Antenna connection device for electronic equipment

An antenna connection device structure for physically and electrically connecting a wristband-embedded antenna to a wristwatch-type receiver is disclosed. A receiver and leaf spring mounted in a casing having an opening, are joined to a wristband-embedded antenna having a connection terminal, by means of a connector. The connector, which has two ends, fits within and extends through said opening so that it closes the opening in a water-tight fashion and makes electrical contact with said leaf spring. The other end attaches to a connection terminal of the wristband-embedded antenna.

BACKGROUND OF THE INVENTION 
The present invention relates generally to an antenna connection device for 
portable electronic equipment, such as, wristwatch-type pagers, radios, 
and televisions. More particularly, this invention relates to an antenna 
connection device structure wherein a wristband-embedded antenna may be 
removably attached to portable electronic equipment while maintaining a 
high degree of water-resistance, durability and strength. 
Portable electronic equipment, such as, wristwatches with built-in 
receivers, often require antennas for proper operation. One previous 
antenna connection device structure useful for attaching an antenna to a 
wristwatch-type receiver required molding of a lead-wire antenna into the 
case of the wristwatch/receiver. Another previous antenna connection 
device structure required that the lead-wire be introduced to the inside 
of the case through an insulator. 
These structures did not provide the desirable qualities of 
water-resistance, solid body strength and durability. Inadequate 
water-proofing of the connection between the antenna and the receiver has 
been a problem. Previous antenna connection structures have made use of 
plated copper or plated copper alloys but they provide poor corrosion 
resistance, particularly where corrosion is accelerated by the presence of 
perspiration or sea water. These previous antenna connection structures 
have also created difficulties with respect to ease of attachment and 
detachment of the wristband due to the complex antenna connection devices. 
Previous antenna connection structures for these wristband-embedded 
antennas have also resulted in wristbands with poor mechanical 
characteristics, particularly poor tensile stress, twisting stress, and 
bending stress characteristics. 
Therefore, a need exists for an antenna connection device suitable for use 
with portable electronic receivers, wherein an antenna may be connected to 
a receiver in such a way that desirable physical characteristics, such as 
body strength and water-resistance, are achieved. There further exists a 
need for an antenna connection device which provides for a 
wristband-embedded antenna having good tensile stress, twisting stress and 
bending stress characteristics, that is also easy and simple to attach and 
detach. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide an antenna connection 
device structure which provides for the qualities and characteristics, 
such as a high degree of water-resistance, corrosion resistance, solid 
body strength, and durability, not previously obtainable. 
It is a further object of the present invention to provide an antenna 
connection device structure which results in a wristband-embedded antenna 
having good tensile stress, twisting stress and bending stress 
characteristics. 
Accordingly, the present invention provides an antenna connection device 
structure for connecting a wristband-embedded antenna to a wristband-type 
receiver. The preferred embodiment comprises a casing which houses a 
receiver, a wristband-embedded antenna plate, and a connection means for 
physically connecting the wristband to the casing, and simultaneously 
electrically connecting the antenna to the receiver. 
The casing is preferably made from an electrically non-conductive material. 
The casing is provided with a hole, or opening, in at least one side to 
facilitate the physical connection between casing and wristband, and the 
electrical connection between the receiver and the antenna. This opening 
has chamfered surfaces which interact with the packing ring to provide a 
water-tight connection. The antenna is preferably embedded in a wristband 
made from an electrically non-conductive material. 
The connection means utilizes a contact spring, a connector, connector 
packing, attachment screws and a connection terminal to make the 
above-described physical and electrical connections. 
The connector is specially shaped so that it may: 1) fit into and through 
the casing opening in a water-tight manner, 2) make physical and 
electrical connection with the contact spring, 3) receive the connection 
terminal to make a physically strong and electrically conductive 
connection. 
To assemble the structure of the present invention, the connector is 
mounted in the casing such that it is fitted into and extends through the 
opening in the casing so that it pushes against a resilient conductive 
member or contact spring. The connector has a packing groove in which a 
connector packing is inserted. The contact spring is disposed between the 
connector and a receiver housed in the casing, thus establishing 
electrical connection between the receiver and the connector. 
A specially-shaped connection terminal serves as a means to attach the 
wristband to the connector. The connection terminal has two ends, one of 
which is attached to a wristband-embedded antenna. The other end of the 
connection terminal is received by, and fixed to, the connector to make a 
physically strong and electrically conductive connection. Attachment 
screws are used to ensure a durable connection to the casing. 
The connection terminal is characterized by being constructed so that it 
attaches to and detaches from the casing by means of a fixing member such 
as attachment screws. 
The antenna plate, the connecting terminal and the connector, are made of a 
highly corrosion resistant alloy such as stainless steel. 
An advantage of the present invention is that the water-tight performance 
has increased markedly. The two atmospheres of water-tightness achieved by 
previous structures has been increased to between five and ten 
atmospheres, greatly increasing the range of applications in which 
portable electronic equipment such as wristwatches can be used. 
A further advantage of the present invention is a reduction in the staining 
of shirts that comes about due to the corrosion of the 
copper-alloy-plating structure used previously for a variety of contacts. 
Because the antenna plate, connection terminal and connector are all 
fabricated from highly corrosion resistant SUS material, corrosion has 
been eliminated, and a major problem affecting product marketability has 
been resolved. 
A further advantage resulting from the present invention is a higher level 
of mechanical strength in the connection between the casing and the 
wristband antenna. In particular the tensile, twisting, and bending 
strength have been improved. 
A further advantage of the present invention is that the number of parts 
has been reduced, compared to prior art devices thus lowering 
manufacturing costs. Further, the casing and band can be injection molded, 
allowing for an excellent mass production capability. 
A further advantage of the present invention is an increase in design 
freedom, particularly the external appearance design. The large practical 
effect, such as allowing a design that makes the casing and band appear to 
be a single unit, comes about because the band attachment area is the 
screw stop and the wristband is fixed firmly to the casing without any 
gaps.

DETAILED DESCRIPTION OF THE INVENTION 
A detailed description of the embodiments is presented with reference to 
the drawings wherein FIGS. 1-3 represent one embodiment, FIG. 4 represents 
a second embodiment, FIG. 5 is common to both described embodiments and 
like reference numerals designate like parts throughout the figures. 
THE COMPONENTS 
Casing 1, shown in FIG. 1, is made from a hard plastic such as a 
polycarbonate resin containing glass fibers, and has a hole, or opening 
1a, in at least one side to facilitate the physical connection between 
casing and wristband, and the electrical connection between receiver and 
antenna. It will be understood by those skilled in the art that a 
transmitter circuit may be housed within the casing just as easily as a 
receiver circuit. Opening 1a, provides chamfered guide surfaces through 
which connector 5, with connector packing 6 already mounted thereon, will 
be smoothly inserted. FIG. 1 also shows the casing front wherein cover 
glass 7 has been pressed into place through water-tight gasket 9 so that 
cover glass 7 is water-tight. Cover glass 7 is preferably made of an 
inorganic glass and water-tight gasket 9 is preferably made of a synthetic 
resin. Back cover 8 is removably attached, over back cover packing 
material 10, to the back of the casing by means of screws 13. The back 
cover packing may be an O-ring, although no waterproofing problems are 
found with D or F type rings. Back cover 8 is preferably made from a 
stainless steel material and the back cover packing material 10 is 
preferably made of synthetic rubber. 
An internal receiver 11, such as one that would be used for a pager, a 
radio or a television is installed inside the casing. A contact, or 
resilient conductive member 12, functioning like a leaf spring, is 
installed within casing 1 such that it is in electrical contact with 
receiver 11 and is physically adjacent to opening 1a in casing 1. 
Resilient conductive member 12, being a leaf spring, makes biased 
connection and contact with connector 5 inserted in opening 1a. Resilient 
conductive member 12 is secured mechanically at the peripheral portion of 
receiver 11 and is connected electrically by contacting the circuit board 
inside the receiver. 
Antenna plate 3 has a thickness of 0.05 mm to 0.2 mm and a width of 10 mm 
to 17 mm. Preferably antenna plate 3, has a low resistance to high 
frequencies and is made of a stainless steel material that has good 
corrosion resistance, such as SUS304. Connection terminal 4 is attached, 
by means of spot welding, to the one end of antenna plate 3 prior to the 
wristband being formed around antenna plate 3. The connection terminals 
are made from the same type of stainless steel as antenna plate 3. 
SUS means stainless steel according to the JIS code. The following table 
compares the JIS code and the ASTM, AISI codes of the United States: 
______________________________________ 
JIS ASTM, AISI 
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SUS 304 AISI 304 
SUS 316L AISI 316L 
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Wristband 2 is made of a synthetic rubber such as polyurethane rubber or 
silicon rubber. Antenna plate 3 is insert-molded in wristband 2 and is a 
single unit in order to make bending possible. An antenna plate made of 
stainless plate material could easily be bent or broken when used by 
itself. However, when it is formed with rubber, its quality is improved, 
and the combined structure can be bent flexibly because stress is 
dispersed in the rubber part. 
Connection terminals 4 each having a flat portion and an angled portion, 
are made of the same type of stainless steel material as antenna plates 3. 
The angled portion is the same width as the antenna plates 3. 
The angle between the flat portion and the angled portion of connection 
terminal 4 is determined as a function of the size of the case and the 
cross sectional size of a human wrist. If the case size is large, the 
angle is large. If the case is small, the angle is small and the angled 
portion reaches closer to the horizontal plane of the flat portion. A 
large human wrist requires that the angle be small (i.e. reaching toward 
the horizontal plane of the flat portion). A small wrist requires the 
angle to be larger to accommodate the quick drop-off from the casing to 
the sides of the wrist. The bending angle is preferably set in the range 
of about 30.degree. to about 60.degree.. 
Connector 5 has a first portion 5b and a second portion 5c, wherein said 
first portion 5b is mounted in casing 1 through opening 1a, and the second 
portion 5c receives wristband connection terminal 4. Connector 5 is 
specially shaped so as to receive connection terminal 4. 
Packing groove 5a is formed on first portion 5b of connector 5. There is no 
corresponding groove on case 1. Connector annular packing 6, which is 
preferably made of synthetic rubber, is an annular sealing ring to seal 
the gap formed between packing groove 5a and casing opening 1a. 
THE ASSEMBLY 
The angled portion of each connection terminal 4 is spot welded to antenna 
plates 3 to form a subassembly. Antenna plate 3 and connection terminal 4, 
after being formed into a single unit by spot welding, are set in a mold 
and wristband 2 is completed by the liquid injection molding of a 
synthetic rubber, such as, polyurethane rubber or silicon rubber. 
The exposed end, i.e. the flat portion, of connection terminal 4 and 
connector 5 are attached so as to form a single unit by means of a 
mechanical connection. Once the mechanical connection between connector 5 
and connection terminal 4 has been made, electrical connection is achieved 
by caulking or welding. Alternatively connection terminal 4 and connector 
5 may be connected together through a stainless steel process such as 
metal injection molding. 
FIG. 2 shows a cross section of that part of wristband 2 that is removably 
attached to casing 1 in the manner of the present invention. Antenna plate 
3, which is insert-molded into the wristband, is fixed permanently into 
place in a manner that allows 20 kilograms or more of pulling force to be 
obtained by the non-linear spot welding of three to six places 4a on lower 
surface of angled section 4b of connection terminal 4. Antenna plate 3 and 
connecting terminal 4, thus form a single unit in the assembly and are 
covered by the synthetic rubber wristband. However, one end 4c of 
connection terminal 4 is exposed and that end is fixed to casing 1. The 
attachment of wristband 2 to casing 1 is accomplished by wristband 
attachment screws 14 which make a secure connection and also provide for 
removal of wristband 2 when necessary. Wristband attachment screws 14 are 
preferably self-tapping screws. 
As shown in FIG. 3, wristband attachment screws 14 are provided in two 
locations, one on either side of connector 5, in a symmetrical arrangement 
transversely to the elongated extent of casing 1. The width of antenna 
plate 3 is the same as that of the spot welded section 4b of connection 
terminal 4, simplifying alignment during spot welding of these two 
components. There are a number of spot welds 4a, but they are not formed 
in co-linear fashion but are formed in an offset fashion. They are divided 
into two rows to provide strength. According to tests conducted, this type 
of connection configuration has provided a tensile strength in the range 
of 20 kilograms to 40 kilograms. Tensile strength in this range has been 
determined to be adequate for application in a wristwatch-type band with a 
built-in antenna. The standard tensile strength of wristwatch bands is in 
the range of 10 kilograms to 15 kilograms when measured by pulling both 
ends. Thus the structure of the present invention provides an improved 
safety margin. 
Connector 5 and connection terminal 4 are preferably fixed in place by 
caulking. Caulking is a mechanically performed permanent securing process. 
In this case, after the axis of connector 5 is set in the aperture of 
connection terminal 4, plastic deformation is performed on the tip of the 
axis to make it larger than the diameter of the aperture so that it is 
permanently secured. However, their mechanical strength and electrical 
properties will last for a long period of time if they are soldered 
together. 
The permanent securing of connector 5 and connection terminal 4 either by 
means of caulking or soldering is performed before wristband 2 is 
removably secured to casing 1 by attachment screws 14. Wristband 2, 
antenna 3, connection terminal 4, connector 5 and packing 6 are assembled 
as one unit and then mounted on casing 1. 
AN ALTERNATIVE EMBODIMENT 
FIG. 4 shows another embodiment of the present invention. In contrast to 
the embodiment of FIG. 1, this embodiment features connection terminal 4 
and connector 5 being manufactured as a single-unit, or integral, 
connection terminal 24 so that greater thinness and compactness of this 
component is achieved. In addition to improving long-term electrical 
reliability, this structure permits reduction in manufacturing and 
assembly costs since there is a reduction in the number of parts. 
In this alternative embodiment, one end of single-unit connection terminal 
24 is connected to antenna plate 23, which is embedded in wristband 22. 
The other end of single-unit connection terminal 24 is constructed with 
manufacturing tolerances such that a water-tight connection is formed by 
the placement of connection terminal 24 surrounded by connector annular 
packing 26 in packing groove 24a into opening 21a of casing 21. Connector 
packing 26 is placed in annular packing groove 24a formed on connection 
terminal 24 so that opening 21a is water-tight after insertion of 
connection terminal 24 therein. In addition, connector terminal 24 may be 
made by means of a metal injection molding process of a material such as 
SUS316L or SUS304. 
CONCLUSION 
In the case of a wristwatch-type receiver, the structures described above 
allow for a wristband with separate built-in antenna plates at the 12 
O'clock and 6 O'clock positions. Such a band will function as a loop 
antenna, enhancing the reception effect. 
While the invention has been described in conjunction with several specific 
embodiments, it will be clear to those skilled in the art, that many 
alternatives, modifications and variations are possible in light of the 
foregoing description. For example, the present invention has been 
described in terms of a wristband being used as an antenna for a miniature 
wristwatch-type receiver. However, the present invention may also be 
applied to the antenna connections of other portable electronic equipment, 
such as a pocket watch or a pendant-type device in a configuration that 
uses a wristband-type antenna on one side or on both sides. The present 
invention is applicable to transmitter equipment as well as receiver 
equipment. The specific embodiments described are illustrative of the 
present invention and not intended as limitations. Thus, the invention 
described herein is intended to embrace all such alternatives, 
modifications, variations and applications as fall within the spirit and 
scope of the subjoined claims.