Field of the Invention
The present invention relates to a wireless apparatus
for wirelessly sending and receiving signals.
Background of the Invention
Up to the present, fire alarms have been popularized
that are devices using sensors disposed on the surfaces of
the walls or ceilings of houses and function to sense smoke
and provide notification to residents (e.g., see Japanese
Unexamined Patent Application Publication No. 2010-39936).
Such a type of alarm includes a smoke sensing unit
configured to sense smoke, a speaker configured to issue the
sound of an alarm, and a circuit board configured such that
the smoke sensing unit and the speaker are connected
thereto, and is thus referred to as a "household fire
alarm." The smoke sensing unit senses smoke that is
introduced via an introductory portion. The speaker is
normally disposed on the front side of the fire alarm, that
is, toward the inside of a room so that the sound of the
alarm can efficiently reach residents. The circuit board,
together with the speaker, is disposed on the indoor side of
the fire alarm so that the line connecting the circuit board
to the speaker does not pass through the above-described

introductory portion and does not interrupt the entry of
smoke {e.g., see Fig. 1 of Japanese Unexamined Patent
Application Publication No. 2010-39936).
In wired connection-type household fire alarms, the
wiring passes through spaces above the ceilings, which is
not suitable for existing houses. On the other hand,
wireless-type fire alarms can be easily installed and can
thus be used in not only existing and newly constructed
houses but can also be used in aggregate buildings.
It is important to design such fire alarms so that
they are unnoticeable in order for a passersby to feel a
sense of incompatibility and so that they are compact. A
design is contemplated in which an antenna for wireless
communication to the outside is contained in a fire alarm
such that it is not exposed, thereby achieving a reduction
in the size of the fire alarm.
When an antenna for wireless communication is
contained in the fire alarm disclosed in Japanese Unexamined
Patent Application Publication No. 2010-39936, it is
considered preferable to dispose the antenna in a space (a
space on the rear side of a circuit board, that is, a space
near the surface of a ceiling or the surface of a wall)
provided as an introductory portion for introducing smoke.
The reason for this is that if the antenna is disposed on
the front side of the circuit board, that is, on the inner
side of a room, it is necessary to ensure a space for the

antenna between the circuit board and the front cover of the
fire alarm and it is difficult to reduce the size of the
fire alarm.
However, when the antenna is disposed on the rear side
of the circuit board, there is concern about the reduction
in the gain of the antenna. The same problem is not limited
to a fire alarm configured to detect smoke, and is common to
a fire alarm configured to detect heat as well as to
wireless apparatuses configured to send and receive signals
when the degree of freedom of the layout of an antenna is
low.
Summary of the Invention
In view of the above, an object of the present
invention is to provide a wireless apparatus for
transmitting and receiving sensing signals via wireless
communication based on radio waves, which is capable of both
achieving the scale-down thereof and improving the gain of
an antenna. Another object of the present invention is to
provide a wireless apparatus, which can realize a small size
so that it is unnoticeable when an event, such as an
abnormality, does not occur, and which can take an
appropriate action in conjunction with another wireless
apparatus when an event, such as an abnormality, occurs.
In accordance with an aspect of the present invention,

there is provided a wireless apparatus including: an
antenna, a circuit board configured to form a wireless
communication circuit that is connected to the antenna, and
a housing configured to accommodate the circuit board and
formed by resin molding, wherein a linear conductor extends
from a ground of the circuit board.
The circuit board may be provided with a concave
cutout portion, the antenna may be disposed on one end side
of the circuit board, and the conductor may extend from the
other end side of the circuit board.
The total electrical length which is a sum of an
overall equivalent electrical length of a wiring pattern and
electrical and electronic circuits on the circuit board,
except for the antenna, and an electrical length of the
conductor may be 1/4 of a wavelength of. a carrier that is
used in wireless communication.
The antenna may be accommodated inside the housing.
The antenna may be disposed between the circuit board
and an attachment surface of the housing.
The conductor may be disposed on a same plane as the
circuit board or may be disposed opposite to the antenna
with the circuit board disposed therebetween.
The conductor may extend along an inside wall of the
housing.
The conductor may extend from the other end side of
the circuit board to one end side thereof.

Ribs adapted to reinforce the housing may be formed on
an inside wall of the housing, the ribs having depressions
adapted to allow the conductor to be fitted thereinto.
A surface of the conductor may be coated with an
insulating coating.
A battery adapted to supply power to the wireless
transmission circuit of the circuit board may be disposed in
the housing, and a front end of the conductor that is not
directly connected to the ground may be directly connected
to a negative electrode of the battery.
In accordance with another aspect of the present
invention, there is provided a wireless abnormality
notification system including a plurality of fire alarms
each including the wireless apparatus as described above and
a sound notification unit configured to issue a sound of an
alarm, wherein any one of the fire alarms that senses a fire
wirelessly communicates with the other fire alarms and
provides notification of the fire to the other fire alarms,
so that a sound notification unit of at least one of the
fire alarms issues a sound to notify the fire.
In accordance with still another aspect of the present
invention, there is provided a wireless remote control
system including: the wireless apparatus as described above,
a receiver configured to receive a wireless signal from the
wireless apparatus, and equipment whose operation is
controlled by the receiver.

In accordance with the present invention, the
conductor extends from the ground of the circuit board, and
thus the ground of the wireless communication circuit is
enhanced, thereby improving the gain of the antenna.
Furthermore, the wireless communication circuit is insulated
from the outside of the wireless apparatus by the housing
formed by the resin molding, and thus the wireless
communication circuit can be protected against an accidental
discharge of static electricity.
Furthermore, the antenna is accommodated inside the
housing, and thus the appearance of the wireless apparatus
can be made simple or improved upon.
Furthermore, the antenna is disposed between the
circuit board and the attachment surface of the housing,
that is, on the rear side of the circuit board, and thus the
front side of the circuit board can be made compact.
Furthermore, components other than the antenna may be
disposed between the circuit board and the attachment
surface of the housing. Accordingly, the degree of freedom
of the layout of parts within the housing can be increased.
Furthermore, the conductor is disposed in the same
plane as the circuit board or is disposed opposite to the
antenna with the circuit board disposed therebetween, and
thus it is possible to avoid the interference between the
conductor and the antenna while reducing the size of the
wireless apparatus.

Furthermore, the conductor that forms the ground of
the wireless communication circuit extends along the inside
wall of the housing, and thus the ground can be efficiently
enhanced regardless of the limited size of the housing.
Furthermore, the conductor extends from the other end
side of the circuit board to one end side thereof, and thus
the ground of the wireless communication circuit can be
further enhanced.
Furthermore, the conductor can be securely held with
the simple configuration while increasing the strength of
the housing, and the reliability of the wireless apparatus
is increased.
Furthermore, the coating formed on the surface of the
conductor can reliably insulate the conductor from other
electrical configurations, and the reliability of the
wireless apparatus is increased.
Furthermore, the front end of the conductor connected
to the ground of the wireless communication circuit is
directly connected to the negative electrode of the battery,
thereby simplifying the configuration of the wiring of the
circuit board and also achieving a reduction in the cost.
Furthermore, when any one of the fire alarms senses a
fire, the sound notification units of the other fire alarms
issue a large sound to notify the fire, so that notification
of the fire can be provided immediately after the fire has
occurred. Furthermore, even a small-sized fire alarm can

increase the gain of the antenna, and thus the reliability
of wireless communication can be sufficiently ensured.
Furthermore, it is possible to increase the gain of
the antenna of the wireless apparatus while reducing the
size of the wireless apparatus, thereby sufficiently
ensuring the reliability of wireless communication between
the wireless apparatus and the receiver and also accurately
controlling the operation of the equipment.
Brief Description of the Drawings
Fig. 1 is a perspective view showing the use of a fire
alarm in which a wireless apparatus in accordance with the
present invention is contained;
Fig. 2 is an assembly perspective view showing the
configuration of a fire alarm which contains a wireless
apparatus in accordance with a first embodiment of the
present invention;
Fig. 3 is a plan view showing the configuration of the
fire alarm;
Fig. 4 is a sectional view showing the configuration
of the fire alarm;
Fig. 5 is an assembly perspective view showing the
configuration of a fire alarm in which a wireless apparatus
is contained in accordance with a second embodiment of the
present invention;

Fig. 6 is a plan view showing the configuration of the
fire alarm;
Fig. 7 is a diagram showing the configuration and
operation of a wireless abnormality notification system
using the wireless apparatus of the present invention;
Fig. 8 is a diagram showing the configuration and
operation of a wireless remote control system using the
wireless apparatus of the present invention;
FIG. 9 is a perspective view showing the use of a
human body sensor which contains a wireless apparatus in
accordance with the present invention;
FIG. 10 is a front view showing the configuration of a
human body sensor in accordance with a third embodiment of
the present invention, with its cover removed;
FIG. 11 is a sectional view showing the configuration
of the peripheral portion of the housing of the human body
sensor;
FIG. 12 is a front view showing the configuration of a
human body sensor in accordance with a third embodiment of
the present invention, with its cover removed; and
FIG. 13 is a front view showing the configuration of
an electronic apparatus which contains the wireless
apparatus, which is a modified example of the prevent
invention, with its cover removed.

Detailed Description of the Preferred Embodiments
(First Embodiment)
A fire alarm configured using a wireless apparatus in
accordance with a first embodiment of the present invention
will now be described. A fire alarm 1 uses a battery as a
power source, and senses smoke to send a sensing signal via
wireless communication based on radio waves. As shown in
Fig. 1, the fire alarm 1 is attached, for example, onto the
surface of a ceiling with a double-sided adhesive tape, an
adhesive, screws or the like. Although in the drawing, the
fire alarm 1 is illustrated as being provided on the surface
of the ceiling, it may be provided on the surface of a wall.
Fig. 1 illustrates a situation in which the wireless
household fire alarm 1 and an indoor intercom unit 100
communicate with each other via a wireless connection.
Here, the indoor intercom unit 100 may be communicatively
connected to a sub-main unit or the like via a wired
connection using an intercom line or a power line, rather
than via wireless communication. Here, for the sake of
shortening the description, the indoor intercom unit 100
will be described not as a sub-main unit but a main unit.
The main unit 100 provided on the surface of a wall is
provided with a wireless reception unit that receives a
sensing signal from the fire alarm 1. When the fire alarm 1
senses smoke, it issues the sound of an alarm and sends a

sensing signal. The sensing signal sent by the fire alarm 1
is received by the main unit 100 of an intercom and then
sent to one or more subsidiary units (not shown) that are
provided in respective rooms. When the main unit 100 and
subsidiary unit of the intercom receive a sensing signal,
they operate while issuing a large alarm sound, thereby
notifying residents of the occurrence of a fire.
Figs. 2, 3 and 4 show the configuration of the fire
alarm 1. The fire alarm 1 includes a smoke sensing unit 2,
a circuit board 3, a speaker 4, an antenna 5, a battery 6, a
first housing 7, a second housing 8, an attachment base 9, a
front cover 10, and a conductor 11. Fig. 3 shows the fire
alarm 1 with the base 9 and the second housing 8 removed,
which is viewed from the rear side thereof.
The antenna 5 and the conductor 11 are formed of
linear conductors, and extend from approximately opposite
corners of the circuit board 3 along the inner
circumferential surface of the first housing 7. The antenna
5 is disposed on the rear side of the circuit board 3. The
conductor 11 is disposed in the same plane as the circuit
board 3 or on the front side of the circuit board 3.
The smoke sensing unit 2 is disposed on the rear side
of the circuit board 3, and senses smoke and then outputs an
electrical signal. The configuration of the smoke sensing
unit 2 is equivalent to that disclosed in Japanese
Unexamined Patent Application Publication 2010-39936, and

thus a description thereof will be omitted.
A control unit or a wireless transmission circuit is
formed on the circuit board 3. The control unit causes the
speaker 4 to issue a loud sound, or controls the wireless
transmission circuit in response to the electrical signal
output from the smoke sensing unit 2. Since the wireless
transmission circuit includes an oscillation circuit, etc.,
it generates carrier waves at a predetermined frequency,
superimposes a sensing signal on the carrier signal and then
sends the carrier signal. Terminals 3a and 3b to which the
antenna 5 and the conductor 11 are connected are provided at
ends of the circuit board 3. The terminal 3a is connected
to the wireless transmission circuit, and the terminal 3b is
connected to the ground of the circuit board 3.
The speaker 4 is disposed near the front cover 10,
that is, on the inner side of the fire alarm 1 mounted on
the surface of a ceiling or the surface of a wall. The
speaker 4 is provided in approximately the same plane as the
circuit board 3. Accordingly, a connection line that
connects the circuit board 3 to the speaker 4 can be
disposed in front of the partition 7y of the first housing
7, and the inflow of smoke into the smoke sensing unit 2 is
not disrupted.
The antenna 5 is connected to the terminal 3a at the
base portion 5a thereof, is erected to be approximately
perpendicular to the circuit board 3, is bent at

approximately 90 degrees in parallel with the circuit board
3, is curved along the circumferential wall of the first
housing 7, and then is bent not to interfere with the
battery 6 and the smoke sensing unit 2. The distance
between the portions of the antenna 5 and the circuit board
3 which are in parallel is approximately established so that
desired gain can be achieved.
The antenna 5 is disposed in an introductory portion
7e behind the partition 7y of the first housing 7. That is,
the antenna 5 is attached to the circuit board 3, and is
disposed between the circuit board 3 . and the mounting
surface of the base 9. The base portion 5a of the antenna 5
is inserted through a hole 7d formed in the first housing 7
to the front, and is then connected to the terminal 3a. A
screw or the like (not shown) is used to connect the base
portion 5a with the terminal 3a, if desired. The battery 6
is mounted on a battery seat 8a of the second housing 8, and
supplies power to the components. The length of the antenna
5 is preferably set such that the electrical length thereof
is about 1/4 of the wavelength X (lambda) of a carrier that
is used in wireless communication.
The first housing 7 has a slit 7a configured to allow
the outside of the fire alarm 1 to communicate with the
introductory portion 7e, an opening 7c configured to insert
the smoke sensing unit 2 through the introductory portion
7e, an opening 7b configured to avoid the interference of

the battery 6, and a hole 7d configured to allow the base
portion 5a of the antenna 5 to pass therethrough. The slit
7 a is formed through the circumferential wall 7x of the
first housing 7, and the opening 7b, the opening 7c and the
hole 7d are formed through the partition 7y of the first
housing 7. The internal space of the fire alarm 1 is
partitioned into a front side and a rear side by the
partition 7y. The second housing 8 has the battery seat 8a
configured such that the battery 6 is mounted thereon and a
depression 8b configured to avoid the interference of the
smoke sensing unit 2. The space surrounded by the first
housing 7 and the second housing 8 forms the introductory
portion 7e that introduce smoke to a location near the smoke
sensing unit 2. Furthermore, ribs 7z adapted to reinforce
the first housing 7 are appropriately provided on the inside
surface of the circumferential wall 7x.
The attachment base 9 has an attachment surface that
allows the fire alarm 1 to be attached on the surface of a
ceiling or the surface of a wall. Furthermore, when the
battery 6 is replaced, the body portion of the fire alarm 1
is separated by separating the second housing 8 from the
attachment base 9, thereby facilitating access to the
battery 6. The front cover 10 is mounted on the front of
the first housing 7. Slits 10a adapted to efficiently
transmit the sound of the speaker 4 are provided in the
front cover 10. Furthermore, a housing including the first

housing 7, the second housing 8, the attachment base 9 and
the front cover 10 is formed by resin molding in order to
insulate the circuit board 3 from the outside of the fire
alarm 1 and protect the circuit board 3 against the entry of
an accidental discharge of static electricity.
The conductor 11 is a so-called counterpoise and is
connected to the ground of the circuit board 3 via the
terminal 3b. A screw or the like {not shown) is used to
connect the conductor 11 to the terminal 3b, if desired.
Accordingly, the conductor 11 extends from the ground of the
circuit board 3. The conductor 11 is disposed in the same
plane as the circuit board 3. If there is a space between
the circuit board 3 and the front cover 10, the conductor 11
may be disposed opposite to the antenna 5 in front of the
circuit board 2, that is, with the circuit board 3 disposed
between the conductor 11 and the antenna 5. Furthermore,
the conductor 11 extends along the inside surface of the
circumferential wall 7x of the first housing 7, and is
inserted into and maintained in depressions 7f formed in the
ribs 7z provided on the inside of the circumferential wall
7x. Here, since the electrical length from one end of the
circuit board 3 to the other end thereof is designed to
correspond to 1/4 (quarter wavelength) of the wavelength X
of a carrier for a wireless signal, it is preferable that,
in a well-known antenna gain test, the length of the
conductor 11 is made variable and by using the length of

conductor 11 as a parameter, the length of the conductor 11
is determined such that the carrier for the wireless signal
can be received in excess of a prescribed reception level in
terms of design. The circuit board 3 (of course, except for
the conductor 11) designed as described above is configured
such that the total electrical length which is the sum of
the overall equivalent electrical length of a wiring pattern
and electric and electronic circuits on the circuit board 3
and the electrical length of the conductor 11 is equivalent
to 1/4 (quarter wavelength) of the wavelength of a carrier
that is used in wireless communication.
In accordance with the fire alarm 1 configured as
described above, the conductor 11 extends from the ground of
the circuit board 3, and thus the ground of the circuit
board 3 is enhanced, thereby enhancing the gain of the
antenna 5. Furthermore, the circuit board 3 is insulated
from the outside of the fire alarm 1 by the first housing 7,
the second housing 8, the attachment base 9 and the front
cover 10 formed by resin molding, thereby protecting the
fire alarm 1 against the entry of an accidental discharge of
static electricity.
Furthermore, the antenna 5 is accommodated in the
first housing 7, the second housing 8, the attachment base 9
and the front cover 10, and thus the appearance of the fire
alarm 1 is simplified and refined. Furthermore, the antenna
5 is attached to the circuit board 3 and disposed between

the circuit board 3 and the mounting surface of the base 9,
thereby allowing the front side of the circuit board 3 to be
compact. Furthermore, in the case in which it is necessary
to attach a component (for example, the smoke sensing unit
2) to the circuit board 3 and dispose the component between
the circuit board 3 and the attachment surface of the base 9
in addition to the antenna 5, it is possible to accommodate
the component together with the antenna 5. Accordingly, the
degree of freedom of the layout of parts in the housing can
be increased.
Furthermore, the conductor 11 is disposed in the same
plane as the circuit board 3, or is disposed opposite to the
antenna 5 with the circuit board 3 disposed therebetween,
and thus the size of the fire alarm 1 can be reduced and the
interference between the conductor 11 and the antenna 5 can
be prevented. Furthermore, the conductor 11 that forms the
ground of the circuit board 3 extends along the inside wall
pf the first housing 7, and thus the ground can be
efficiently enhanced in spite of a limited housing size.
Furthermore, the ribs 7z adapted to reinforce the
first housing 7 are formed on the inside of the
circumferential wall 7x and the depressions adapted to
maintain the conductor 11 are formed in the ribs 7z, so that
the strength of the first housing 7 can be increased with
the simple configuration thereof and the conductor 11 can be
reliably maintained, which increases the reliability of the

fire alarm 1.
(Second Embodiment)
Figs. 5 and 6 show a fire alarm using a wireless
apparatus in accordance with a second embodiment of the
present invention. The fire alarm 50 of the second
embodiment is different from the fire alarm 1 of the first
embodiment in that the former senses heat and the latter
senses smoke.
The fire alarm 50 includes a heat sensing unit 52, a
circuit board 3, a speaker 4, an antenna 5, a battery 6, a
housing 58, an attachment base 9, a front cover 10, and a
conductor 11. Furthermore, Fig. 6 shows the fire alarm 50
with the base 9 and the housing 58 having been removed,
which is viewed from the rear side thereof.
The antenna 5 and the conductor . 11 are formed of
linear conductors, and extend from approximately opposite
corners of the circuit board 3 along the inner
circumferential surface of the housing 58. The antenna 5 is
disposed on the rear side of the circuit board 3. The
conductor 11 is disposed in the same plane as the circuit
board 3 or on the front side of the circuit board 3.
The heat sensing unit 52 is disposed on the front side
of the circuit board 3, and senses heat and then outputs an
electrical signal.
A hole 10b adapted to allow the heat sensing unit 52
to protrude and a guard portion 10c adapted to protect the

tip of the heat sensing unit 52 are formed on the front
cover 10. In this embodiment, the heat sensing unit 52 is
exposed to the outside of the front cover 10, and thus the
introductory portion 7e adapted to introduce smoke is not
necessary, with the result that the first housing 7 having
the slit 7a is omitted. Since the dispositions and shapes
of the antenna 5 and the conductor 11 in the fire alarm 50
of the second embodiment are the same as those in the fire
alarm 1 of the first embodiment, descriptions thereof will
be omitted.
An example of the use of this embodiment will now be
described with reference to Fig. 7. The wireless
transceiver of this embodiment is used for a specific type
of wireless apparatuses Xn (n is a natural number). The
specific type of wireless apparatuses Xn includes at least
one type of environmental measurement sensors selected from
among a variety of types of environmental measurement
sensors Sm {m is a natural number) , including optical
sensors SI, heat sensors S2, chemical sensors S3, and
pressure sensors S4, • • •. The wireless apparatuses Xn are
some types of sensors that have sensing functionality
capable of sensing changes in areas near the locations at
which they are installed after they have been attached to
the surface of a ceiling or the surfaces of walls and send
radio waves to other wireless apparatuses Xn when sensing
the changes in the surrounding environment so that the other

wireless apparatuses Xn can become aware of the changes.
Here, the types of environmental measurement sensors Sm are
not necessarily uniform, but may vary for the wireless
apparatuses Xn.
For example, the wireless apparatus XI solely
activates its own wireless transceiver at specific reception
intervals. Furthermore, if the wireless apparatus XI cannot
receive a first type of wireless signal Sigl having a finite
time length from any one of the other wireless apparatuses
X2, X3, X4, and ■ • •, the wireless apparatus XI immediately
stops its own wireless transceiver, thereby preventing the
power of a battery from being consumed. Meanwhile, if the
wireless apparatus XI can receive the first type of wireless
signal Sigl, the wireless apparatus XI sends a second type
of wireless signal Sig2 indicative of the fact that a first
type of wireless signal Sigl could be received from its own
wireless transceiver. The second type of wireless signal
Sig2 is indicative not only of the fact that a first type of
wireless signal Sigl could be received, but also of the
purport of the transmission of the first type of wireless
signal Sigl to a plurality of other unspecified wireless
apparatuses X2, X3, X4, and • • •.
As illustrated in Fig. 7, these wireless apparatuses
Xn have at least one of a display notification unit XI00
adapted to appeal to a humans' visual sensation and a sound
notification unit (speaker) XI01 adapted to appeal to the

ear. When any one of the wireless apparatuses Xn (in Fig.
7, the wireless apparatus XI) senses an abnormality in the
surroundings, the wireless apparatus Xn activates the
display notification unit X100 or the sound notification
unit X101, thereby providing notification of the occurrence
of the abnormality, and also sends the first type of
wireless signal Sigl.
All the wireless apparatuses except for the wireless
apparatus that received the corresponding first type of
wireless signal Sigl (in Fig. 7, only the wireless apparatus
X2 closest to the wireless apparatus XI} receive the
corresponding first type of wireless signal Sigl, and
perform address analysis thereon. Furthermore, a second
type of wireless signal Sig2 is sent to the other wireless
apparatuses that have not received the corresponding first
type of wireless signal Sigl (in Fig. 7, the wireless
apparatuses X3 and X4, other than the wireless apparatuses
XI and X2).
Thereafter, the wireless apparatus X3 that has
received a second type of wireless signal Sig2 sends a
second type of wireless signal Sig2 to the wireless
apparatus X4 (the reason for this is to, in the wireless
apparatus X3, prevent it from being determined whether the
second type of wireless signal Sig2 sent from the wireless
apparatus X2 could have been received by the wireless
apparatus X4.

Accordingly, not only the one wireless apparatus XI
that first sensed the occurrence of an abnormality but also
the grouped wireless apparatuses XI, X2, X3 and X4 all
operate in conjunction with each other, and may notify the
surroundings of the occurrence of the abnormality. Examples
of the wireless communication system for providing
notification of the alarm include a household fire alarm (a
fire alarm having a sound notification unit) and a system
thereof {a wireless abnormality notification system). This
system may be of a wireless communication type that provides
notification in the above-described wireless transmission
sequence, or of a wireless communication type that
communicates in time division slots using the same carrier
frequency. Furthermore, it may be of a wireless
communication type that performs transmission in a multi-hop
manner.
Furthermore, the wireless transceiver related to the
present invention may be applied not only to the above-
described surrounding monitoring system using the wireless
sensor group, but also to the wireless transmitter Yl and
wireless receiver Y2 of the wireless remote control system
such as that shown in FIG. 8. This wireless transmitter Yl
has at least transmission functionality of the wireless
transceiver related to the present invention, and also
includes an object sensor YS capable of sensing the approach
of an object, such as a human body or an obstacle, in a

contact or non-contact manner. The wireless receiver Y2 has
at least reception functionality of the wireless
transceiver, and also includes equipment control
communication means YC. The equipment control communication
means YC performs remote communication, having weak
possibility of interfering with wireless communication with
the wireless transmitter, with an air conditioning
apparatus, a lighting apparatus, an equipment power source,
or equipment responsible for the handling of an environment
in a specific place. Signals may be sent between the
equipment control communication means YC and the equipment
via a wired connection or a wireless connection.
The wireless transmitter that has sensed the approach
of a human body or an obstacle thereto using the object
sensor YS sends a wireless signal Sig3 indicative of the
sensing of the object sensor YS to the wireless receiver Y2
by operating the wireless transceiver. The wireless
receiver Y2 that has received the wireless signal Sig3
remotely controls equipment control communication means YC
via an equipment control algorithm (which may perform only
ON and OFF of the power source of equipment, such as an air
conditioning apparatus or a lighting apparatus) that was
applied to the equipment control communication means YC in
advance. That is, the wireless receiver Y2 selects target
equipment from among a group of equipment including an air
conditioning apparatus, a lighting apparatus and an

equipment power source, determines the operating mode of the
target equipment in accordance with the received wireless
signal Sig3, and performs remote control of the equipment
based on the results of the selection and the determination.
Furthermore, in this case, the wireless receiver Y2
may send an answerback signal Sig4 indicative of the
successful reception or the analysis of content to the
wireless transmitter Y from its wireless transceiver. In
this case, each of the wireless transmitter Yl and the
wireless receiver Y2 needs to have wireless transmission
■functionality and wireless reception functionality, and, for
example, the wireless transceiver may employ different
frequencies for transmission and reception as carrier
frequencies that carry wireless signals.
Furthermore, the present invention is not limited to
the configuration of the embodiment, but at least the
conductor 11 may extend from the ground of the circuit board
3. Furthermore, in the circuit board 3, the wireless
transmission circuit is responsible for the function of
sending the sensing signal of the smoke sensing unit 2 via
wireless communication based on radio waves, and a variety
of modifications may be made depending on the purposes. For
example, in the case in which the wireless apparatus of the
present invention is applied to a wireless apparatus
requiring wireless reception functionality (in the above-
described embodiment, the main unit 100 of the intercom or

the like), a wireless reception circuit may be provided in
place of the wireless transmission circuit. Furthermore, an
apparatus requiring wireless transmission and reception
functions are preferably provided with wireless transmission
and reception circuits. This means that targets to which
the conductor 11 of the present invention is applied may be
not only a wireless receiver but also a wireless transmitter
and may also be widely applied to wireless transceivers,
such as a typical wireless apparatus in which the degree of
freedom of the layout of an antenna is low.
Furthermore, the length of the conductor 11 may be
appropriately determined depending on the frequency. For
example, the conductor 11 may extend from one end of the
rectangular circuit board 3 to the other end thereof. Using
this configuration, the further enhancement of the ground of
the circuit board 3 is made possible. Furthermore, an
insulating coating may be applied to the surface of the
conductor 11, if desired. Using this configuration, the
conductor 11 can be reliably insulated from the other
electrical configurations and the reliability of the fire
alarm is also improved by the coating formed on the surface
of the conductor 11.
Furthermore, the front end of the conductor 11 that is
not connected to the ground terminal 3b may be directly
connected to the negative electrode of the battery 6. With
"such configuration, the front end of the conductor 11 that

is connected to the ground of the circuit board 3 is
directly connected to the negative electrode of the battery
6, so that the configuration of the wiring on the circuit
board 3 can be simplified and a reduction in cost can be
achieved.
Furthermore, the length of the ground can be increased
by winding the conductor 11 around a spirally shaped object
or forming the conductor 11 in a meandering shape along the
inside wall of the first housing 7. Furthermore, the
connection between the conductor 11 and the ground is not
limited to a connection using a screw, but may be a
connection that uses a connector or a connection formed
using soldering.
Furthermore, the wireless apparatus is not limited to
the shape in which it is contained in the above-described
disk-shaped fire alarm, but may be widely applied to, for
example, typical box-shaped electronic apparatuses having
wireless communication functionality.
(Third Embodiment)
A human body sensor employing a wireless apparatus in
accordance with a third embodiment of the present invention
will be described. The human body sensor 201 uses a battery
as its power source and sends sensing signals via wireless
communication based on radio waves, like the fire alarm 1 of
the above embodiment. As shown in FIG. 9, the human body
sensor 201 is attached to, for example, a ceiling using

double-sided adhesive tape, an adhesive, or a screw. A
switch 2 02 provided on the surface of a wall is provided
with a wireless reception unit adapted to receive a sensing
signal from the human body sensor 201. Furthermore, the
switch 202 is connected to a lighting apparatus 203 provided
on the ceiling via an electric line 204.
The switch 202 is, for example, an electronic switch
(load control device) using a noncontact switch device such
as a triac, and may replace a conventional two-wire switch
that mechanically switches between contacts, without
requiring wiring work. In line with this, the human body
sensor 201 may be also installed additionally in an existing
house without requiring wiring work. The human body sensor
201 and the switch 202 may communicate with each other, via,
for example, wireless communication based on radio waves,
such as a specific low-power wireless communication.
Accordingly, when the presence of a human is sensed by the
human body sensor 201, a sensing signal is sent to the
switch 2 02 and then the switch 202 turns on the lighting
apparatus 203. Furthermore, when the presence of a human is
not sensed anymore by the human body sensor 201, a non-
sensing signal is sent to the switch 202 after the passage
of a predetermined amount of time and then the switch 2 02
turns off the lighting apparatus 203.
Fig. 10 shows the configuration of an example of the
human body sensor 201 with the cover of the human body

sensor 201A removed. This human body sensor 201A is
attached to a ceiling using double-sided adhesive tape, as
described above. The housing 210 is approximately circular
in shape when viewed from the front thereof. The housing
210 is formed by resin molding in order to insulate the
wireless transmission unit 225 from the outside of the human
body sensor 201A and to protect the wireless transmission
unit 22 5 against the entry of an accidental discharge of
static electricity. A sensor unit 211 formed of an infrared
sensor, or an illuminance sensor is provided at the center
of a mounting surface 210a of the housing 210 (opposite to
the surface attached onto the ceiling using the double-sided
adhesive tape) . The sensor unit 211 is, for example,
circular in shape when viewed from the front thereof.
Furthermore, a circuit board 220 and a battery 212 are
mounted on the mounting surface 210a.
Part of the periphery of the circuit board 220 is
rounded to correspond with the circular shape of the housing
210, and the remaining part thereof is cut out at right
angles to avoid the sensor unit 211 and the battery 212.
That is, the circuit board 220 has first and second sides
221 and 2 22 which are perpendicular to each other, and the
portion in which the first and second sides 221 and 222 form
right angles is a cutout portion. Furthermore, the first
and second sides 221 and 222 are disposed on the mounting
surface 210a to be approximately equidistant to the sensor

unit 211 (in the example of Fig. 10, to approximately
circumscribe the circle of the sensor unit 211). Since the
sensor unit 211 and the battery 212 having large heights can
be disposed in the cutout portion of the circuit board 220
as described above, it is easy to suppress the height of the
human body sensor 201A.
The circuit board 220 includes a wireless transmission
unit (wireless communication circuit) 225 configured to send
a sensing signal of the sensor unit 211 via wireless
communication based on radio waves, a sensor unit 211, a
control unit 22 6 configured to control the wireless
transmission unit 225, and a manipulation unit 227
configured to check whether radio waves can be correctly
sent when the human body sensor 21A is installed.
The control unit 22 6 is formed of, for example, a CPU
configured to perform computation, ROM configured to store a
control program, or RAM configured to temporarily store the
results of computation. The control unit 226
comprehensively evaluates the results of the sensing of the
sensor unit 211, more specifically the fact that an infrared
sensor senses infrared rays at a specific wavelength or does
not sense them, or the fact that it is determined by a
illuminance sensor that the surrounding brightness is equal
to or greater than a specific luminance, or is lower than
the specific luminance, and determines whether to send a
predetermined sensing signal or a non-sensing signal based

"on the results of the evaluation. The wireless transmission
unit 225 converts the sensing signal or non-sensing signal
sent from the control unit 226 into a radio wave signal at a
predetermined frequency, and sends the resulting signal via
the antenna 225a. The antenna 225a may be rotated around a
horizontal shaft provided on the housing 210.
Furthermore, the wireless transmission unit 225 is
provided with an oscillation circuit, so that it generates
carrier radio waves at a predetermined frequency and then
sends the carrier signal and the sensing signal with the
sensing signal superimposed on the carrier signal. The
manipulation unit 227 includes an operation mode switch 227a
configured to switch between a common use mode and a
registration mode upon making a new setting or changing the
settings, a brightness setting trimmer 22 7b configured to
set the brightness of a surrounding environment by
automatically controlling the turning on and off of the
lighting apparatus 203 based on the human body sensor 201A,
a lighting time setting switch 227c configured to turn on
the lighting apparatus 203 for a predetermined time period
after the presence of a human is not sensed by the human
body sensor 201A, and a determination switch 227d and a
registration switch 227e configured to be used in
registration mode.
Meanwhile, an increase in the length of a ground
formed on the circuit board 220 is effective at reducing the

size of the housing 210 of the human body sensor 201A and
suppressing any reduction in the gain of the antenna.
However, while reducing the size of the housing 210 as is
required, it is necessary to concurrently enhance the ground
of the wireless transmission unit 22 5 within the size
confines of the circuit board 220. In this embodiment, the
ground is enhanced by disposing the antenna 225a on one end
side 220a and drawing the conductor 229 connected to the
ground terminal (connector) 22 8 of the circuit board 220
from the other end side 220b, with the cutout portion of the
circuit board 220 being disposed therebetween. That is,
since the ground terminal 228 is connected to the ground on
the other end side 220b of the circuit board 220, the ground
of the wireless transmission unit 225 extends up to the
front end of the conductor 22 9 to be formed throughout
approximately entire circumference of the inside wall of the
housing 210. Accordingly, the ground of the wireless
transmission unit 225 is enhanced, thereby improving the
gain of the antenna 225a. Furthermore, the length of the
antenna 22 5a is preferably set such that the electrical
length is approximately 1/4 of the wavelength X (lambda) of
a carrier that is used in wireless communication.
The conductor 229 is a so-called counterpoise and
extends from the other end 220b of the circuit board 220 to
one end 220a thereof along the inside wall of the housing
210. Accordingly, in the housing 210 having a limited size.

the length of the conductor 22 9 can be maximally achieved
and the ground of the wireless transmission unit 225 can be
efficiently enhanced. Here, since the electrical length
from the other end 220b of the circuit board 220 to one end
22 0a thereof is designed to correspond to 1/4 (quarter
wavelength) of the wavelength X of a carrier for a wireless
signal, it is preferable that, in a well-known antenna gain
test, the length of the conductor 229 is made variable and
by using the length of the conductor 229 as a parameter, the
length of the conductor 22 9 is determined such that the
carrier for the wireless signal can be received in excess of
a prescribed reception level in terms of design. The
circuit board 220 (of course, except for the conductor 229)
designed as described above is configured such that the
total electrical length which is the sum of the overall
equivalent electrical length of a wiring pattern and
electric and electronic circuits on the circuit board 220
and the electrical length of the conductor 229 is equivalent
to 1/4 (quarter wavelength) of the wavelength of a carrier
that is used in wireless communication.
Fig. 11 shows the circumferential portion of the
housing 210 and the section of the conductor. Ribs 210b are
formed along the circumferential portion of the housing 210
at appropriate intervals. The ribs 210b are extended from
the mounting surface 210a of the housing 210 and across the
inside wall 210c of the circumferential portion, thereby

increasing the strength of the housing 210. Furthermore,
depressions 210d adapted to maintain the conductor 22 9 are
formed in the portions where the ribs 210b and the inside
wall 210c are joined to each other.
The conductor 22 9 includes a metallic line 22 9a and an
insulating coating 229b formed on the surface of the
metallic line 229a. The insulating coating 229b prevents a
short circuit of the metallic line 229a with other
electrical configurations. Furthermore, the width of the
depressions 210d formed in the ribs 210b is the same or
slightly smaller than that of the conductor 229.
Accordingly, the conductor 22 9 is press-fitted into the
depressions 210d and thus the conductor 229 is securely
retained therein, thereby increasing the reliability of the
function of improving the gain of the antenna 225a.
In the human body sensor 2 01A of this embodiment, the
wireless transmission unit 225 is responsible for the
transmission function of sending a sensing signal of the
sensor unit 211 via wireless communication based on radio
waves, and may vary depending on its purpose. For example,
when the wireless apparatus of the present invention is
applied to a wireless apparatus (in the above-described
embodiment, switch 2 02) requiring wireless reception
functionality, a wireless reception unit (wireless
communication circuit) may be preferably used as a
substitute for the wireless transmission unit 225.

Furthermore, in an apparatus requiring both wireless
transmission functionality and wireless reception function,
the wireless transmission unit 225 and the wireless
reception unit may be preferably provided. This means that
targets to which the conductor 22 9 of the present invention
is applied may be not only a wireless receiver but also a
wireless transmitter, may be wireless transceivers, and the
conductor 229 of the present invention may also be widely
applied to general wireless apparatuses.
{Fourth Embodiment)
Fig. 12 shows a human body sensor 201B using a
wireless apparatus in accordance with a fourth embodiment.
In the human body sensor 201B, a conductor 229 is directly
connected to the negative electrode of the battery 212.
That is, a terminal 229c that is connected to the negative
electrode of the installed battery 212 is provided on the
front end of the conductor 22 9 that is not connected to a
ground terminal 228.
In accordance with the human body sensor 201B of the
fourth embodiment, the front end of the conductor 22 9 is
directly connected to the negative electrode of the battery
212, and thus it is not necessary to provide a separate
conductor that connects the negative electrode of the
battery 212 with the ground of the circuit board 22 0.
Accordingly, the configuration of the human body sensor can
be simplified, and the cost can be reduced.

Furthermore, the present invention is not limited to
the configuration of the present embodiment, but may be at
least configured such that an antenna 225a is disposed on
one end side 220a of the circuit board 220 and the conductor
229 connected to the ground of the circuit board 220 extends
from the other end side 220b thereof, with the cutout
portion of the circuit board 220 being disposed
therebetween.
Furthermore, the present invention may be variously
modified, and thus the length or shape of the conductor that
extends the ground may be selected depending on the
wavelength of radio waves that are used in communication.
For example, the conductor 229 of a length corresponding to
the wavelength can be securely maintained by forming the
ribs 210b along the entire inside wall of the housing 210
and disposing the conductor 229 along the entire inside wall
of the housing 210, if desired. Furthermore, the length of
the ground can be increased by winding the conductor 11
around a spirally shaped object or forming the conductor 11
in a meandering shape along the inside wall of the housing
210. Furthermore, the connection between the conductor 229
and the ground is not limited to the connection using the
connector shown in FIG. 10 or the like, but may be a
connection using soldering.
Furthermore, the wireless apparatus is not limited to
the above-described disk-shaped human body sensor, but may

be widely applied to, for example, typical box-shaped
electronic apparatuses having wireless communication
functionality, such as that shown in Fig. 13. The wireless
apparatus of such an electronic apparatus 201C includes an
antenna 225a, a circuit board 240 configured to form a
wireless communication circuit, a battery 212 disposed in
the cutout portion of the circuit board 240, and a housing
230 configured to accommodate the circuit board 240 and the
battery 212. The antenna 225a is disposed on one end side
240a of the circuit board 240 and a conductor 249 connected
to the ground terminal 248 of the circuit board 240 is drawn
from the other end side 2 4 0b thereof, with the cutout
portion being disposed therebetween. In this electronic
apparatus 201C, it is preferred in terms of the enhancement
of the ground of the circuit board 240 that the conductor
249 extend to the one end side 240a of the circuit board 240
along the inside wall of the housing 230.

What is claimed is:
1. A wireless apparatus comprising:
an antenna, a circuit board configured to form a
wireless communication circuit that is connected to the
antenna, and a housing configured to accommodate the circuit
board and formed by resin molding,
wherein a linear conductor extends from a ground of the
circuit board.
2. The wireless apparatus of claim 1, wherein a total
electrical length which is a sum of an overall equivalent
electrical length of a wiring pattern and electrical and
electronic circuits on the circuit board, except for the
antenna, and an electrical length of the conductor is 1/4 of
a wavelength of a carrier that is used in wireless
communication.
3. The wireless apparatus of claim 1, wherein the circuit
board is provided with a concave cutout portion, the antenna
is disposed on one end side of the circuit board, and the
conductor extends from the other end side of the circuit
board.
4. The wireless apparatus of claim 3, wherein a total
electrical length which is a sum of an overall equivalent

electrical length of a wiring pattern and electrical and
electronic circuits on the circuit board, except for the
antenna, and an electrical length of the conductor is 1/4 of
a wavelength of a carrier that is used in wireless
communication.
5. The wireless apparatus of claim 1, wherein the antenna
is accommodated inside the housing.
6. The wireless apparatus of any one of claims 1, 2 and 5,
wherein the antenna is disposed between the circuit board
and an attachment surface of the housing.
7. The wireless apparatus of any one of claims 1, 2 and 5,
wherein the conductor is disposed on a same plane as the
circuit board or is disposed opposite to the antenna with
the circuit board disposed therebetween.
8. The wireless apparatus of any one of claims 1 to 4,
wherein the conductor extends along an inside wall of the
housing.
9. The wireless apparatus of any one of claims 1 to 4,
wherein the conductor extends from the other end side of the
circuit board to one end side thereof.

10. The wireless apparatus of any one of claims 1 to 4,
wherein ribs adapted to reinforce the housing are formed on
an inside wall of the housing, the ribs having depressions
adapted to allow the conductor to be fitted thereinto.
11. The wireless apparatus of any one of claims 1 to 4,
wherein a surface of the conductor is coated with an
insulating coating.
12. The wireless apparatus of any one of claims 1 to 4,
wherein a battery adapted to supply power to the wireless
transmission circuit of the circuit board is disposed in the
housing, and a front end of the conductor that is not
directly connected to the ground is directly connected to a
negative electrode of the battery.
13. A wireless abnormality notification system comprising a
plurality of fire alarms each including the wireless
apparatus set forth in any one of claims 1, 2 and 5 and a
sound notification unit configured to issue a sound of an
alarm, wherein any one of the fire alarms that senses a fire
wirelessly communicates with the other fire alarms and
provides notification of the fire to the other fire alarms,
so that a sound notification unit of at least one of the
fire alarms issues a sound to notify the fire.

14. A wireless remote control system comprising:
the wireless apparatus set forth in any one of claims
1 to 4, a receiver configured to receive a wireless signal
from the wireless apparatus, and equipment whose operation
is controlled by the receiver.