such as carbon or a metallic resin. This allows the case back member 3 to have high strength and be virtually unaffected by impacts. In this embodiment, the case 1 has a recess 16 (see Figure 9) on its rear end face for arranging a waterproofing member such as a waterproofing ring (not shown), and the case back member 3 is attached to the case 1 via the waterproofing member using screws (not shown). By attaching the case back member 3 via the waterproofing member, the opening on the rear side of the case 1 (the non-visible side in the watch) can be closed while ensuring waterproofness (airtightness) inside the case 1.

[0016] In this embodiment, a piezoelectric sound-generating unit 4 is arranged inside the back cover member 3 (see Figures 11 and 12). The piezoelectric sound-generating unit 4 provides various notifications to the user by generating a beep sound (sounding a buzzer), and is a unimorph structure in which a piezoelectric body 41 is bonded to a diaphragm 42. The diaphragm 42 is a metal plate member (sheet metal) such as stainless steel (SUS), and as will be described later, it is a metal plate that functions as GND (this is also called the "GND function part"). The piezoelectric sound-generating unit 4 is attached to the inner surface of the back cover member 3 by, for example, double-sided tape 45 (see Figure 12), and is connected to a circuit board (not shown). Note that the diaphragm 42 is not limited to stainless steel (SUS), but may be brass, nickel, or the like.

[0017] Although detailed illustrations and explanations are omitted, the inside of case 1 (the storage space mentioned above) houses the control unit, operating unit, battery, and other components of the electronic device, the clock 100. The operating unit is a component that enables the clock 100 to display various information. For example, Figure 1 illustrates a case where the clock 100 is a digital display system that includes a display unit 12, such as a liquid crystal display panel, as the operating unit. However, the operating unit is not limited to the display unit 12, such as a liquid crystal display panel. For example, if the clock 100 is an analog display system, the operating unit may include a pointer, a gear train (gear train mechanism) or drive unit (motor, etc.) that rotates the pointer, instead of the above components. The clock 100 may also be a hybrid type that has both digital and analog displays, in which case it will have components of both types as the operating unit. The control unit is mounted on a circuit board (not shown) and controls the display operation and other functions performed by the operating unit.

[0018] An antenna 13 is also located inside the case 1. In the example shown in Figure 1, the antenna 13 is formed in a substantially ring shape and is located below the aforementioned windbreak member 14 (see Figures 3 and 4). Note that the shape of the antenna 13 and the position in which the antenna 13 is provided are not limited to the illustrated example. In this embodiment, the antenna 13 is, for example, a GPS antenna capable of receiving GNSS (GPS / GLONASS / QZSS / SBAS) signals transmitted from GPS satellites (including multiple types such as GLONASS in addition to GPS, but hereinafter simply referred to as "GPS"). GPS satellites are equipped with atomic clocks and transmit data containing time information from these atomic clocks. By receiving GNSS (GPS) signals and other signals transmitted from GPS satellites with antenna 13, extremely high-precision time information can be obtained at any receiving point on the ground.

[0019] Furthermore, as shown in Figures 1 to 6, a buffer bezel 5 is provided on the outside of the case 1 in this embodiment. The buffer bezel 5 is a buffering member that covers almost the entire side surface of the case 1. Specifically, the buffer bezel 5 is provided so as to surround the opening on the surface side (the viewing side in the watch) of the case 1 and covers almost the entire side surface of the case 1. The buffer bezel 5 is provided with a covering portion 51 that covers the band attachment portion 11 of the case 1 at a position corresponding to the band attachment portion 11. The buffer bezel 5 also has an insertion hole 52 that penetrates from the inside to the outside, corresponding to the position where the metal button 7, described later, will be attached. The material used to form the buffer bezel 5 is not particularly limited, but for example, it can be made of a resin such as urethane. The buffer bezel 5 only needs to be made of a material that has a buffering effect and can be restored to its original shape even if it is pressed and deformed, and is not limited to being made of a resin such as urethane.

[0020] Furthermore, the case 1 is externally covered with multiple metal parts made of metal material. In this embodiment, the metal parts include a metal bezel 6, a metal button 7, and a metal button pipe 75. As shown in Figures 2, 5 to 7(a) and 7(b), the metal bezel 6 is provided so as to overlap the outside of the buffer bezel 5 on the sides of the case 1 at the 3 o'clock and 9 o'clock positions in an analog watch. By partially positioning the metal bezel 6 from the outside of the buffer bezel 5, the appearance of the watch 100 can be improved and a sense of luxury can be created. Note that the specific shape of the metal bezel 6, the position and range in which the metal bezel 6 is placed, etc., are not limited to the illustrated examples, and the metal bezel 6 may be placed over a wider area.

[0021] Figure 8(a) is a perspective view showing a metal bezel. Figure 8(a) illustrates a metal bezel 6 located at the 3 o'clock position in an analog watch as an example. In the illustrated example, the metal bezel 6 is secured with screws in two places, and screw holes 61 are formed at the screw-securing locations. As will be described later, the metal bezel 6 of this embodiment is secured to the case 1 by stepped screws 63 (see Figures 10(a) and 10(b)). As shown in Figure 8(a), abutment surface 62 is provided in the screw hole 61 formed in the metal bezel 6, against which the first stepped portion 632 of the stepped screw 63 abuts.

[0022] Furthermore, the clock 100 of this embodiment is provided with metal buttons 7 at the 2 o'clock, 4 o'clock, 8 o'clock, 9 o'clock, and 10 o'clock positions on an analog clock. Each metal button 7 is equipped with a metal button pipe 75, which is a metal component. Figure 8(b) is an exploded perspective view of a metal button, and Figure 8(c) is a perspective view of a metal button pipe. As shown in Figure 8(b), the metal button 7 comprises a button head 71 and a shaft 72. The button head 71 is the part exposed to the outside of the watch 100 and is the part that receives user input. One end of the shaft 72 is connected to the button head 71, and the other end is inserted through the insertion hole 77 (see Figure 8(c)) of the metal button pipe 75, with the other end inserted through the coil spring member 73. Furthermore, the other end of the shaft 72 is inserted into the case 1 through the insertion hole 52 of the buffer bezel 5 and the through hole 17 of the case 1. In this embodiment, in addition to the metal button pipe 75, the button head 71 and the shaft 72 are also metal parts formed from metal material.

[0023] As shown in Figure 8(c), the metal button pipe 75 is a bottomed, substantially cylindrical member with an insertion hole 77 located approximately in the center of the bottom. Around the insertion hole 77, a cylindrical portion 76 is erected from the bottom into the metal button pipe 75, which is approximately concentric with the insertion hole 77 in a plan view. When the shaft portion 72 of the metal button 7 is inserted into the insertion hole 77, one end of the coil spring member 73 is positioned inside the cylindrical portion 76. A recess 711 is formed on the back side of the button head 71 of the metal button 7 around the shaft portion 72 (see Figure 9, etc.), and the other end of the coil spring member 73 is positioned inside the recess 711. As a result, the button head 71 of the metal button 7 and the metal button pipe 75 are connected and electrically connected via the coil spring member 73. Furthermore, a screw hole 78 is formed near the insertion hole 77 at the bottom of the metal button pipe 75, and the metal button pipe 75 is fastened to the case 1 by inserting a screw 74, which is a fastening member, through the screw hole 78.

[0024] Furthermore, the watch 100 has a terminal plate (hereinafter referred to as the "external terminal plate 8") on the outside of the case 1 that is connected to multiple metal parts, and the multiple metal parts, namely the metal bezel 6 and the metal button pipe 75, are attached to the case 1 via the external terminal plate 8. Specifically, the metal bezel 6 and the metal button pipe 75 are appropriately positioned from the outside of the buffer bezel 5, which is attached to cover the outside of the case 1, via the external terminal plate 8, and are fastened to the case 1 by fastening members (a stepped screw 63 which is a fastening member for fastening the metal bezel 6 and a screw 74 which is a fastening member for fastening the metal button pipe 75).

[0025] The external terminal plate 8 is made of a metal material and, as shown in Figure 1, has a component receiving portion 81 which is a flat portion that receives the metal bezel 6 and the metal button pipe 75, and a connecting arm portion 82 which connects the component receiving portions 81 together. The component receiving portion 81 is provided with screw holes 83 through which stepped screws 63 for fixing the metal bezel 6 and screws 74 for fixing the metal button pipe 75 are inserted.

[0026] Stepped screws 63 and 74 secure the metal bezel 6 and metal button pipe 75 to the case 1 via the external terminal plate 8. In other words, both the metal bezel 6 and metal button pipe 75 are fastened together with the external terminal plate 8 to the case 1. By fastening the multiple metal parts, the metal bezel 6 and metal button pipe 75, together with the external terminal plate 8, electrical conductivity is achieved between the members fastened via the same external terminal plate 8 (i.e., the metal bezel 6 and metal button pipe 75) via the external terminal plate 8. In this embodiment, as described above, the button head 71 of the metal button 7 and the metal button pipe 75 also come into contact via the coil spring member 73. Therefore, if the button head 71 is also a metal part made of a metal material, the button head 71 will also come into electrical contact with other metal parts fastened via the same external terminal plate 8. In this way, the metal button 7 is electrically connected to the external terminal plate 8 via the coil spring member 73 and the metal button pipe 75.

[0027] In Figure 3, a cross-sectional view along line III-III in Figure 2, the metal buttons 7 at the 4 o'clock and 10 o'clock positions are enclosed by dashed lines. Similarly, in Figure 4, a cross-sectional view along line IV-IV in Figure 2, the metal buttons 7 at the 2 o'clock and 8 o'clock positions are enclosed by dashed lines. The configuration of the metal buttons 7 and their surroundings, enclosed by dashed lines in each figure, is almost identical. Figure 9 is an enlarged cross-sectional view of the main part of section IX, which is enclosed by a dashed line in Figure 3.

[0028] The metal button 7 shown in Figure 9, etc., is a push button that operates when the user presses the button head 71, which in turn pushes the shaft 72. The button head 71 is movable along the axis of the shaft 72 within the metal button pipe 75. As mentioned above, a coil spring member 73 is positioned between the button head 71 and the metal button pipe 75, so when the button head 71 is pressed, the coil spring member 73 is compressed. When the pressing force is released, the restoring force of the coil spring member 73 pushes the button head 71 back to its original position. As shown in Figure 9, the shaft portion 72 has a groove 721 formed in the part that is inserted into the case 1, and a waterproof ring 722 is fitted inside the groove 721. The number, shape, and arrangement of the waterproof rings 722 are not limited to the illustrated example. The waterproof ring 722 has each outer surface pressed against the inner surface of the through hole 17 formed in the case 1, and slides within the through hole 17 in response to the operation of the metal button 7. This ensures waterproofing between the shaft portion 72 and the through hole 17.

[0029] Furthermore, a groove 723 is formed around the shaft near the tip of the shaft portion 72. When the shaft portion 72 is inserted through the through hole 17, at least the tip portion of the shaft portion 723 protrudes into the case 1. A retaining member 79 is attached to the groove portion 723. The shape of the retaining member 79 is not limited to the illustrated example, but for example, an E-ring or the like can be used as the retaining member 79 that is fitted into the groove portion 723. The retaining member 79, fitted into the groove 723, abuts against the inner circumferential surface of the case 1 in a manner that allows it to move toward and away from it. By the retaining member 79 abutting against the inner circumferential surface of the case 1, the shaft portion 72 of the metal button 7 is configured so that the portion of the shaft 72 that is beyond the groove 723 to which the retaining member 79 is attached does not come out of the case 1.

[0030] As described above, the metal button pipe 75 is fastened to the case 1 with screws 74, with the external terminal plate 8 sandwiched between the external terminal plate 8 and the outer surface of the case 1. Although only the component receiving portion 81 of the external terminal plate 8 is visible in the cross-section shown in Figure 9, as described above, the external terminal plate 8 is connected to multiple metal components by connecting arms 82 which connect multiple component receiving portions 81. One end of the internal terminal plate 9, described later, is in contact with the tip of the shaft portion 72 of the metal button 7, beyond the groove portion 723. As mentioned above, several metal components (metal bezel 6, metal button 7, and metal button pipe 75 in Figure 1) are connected to the external terminal plate 8. One of the metal components (metal bezel 6, metal button 7, and metal button pipe 75 in Figure 1) is electrically connected to the internal terminal plate 9 (either directly or indirectly). When the other end of the internal terminal plate 9 comes into contact with the diaphragm 42, which acts as a GND function, all of the several metal components (metal bezel 6, metal button 7, and metal button pipe 75 in Figure 1) connected to the external terminal plate 8 become conductive to GND, and the potential difference with GND becomes zero. The configuration in which the metal button 7, including the metal button pipe 75, indirectly contacts the diaphragm 42, which acts as a GND function, will be described in detail later.

[0031] Furthermore, in the watch 100 of this embodiment, as shown in Figure 2, a metal bezel 6 is provided on the outermost surface at the 3 o'clock and 9 o'clock positions. Therefore, although the appearance is excellent, if the watch 100 is dropped or subjected to a large impact from the 3 o'clock and 9 o'clock positions, the impact may directly affect the case 1 and various precision components inside the case, potentially causing adverse effects. Therefore, in this embodiment, the following shock-absorbing structure is provided in the area where the metal bezel 6 is located. Figures 10(a) and 10(b) are enlarged cross-sectional views of the X area enclosed by the dashed line in Figure 7(a). The shock absorption structure in the area where the metal bezel 6 is provided is the same on the 3 o'clock side (i.e., the side shown in Figure 7(b)). The configuration of the metal button 7 in the area where the metal bezel 6 is provided is the same as that described in Figure 9, except that the shaft portion 72 is inserted into the case 1 by passing through the insertion hole 67 of the metal bezel 6 instead of the insertion hole 77 of the metal button pipe 75. For this reason, it is only illustrated here, and the explanation is omitted.

[0032] Figure 10(a) shows the metal bezel in a state where no load is applied. As mentioned above, the metal bezel 6 is fastened to the case 1 by stepped screws 63. Specifically, a stop surface 62 is provided in the screw hole 61 of the metal bezel 6, against which the first stepped portion 632 of the stepped screw 63 abuts. When the stepped screw 63 is fastened, the lower surface of the first stepped portion 632 (the right side in Figure 10(a)) abuts against the upper surface of the stop surface 62 (the left side in Figure 10(a)). This allows the metal bezel 6 to have electrical contact with the stepped screw 63.

[0033] Furthermore, the second stepped portion 633 of the stepped screw 63 is in contact with the external terminal plate 8 (the component receiving portion 81 of the external terminal plate 8). The stepped screw 63 acts as a fastening member, fastening the metal bezel 6 and the external terminal plate 8 to the case 1 together, with the external terminal plate 8 (the component receiving portion 81 of the external terminal plate 8) sandwiched between the metal bezel 6 and the case 1. In this embodiment, a buffer bezel 5 is positioned between the case 1 and the metal bezel 6 as a buffering member. As shown in Figure 10(a), the thickness of the buffer bezel 5 when no load is applied to the metal bezel 6 is defined as "thickness t1". At this time, a gap C is provided between the metal bezel 6, which is an exterior member, and the case 1 as a movable space capable of absorbing the displacement of the metal bezel 6. The "thickness t1" of the buffer bezel 5 and the size of the gap C as a movable space can be set as appropriate.

[0034] In contrast, Figure 10(b) shows the metal bezel under load. When the metal bezel 6, an exterior component of the watch 100, is subjected to impact, such as from a fall, the metal bezel 6 is pushed toward the case 1 and displaced. At this time, the metal bezel 6 can move by the amount of the gap C, and the buffer bezel 5 is crushed by the amount that the metal bezel 6 moves. Therefore, when the metal bezel 6 is under load, the thickness of the buffer bezel 5 becomes "thickness t2," which is thinner than the "thickness t1" when there is no load. Also, the gap C decreases in proportion to the amount the metal bezel 6 moves. In the illustrated example, the state in which the metal bezel 6 has moved to the point where the gap C is almost gone is shown.

[0035] When the metal bezel 6 is displaced toward the case 1, the abutment surface 62 of the metal bezel 6 separates from the first stepped portion 632 of the stepped screw 63. As a result, electrical conductivity is lost in the metal bezel 6 while it is separated. However, once the load on the metal bezel 6 is removed (i.e., once the impact subsides), the buffer bezel 5 returns to its original shape. This pushes the metal bezel 6 back up to its original position, causing the first stepped portion 632 of the stepped screw 63 to abut against the abutment surface 62 of the metal bezel 6 again, restoring electrical conductivity.

[0036] Figure 11 is a plan view of the back cover member in the embodiment, and Figure 12 is an exploded perspective view of the main parts of the back cover member shown in Figure 11. As described above, the piezoelectric sound generation unit 4 is attached to the inner surface of the back cover member 3 with double-sided tape 45 or the like. Figure 13 is a perspective view of the main components of the piezoelectric sound generation unit. In this embodiment, the diaphragm 42 of the piezoelectric sound generation unit 4 is a metal plate that functions as a GND (GND functional part). As shown in Figure 13, the diaphragm 42 has a spring-shaped portion 43 in all or part of the position corresponding to the internal terminal plate 9.

[0037] The spring-shaped portion 43 is formed by bending a part of the diaphragm 42 toward the back surface in a roughly L-shape, creating a leaf spring shape. An elastic body 44 is positioned on the back side of the spring-shaped portion 43 (between the back cover member 3 and the spring-shaped portion 43). The elastic body 44 is an auxiliary member that generates the necessary load in the spring-shaped portion 43. In other words, the spring-shaped portion 43 is provided to stably support the end of the internal terminal plate 9 when the internal terminal plate 9 is positioned. The elastic body 44 ensures the necessary contact pressure and stabilizes the contact resistance with the internal terminal plate 9.

[0038] The elastic body 44 is attached to the back surface of the spring-shaped portion 43 with double-sided tape or the like. A high-performance urethane foam, such as a microcell polymer sheet (e.g., "PORON" (registered trademark) manufactured by Rogers Inoac Co., Ltd.), is preferably used as the elastic body 44. The material of the elastic body 44 is not particularly limited; it can be any material capable of stabilizing the load on the leaf spring-shaped portion 43. For example, the elastic body 44 may be a coil spring or the like. Figure 14 is a cross-sectional view of the main part of the case back along the line XIV-XIV in Figure 11. As shown in Figure 14, etc., a recess 31 is formed on the inner surface of the back cover member 3 at a position corresponding to the spring-shaped portion 43, where the elastic body 44 provided on the back surface of the spring-shaped portion 43 is positioned, so that the elastic body 44 is stably positioned.

[0039] Preferably, the spring-shaped portion 43 is provided corresponding to the position of each metal button 7. This ensures that the internal terminal plate 9, which contacts the shaft portion 72 of each metal button 7, makes reliable contact with the diaphragm 42, which serves as the GND function portion, and establishes electrical conductivity. However, although an internal terminal board 9 is provided to correspond to the metal button 7, there are cases where it is not possible to provide a spring-shaped portion 43 in the position corresponding to the internal terminal board 9 due to the arrangement of various components housed within the case 1.

[0040] In this embodiment, multiple metal components (metal bezel 6 and metal button pipe 75) are connected to a single external terminal board 8 and fastened together to the case 1. Therefore, even if there is a location where the spring-shaped portion 43 cannot be placed in a position corresponding to an internal terminal board 9, if at least one of the internal terminal boards 9 corresponding to other metal components connected to the same external terminal board 8 is reliably connected to the diaphragm 42, all metal components connected to the external terminal board 8 can be electrically connected to the diaphragm 42 as a GND function unit, resulting in a state of zero potential difference with GND. The clock 100 of this embodiment is provided with five metal buttons 7, each with a corresponding internal terminal plate 9. Figures 12 and 13 illustrate a case where four of these internal terminal plates 9 are corresponding to four spring-shaped portions 43 on the diaphragm 42.

[0041] Figure 15 is a perspective view of the internal terminal board in the embodiment. The internal terminal board 9 connects the metal components, such as the metal bezel 6 and the metal button pipe 75, to the diaphragm 42, which is a metal plate that functions as a ground, thereby creating electrical conductivity. As shown in Figure 15, the internal terminal plate 9 of this embodiment has a first portion 91 that is connected to a metal component and a second portion 92 that is bent in a first direction α (see Figure 16) from the lower end side of the first portion 91, and is formed in a substantially L-shape when viewed from the side. As shown in Figure 16, in this embodiment, the first direction α is the direction from the inside to the outside of the case 1.

[0042] A curved portion 911 is formed at the upper end (free end) of the first portion 91, and is designed to receive and contact the tip of the shaft portion 72 of the metal button 7. The second portion 92 makes surface contact with the diaphragm 42, which is a metal plate (specifically, the spring-shaped portion 43 which is integrally formed with the diaphragm 42). At the location where the spring-shaped portion 43 is provided, the spring-shaped portion 43 is pushed up by the elastic body 44, so that it contacts the second portion 92 from the diaphragm 42 side, allowing the internal terminal plate 9 and the diaphragm 42 to make stable contact. In addition, double-sided tape 94 is placed on the first portion 91 of the internal terminal plate 9, and the first portion 91 of the internal terminal plate 9 is attached to the case 1 via the double-sided tape 94.

[0043] In particular, the diaphragm 42 of the piezoelectric sound-producing unit 4 is relatively thin in thickness for the purpose of vibrating the piezoelectric element 41, and it is difficult to generate the desired load by simply providing a spring-shaped portion 43 in the shape of a leaf spring. Furthermore, when the piezoelectric sound-producing unit 4 is provided on the back cover member 3 as in this embodiment, repeated opening and closing operations tend to cause poor contact, and even if contact is made and conductivity is established, the contact resistance value is not stable (it tends to change). In this regard, by providing an elastic body 44 on the back surface of the spring-shaped portion 43 and configuring it to be pushed up by the elastic body 44, the necessary contact pressure with the internal terminal plate 9 can be secured, and the internal terminal plate 9 and the diaphragm 42 can be reliably electrically connected. In addition, even if the opening and closing operations are repeated, the spring-shaped portion 43 is less likely to wear down and can maintain a stable contact resistance for a long time. This stabilizes the resistance value of GND and strengthens GND.

[0044] Furthermore, in this embodiment, the internal terminal plate 9 has a bent portion 93 that is approximately inverted L-shaped in side view, which is formed by bending the lower end of the first portion 91 in a second direction β (see Figure 16) opposite to the first direction α, and the second portion 92 is formed by bending from the lower end of the bent portion 93 in the first direction α. By first bending the internal terminal plate 9 in the second direction β, causing it to bulge inward towards the case 1, and then bending it in the first direction α to form the second portion 92, the length of the second portion 92 in the first direction α can be increased. Therefore, even considering the bending radius when bending in the first direction α, sufficient length of the second portion 92 can be secured, increasing the contact area between the internal terminal plate 9 and the diaphragm 42, allowing for more stable contact and electrical conductivity.

[0045] In particular, as mentioned above, a waterproof member is provided between the back cover member 3 and the case 1 to waterproof the gap, and a recess 16 is formed at the lower end of the case 1 for positioning this waterproof member. The waterproof member may shift position slightly even within the recess 16. For this reason, in order to ensure waterproofing, it is necessary to secure an area where the back cover member 3 and the case 1 overlap with some margin. Since the internal terminal plate 9 and the diaphragm 42 cannot be placed within this area, if the second part 92 is formed by directly bending the first part 91, which is almost in contact with the inner surface of the case 1, in the first direction α, then the length of the second part 92 in the first direction α will be almost nonexistent. In addition, various resin parts are present near the inner surface of the case 1 around the diaphragm 42, so it is necessary to avoid interference with these. In this regard, by providing a bent portion 93 to slightly release it from the inner wall of the case and then bending it in the first direction α to form the second portion 92, it is possible to increase the contact width with the diaphragm 42 (the width over which the second portion 92 makes surface contact with the diaphragm 42 (the spring-shaped portion 43 of the diaphragm 42)) and avoid interference with various components.

[0046] Figure 16 is an enlarged cross-sectional view of the XVI region enclosed by the dashed line in Figure 4. As shown in Figure 16, the first portion 91 of the internal terminal plate 9 is positioned to contact the tip of the shaft portion 72 of the metal button 7. The internal terminal plate 9 is bent in a second direction β at its lower end, and then bent in a first direction α to form a second portion 92, which makes surface contact with the diaphragm 42 (the spring-shaped portion 43 of the diaphragm 42). More specifically, the second portion 92 makes surface contact with the spring-shaped portion 43 which is integrally formed with the diaphragm 42. As a result, the internal terminal plate 9 maintains stable electrical contact with the metal plate diaphragm 42. In this case, the internal terminal plate 9 is sandwiched between the case 1 and the metal plate (the spring-shaped portion 43 of the diaphragm 42).

[0047] The shaft portion 72 of the metal button 7 is in direct or indirect contact with the metal button pipe 75, which is a metal component. By bringing the internal terminal plate 9, which is in contact with the shaft portion 72, into contact with the diaphragm 42, which functions as GND, a conductive path to GND is secured for the metal button pipe 75 and the multiple metal components connected to the same external terminal plate 8 as the metal button pipe 75, allowing them to be connected to GND collectively. This enhances the GND connection. Although case 1 has a recess 16 on its rear end face for arranging a waterproofing member, as shown in Figure 16, both the internal terminal board 9 and the diaphragm 42, which is a metal plate, are positioned in areas that do not overlap with the recess 16 (areas inside case 1 relative to the recess 16). Therefore, the waterproofing between the back cover member 3 and case 1 is not impaired.

[0048] [Effect] When assembling the watch 100 of this embodiment, the movement is housed in the case 1 and the viewing opening is closed with the crystal member 14. A buffer bezel 5 is placed to cover the outside of the case 1 as a buffer member, and a metal bezel 6 and a metal button pipe 75 (metal buttons 7 attached to the metal button pipe 75), which are metal parts, are attached from the outside via an external terminal plate 8. At this time, the metal bezel 6 is attached to the case 1 by stepped screws 63, and the metal button pipe 75 is attached to the case 1 by screws 74. By screwing the external terminal plate 8 in between the multiple metal parts and the case 1 in this manner, the external terminal plate 8 and the multiple metal parts are fastened together to the case 1.

[0049] The shaft portion 72 of the metal button 7, which is inserted through the insertion hole 77 of the metal button pipe 75, is inserted into the through hole 17 of the case 1, and its tip is positioned inside the case 1. A retaining member 79 is attached to the tip of the shaft portion 72, which is positioned inside the case 1, to prevent the shaft portion 72 from coming loose and falling out of the case 1. In addition, an internal terminal plate 9 is positioned so that the first part 91 contacts the tip of the shaft portion 72.

[0050] Once the components of each part are installed, the opening on the non-visible side is closed with the back cover member 3. At this time, a protective member is placed in the recess 16 of the case 1 to ensure waterproofing between the back cover member 3 and the case 1, and the back cover member 3 is screwed to the case 1. With the back cover member 3 attached, the spring-shaped portion 43 of the diaphragm 42 is positioned below the second portion 92 of the internal terminal plate 9, and the second portion 92 of the internal terminal plate 9 makes secure surface-to-surface contact with the spring-shaped portion 43, which is being pushed up by the elastic body 44, thereby enabling electrical conductivity. By making contact over a surface in this way, stable contact and electrical conductivity can be achieved without being affected by misalignment or other factors. In areas where the spring-shaped portion 43 is not provided, there may be no GND path because the spring-shaped portion 43 is not provided at the end of the internal terminal plate 9. However, multiple metal components are fastened together with the external terminal plate 8 on the outside of the case 1 and are electrically connected to each other. Therefore, if even one of the multiple metal components that are in contact with a single external terminal plate 8 is in contact with the spring-shaped portion 43, all the metal components in contact with that external terminal plate 8 can be electrically connected to GND, thereby strengthening the GND.

[0051] This ensures a conductive path from the multiple externally mounted metal components (metal bezel 6, metal button pipe 75, etc.) to the GND inside the case 1 (diaphragm 42 which functions as GND), allowing multiple metal components to be reliably connected to GND. By connecting the metal component to GND, the sensitivity (performance) of the antenna 13 located inside the clock 100 can be prevented from being affected by the metal component, thereby realizing a highly reliable clock 100 for time correction and other functions using the antenna 13.

[0052] Furthermore, the metal bezel 6, which serves as an exterior component, is attached to the case 1 using stepped screws 63, and a gap C is provided between the metal bezel 6 and the case 1 as a movable space that allows the movement of the metal bezel 6. This makes it possible to absorb the displacement of the metal bezel 6 in the gap C even if the metal bezel 6 is pushed in by an impact such as dropping. This prevents the impact from being directly transmitted to the case 1 or the precision parts inside the case. In addition, by placing a buffer bezel 5 as a cushioning member between the metal bezel 6 and the case 1, the impact can be absorbed and mitigated. For this reason, there is no need to reinforce the case 1 itself with various additives, and there is no impact on antenna performance due to additives.

[0053] [effect] As described above, the electronic device clock 100 in this embodiment is enclosed in a case 1 and comprises a metal part made of metal material, such as the button head 71 and metal button pipe 75 of a metal button 7, a diaphragm 42 which is a metal plate provided inside the back side of the case 1 and functions as a GND, and an internal terminal plate 9 which connects the button head 71 and metal button pipe 75 of the metal button 7 to the diaphragm 42 which is a metal plate. The internal terminal plate 9 is sandwiched between the case 1 and the diaphragm 42 (spring-shaped portion 43 of the diaphragm 42). This allows various metal components to be stably connected to GND via the internal terminal plate 9, even when the diaphragm 42 and other components on the back cover member 3 function as GND. Therefore, especially when the clock 100 is configured in this way as in this embodiment, a stable conductive path can be secured from metal parts such as the metal buttons 7 to the GND function part (diaphragm 42 in this embodiment) inside the case 1, and each metal part can be kept in a state of zero potential difference with GND. This makes it possible to suppress the influence of metal parts on precision equipment inside the clock 100, such as the antenna 13. In addition, the internal terminal plate 9 is stabilized by being sandwiched between the case 1 and the diaphragm 42 (spring-shaped part 43 of the diaphragm 42), which is a metal plate, and is less likely to shift even when subjected to impact.

[0054] Furthermore, the internal terminal plate 9 of this embodiment has a first portion 91 that is connected to a metal component (in this embodiment, the shaft portion 72 of the metal button 7), and a second portion 92 that is bent in a first direction α from the lower end side of the first portion 91, and is formed in a substantially L-shape when viewed from the side, with the second portion 92 making surface contact with the diaphragm 42, which is a metal plate that functions as GND. Therefore, the contact area between the internal terminal board 9 and the diaphragm 42, which acts as GND, is large, allowing for stable conductivity with GND.

[0055] Furthermore, the internal terminal plate 9 of this embodiment has a bent portion 93 that is approximately inverted L-shaped in side view, which protrudes by bending the lower end side of the first portion 91 in a second direction β opposite to the first direction α, and the second portion 92 is formed by bending from the lower end side of the bent portion 93 in the first direction α. In this way, by first bending the material in the opposite direction and then forming the second portion 92 toward the first direction α, the length of the second portion 92 in the first direction α can be increased. As a result, the contact area between the second portion 92 and the diaphragm 42 can be increased, and even if there is some misalignment, reliable conductivity to GND can be ensured.

[0056] Furthermore, Case 1 of this embodiment has a recess 16 on the rear end face for arranging a waterproofing member, and the diaphragm 42, which is a metal plate that functions as an internal terminal board 9 and GND, is arranged in an area that does not overlap with this recess 16. This ensures waterproofing between the case 1 and the back cover member 3, even with the internal terminal board 9 and diaphragm 42 installed.

[0057] In this embodiment, the diaphragm 42, which is a metal plate that functions as a GND, has a spring-shaped portion 43 in all or part of the position corresponding to the internal terminal plate 9. By making the part that contacts the internal terminal plate 9 spring-shaped in this way, the internal terminal plate 9 can be made more stable and conduction to the diaphragm 42 more easily.

[0058] In this embodiment, the elastic body 44 is arranged on the back side of the spring-shaped portion 43. In this embodiment, the diaphragm 42 of the piezoelectric sound-producing unit 4, which functions as GND, is relatively thin in thickness for the purpose of vibrating the piezoelectric body 41, and even if a spring-shaped portion 43 is provided in the shape of a leaf spring, it is difficult to generate the desired load with that alone. Furthermore, when the piezoelectric sound-producing unit 4 is provided on the back cover member 3 as in this embodiment, repeated opening and closing operations are prone to causing poor contact, and even if contact is made and conductivity is established, the contact resistance value may not be stable. In this regard, by providing an elastic body 44 on the back surface of the spring-shaped portion 43 and using the elastic body 44 to push it up, the necessary contact pressure with the internal terminal plate 9 can be secured, and the internal terminal plate 9 and the diaphragm 42 can be reliably connected. Furthermore, even if the opening and closing operation is repeated, the spring-shaped portion 43 is less likely to wear down, and a stable contact resistance can be maintained for a long time. This stabilizes the resistance value of GND and strengthens the GND.

[0059] In this embodiment, an antenna 13 is provided inside the case 1. When a metal component made of a conductive material such as metal is mounted on an electronic device such as a clock 100, it affects the antenna sensitivity of the antenna 13 inside the electronic device. To eliminate the effect on antenna sensitivity, it is necessary to connect the conductive material such as metal to GND and make the potential difference zero. In this embodiment, the internal terminal plate 9, which is connected to the metal component, can be reliably connected to the diaphragm 42, which functions as GND. This allows for a relatively simple configuration that minimizes the impact on antenna 13, enabling highly accurate radio wave reception.

[0060] [Differentiation] Figure 17 is an enlarged cross-sectional view of a key part of a modified version of the clock shown in Figure 2. Figure 17 shows an example in which an internal terminal board according to one modification is applied to the same part as shown in Figure 16. As shown in Figure 17, the internal terminal plate 9a has a first portion 91a that is connected to the metal button 7, and a second portion 92a that is bent in a first direction from the lower end of the first portion 91a. The internal terminal plate 9a is formed in a substantially L-shape when viewed from the side, and the second portion 92a is structured to make surface contact with the metal plate (diaphragm 42 in this embodiment). That is, the first portion 91a of the internal terminal plate 9a is positioned to contact the tip side of the shaft portion 72 of the metal button 7. The internal terminal plate 9a is also bent in a first direction α at its lower end to form the second portion 92a, and this second portion 92a makes surface contact with the diaphragm 42 (spring-shaped portion 43 of the diaphragm 42). Thus, the internal terminal plate 9a has only an L-shape and does not have a bent portion 93. Therefore, the L-shaped internal terminal plate 9a has a first portion 91a and a second portion 92a that are perpendicular to each other. However, since the internal terminal plate 9a is bent in a first direction α at the lower end of the first portion 91a to form the second portion 92a, an R-shape (bend R) is formed at the bending angle between the first portion 91a and the second portion 92a by bending, which is a sheet metal processing that utilizes the ductility of metal. As a result, the internal terminal plate 9a is separated from the case 1 by the amount of this bend R, but by making the double-sided tape 94 that attaches the first portion 91a to the case 1 thicker, the gap created between the first portion 91a and the case 1 by the amount of the bend R is filled. Although embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to these embodiments, and various modifications are possible without departing from the spirit of the invention.

[0061] For example, in this embodiment, we have illustrated a case where the buffer bezel 5, as a buffering member, covers almost the entire case 1, and the metal bezel 6 is positioned at the 3 o'clock and 9 o'clock positions on an analog clock. However, the positions and ranges in which the buffer bezel 5 and metal bezel 6 are provided are not limited to those shown in this embodiment. In this embodiment, the entire metal bezel 6 overlaps the buffer bezel 5, but the metal bezel 6 may only partially overlap the buffer bezel 5.

[0062] In this embodiment, the external terminal board 8 is positioned at the 3 o'clock and 9 o'clock positions of the analog clock and is fastened together with at least one metal bezel 6 and the case 1, respectively. However, the position and range of the external terminal board 8, and the number and type of metal components connected to one external terminal board 8 are not limited to those exemplified in this embodiment. More metal bezels 6 and metal button pipes 75 may be connected to one external terminal board 8. In this case as well, if any one of the metal components connected by the external terminal board 8 is connected to GND, all metal components connected to the external terminal board 8 can be connected to GND.

[0063] Furthermore, in this embodiment, the diaphragm 42 of the piezoelectric sound generation unit 4 is shown as a GND functional part that functions as GND, but the GND functional part can be any metal member provided inside the case 1 and indirectly connected to the external terminal plate 8, and is not limited to the diaphragm 42.

[0064] Furthermore, although this embodiment illustrates a case where the electronic device is a wristwatch-type clock 100, the electronic device is not limited to this. For example, it can be widely applied to electronic devices such as various smartwatches and sports watches, as well as wearable devices that acquire biometric information such as heart rate and blood flow in addition to time.

[0065] Although several embodiments of the present invention have been described above, the scope of the present invention is not limited to the embodiments described above, but includes the scope of the invention as described in the claims and its equivalents. [Explanation of Symbols]

[0066] 1 case 13 Antennas 14 Windshield component 17 Through hole 3. Back cover component 31 Recess 4. Piezoelectric sound-producing unit 42. Diaphragm (GND function part, metal plate that functions as GND) 43 Spring-shaped part 44 Elastic body 5. Buffer bezel (cushioning material) 6. Metal bezel (metal part) 62 Buttock surface 63 Stepped screw (fastening component) 7. Metal buttons (metal parts) 72 Shaft section 74 Screws (fastening components) 75 Metal button pipe (metal part) 8 External terminal board 81 Parts receiving section 9 Internal terminal board 91. First part 92 First part 100 Watches (Electronic Devices) C Gap (movable space)

Claims

1. Metal parts provided in the case, A GND function unit provided inside the aforementioned case, The metal component has an internal terminal that connects to the GND function unit, Equipped with, The aforementioned internal terminal is sandwiched between the case and the GND function unit. An electronic clock characterized by the following features.

2. The internal terminal has a first portion connected to the metal component and a second portion bent in a first direction from the lower end of the first portion, and is formed in a substantially L-shape when viewed from the side. The second portion makes surface contact with the GND functional portion. The electronic clock according to feature 1.

3. The internal terminal has a bent portion that is approximately an inverted L-shape in side view, which protrudes by bending the lower end of the first portion in a second direction opposite to the first direction, and the second portion is formed by bending from the lower end of the bent portion in the first direction. The electronic clock according to feature 2.

4. The case has a recess on the rear side end surface for arranging a waterproofing member, The internal terminal and the GND function section are arranged in a region that does not overlap with the recess. The electronic clock according to feature 1.

5. The GND function unit has a spring-shaped portion in all or part of the position corresponding to the internal terminal, The electronic clock according to feature 1.

6. An elastic body is arranged on the back side of the spring-shaped portion. The electronic clock according to feature 5.

7. An antenna is provided inside the aforementioned case. The electronic clock according to feature 1.

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