Communications: electrical – Condition responsive indicating system – Specific condition
Reexamination Certificate
1998-12-24
2001-10-16
Tong, Nina (Department: 2632)
Communications: electrical
Condition responsive indicating system
Specific condition
C340S545600, C340S568100, C340S570000, C340S571000, C340S572500, C340S572600
Reexamination Certificate
active
06304182
ABSTRACT:
TECHNICAL FIELD
The present invention relates to an apparatus detecting a burglar by detecting with using an radio wave whether a tag having a resonance circuit block is in a predetermined location and the like.
BACKGROUND ART
Heretofore, a tag is disclosed in Japanese Unexamined Patent Publication No. 8-185584, the tag which is constructed such that a resonance circuit block of the tag attached to an object for monitoring a burglar resonates with a specific frequency from a radio wave transmission unit, separation detection means detects whether the tag is separated from the object for monitoring a burglar, and a separation information block controls warning sound output means on the basis of a detection output of this separation detection means. In this burglar-alarm tag, the resonance circuit block is constructed with forming conductive metal foil, having a predetermined shape, by etching and the like in both sides of a thin film of an insulating dielectric. For example, a coil portion formed in a spiral shape with conductive metal foil, and a surface-side planer pattern of a capacitor, connected to the coil portion, in the central portion of the spiral of this coil portion are formed on the surface of the thin film.
In an entrance of an outlet selling the object for monitoring a burglar, a transmission antenna and a reception antenna are installed in a predetermined interval, and these antennas are electrically connected to a control block. The control block is constructed such that the control block makes the transmission antenna transmit a radio wave having a frequency resonating in the resonance circuit block and always checks a signal level of a signal received from the reception antenna. Furthermore, a speaker sounding an alarm is connected to a control output terminal of the control block.
With using a burglar-alarm tag constructed in this manner, a radio wave transmitted from a transmission antenna resonates in a resonance circuit block of the tag attached to an object for monitoring a burglar if an object for monitoring a burglar passes between the transmission antenna and a reception antenna without payment. Hence, the reception antenna receives an input signal whose reception level is modulated. In consequence, the control block sounds an alarm from a speaker and can check takeout of an unpaid product. In regard to a paid-up product, a tag is disabled by breaking a capacitor through applying a strong radio wave, or an alarm is disabled by temporarily stopping the alarm speaker.
Nevertheless, the above burglar-alarm tag requires a transmission antenna and a reception antenna, which are comparatively large, so as to detect a burglar of a product with the tag. Therefore, this type of tag has a defect that a comparatively wide space is required as an installation space of these antennas.
In addition, the above burglar-alarm tag has a possibility of a malfunction in a location with plenty of electrical noise of a computer and the like.
Furthermore, in regard to the above burglar-alarm tag, a central line of the helical coil portion extends in the direction orthogonal to a mounting surface of an object, and hence a radio wave transmitted from the resonance circuit block passes the object. Therefore, if this tag is attached on an object whose surface is made of conductive material such as aluminum or ferromagnetic material such as a steel sheet, self inductance of the coil portion changes. Hence, in comparison with a case that the tag is attached to an object whose surface is made of insulating-material or non-magnetic material, the tag has a possibility of not operating as a burglar-alarm tag due to an influence of a change of a resonance frequency in the resonance circuit block and the like.
DISCLOSURE OF INVENTION
An object of the present invention is to provide a radio wave type burglar detection apparatus that can be installed in a comparatively small space, can prevent a malfunction even if the apparatus is installed in a location with plenty of electrical noise, and can surely detect the presence and absence of a tag even if the tag is placed in the vicinity of an object made of metal.
Another object of the present invention is to provide a radio wave type burglar detection apparatus that can increase a ratio (SIN ratio) between a signal transmitted by the tag detection sensor and a signal generated by electrical noise of a computer and the like by making a radio wave, which is transmitted by the tag detection sensor, have directivity.
Still another object of the present invention is to provide a radio wave type burglar detection apparatus that can immediately detect abnormal operation caused by a failure and the like of a tag, a tag detection sensor, a drawer sensor, or an upper lid sensor, and hence can increase the reliability of the apparatus.
The embodiment of the invention shown in
FIGS. 1 and 3
is a radio wave type burglar detection apparatus comprising: a tag
11
that has a resonance circuit block
12
and is placed with an object
15
in a predetermined location; a tag detection sensor
16
that is installed in the vicinity of the tag
11
placed in the predetermined location and detects whether the tag
11
is present in the predetermined location; and a control circuit
19
controlling alarm means
18
on the basis of an detection output of the tag detection sensor
16
.
Since the tag detection sensor
16
detects that the tag
11
is present in the predetermined location if the tag
11
is placed in the predetermined location with the object
15
, the control circuit
19
does not activate the alarm means
18
. In addition, if the tag
11
is taken out from the predetermined location with the object
15
, the tag detection sensor
16
detects that the tag
11
is not present in the predetermined location, and hence the control circuit
19
activates the alarm means
18
.
The embodiment of the invention shown in
FIGS. 1 and 3
is a radio wave type burglar detection apparatus comprising: a tag
11
having a resonance circuit block
12
; a box
13
containing a drawer
14
where the tag
11
is contained with an object
15
; a tag detection sensor
16
that is installed in the box
13
and detects whether the tag
11
is present within the drawer
14
; a drawer sensor
17
detecting whether the drawer
14
is drawn; and a control circuit
19
controlling alarm means
18
on the basis of each detection output of the tag detection sensor
16
and drawer sensor
17
.
In this radio wave type burglar detection apparatus, since the drawer sensor
17
detects that the drawer
14
is not drawn if the drawer
14
is contained in the box
13
, the control circuit
19
does not activate the alarm means
18
regardless of whether the tag
11
is present within the drawer
14
or not. In addition, if the drawer
14
is drawn from the box
13
, the drawer sensor
17
detects that the drawer
14
is drawn, and at the same time, the tag detection sensor
16
detects that the tag
11
is present within the drawer
14
. Therefore, the control circuit
19
does not activate the alarm means
18
. Furthermore, if the tag
11
is taken out with the object
15
from the drawer
14
with drawing the drawer
14
, the tag detection sensor
16
detects that the tag
11
is not present within the drawer
14
. Therefore, the control circuit
19
activates the alarm means
18
.
The embodiment of the invention shown in
FIG. 7
is a radio wave type burglar detection apparatus comprising: a tag
11
having a resonance circuit block; a box
63
that contains the tag
11
with an object
15
and has an upper lid
63
b
that can be opened and closed; a tag detection sensor
66
that is installed in the box
63
and detects whether the tag
11
is present within the box
63
; an upper lid sensor
67
detecting whether the upper lid
63
b
is opened or closed; and a control circuit
19
controlling alarm means
18
on the basis of each detection output of the tag detection sensor
66
and upper lid sensor
67
.
In this radio wave type burglar detection apparatus, since the upper lid se
Endo Takanori
Ishiyama Kouichi
Miyake Masami
Mori Tomohiro
Osawa Shigeyuki
Mitsubishi Materials Corporation
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
Tong Nina
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