JP3982420B2 - Glass break sensor - Google Patents

Description

【００２１】
一方、動作確認モードにおいては、第２のコンデンサＣ０がコンデンサＣに並列に接続されることによりフィルタ回路２１のキャパシタンスは増大する。つまり、第２のコンデンサＣ０とスイッチＳＷ１とがキャパシタンス変更手段として機能する。動作確認モードにおけるフィルタ回路２１のカットオフ周波数ｆ’は次式２で表される。
【００２２】
【数２】

【００２３】
ここで、ガラス板が破壊されるときの圧電素子１の出力は例えば図３の曲線Ａで示すようになり、ピークを数百ｋＨｚの周波数に有する。また、ガラス板が破壊されないときの圧電素子１の出力は図３の曲線Ｂで示すようになり、ガラス板が破壊されるときよりも低い周波数にピークを有する。
【００２４】
つまり、第２のコンデンサＣ０のキャパシタンスを適当に選ぶことにより、動作確認モードにおけるフィルタ回路２１のカットオフ周波数ｆ’を低くして、圧電素子１の出力のうちガラス板が破壊されない振動の周波数の成分をフィルタ回路２１が通過させるようにすることができる。
【００２５】
上記構成によれば、使用者が動作確認モードに切り換えて動作を確認した後、通常モードに戻すのを忘れてしまっても、復帰時間が経過した後に自動的に通常モードに復帰するから、その後の誤動作の発生を防ぐことができる。
【００２６】
なお、第２のコンデンサＣ０とスイッチＳＷ１との直列回路を設ける代わりに、図４に示すようにスイッチＳＷ２と第２のインダクタＬ０との並列回路をインダクタＬに直列に接続してもよい。スイッチＳＷ２は通常モードにおいてはオン状態となり、動作確認モードにおいてはオフ状態となるように計時復帰回路７によってオンオフ制御される。つまり、動作確認モードにおいては通常モードよりもフィルタ回路２１のインダクタンスが増大する。言い換えると、スイッチＳＷ２と第２のインダクタＬ０との並列回路がインダクタンス変更手段として機能する。この構成によれば、フィルタ回路２１の動作確認モードにおけるカットオフ周波数ｆ’は次式３のように表される。
【００２７】
【数３】

【００２８】
第２のインダクタＬ０のインダクタンスを適当に選ぶことにより、先に述べたキャパシタンス変更手段と同様に、動作確認モードにおけるフィルタ回路２１のカットオフ周波数ｆ’を低くして、圧電素子１の出力のうちガラス板が破壊されない振動の周波数の成分がフィルタ回路２１を通過可能とすることができる。
【００２９】
（実施形態２）
本実施形態の基本的な構成は実施形態１と同様であるので、共通する部分については同じ符号を付して説明を省略し、異なる部分についてのみ詳細に説明する。本実施形態においては、フィルタ回路２１は圧電素子１の出力のうちガラス板が破壊されるときの固有周波数の成分を通過させるものである。また、図５に示すように、通常モードにおいてはオフ状態となり動作確認モードにおいてはオン状態となるように計時復帰回路７によってオンオフ制御されるスイッチＳＷ３と、スイッチＳＷ３がオン状態であるときにフィルタ回路２１の出力に一定値Ｖｂを加える直流電源Ｅとを備える。その他の構成は実施形態１と同様である。
【００３０】
フィルタ回路２１の出力に一定値Ｖｂを加えるということは、相対的に破壊検出閾値ＶｔｈをＶｂだげ減少させるのと同じことになる。つまり、スイッチＳＷ３と直流電源Ｅとが閾値変更手段として機能する。ここで、ガラス板が破壊されるときの固有周波数の成分は、ガラス板が破壊されない振動には少ないから、通常モードにおける破壊検出閾値Ｖｔｈはガラス板が破壊されない振動で比較回路２２が破壊検出信号を出力しないように設定されている。しかし、上記構成によれば、一定値Ｖｂの値を十分に大きくとれば、動作確認モードにおいてはガラス板が破壊されない振動でも比較回路２２が破壊検出信号を出力するようにすることができる。
【００３１】
なお、閾値変更手段は破壊検出閾値を上記のように相対的に変化させる回路に限られず、破壊検出閾値の絶対値を変更する回路としてもよい。例えば、比較回路２２はフィルタ回路２１の出力と破壊検出閾値としての参照電圧とを比較するコンパレータとし、通常モードにおける破壊検出閾値となる第１の電圧を分圧して第２の電圧を生成する分圧抵抗と、通常モードにおいては第１の電圧を参照電圧として比較回路２２に入力し動作確認モードにおいては第２の電圧を参照電圧として比較回路２２に入力するように計時復帰回路７によって切り換え制御される切り換えスイッチとを設ければよい。
【００３２】
または、閾値変更手段を用いる代わりに、図６に示すように、インダクタＬに直列に接続され通常モードにおいてはオン状態となり動作確認モードにおいてはオフ状態となるように計時復帰回路７によってオンオフ制御されるスイッチＳＷ４を設けてもよい。動作確認モードにおいてはスイッチＳＷ４によってインダクタＬが切り離され、圧電素子１の出力がフィルタ回路２１を通さずにそのまま比較回路２２に入力されるのと同じことになる。この構成を採用すれば、動作確認モードでガラス板が破壊されない振動を受けた際の比較回路２２への入力が、通常モードでガラス板が破壊されたときと同様に大きくなるから、比較回路２２に破壊検出信号を出力させることができる。
【００３３】
（実施形態３）
本実施形態の基本的な構成は実施形態１と同様であるので、共通する部分については同じ符号を付して説明を省略し、異なる部分についてのみ詳細に説明する。本実施形態は、図７に示すように、計時復帰回路７に代えて、動作確認モードに切り換えられている間に圧電素子１の出力と予め定められた復帰閾値とを比較し、圧電素子１の出力が復帰閾値よりも大きくなった回数を計数するとともに、動作確認モードに切り換えられてから圧電素子１の出力が復帰閾値よりも大きくなった回数が予め定められた復帰回数に達したときに判定手段２の動作を通常モードに復帰させる計数復帰手段としての計数復帰回路８を備える。計数復帰回路８は、計時復帰回路７と同様に、選択部６及び状態判別回路９とともに切換手段としても機能する。その他の構成は実施形態１と同様である。
【００３４】
上記構成によれば、使用者が選択部６を動作確認モードに切り換えて動作を確認した後、通常モードに戻すのを忘れてしまっても、復帰閾値よりも大きな出力を圧電素子１が復帰回数だけ発生した後に自動的に通常モードに復帰するから、その後の誤動作の発生を防ぐことができる。
【００３５】
なお、復帰回数は１回であってもよく、この場合、計数復帰回路８は実際には圧電素子１の出力が復帰閾値よりも大きくなった回数を計数する必要はない。また、通常モードと動作確認モードとで判定手段２の動作を異ならせる構成は実施形態１及び実施形態２で述べたどの構成であってもよい。
【００３６】
【発明の効果】
請求項１の発明は、建物において室内外を仕切るガラス板に取りつけられ、前記ガラス板の振動を電気信号に変換する検出手段と、前記検出手段の出力に応じて破壊検出信号を出力する判定手段とを備えるガラス破壊センサにおいて、前記検出手段の出力が前記ガラス板が破壊される時の振動に相当するときに前記判定手段が前記破壊検出信号を出力する通常モードと、前記検出手段の出力がガラス板が破壊されない振動に相当するときに前記判定手段が前記破壊検出信号を出力する動作確認モードとを択一的に切り換える切換手段と、前記動作確認モードに切り換えられてから経過した時間を計測するとともに予め設定された復帰時間が経過した後に前記判定手段の動作を前記通常モードに復帰させる計時復帰手段とを備えるので、使用者が動作確認モードに切り換えて動作を確認した後、通常モードに戻すのを忘れてしまっても、復帰時間が経過した後に自動的に通常モードに復帰するから、その後の誤動作の発生を防ぐことができる。
【００３７】
請求項２の発明は、建物において室内外を仕切るガラス板に取りつけられ、前記ガラス板の振動を電気信号に変換する検出手段と、前記検出手段の出力に応じて破壊検出信号を出力する判定手段とを備えるガラス破壊センサにおいて、前記検出手段の出力が前記ガラス板が破壊される時の振動に相当するときに前記判定手段が前記破壊検出信号を出力する通常モードと、前記検出手段の出力がガラス板が破壊されない振動に相当するときに前記判定手段が前記破壊検出信号を出力する動作確認モードとを択一的に切り換える切換手段と、前記動作確認モードに切り換えられている間に前記検出手段の出力と予め定められた復帰閾値とを比較し、前記検出手段の出力が復帰閾値よりも大きくなった回数を計数するとともに、前記動作確認モードに切り換えられてから前記検出手段の出力が復帰閾値よりも大きくなった回数が予め定められた復帰回数に達したときに前記判定手段の動作を前記通常モードに復帰させる計数復帰手段とを備えるので、使用者が動作確認モードに切り換えて動作を確認した後、通常モードに戻すのを忘れてしまっても、復帰閾値よりも大きな出力を検出手段が復帰回数だけ発生した後に自動的に通常モードに復帰するから、その後の誤動作の発生を防ぐことができる。
【００３８】
請求項３の発明は、請求項１又は請求項２の発明において、前記判定手段は、前記通常モードにおいては前記ガラス板が破壊されるときの固有周波数の成分を通過させるとともに前記動作確認モードにおいては前記ガラス板が破壊されないときの振動の周波数の成分を通過させるフィルタ手段と、予め設定された破壊検出閾値よりも前記フィルタ手段の出力が大きければ破壊検出信号を出力する比較手段とを備えるので、動作確認モードに切り換えてからガラス板が破壊されない振動を加えることによってガラスが破壊されたときと同様の動作をさせることができる。
【００３９】
請求項４の発明は、請求項３の発明において、前記フィルタ手段は、ＬＣハイパスフィルタからなり、前記動作確認モードにおいて前記フィルタ手段のキャパシタンスを前記通常モードに比べて大きくするキャパシタンス変更手段を備えるので、動作確認モードにおいて検出手段の出力のうちガラス板が破壊されない振動の周波数の成分がフィルタ手段を通過可能とすることができる。
【００４０】
請求項５の発明は、請求項３の発明において、前記フィルタ手段は、ＬＣハイパスフィルタからなり、前記動作確認モードにおいて前記フィルタ手段のインダクタンスを前記通常モードに比べて大きくするインダクタンス変更手段を備えるので、動作確認モードにおいて検出手段の出力のうちガラス板が破壊されない振動の周波数の成分がフィルタ手段を通過可能とすることができる。
【００４１】
請求項６の発明は、請求項１又は請求項２の発明において、前記判定手段は、前記検出手段の出力のうち前記ガラス板が破壊されるときの固有周波数の成分を通過させるフィルタ手段と、予め設定された破壊検出閾値よりも前記フィルタ手段の出力が大きければ破壊検出信号を出力する比較手段と、前記動作確認モードにおいて前記破壊検出閾値を前記通常モードに比べて低くする閾値変更手段とを備えるので、動作確認モードにおいては、ガラス板が破壊されない振動すなわち検出手段の出力のうち固有周波数の成分が少ない振動であっても、ガラスが破壊されたときと同様の動作をさせることができる。
【００４２】
請求項７の発明は、請求項１又は請求項２の発明において、前記判定手段は、前記検出手段の出力のうち前記ガラス板が破壊されるときの固有周波数の成分を通過させるフィルタ手段と、予め設定された破壊検出閾値よりも入力が大きければ破壊検出信号を出力する比較手段とを備え、前記通常モードにおいては前記フィルタ手段の出力が前記比較手段に入力され、前記動作確認モードにおいては前記検出手段の出力が前記フィルタ手段を通さずに前記比較手段に入力されるので、動作確認モードにおいては、ガラス板が破壊されない振動すなわち検出手段の出力のうち固有周波数の成分が少ない振動であっても、ガラスが破壊されたときと同様の動作をさせることができる。
【図面の簡単な説明】
【図１】本発明の実施形態１を示すブロック図である。
【図２】同上の要部を示す説明図である。
【図３】検出手段の出力の一例を示すグラフである。
【図４】本発明の実施形態１の別の形態の要部を示す説明図である。
【図５】本発明の実施形態２の要部を示す説明図である。
【図６】同上の別の形態の要部を示す説明図である。
【図７】本発明の実施形態３を示すブロック図である。
【図８】従来例を示すブロック図である。
【符号の説明】
１ 圧電素子
２ 判定手段
６ 選択部
７ 計時復帰回路
８ 計数復帰回路
９ 状態判別回路
２１ フィルタ回路
２２ 比較回路[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a glass breakage sensor that is attached to a glass plate that partitions the interior and exterior of a building and detects the breakage of the glass plate.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there has been provided a glass breakage sensor for crime prevention that is attached to a glass plate such as a glass door that partitions the interior and exterior of a building and detects the breakage of the glass plate (for example, see Patent Document 1). As shown in FIG. 8, this type of glass breakage sensor turns on and off the piezoelectric element 1 that detects the vibration of the glass plate, the determination unit 2 that outputs a breakage detection signal in accordance with the output of the piezoelectric element 1, and the power supply. And a power switch 3. The destruction detection signal is used, for example, as a trigger for driving the alarm unit 5 in which the alarm driving circuit 4 generates an alarm by sound or light.
[0003]
The judging means 2 includes a filter circuit 21 that passes a component of a natural frequency that is a frequency at which a peak occurs when the glass plate is broken among outputs of the piezoelectric element 1, an output of the filter circuit 21, and a preset breakage A comparison circuit 22 that compares the detection threshold value Vth and outputs a destruction detection signal if the output of the filter circuit 21 is larger than the destruction detection threshold value Vth is provided.
[0004]
Here, in order to prevent malfunction due to simple vibration that does not destroy the glass plate, such as vibration when opening and closing the glass door, the frequency of the peak of the output of the piezoelectric element 1 at which the glass plate is not broken is generated. The component is blocked by the filter circuit 21. For this reason, it is difficult to confirm the operation of the glass breaking sensor by simply vibrating the glass plate. Therefore, the normal mode in which the determination means 2 outputs a breakage detection signal when the output of the piezoelectric element 1 corresponds to vibration when the glass plate is broken, and the output of the piezoelectric element 1 corresponds to vibration that does not break the glass plate. There has been proposed a glass breakage sensor provided with switching means (not shown) for selectively switching between the operation confirmation mode in which the determination means 2 outputs a breakage detection signal. In this glass breakage sensor, the operation can be confirmed without breaking the glass plate by switching the switching means to the operation confirmation mode and vibrating the glass plate.
[0005]
[Patent Document 1]
JP 2000-46268 (page 3-5, FIG. 5)
[0006]
[Problems to be solved by the invention]
However, since the switching means is generally provided at an inconspicuous position, the user may forget to return to the normal mode after switching to the operation confirmation mode and confirming the operation. Further, a switch common to the power switch 3 may be used as a switching means. In this case, when the user turns on the power, the normal mode may be erroneously set as the operation confirmation mode. It was. And, when left in the operation confirmation mode, malfunctions due to vibration that the glass plate is not broken frequently occur.
[0007]
The present invention has been made in view of the above reasons, and an object of the present invention is to provide a glass breakage sensor that can automatically return from the operation confirmation mode for confirming the operation to the normal mode in which the normal operation is performed. is there.
[0008]
[Means for Solving the Problems]
The invention of claim 1 is a detector that is attached to a glass plate that partitions the interior and exterior of a building, and that converts vibration of the glass plate into an electrical signal, and a determination unit that outputs a destruction detection signal in accordance with the output of the detector A normal mode in which the determination means outputs the break detection signal when the output of the detection means corresponds to vibration when the glass plate is broken, and the output of the detection means is Switching means for selectively switching the operation check mode in which the determination means outputs the break detection signal when the glass plate corresponds to vibration that does not break, and the time elapsed since switching to the operation check mode is measured. And a time-counting return means for returning the operation of the determination means to the normal mode after a preset return time has elapsed. That.
[0009]
The invention according to claim 2 is a detector that is attached to a glass plate that partitions the interior and exterior of a building, and that converts vibrations of the glass plate into an electrical signal, and a determination unit that outputs a destruction detection signal according to the output of the detector A normal mode in which the determination means outputs the break detection signal when the output of the detection means corresponds to vibration when the glass plate is broken, and the output of the detection means is Switching means for selectively switching the operation check mode in which the determination means outputs the break detection signal when the glass plate corresponds to vibration that is not broken, and the detection means while being switched to the operation check mode Is compared with a predetermined return threshold, and the number of times the output of the detecting means is larger than the return threshold is counted, and the operation check mode is Counting return means for returning the operation of the determination means to the normal mode when the number of times the output of the detection means has become larger than the return threshold after switching has reached a predetermined return number. Features.
[0010]
According to a third aspect of the present invention, in the first or second aspect of the present invention, the determination means allows the natural frequency component when the glass plate is broken to pass in the normal mode and in the operation confirmation mode. Comprises filter means for passing a vibration frequency component when the glass plate is not broken, and comparison means for outputting a break detection signal if the output of the filter means is larger than a preset break detection threshold. It is characterized by.
[0011]
According to a fourth aspect of the present invention, in the third aspect of the present invention, the filter means includes an LC high-pass filter, and includes a capacitance changing means for increasing a capacitance of the filter means in the operation check mode as compared with the normal mode. It is characterized by.
[0012]
According to a fifth aspect of the present invention, in the third aspect of the present invention, the filter means includes an LC high-pass filter, and includes an inductance changing means for increasing an inductance of the filter means in the operation check mode as compared with the normal mode. It is characterized by.
[0013]
The invention according to claim 6 is the invention according to claim 1 or 2, wherein the determination means is a filter means for passing a component of the natural frequency when the glass plate is broken among the outputs of the detection means, Comparing means for outputting a destruction detection signal if the output of the filter means is larger than a preset destruction detection threshold value, and threshold value changing means for lowering the destruction detection threshold value in the operation check mode compared to the normal mode. It is characterized by providing.
[0014]
The invention according to claim 7 is the invention according to claim 1 or 2, wherein the determination means is a filter means for passing a component of the natural frequency when the glass plate is broken among the outputs of the detection means, Comparing means for outputting a destruction detection signal if the input is larger than a preset destruction detection threshold, the output of the filter means is input to the comparison means in the normal mode, and the operation confirmation mode The output of the detection means is input to the comparison means without passing through the filter means.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0016]
(Embodiment 1)
In the present embodiment, as shown in FIG. 1, a piezoelectric element 1 serving as a detection unit that converts vibration of a glass plate into an electric signal, and a determination unit 2 that outputs a breakage detection signal according to the output of the piezoelectric element 1. Prepare. Moreover, the alarm part 5 which generate | occur | produces the sound and light for alert | reporting destruction of a glass plate, and the alarm drive circuit 4 which drives the alarm part 5 by using a breakage detection signal as a trigger are provided.
[0017]
The operation of the judging means 2 includes a normal mode in which a breakage detection signal is output when the output of the piezoelectric element 1 corresponds to a vibration when the glass plate is broken, and a vibration in which the output of the piezoelectric element 1 does not break the glass plate. There are two types, an operation confirmation mode for outputting a destruction detection signal when And the selection part 6 for selecting the operation | movement of the determination means 2 alternatively by a user's operation, and the state determination circuit which determines the state of the selection part 6, and produces | generates the output according to the state of the selection part 6 9 and a time recovery circuit 7 for switching the operation of the determination means 2 in accordance with the output of the state determination circuit 9 are provided. That is, the selection unit 6, the time recovery circuit 7, and the state determination circuit 9 function as switching means. The time-counting return circuit 7 measures the time elapsed since the selection unit 6 was switched to the operation confirmation mode, and returns the time-counting return for returning the operation of the determining means 2 to the normal mode after a preset return time has elapsed. It also works as a means.
[0018]
The determination means 2 is a filter as a filter means for allowing the natural frequency component when the glass plate is broken in the normal mode to pass and the vibration frequency component when the glass plate is not broken in the operation check mode. A circuit 21 and a comparison circuit 22 as a comparison means for outputting a destruction detection signal if the output of the filter circuit 21 is larger than a preset destruction detection threshold Vth.
[0019]
For example, the filter circuit 21 is an LC high-pass filter having a capacitor C connected in series to the piezoelectric element 1 and an inductor L connected in parallel to the series circuit of the piezoelectric element 1 and the capacitor C as shown in FIG. A series circuit of the second capacitor C0 and the switch SW1 is connected to the capacitor C in parallel. The switch SW1 is turned on and off by the time reset circuit 7 so that it is turned off in the normal mode and turned on in the operation confirmation mode. Since the capacitor C0 is not connected in the normal mode, the cut-off frequency f of the filter circuit 21 is expressed by the following equation 1.
[0020]
[Expression 1]

[0021]
On the other hand, in the operation confirmation mode, the capacitance of the filter circuit 21 is increased by connecting the second capacitor C0 in parallel with the capacitor C. That is, the second capacitor C0 and the switch SW1 function as capacitance changing means. The cutoff frequency f ′ of the filter circuit 21 in the operation confirmation mode is expressed by the following equation 2.
[0022]
[Expression 2]

[0023]
Here, the output of the piezoelectric element 1 when the glass plate is broken is as shown by a curve A in FIG. 3, for example, and has a peak at a frequency of several hundred kHz. Further, the output of the piezoelectric element 1 when the glass plate is not broken is as shown by the curve B in FIG. 3, and has a peak at a lower frequency than when the glass plate is broken.
[0024]
That is, by appropriately selecting the capacitance of the second capacitor C0, the cut-off frequency f ′ of the filter circuit 21 in the operation confirmation mode is lowered, and the frequency of the vibration that does not destroy the glass plate in the output of the piezoelectric element 1 is obtained. The component can be passed through the filter circuit 21.
[0025]
According to the above configuration, even if the user forgets to return to the normal mode after switching to the operation check mode and confirming the operation, it automatically returns to the normal mode after the return time has elapsed. Can be prevented from occurring.
[0026]
Instead of providing a series circuit of the second capacitor C0 and the switch SW1, a parallel circuit of the switch SW2 and the second inductor L0 may be connected in series to the inductor L as shown in FIG. The switch SW2 is turned on and off by the time reset circuit 7 so that it is turned on in the normal mode and turned off in the operation confirmation mode. That is, in the operation confirmation mode, the inductance of the filter circuit 21 increases compared to the normal mode. In other words, a parallel circuit of the switch SW2 and the second inductor L0 functions as inductance changing means. According to this configuration, the cut-off frequency f ′ in the operation confirmation mode of the filter circuit 21 is expressed as the following Expression 3.
[0027]
[Equation 3]

[0028]
By appropriately selecting the inductance of the second inductor L0, the cut-off frequency f ′ of the filter circuit 21 in the operation check mode can be lowered in the operation confirmation mode, as in the capacitance changing means described above, and the output of the piezoelectric element 1 can be reduced. The component of the vibration frequency that does not break the glass plate can pass through the filter circuit 21.
[0029]
(Embodiment 2)
Since the basic configuration of the present embodiment is the same as that of the first embodiment, common portions are denoted by the same reference numerals, description thereof is omitted, and only different portions are described in detail. In the present embodiment, the filter circuit 21 passes the component of the natural frequency when the glass plate is broken among the outputs of the piezoelectric element 1. Further, as shown in FIG. 5, a switch SW3 that is controlled to be turned on / off by the timing recovery circuit 7 so as to be turned off in the normal mode and turned on in the operation confirmation mode, and a filter when the switch SW3 is turned on. And a DC power source E that applies a constant value Vb to the output of the circuit 21. Other configurations are the same as those of the first embodiment.
[0030]
Adding a constant value Vb to the output of the filter circuit 21 is the same as relatively reducing the breakdown detection threshold Vth by Vb. That is, the switch SW3 and the DC power source E function as a threshold value changing unit. Here, since the component of the natural frequency when the glass plate is broken is small for the vibration that does not break the glass plate, the breakdown detection threshold Vth in the normal mode is the vibration that does not break the glass plate, and the comparison circuit 22 detects the break detection signal. Is set not to output. However, according to the above configuration, if the value of the constant value Vb is sufficiently large, the comparison circuit 22 can output a breakage detection signal even in a vibration in which the glass plate is not broken in the operation check mode.
[0031]
The threshold value changing means is not limited to the circuit that relatively changes the destruction detection threshold value as described above, and may be a circuit that changes the absolute value of the destruction detection threshold value. For example, the comparison circuit 22 is a comparator that compares the output of the filter circuit 21 with a reference voltage serving as a breakdown detection threshold, and generates a second voltage by dividing the first voltage that is the breakdown detection threshold in the normal mode. Switching control is performed by the clock recovery circuit 7 so that the first voltage is input to the comparison circuit 22 as a reference voltage in the normal mode and the second voltage is input to the comparison circuit 22 as the reference voltage in the operation confirmation mode. It is sufficient to provide a changeover switch.
[0032]
Alternatively, instead of using the threshold value changing means, as shown in FIG. 6, it is connected to the inductor L in series and is controlled to be turned on / off by the time-counting return circuit 7 so that it is turned on in the normal mode and turned off in the operation confirmation mode. A switch SW4 may be provided. In the operation confirmation mode, the inductor L is disconnected by the switch SW4, and the output of the piezoelectric element 1 is input to the comparison circuit 22 as it is without passing through the filter circuit 21. If this configuration is adopted, the input to the comparison circuit 22 when receiving a vibration that does not cause the glass plate to be broken in the operation confirmation mode is increased in the same manner as when the glass plate is broken in the normal mode. Can output a destruction detection signal.
[0033]
(Embodiment 3)
Since the basic configuration of the present embodiment is the same as that of the first embodiment, common portions are denoted by the same reference numerals, description thereof is omitted, and only different portions are described in detail. In the present embodiment, as shown in FIG. 7, instead of the timing recovery circuit 7, the output of the piezoelectric element 1 is compared with a predetermined return threshold during switching to the operation confirmation mode, and the piezoelectric element 1 is compared. When the number of times the output of the piezoelectric element 1 has become larger than the return threshold after switching to the operation check mode has reached a predetermined number of return. A count return circuit 8 is provided as a count return means for returning the operation of the determination means 2 to the normal mode. The count return circuit 8 also functions as a switching unit together with the selection unit 6 and the state determination circuit 9 in the same manner as the time count return circuit 7. Other configurations are the same as those of the first embodiment.
[0034]
According to the above configuration, even if the user switches the selection unit 6 to the operation confirmation mode and confirms the operation, and forgets to return to the normal mode, the piezoelectric element 1 outputs an output larger than the return threshold. Since it automatically returns to the normal mode after it has occurred, subsequent malfunctions can be prevented.
[0035]
Note that the number of return times may be one. In this case, the count return circuit 8 does not actually need to count the number of times that the output of the piezoelectric element 1 has become larger than the return threshold value. In addition, the configuration in which the operation of the determination unit 2 is different between the normal mode and the operation confirmation mode may be any configuration described in the first and second embodiments.
[0036]
【The invention's effect】
The invention of claim 1 is a detector that is attached to a glass plate that partitions the interior and exterior of a building, and that converts vibration of the glass plate into an electrical signal, and a determination unit that outputs a destruction detection signal in accordance with the output of the detector A normal mode in which the determination means outputs the break detection signal when the output of the detection means corresponds to vibration when the glass plate is broken, and the output of the detection means is Switching means for selectively switching the operation check mode in which the determination means outputs the break detection signal when the glass plate corresponds to vibration that does not break, and the time elapsed since switching to the operation check mode is measured. And a time-counting return means for returning the operation of the determination means to the normal mode after a preset return time has elapsed. Even if you forget to return to the normal mode after switching to the operation check mode and confirming the operation, it will automatically return to the normal mode after the return time has elapsed, so you can prevent the occurrence of subsequent malfunctions .
[0037]
The invention according to claim 2 is a detector that is attached to a glass plate that partitions the interior and exterior of a building, and that converts vibrations of the glass plate into an electrical signal, and a determination unit that outputs a destruction detection signal according to the output of the detector A normal mode in which the determination means outputs the break detection signal when the output of the detection means corresponds to vibration when the glass plate is broken, and the output of the detection means is Switching means for selectively switching the operation check mode in which the determination means outputs the break detection signal when the glass plate corresponds to vibration that is not broken, and the detection means while being switched to the operation check mode Is compared with a predetermined return threshold, and the number of times the output of the detecting means is larger than the return threshold is counted, and the operation check mode is Since it comprises a count return means for returning the operation of the determination means to the normal mode when the number of times that the output of the detection means has become larger than the return threshold after switching has reached a predetermined return number, Even if the user switches to the operation check mode and confirms the operation, and forgets to return to the normal mode, the output automatically exceeds the return threshold after the detection means has generated the output greater than the return threshold, and then automatically returns to the normal mode. Therefore, the subsequent malfunction can be prevented.
[0038]
According to a third aspect of the present invention, in the first or second aspect of the present invention, the determination means allows the natural frequency component when the glass plate is broken to pass in the normal mode and in the operation confirmation mode. Comprises filter means for passing a vibration frequency component when the glass plate is not broken, and comparison means for outputting a break detection signal if the output of the filter means is larger than a preset break detection threshold. By switching to the operation confirmation mode and applying vibration that does not break the glass plate, the same operation as when the glass is broken can be performed.
[0039]
According to a fourth aspect of the present invention, in the third aspect of the present invention, the filter means includes an LC high-pass filter, and includes a capacitance changing means for increasing the capacitance of the filter means in the operation check mode as compared with the normal mode. In the operation confirmation mode, it is possible to allow the vibration frequency component that does not break the glass plate among the outputs of the detection means to pass through the filter means.
[0040]
According to a fifth aspect of the present invention, in the invention of the third aspect, the filter means comprises an LC high-pass filter, and includes an inductance changing means for increasing the inductance of the filter means in the operation check mode as compared with the normal mode. In the operation confirmation mode, it is possible to allow the vibration frequency component that does not break the glass plate among the outputs of the detection means to pass through the filter means.
[0041]
The invention according to claim 6 is the invention according to claim 1 or 2, wherein the determination means is a filter means for passing a component of the natural frequency when the glass plate is broken among the outputs of the detection means, Comparing means for outputting a destruction detection signal if the output of the filter means is larger than a preset destruction detection threshold value, and threshold value changing means for lowering the destruction detection threshold value in the operation check mode compared to the normal mode. Thus, in the operation confirmation mode, even if the vibration is such that the glass plate is not broken, that is, the vibration having a low natural frequency component in the output of the detection means, the same operation as when the glass is broken can be performed.
[0042]
The invention according to claim 7 is the invention according to claim 1 or 2, wherein the determination means is a filter means for passing a component of the natural frequency when the glass plate is broken among the outputs of the detection means, Comparing means for outputting a destruction detection signal if the input is larger than a preset destruction detection threshold, the output of the filter means is input to the comparison means in the normal mode, and the operation confirmation mode Since the output of the detection means is input to the comparison means without passing through the filter means, in the operation confirmation mode, the vibration that does not break the glass plate, that is, the vibration that has a low natural frequency component in the output of the detection means. Also, the same operation as when the glass is broken can be performed.
[Brief description of the drawings]
FIG. 1 is a block diagram showing Embodiment 1 of the present invention.
FIG. 2 is an explanatory view showing the main part of the above.
FIG. 3 is a graph showing an example of an output of a detection unit.
FIG. 4 is an explanatory diagram showing a main part of another embodiment of the first embodiment of the present invention.
FIG. 5 is an explanatory diagram showing a main part of a second embodiment of the present invention.
FIG. 6 is an explanatory view showing a main part of another embodiment of the same as above.
FIG. 7 is a block diagram showing Embodiment 3 of the present invention.
FIG. 8 is a block diagram showing a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Piezoelectric element 2 Judging means 6 Selection part 7 Time reset circuit 8 Count return circuit 9 State discrimination circuit 21 Filter circuit 22 Comparison circuit

Claims (7)

In a glass breakage sensor, which is attached to a glass plate that partitions the interior and exterior of a building, and includes a detection unit that converts vibration of the glass plate into an electrical signal, and a determination unit that outputs a breakage detection signal in accordance with the output of the detection unit. A normal mode in which the determination means outputs the destruction detection signal when the output of the detection means corresponds to vibration when the glass plate is broken; and the output of the detection means is vibration that does not break the glass plate. A switching means for selectively switching between the operation confirmation mode in which the determination means outputs the destruction detection signal at a corresponding time, a time elapsed after switching to the operation confirmation mode, and a preset return And a time resetting means for returning the operation of the judging means to the normal mode after a lapse of time. . In a glass breakage sensor, which is attached to a glass plate that partitions the interior and exterior of a building, and includes a detection unit that converts vibration of the glass plate into an electrical signal, and a determination unit that outputs a breakage detection signal in accordance with the output of the detection unit. A normal mode in which the determination means outputs the destruction detection signal when the output of the detection means corresponds to vibration when the glass plate is broken; and the output of the detection means is vibration that does not break the glass plate. A switching means for selectively switching the operation check mode in which the determination means outputs the destruction detection signal at a corresponding time, and an output of the detection means during the switching to the operation check mode is predetermined. Compared with the return threshold, counts the number of times the output of the detection means becomes larger than the return threshold, and whether the operation check mode is switched to The glass comprising: a count return means for returning the operation of the determination means to the normal mode when the number of times the output of the detection means has become larger than the return threshold reaches a predetermined return number. Destructive sensor. In the normal mode, the determination means passes a natural frequency component when the glass plate is broken, and passes a vibration frequency component when the glass plate is not broken in the operation check mode. The glass breakage sensor according to claim 1 or 2, further comprising: means and a comparison means for outputting a breakage detection signal when the output of the filter means is larger than a preset breakage detection threshold. 4. The glass breakage sensor according to claim 3, wherein the filter means comprises an LC high-pass filter, and includes a capacitance changing means for increasing the capacitance of the filter means in the operation check mode as compared with the normal mode. 4. The glass breakage sensor according to claim 3, wherein the filter means comprises an LC high-pass filter, and includes an inductance changing means for increasing an inductance of the filter means in the operation check mode as compared with the normal mode. The determination means includes a filter means for passing a component of a natural frequency when the glass plate is broken among the outputs of the detection means, and a breakage if the output of the filter means is larger than a preset breakage detection threshold. The glass breakage sensor according to claim 1, further comprising: a comparison unit that outputs a detection signal; and a threshold value changing unit that lowers the breakage detection threshold in the operation check mode as compared with the normal mode. . The determination means outputs a break detection signal if the input is larger than a preset break detection threshold, and a filter means that passes a component of the natural frequency when the glass plate is broken among the outputs of the detection means And in the normal mode, the output of the filter means is input to the comparison means, and in the operation check mode, the output of the detection means is input to the comparison means without passing through the filter means. The glass breakage sensor according to claim 1 or 2, wherein

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