JP4382471B2 - Security glass and security equipment - Google Patents

Description

The present invention relates to a crime prevention glass and a crime prevention device that are suitable for detecting fraud involving glass destruction.

Conventionally, a security device disclosed in Patent Document 1 is known. As shown in FIG. 2, this crime prevention device forms a metal conductive layer 54 on one side of a transparent insulating resin layer 53 to prepare a resin material 52 with a conductive layer, and laminates two of them to form a conductive layer on both sides. 54 is arranged.

A glass plate 55 is laminated so as to be in contact with each conductive layer 54 to form a security glass 56, and a terminal 58 connected to each of the conductive layers 54 is connected to a capacitance detector 57. The capacitance detector 57 includes an alarm 59 that converts the alarm signal into a sound signal or an optical signal. Note that the end portion of the security glass 56 is fixed by a frame 60.

  In the crime prevention device disclosed in Patent Document 1, two stacked conductive films 54 and 54 form a capacitor. Then, in order to detect the capacitance of the capacitor formed on the glass surface, one end of the lead wire is connected to the two conductive films 54, 54, and the other end of the lead wire is connected to the capacitance detector 57. Connected. As a result, the capacitance detector 57 detects the capacitance of the capacitor by the two conductive films 54 and 54 that change by approaching or contacting the security glass 56.

JP 2002-352342 A

  However, the purpose of the glass break detector is to detect that the glass has been broken. That is, the purpose is to detect when the glass is broken or when the glass is cracked. For this reason, in the configuration disclosed in Patent Document 1, a change in capacitance occurs even when a person approaches the security glass, and it is also detected that a cat or dog has touched a window other than the original glass breakage. To do. In this case, although the glass is not broken, a buzzer sounds, an abnormality report, etc. appear, which is not preferable as a glass breakage detector.

In addition, when a portion of the glass is cracked, the surface area of the capacitor does not change as the capacitance changes, and the crack may not be detected. Furthermore, in the conventional glass breakage detector, it is necessary to always apply a predetermined voltage between the conductive layers, and there is a problem that power consumption increases.

Accordingly, an object of the present invention is to realize a crime prevention device capable of reliably detecting glass breakage with low power consumption and capable of detecting glass breakage without erroneous determination due to human approach.

In order to achieve such an object, the first invention provides the electret layer by disposing a conductive layer on both sides of an electret layer formed of an electret material and laminating a glass layer so as to be in contact with each conductive layer. And the conductive layer and the glass layer are integrated, and the security glass in which the lead wire is connected to the conductive layer, and the integration of each layer of the security glass is connected to the lead wire and the glass layer is broken. accompanying departing provide comprised security device and a detector for detecting a voltage fluctuation between the lead wire caused by distance variation of the conductive layers.

According to such a security device, since the conductive layer is integrated with the glass, the vibration caused by the glass breakage can be observed, and the glass breakage can be detected.

Moreover, 2nd invention arrange | positions a conductive layer on both surfaces of the electret layer formed with an electret material, and laminates | stacks a glass layer so that each conductive layer may be touched, and the said electret layer, the said conductive layer, and the said A crime prevention glass integrated with a glass layer is provided.

  According to such a security glass, since the electret layer and the conductive layer can be formed integrally, a security glass capable of detecting glass breakage can be realized.

According to the first invention and the second invention, the function as a condenser microphone formed by the electret material and the conductive layer can be exerted on the entire glass surface, and the vibration acting on the glass layer can be detected with high sensitivity. Therefore, the crime prevention performance can be improved.

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a system configuration diagram of a security device having a security glass according to the present invention.

The security glass 1 is used in a state of being fitted into a sash 7 installed on a window frame of a building.
The crime prevention glass 1 is provided with an electret material 4 sandwiched between two pieces of glass 2 by a conductive layer 3 having conductivity.

The glass 2 is a heat-treated glass, and uses a glass that breaks down when it is destroyed. The heat-treated glass is a glass that takes a manufacturing process in which the float glass is heat-treated and rapidly cooled.

Lead wires 5 are connected to the conductive layer 3, and the other end of the lead wire 5 is connected to a glass breakage detector 6 described later.

The electret material 4 is semi-permanently polarized in the direction of the conductive layer 3 on both sides, and the conductive layer 3 is further deposited.

In the production of the security glass, the conductive layer 3 that is a transparent electrode is disposed on one side of the glass 2. Polymer materials such as polypropylene, Teflon (registered trademark), and Mylar are arranged such that the two glass plates 2 on which the conductive layer 3 is arranged face each other. Then, heating is performed in this state to melt the polymer material, and a DC high voltage is applied to the conductive layer 3. When cooled and solidified as it is, polarization (charge retention) occurs. That is, the polymer material is converted into an electret, and the electret material 4 is formed. Thus, since the heat treatment in the manufacturing process of heat-treated glass and the heat treatment for electretization of the polymer material can be performed in the same process, the manufacturing process of the security glass can be simplified.
The heating temperature is preferably higher than the melting point of the polymer material (for example, polypropylene is 160 ° C. to 170 ° C.).

The glass breakage detector 6 includes a capacitance detection unit 61, a glass breakage determination unit 62, an output unit 63, and a power source 64.

The capacitance detection unit 61 is connected to the lead wire 5 and detects a change in capacitance caused by vibration in the electret material 4 between the conductive layers 3 as a voltage change.
That is, when the conductive layer 3 is arranged on both sides of the electret material 4, it becomes a capacitor on the equivalent circuit. When this conductive layer 3 is used as an electrode, the voltage from the lead wire 5 is received by a high impedance amplifier, the impedance is converted, and the output voltage is observed. When the output voltage is observed, the voltage change of the signal according to the interval between the conductive layers 3, that is, the thickness of the electret material Can be detected. As a result, since the conductive layer 3 is integrated with the glass 2, vibrations caused by glass breakage can be observed.
Normally, since the electret material 4 is sandwiched between the glass 2, there is almost no vibration, the distance between the conductive layers 3, that is, the capacitance does not change, and the voltage hardly changes.
However, if the glass is broken, vibrations are transmitted to the electret material 4 and the capacitance between the conductive layers 3 varies significantly. This change in voltage is detected by the capacitance detector 61. In addition, since the glass 2 is shattered when broken because of the heat-treated glass, a change in voltage, which is a change in capacitance due to the electret material, is further increased. In addition, due to the physical property (electret effect) of holding the charge of the electret material 4, it is not necessary to apply a voltage from the conductive layer 3 to the electret material 4, so that power consumption from the power source 64 can be suppressed. .

The glass breakage determination unit 62 determines glass breakage if the change in capacitance detected by the capacitance detection unit 61 is equal to or greater than a predetermined value, and notifies the outside from the output unit 63. Since the electret material 4 is used and the electrostatic capacity is significantly different between the case where the glass 2 is broken and the case where the glass 2 is broken, the glass breakage determination unit 62 clearly discriminates between glass breakage and other cases. Is possible.

Although not shown, a security device is connected to the output unit 63, and an alarm buzzer can be sounded through the security device, or an abnormality can be reported from the security device to an external monitoring center. Further, the glass breakage determination unit 62 does not perform any special operation unless the capacitance changes.

Configuration diagram of crime prevention device and crime prevention glass according to the present invention The block diagram which shows the prior art.

Explanation of symbols

1: Security glass 2: Glass 3: Conductive layer 4: Electret material 5: Lead wire 6: Glass breakage detector 61: Capacitance detection unit 62: Glass breakage determination unit 63: Output unit 64: Power supply 7: Sash

Claims (2)

The electret layer, the conductive layer, and the glass layer are integrated by arranging conductive layers on both sides of the electret layer formed of the electret material and laminating the glass layers so as to be in contact with the respective conductive layers, Crime prevention glass with lead wires connected to the conductive layer;
Connected to said lead wire from said integration of layers of security glass due to the disengages detector for detecting a voltage fluctuation between the lead wire caused by distance variation of the conductive layers by disruption of the glass layer Security device characterized by being configured. The electret layer, the conductive layer, and the glass layer are integrated by arranging conductive layers on both sides of the electret layer formed of the electret material and laminating the glass layers so as to be in contact with the respective conductive layers. Security glass characterized by

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