JPH0219517B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an abnormality detection device in an elevator car, and in particular provides a device that is effective in detecting abnormalities such as violent behavior by passengers, mischief by children, and fire.

Traditionally, crime prevention and disaster prevention devices in elevator cars include communication devices and emergency buttons, but victims are not always able to operate these in the event of an act of violence. , and cannot be detected if it is a child's prank.
One possible countermeasure for these problems is to keep the communication device working all the time, but in this case, the manager needs to always pay attention to the conversations inside the car. There is also a method of installing a TV camera inside the car, but this is expensive and requires monitoring the TV all day long, and it also involves privacy issues and makes passengers feel uncomfortable.
There is also the problem that the design inside the basket creates a sense of discomfort. For this reason, a method has been proposed in which a sound level meter and a noise calculation device are installed inside the car.
The system is designed to detect when abnormally loud noises such as screams are emitted, but the victim does not always shout, and when the background noise inside the car changes suddenly, or when there is loud talking or laughter. Sometimes there are problems such as false detection. In addition, a crime prevention switch is installed inside the car, and when a passenger enters the car and feels uneasy, they operate this switch, and if the switch is not returned to its original position after a predetermined period of time, an alarm will be issued. Although there is a method to do this, there are various problems such as when the switch is turned off midway or when the operator forgets to operate it.

By the way, in order to solve these various problems, the applicant has proposed, for example, Japanese Patent Application No. 56-10997 "Situation Detection Device" and Japanese Patent Application No. 56-13678 "Situation Detection Device".
We have proposed a device that detects abnormalities in elevator cars and various other situations by capturing changes in the spatial distribution of brightness and infrared rays emitted from heat sources such as the human body.

This application is based on the above-mentioned Japanese Patent Application No. 56-10997 or Japanese Patent Application No.
The principle is the same as No. 56-13678, but
It is particularly effective for detecting infrared rays emitted from heat sources such as the human body.

In other words, unless an object is in an absolute atmosphere, it emits infrared rays according to its temperature. This application utilizes infrared radiation from this object to determine passenger movements and detect abnormalities, but the most distinctive feature of this application is the simple processing of the reflective surface of the condenser. This eliminates the need for a convex detector having a plurality of reflective surfaces as used in the prior application as a spatial pattern detector. In other words, the detection pattern is formed using an inexpensive structure in which a large number of planar reflective surfaces are arranged in a matrix on the condenser itself.

The present invention will be explained below with reference to the drawings. FIG. 1 is a plan view of a condenser constituting the present invention, and FIG. 2 is a sectional view taken along line A-A' in FIG. In the figure, 1 is a reflective condenser, and 2 is a planar reflective surface arranged vertically and horizontally on a condensing surface, and is formed of, for example, an aluminum vapor-deposited film. The shape of this reflective condenser can be easily formed, for example, by precision casting. Figure 3 is a diagram showing the principle of detection when using this reflective condenser. 3 is the detection element, 4 is its output signal, 10 is an infrared radiation source such as a person, and 10' and 10'' are its X 11, 11' and 11'' are infrared rays, 12 is an optical filter to prevent wind and dust, and is made of a material with good infrared transmittance, such as polyethylene. Consists of film. In FIG. 3, when an infrared radiation source 10 such as a person moves in the X direction, infrared rays 11, 11',
11", and this light beam is reflected by the reflective surface 2 and enters the sensing element 3. Due to the movement of the infrared radiation source 10, the sensing element 3 undergoes a temperature change due to the infrared rays 11 to 11", as shown in FIG. It emits an output signal 4 like this. FIG. 4 is a diagram showing changes in the output signal 4 over time t. Here, a thermal type is suitable for the sensing element 3 (there is also a semiconductor type, but it requires cooling), and the thermal type includes a pyroelectric type (using ferroelectric material) and a thermopile type (using a thermocouple). , thermistor type (thermistor porometer), etc. Among these, the pyroelectric type, which utilizes the pyroelectric effect of ferroelectric materials, has higher responsiveness and a better S/N ratio than other types, so
This element is suitable for detecting abnormalities inside the car.

Note that the same output as shown in FIG. 4 can be obtained even if the infrared radiation source 10 is moved not only in the X direction but in any direction.

FIG. 5 shows another embodiment of the reflective condenser, and FIG. 6 is a sectional view taken along line BB' in FIG.

This reflective condenser 5 also has a detection pattern made up of a large number of planar reflective surfaces 6, as in the previous embodiment, and is capable of detecting infrared rays from any direction. Numeral 7 is a slit groove for dividing the reflecting surface 6 into a large number of parts. Note that the detection pattern of the reflective surface is not limited to these embodiments, and the shape and number of reflective surfaces are arbitrary.

FIG. 7 is a block diagram showing one embodiment of the present invention. The reflective condenser 1 and the detection element 3 are installed at an appropriate position such as the ceiling of an elevator car, and infrared rays 11 from an infrared radiation source 10 such as a passenger pass through an optical filter 12 and reach a reflective surface 2 as shown in FIG. The light is reflected by the light and enters the detection element 3. When the passenger moves, since a plurality of reflective surfaces 2 form a detection pattern, the output signal 4 becomes as shown in FIG. 4, and its frequency is proportional to the speed of the person's movement. Furthermore, it is possible to obtain a signal containing frequency components corresponding not only to the movement of a person but also to the movement of part of a hand or foot. Reference numeral 20 denotes an amplifier for amplifying the output signal 4, and its output 20a is input to a bandpass filter 21.
The band filter 21 cuts low and high frequencies to remove amplifier drift and noise components, and outputs an output signal 21a. A level detector 22 uses a window comparator and extracts an amplitude signal of a certain value or more as an output 22a. 23
The frequency detection circuit generates an output 25 when an input frequency higher than a set value is detected. Therefore, with the above configuration, when the movement of a person becomes abnormally rapid, output 25 is generated. In other words, passengers usually move slowly in an elevator car, especially when the car is in operation, so if the movement becomes violent, this will be detected and the output 2 will be issued to indicate that an abnormality has occurred.
If 5 is used to issue a warning or report, it will be highly effective in preventing acts of violence and mischief by children.

Here, the detection element 3 is preferably of the pyroelectric type in terms of characteristics as described above, but the sensitivity characteristics of this sensor are almost flat in the wavelength range of 0.2 to 20 .mu.m.
Therefore, in this case, since it has sensitivity characteristics even to visible light, there is a risk of malfunction due to blinking of the indicator inside the car. To avoid this, using an interference filter as a window material for the element improves reliability and can be expected to be even more effective. In other words, if the human body temperature is 36.5℃, the peak wavelength of the infrared rays emitted will be 9.36μm (according to Vienna's displacement law regarding radiation of objects), and between 400 and 700℃.
In the case of flame, the peak wavelength is approximately 5 to 3 μm. Therefore, in this case, if a 3 μm cut-on filter is used for the window material, it will cut out wavelengths of 3 μm or less, making it possible to detect only fires and abnormal human movements. It becomes possible to do so. Further, the frequency detection circuit 23 may count the number of pulses within a predetermined time, and output the output 25 if the number is equal to or greater than a set value.

FIG. 8 is a block diagram showing another embodiment of the present invention. In FIG. 8, 7 is the above-mentioned interference filter. A lens 8 is used in the detection section to enhance the effect of condensing infrared rays. In this case, the material of the lens is preferably germanium or silicon, which has good infrared transmittance. Further, in this embodiment, the positions of the amplifier 20 and the bandpass filter 21 of the above embodiment are exchanged. 30 is a frequency detection circuit, 31
is a pulse number detection circuit that detects the number of pulses within a predetermined time. Reference numerals 33 and 34 denote RS flip-flop circuits, which generate outputs 33a and 34a for a certain length of time if the frequency exceeds a set value or the number of pulses exceeds a predetermined number within a predetermined time. 35 is an AND circuit,
36 is its output signal. Frequency detection circuit 30
The speed of movement is determined by detecting the frequency of each instant, and the pulse number detection circuit 31 detects the number of pulses within a predetermined time to determine the magnitude of the movement within the predetermined time, that is, the amount of movement and the duration. You can get the amount corresponding to the time. Accordingly
By using the AND circuit 35, a more reliable output signal 36 can be generated by detecting not only the speed of movement but also only those that involve a certain degree of continuation of movement.

As described above, according to the present invention, a detection pattern is formed by arranging a large number of planar reflective surfaces vertically and horizontally on the condensing surface of the condenser, so infrared rays can be detected with a simpler and cheaper configuration. It is possible to detect various abnormalities inside an elevator car, and can be expected to have a great effect on crime prevention and disaster prevention.

[Brief explanation of drawings]

Fig. 1 is a plan view of the condenser constituting the present invention, Fig. 2 is a sectional view taken along line A-A' in Fig. 1, Fig. 3 is an explanatory diagram of the principle of the invention, and Fig. 4 is an illustration of the output signal. An explanatory diagram showing the changes, FIG. 5 is a diagram showing another embodiment of the condenser,
6 is a sectional view taken along the line B-B' in FIG. 5, FIG. 7 is a block diagram showing one embodiment of the present invention, and FIG. 8 is a block diagram showing another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...Reflection concentrator, 2...Reflection surface, 3...Detection element, 10...Infrared radiation source, 11...Infrared radiation,
20...Amplifier, 21...Band filter, 22...
...Level detector, 23, 30...Frequency detection circuit, 31...Pulse number detection circuit, 35...AND
circuit.

Claims (1)

[Claims] 1. A light concentrator installed in an elevator car and having a large number of planar reflective surfaces arranged vertically and horizontally on a condensing surface, a detection element that emits an output signal corresponding to the infrared light collected by the condenser, and An elevator car abnormality detection device comprising a circuit that generates an output when the frequency of an output signal exceeds a predetermined value.