JPH08124042A - Optical axis setting method for infrared sensor - Google Patents

Abstract

PURPOSE: To easily set an optical axis of an infrared sensor and also to prevent the malfunction of the sensor due to an execution mistake. CONSTITUTION: The switches SW1 and SW2 are provided between a processing circuit 13 and the preamplifiers 121 and 122 which amplify the light reception output of both light receiving parts 11a and 11b of a light receiver 10. When the power supplies of the receiver 10 and a projector 1 are applied, the infrared beams are transmitted from the projecting parts 2a and 2b. At the same time, the switches SW1 and SW2 of the upper and lower stages of the receiver 10 are turned on and off respectively. Thus only the output of the part 11a of the upper stage is inputted to the circuit 13. Therefore the optical axes of both parts 2a and 11a are adjusted so that the output of the part 11a exceeds a prescribed level. In the same way, the optical axes of both parts 2b and 11b of the lower stages are also adjusted. Then an infrared sensor is actuated only when the approximate coincidence of axes is secured between two pairs of parts 2a and 2b and 11a and 11b respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared type detection device having a light projector having a plurality of light projecting portions and a light receiver having a plurality of light receiving portions for receiving an infrared beam emitted from the light projecting portions. In the device, the present invention relates to a method for setting an optical axis of an infrared detector for making the optical axes of the light projecting section and the light receiving section substantially coincide with each other.

[0002]

2. Description of the Related Art Conventionally, when one infra-red beam is made to travel between a projector and a photo-receiver, which face each other, and when the infrared beam is blocked by an intruder, the photo-received output of the photo-receiver is reduced. Infrared detectors are used which are used to detect an intruder and output a detection signal for issuing an alarm.

However, when the above detector is installed outdoors to detect an intruder, the infrared beam may be blocked by a small bird or a leaf of a tree, which often causes a malfunction. Therefore, in order to avoid such a malfunction, a so-called double beam type infrared detector as shown in FIG. 4 is provided. This infrared detector includes a light projector 1 ′ including a pair of light projecting portions 2a and 2b for transmitting an infrared beam, and a light receiver 10 ′ including a pair of light receiving portions 11a and 11b for receiving each infrared beam. Equipped with respective light projecting portions 2a, 2
The light projecting device 1'and the light receiving device 10 'are arranged to face each other with their optical axes substantially aligned so that the infrared beam is projected and received between b and the light receiving portions 11a and 11b. The distance between the two infrared beams is about 20 cm. In this infrared detector, even if one infrared beam is blocked, the detection signal is not output, and the infrared beams received by the two light receiving portions 11a and 11b of the light receiver 10 'are blocked at the same time. The detection signal is output for the first time. Therefore, it is possible to prevent a malfunction due to one infrared beam being blocked by a small bird or a tree leaf.

FIG. 5 is a schematic circuit block diagram of the above-described light receiver 10 '. In this light receiver 10 ′, each light receiving unit 11
The output according to the received light amount of a and 11b is output by the preamplifier 1
After being respectively amplified by 2 ₁ and 12 ₂ , the amplified output is processed in the processing circuit unit 13. In the processing circuit section 13, the outputs of the respective preamplifiers 12 ₁ and 12 ₂ are combined together to obtain L
Noise due to disturbances such as sunlight is removed by the C filters 14 ₁ and 14 ₂ , and only the signal of the frequency corresponding to the infrared beam from the projector 1 ′ is selectively amplified in the bandpass amplifiers 15 ₁ and 15 ₂ to obtain the data. The detection unit 16 detects the output according to the infrared beam, and when the detection output is less than a predetermined value, it is determined that the two infrared beams are simultaneously blocked and a detection signal is output. An automatic gain control circuit (AGC) 17 is provided between the input end and the output end of the bandpass amplifiers 15 ₁ and 15 ₂ .

[0005]

By the way, in the above-mentioned double-beam type infrared detector, the optical axes of the projector 1'and the photodetector 10 'must be substantially aligned when they are installed. . To this end, first, the light projecting unit 2a and the light receiving unit 11 on one side (for example, the upper stage in FIG. 4).
a is shielded by using a light shielding plate (not shown), and the infrared beam is projected and received only by the other light projecting section 2b (lower stage in FIG. 4) and the light receiving section 11b, and a predetermined output is obtained at the light receiving section 11b. The light projector 1'and the light receiver 10 'are moved so that the optical axis is adjusted. Next, the light-projecting section 2b and the light-receiving section 11b on the opposite side are shielded by a light-shielding plate, and the optical axis is adjusted in the same manner.
It was set so that the optical axis of 11b may be substantially matched.

However, in the above setting method, there is no problem as long as the adjustment of the optical axis is surely performed in the combination of the light projecting sections 2a, 2b and the light receiving sections 11a, 11b, but in terms of the detection method, For example, one light emitting unit 2a and one light receiving unit 1
Even when only the optical axis of 1a substantially coincides, the detection signal is output only by cutting off the infrared beam on the substantially coincident side, and the merit of the double beam system is not utilized. Malfunction cannot be prevented. For example, when the construction is completed without causing the optical axes of the one light projecting portion 2b and the light receiving portion 11b to substantially coincide with each other, the light projecting device 1'and the light receiving device 10 'are in a detectable operating state in that state, There is a problem that there is a risk of malfunction. In addition, there is also a problem in that a light-shielding plate must be used for adjusting the optical axis, and the adjustment is time-consuming.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide an optical axis setting method for an infrared detector, which can easily adjust the optical axis and prevent malfunction due to a mistake in construction. .

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a projector having a plurality of light projecting portions for transmitting an infrared beam, and a plurality of light projecting portions with their optical axes substantially aligned with each other. A method for setting an optical axis of an infrared detector, comprising: a light receiver having a plurality of light receiving portions for receiving each infrared beam, and outputting a detection signal when a plurality of infrared beams are simultaneously blocked. , The infrared rays are sequentially sent from a plurality of light emitting parts provided in the light emitter, and only the light receiving part whose optical axis is substantially aligned with the light emitting part sending out the infrared beam is operated, and the output of the light receiving part is predetermined. Adjusting the optical axes of the light emitter and the light receiver so that the value is equal to or more than the value, and operating state in which the light emitter and the light receiver can be detected only when the adjustment of the optical axes of all the light emitters and the light receivers is completed. It is characterized by

[0009]

According to the above construction, the infrared beams are sequentially transmitted from the plurality of light projecting units provided in the light projector, and only the light receiving unit whose optical axis is substantially aligned with the light projecting unit transmitting the infrared beam is operated. Then, the optical axes of the light emitting unit and the light receiving unit are adjusted so that the output of the light receiving unit becomes a predetermined value or more, and the light emitting unit and the light receiving unit are adjusted only when the optical axis adjustment is completed. Since the receiver is set to be in a detectable operating state, the infrared detector will not be in a detectable operating state even if there is a light emitting section and a light receiving section whose optical axes do not substantially match, and the construction can be performed. It is possible to prevent malfunctions due to mistakes, and it is possible to easily adjust the optical axis without using a light shielding plate as in the conventional case.

[0010]

【Example】

(Embodiment 1) FIG. 1 is a circuit block diagram showing a photodetector 10 of an infrared detector of this embodiment. In this embodiment, the preamplifier 1 that amplifies the light receiving output of each of the light receiving units 11a and 11b.
A switch S is provided between 2 ₁ and 12 ₂ and the processing circuit unit 13.
W ₁ and SW ₂ are provided, and the projector 1 and the processing circuit unit 1 are provided.
Other configurations including 3 are the same as those of the conventional infrared detector of the double beam system, and therefore description thereof will be omitted.

Generally, the setting of the optical axis is carried out as an initial adjustment at the time of construction for installing the light projector 1 and the light receiver 10. Therefore, in the present embodiment, the optical axis setting is automatically performed when the power of the light projector 1 and the light receiver 10 is turned on. This is, for example, the projector 1 and the receiver 10.
Each control microcomputer (not shown)
It is sufficient to provide the above, and perform the initialization operation when the power is turned on. In addition to this, a dedicated set switch (not shown) for setting the optical axis may be provided, and the optical axis may be set when the set switch is operated.

Next, a method of setting an optical axis in the infrared type detector having the above configuration will be described with reference to the flow chart shown in FIG. When the power of the light projector 1 and the light receiver 10 is turned on (step 1), an infrared beam is sent from the light projector 1, and the switch SW ₁ of the light receiver 10 is turned on and the switch SW ₂ is turned off (step 2). As a result, only the light receiving output of the upper light receiving unit 11a is input to the processing circuit unit 13 via the preamplifier 12 ₁ . In other words, this is the same as when the light receiving portion 11b in the lower stage of the light receiver 10 is shielded by the light shielding plate. In this state, the optical axes of the upper light projecting section 2a and the light receiving section 11a are adjusted (step 3) so that the signal level in the processing circuit section 13 becomes a predetermined value or more (step 4). As a result, the optical axes of the upper light projecting section 2a and the light receiving section 11a can be made substantially coincident with each other, and when the upper optical axis adjustment is completed, the upper light projecting section 2a of the projector 1 is set to a light emitting state (step 5).

Then, the switch SW ₁ of the light receiver 10 is turned off and the switch SW ₂ is turned on (step 6), and only the light receiving output of the lower light receiving portion 11b is input to the processing circuit portion 13 via the preamplifier 12 _2. In this state, the optical axes of the lower light projecting unit 2b and the light receiving unit 11b are similarly adjusted in this state (step 7) so that the signal level in the processing circuit unit 13 becomes a predetermined value or more (step 7). 8). As a result, the optical axes of the lower projecting section 2b and the light receiving section 11b can be made to substantially coincide with each other, and when the lower optical axis adjustment is completed, the lower projecting section 2b of the projector 1 is set to the light emitting state (step. 9). When the adjustment of the optical axes of the upper and lower light projecting sections 2a and 2b and the light receiving sections 11a and 11b is completed as described above, the two switches SW ₁ and SW ₂ are both turned on to detect the infrared detector. The operation state is set to a possible state (step 10), and a warning state for detecting an intruder is set (step 11).

According to the above method, since the light receiving parts 11a and 11b of the light receiver 10 are shielded in a circuit manner to adjust the optical axis, the optical axis can be adjusted without using the light shielding plate.
Further, two sets of light projecting units 2a and 2b and light receiving units 11a and 11b are provided.
Since the infrared detector is put into the operating state only after the optical axes of the optical axes of the two are adjusted to be substantially coincident with each other, the light projecting sections 2a and 2b and the light receiving section 11 whose optical axes are not substantially coincident with each other at the time of construction.
When a and 11b are present, the infrared type detector does not enter a detectable operating state, and it is possible to prevent a malfunction from occurring due to a construction error.

(Embodiment 2) FIG. 3 shows the infrared type inspection of this embodiment.
It is a diagram showing a schematic configuration of the intellectual device, in the basic configuration
Is the double-beam infrared detection of the conventional and the first embodiment
The same parts as those in
The description is omitted. As shown in FIG. 3, the projector 1 includes a pair of projectors.
Light emitting diode LED₁, LED₂Is a light emitting drive circuit
3 are connected in series, and each light emitting diode LE
D₁, LED ₂Switch SW in parallel with₁’, SW₂'When
Resistance R₁, R₂Are configured by connecting a series circuit of
You. In addition, light emitting diode LED₁, LED₂Is the floodlight section
2a and 2b. And light emitting diode LED₁,
LED₂The infrared beam emitted from
Then, it is diffused and sent to the light receiver 10.

On the other hand, the light receiver 10 is provided with a lens 18 for focusing each infrared beam on the light receiving portions 11a and 11b. The light receiving outputs of the light receiving units 11a and 11b are amplified by the preamplifiers 12 ₁ and 12 _2, respectively, and then sent to the processing circuit unit 13 to be processed and detected only when two infrared beams are simultaneously blocked. It is designed to output a signal. In this embodiment, similarly to the first embodiment, switches SW ₁ and SW ₂ are provided between the preamplifiers 12 ₁ and 12 ₂ and the processing circuit unit 13, respectively.

Next, a method of setting the optical axis in the infrared type detector having the above structure will be described. First, when power is applied to the light emitter 1 and the light receiver 10 as in the first embodiment, the switch SW ₁ ′ of the light emitter 1 is on, the switch SW ₂ ′ is off, and the switch SW _{1 of the} light receiver 10 is on and the switch SW. ₂ is off. Here, the power supply to the projector 1 and the ON / OFF operation of the switches SW ₁ ′ and SW ₂ ′ are controlled by a wired or wireless remote control signal.
The remote control may be performed in synchronization with ON / OFF of the switches SW ₁ and SW ₂ of 0, which can be realized by a known technique.

When the switch SW ₁ 'of the projector 1 is turned on and the switch SW ₂ ' is turned off, the two light emitting diodes L
ED ₁ , LED ₂ upper light emitting diode LED ₁
Only glows. Further, if the switch SW ₁ of the light receiver 10 is turned on and the switch SW ₂ is turned off, the light receiving unit 1 in the upper stage is
Only the received light output of 1a is input to the processing circuit unit 13 via the preamplifier 12 ₁ . That is, only one infrared beam is sent from the light projector 1 to the light receiver 10, and the noise of the disturbance in the light receiver 11b in the lower stage of the light receiver 10 is not input to the processing circuit unit 13. Therefore, in this state, the optical axes of the upper light projecting unit 2a and the light receiving unit 11a are adjusted so that the signal level in the processing circuit unit 13 becomes a predetermined value or more. As a result, the optical axes of the upper light projecting section 2a and the light receiving section 11a can be made substantially coincident with each other. Similarly, when the switch SW ₁ ′ of the projector 1 is turned off and the switch SW ₂ ′ is turned on, only the lower light emitting diode LED ₂ among the _two light emitting diodes LED ₁ and LED ₂ emits light. Further, if the switch SW ₁ of the light receiver 10 is turned off and the switch SW ₂ is turned on, only the light reception output of the lower light receiving portion 11b is input to the processing circuit portion 13 via the preamplifier 12 ₁ . Therefore, in this state, the optical axes of the lower light projecting unit 2b and the light receiving unit 11b are adjusted so that the signal level in the processing circuit unit 13 becomes a predetermined value or more. As a result, the lower light projecting section 2b
The optical axes of the light receiving section 11b and the light receiving section 11b can be substantially matched.

In this way, when the adjustment of the optical axes of the upper and lower stages is completed and substantially coincides with each other, the switch S of the projector 1 is switched.
By turning off W ₁ ′ and SW ₂ ′ and turning on the switches SW ₁ and SW ₂ of the light receiver 10, two infrared beams are sent from the projector 1 to the light receiver 10 and the infrared type is used. The detector is set to a detectable operating state.

According to the above method, as compared with the case of the first embodiment, the light projecting portions 2a and 2b of the light projecting device 1 are also sequentially irradiated with the infrared beams, respectively. Therefore, the light receiving device 1
It is possible to more accurately make the optical axes substantially coincident with each other without being affected by the infrared beam from the light projecting sections 2a and 2b, which is the pair of the zero light receiving sections 11a and 11b. Although the double beam system in which two infrared beams are transmitted has been described in the above-described first and second embodiments, the present invention is also applicable to the setting of the optical axis of the infrared type detector using three or more infrared beams. It goes without saying that the technical idea of the invention can be applied.

[0021]

According to the present invention, a projector having a plurality of projectors for transmitting infrared beams, and a plurality of receivers for receiving the infrared beams with their optical axes substantially aligned with the projectors, respectively. A method of setting an optical axis of an infrared detector, comprising: a light receiver provided with, which outputs a detection signal when a plurality of infrared beams are simultaneously blocked. In addition to transmitting the infrared beam, only the light receiving section that should have its optical axis substantially aligned with the light projecting section transmitting the infrared beam is operated, and the light projecting section and the light receiving section are set so that the output of the light receiving section becomes a predetermined value or more. Adjust the optical axis with
Since the projectors and receivers are set to the operating state in which they can be detected only when the adjustment of the optical axes of all the projectors and the receivers is completed, even if one of the projectors has optical axes that do not substantially match. When the light receiving part is present, the infrared type detector does not become in a detectable operating state, and it is possible to prevent malfunctions due to construction mistakes, and it is possible to easily adjust the optical axis without using a light shielding plate as in the past. The effect is that you can.

[Brief description of drawings]

FIG. 1 is a schematic block diagram showing a light receiver according to a first embodiment.

FIG. 2 is a flowchart for explaining the optical axis setting method of the above.

FIG. 3 is a schematic block diagram showing a second embodiment.

FIG. 4 is a schematic configuration diagram showing a conventional example.

FIG. 5 is a circuit block diagram of a light receiver in the above.

[Explanation of symbols]

1 projector 2a, 2b projecting portion 10 light receiver 11a, 11b light receiving portion SW _1, SW ₂ switch SW ₁ ', SW _2' switch

Claims (1)

[Claims] 1. A light receiver including a plurality of light-projecting units for transmitting infrared beams, and a plurality of light-receiving units for receiving each infrared beam with their optical axes substantially aligned with the plurality of light-projecting units. A method for setting an optical axis of an infrared type detector that includes a light source and outputs a detection signal when a plurality of infrared beams are simultaneously blocked, and the infrared beams are sequentially transmitted from a plurality of light projecting units included in the light projector. In addition, the optical axis of the light emitting section and the optical axis of the light receiving section are operated so that the output of the light receiving section becomes a predetermined value or more by operating only the light receiving section whose optical axis should be substantially aligned with the light emitting section transmitting the infrared beam. And setting the optical axis of the infrared detector so that the light emitter and the light receiver can be detected only when the adjustment of the optical axes of all the light emitters and the light receivers is completed. .