JPH08235455A - Heat ray sensor - Google Patents

Abstract

PURPOSE: To automatically set the sensitivity and the pulse count value according to the adjustment of the angle in the up-down direction. CONSTITUTION: When the angle adjustment of an optical system 1 is performed by an up-and-down direction angle adjusting mechanism 19, a rotary encoder 20 outputs the signal corresponding to the up-down direction angle set at this time. When a controller 6 receives this signal, the controller refers to an LUT 21, reads the reference voltage Vref corresponding to the set angle and a pulse count value, gives the reference voltage Vref to a comparator 5, sets the pulse count value inside and uses the value at the time of processing a pulse count.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat ray sensor, and more particularly to a heat ray sensor for automatically setting parameter values such as sensitivity and pulse count value according to a set angle of the heat ray sensor.

[0002]

2. Description of the Related Art A heat ray sensor is usually mounted on a ceiling, and its optical system is designed so that its angle can be adjusted so that a warning zone can be set at a desired place. Depending on the set angle of the system, sensitivity,
It is desired to adjust the values of parameters such as pulse count.

The reason therefor will be described below. First, prior to that, the structure of the heat ray sensor will be briefly described.

The heat ray sensor has a structure as schematically shown in FIG. The optical system 1 is composed of an optical member 2 and a pyroelectric element 3. The optical member 2 is for forming a warning zone, and the pyroelectric element 3 is arranged at a substantially focal position of the optical member 2. The optical member 2 is usually composed of a reflecting mirror, but the Fresnel lens may be formed of a material such as high-density polyethylene that transmits far infrared rays. In addition, there are usually a plurality of warning zones formed by the optical member 2.

Although not shown in FIG. 4, the optical system 1
The vertical angle and the horizontal angle can be adjusted by an appropriate angle adjusting mechanism, so that the warning zone can be set at a desired position. Since the angle adjusting mechanism of the optical system 1 is well known, detailed description thereof will be omitted.

Here, the vertical direction and the horizontal direction will be defined. In this specification, the vertical direction is as shown in FIG. 5A.
5B, the left-right direction is the direction indicated by the arrow 11 in FIG.
The direction indicated by arrow 12 in FIG. In addition,
FIG. 5A is a cross-sectional view when the heat ray sensor 10 is mounted on the ceiling, and FIG. 5B is a plan view thereof, showing a case where there are four warning zones. 5A and 5B, when the approximate center position of the four warning zones is P, the distance from the heat ray sensor 10 to the point P will be referred to as a warning distance.

That is, it can be said that the up-down direction is the direction in which the warning distance changes and the left-right direction is the direction in which the warning distance does not change.

Now, in FIG. 4, the output of the pyroelectric element 3 is amplified by the amplifier 4 and input to the comparator 5. The comparator 5 compares the output voltage of the amplifier 4 with the reference voltage V _ref, and outputs a pulse if the output voltage of the amplifier 4 is equal to or higher than the reference voltage V _ref . This pulse is input to the control device 6 including a microprocessor and its peripheral circuits.

The controller 6 starts a timer when the first pulse is input and counts the input pulse.
Then, when the count value of the input pulse reaches the set value within a predetermined time set in advance, it is determined that there is an intruder and an alarm signal is output. If the pulse count value has not reached the set value when the predetermined time has elapsed, the control device 6 clears the count value and the timer.

This is a pulse count function, and the value of this pulse count, that is, how many pulses are output from the comparator 5 within a predetermined time, is output as an alarm signal or the value of the number of input pulses is set. The DIP switch 7 is provided for this purpose. Therefore, by operating the DIP switch 7, the pulse count value can be set to a desired value.

The pulse count value is usually set to a value greater than one. This is a function provided based on the fact that an intruder moves around so that it is very likely to cross multiple warning zones.However, it is possible to prevent false alarms, that is, to prevent false alarm signals from being output. I also have. That is, for example, if the control device 6 outputs an alarm signal immediately when one pulse is always output from the comparator 5, the pyroelectric element 3 detects a temperature change. An alarm signal will be output if there is a temperature change for any reason in the two alert zones, but this alarm signal is not based on an intruder, so it is a false alarm. However, since the value of the pulse count can be generally set arbitrarily, it goes without saying that the value of the pulse count can be set to 1 according to the installation situation of the heat ray sensor 10 or the purpose of use.

Now, assuming that the angle adjustment mechanism adjusts the vertical angle of the optical system 1 so that the caution distance is shortened, in this case, the size of each caution zone becomes smaller, and therefore the pulse count value is set to be smaller. Clearly, it will need to be reset to a larger value. This is the case when the vertical angle is adjusted so that the warning distance is halved when the pulse count value is 2, and the pulse count value is left as it is without being reset. It is easy to understand if you think about it. That is, in this case, no alarm signal is output because the alarm signal is not output even if the temperature changes in one warning zone before the angle adjustment, but after the angle adjustment, the area of each warning zone Is 1/4 before the angle adjustment, so if there is a temperature change within the same range as one warning zone before the angle adjustment, temperature changes will occur in multiple warning zones,
As a result, an alarm signal is output and a false alarm occurs.

Therefore, on the contrary, when the vertical angle is adjusted so that the warning distance becomes longer, it is necessary to reset the pulse count value to a smaller value.

The necessity of resetting the pulse count value when the vertical angle of the optical system 1 is adjusted has been described above. Next, the necessity of sensitivity adjustment will be described.

Now, assuming that the sensitivity is set to operate well at a certain warning distance, and the angle in the vertical direction is adjusted so that the warning distance is halved from that state,
The amount of energy that the heat ray sensor 10 receives from a heat source such as an intruder is large compared to before the angle adjustment.

Therefore, in this case, the heat ray sensor 10 sensitively detects a small temperature change and outputs an alarm signal, so that there is a high possibility that a false alarm will occur.

Therefore, when the vertical angle is adjusted, it is necessary to adjust the sensitivity accordingly. When the vertical angle is adjusted so that the caution distance is shortened, the sensitivity is adjusted. It is necessary to adjust so as to lower it, and when the vertical angle is adjusted so as to increase the warning distance, it is necessary to adjust so as to increase the sensitivity.

There are two ways to adjust the sensitivity. One is a method of adjusting the gain of the amplifier 4, and the other is a method of adjusting the reference voltage V _ref of the comparator 5. It is clear that the sensitivity can be adjusted by these adjustments. In this specification, the sensitivity is adjusted by adjusting the reference voltage V _ref of the comparator 5, but it is natural that the same effect can be obtained by adjusting the gain of the amplifier 4. .

[0019]

By the way, in the manufacturing stage, the sensitivity and the pulse count value are set so as to operate favorably at a preset warning distance. However, when the heat ray sensor is actually installed. In addition, the vertical angle of the optical system 1 is variously set according to the situation of the installation site or the purpose of use, and the actual warning distance may be different from the preset warning distance. Mostly.

In that case, as described above, it is desired to adjust the sensitivity and the pulse count value according to the actual warning distance, that is, according to the vertical angle of the optical system 1, but the heat ray sensor is desired. It is the reality that the mounting of the device is prioritized, and the troublesome adjustment of the sensitivity and the pulse count value is avoided. This is remarkable as the number of installed heat ray sensors increases.

The present invention is to solve the above-mentioned problems, and it is possible to automatically adjust predetermined parameters such as sensitivity and pulse count value in association with the adjustment of the vertical angle of the optical system. It is intended to provide a heat ray sensor.

[0022]

In order to achieve the above object, the heat ray sensor of the present invention is based on an angle detecting means for detecting a set angle of an optical system and a set angle detected by the angle detecting means. And a setting means for setting the value of a predetermined parameter.

[0023]

In the heat ray sensor of the present invention, when the angle of the optical system is adjusted, the angle detecting means detects it, and the setting means sets a predetermined value according to the angle detected by the angle detecting means. Set the value of the parameter. here,
The parameter may be the sensitivity described in claim 2 or the pulse count value described in claim 3.

As described above, according to the present invention,
Since the values of parameters such as sensitivity and pulse count are automatically set, the heat ray sensor can always be operated in a good state.

Moreover, since it is not necessary for the worker to manually perform the work as in the prior art, it is possible to eliminate the psychological burden on the worker that the predetermined parameters such as the sensitivity and the pulse count have to be set, and the heat ray can be eliminated. The work efficiency when installing the sensor can be improved.

[0026]

Embodiments will be described below with reference to the drawings.
FIG. 1 is a diagram showing a configuration of an embodiment of a heat ray sensor according to the present invention, in which 19 is a vertical angle adjusting mechanism, 20 is a rotary encoder, and 21 is a look-up table (hereinafter referred to as LUT). Indicates. The same components as those in FIG. 4 are designated by the same reference numerals.

The rotary encoder 20 detects the vertical angle of the optical system 1, and is linked to the vertical angle adjusting mechanism 19. Therefore, when the vertical angle adjustment mechanism 19 adjusts the vertical angle of the optical system 1, an output according to the set angle is output from the rotary encoder 20 to notify the control device 6.
Here, the vertical angle is assumed to be 0 ° just below the heat ray sensor 10 as shown in FIG. 5A, and can be adjusted to θ ₃ °.

As shown in FIG. 2, the LUT 21 has a reference voltage V _ref of the comparator 5 for determining the sensitivity and a pulse count value written therein in a predetermined angular range in the vertical direction. The value of the reference voltage V _ref and the pulse count value are determined by theoretical calculation or experiment. In FIG. 2, the vertical angle range has three stages, but this is merely an example, and the number of stages is arbitrary.

Next, the operation will be described. The operator adjusts the angle of the optical system 1 by operating the vertical angle adjusting mechanism 19 after attaching the heat ray sensor at a predetermined position. At this time, the rotary encoder 20 detects the vertical angle set by the angle adjustment and notifies the control device 6 of the vertical angle.

When the controller 6 receives the vertical set angle from the rotary encoder 20, the controller 6 reads the reference voltage V _ref and the pulse count value corresponding to the set angle by referring to the LUT 21, and reads the read reference voltage V _ref . The pulse count value that is read out is set inside the comparator 5 and used for pulse count processing.

For example, if the rotary encoder 20 outputs an angle within the range of 0 ° and θ ₁ ° as a result of the angle adjustment, the control device reads the reference voltage V ₁ from the LUT 21 and supplies it to the comparator 5, and The pulse count value P ₁ is read and set for pulse count processing. The pulse count processing is as described above.

As described above, since the sensitivity and the pulse count value are automatically set according to the vertical angle adjustment,
The heat ray sensor always operates in good condition.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and various modifications can be made.

For example, in the above embodiment, the rotary encoder 20 detects the set angle of the vertical direction angle, but it is also possible to detect it by other methods.

FIG. 3 shows an example thereof. In FIG. 3, one end of the variable resistor 30 is grounded, a potential other than ground is applied to the other end, and the movable contactor is connected to the vertical angle adjustment mechanism 19 to move the movable contact in accordance with the vertical angle adjustment. The child is designed to move. Further, the voltage of the movable contactor is input to the control device 6. As a result, when the vertical angle is adjusted, the voltage of the movable contact changes, and the set angle can be detected from the voltage of the movable contact. In this case, the LUT 21 has the reference voltage V of the comparator 5 with respect to the voltage range of the movable contact.
_{The ref} and the pulse count value are written.

As another method, a rotary switch having a plurality of contacts is used, and the contacts are switched according to the set angle in the vertical direction, and the controller 6 determines which contact is in contact. It is also possible to detect the set angle.

In short, it suffices that the vertical setting angle can be detected by some means, and the setting angle detecting means is not limited.

In the above embodiment, the sensitivity adjustment is performed by changing the reference voltage V _ref of the comparator 5, but the gain of the amplifier 4 may be changed as described above. Is.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an exemplary embodiment of the present invention.

FIG. 2 is a diagram showing a structural example of a LUT 21 of FIG.

FIG. 3 is a diagram showing a configuration example for detecting a vertical set angle.

FIG. 4 is a diagram showing a schematic configuration of a conventional heat ray sensor.

FIG. 5 is a diagram for explaining a vertical direction and a horizontal direction.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Optical system, 2 ... Optical member, 3 ... Pyroelectric element, 4 ... Amplifier, 5 ... Comparator, 6 ... Control device, 7 ... Dip switch, 19 ... Vertical angle adjustment mechanism, 20 ... Rotary encoder, 21 ... LUT, 30 ... Variable resistor.

Claims (3)

[Claims] 1. A heat ray sensor comprising: angle detecting means for detecting a set angle of an optical system; and setting means for setting a value of a predetermined parameter based on the set angle detected by the angle detecting means. . 2. The heat ray sensor according to claim 1, wherein the parameter is sensitivity. 3. The heat ray sensor according to claim 1, wherein the parameter is a pulse count.