JPH0231296A - Invader detector using hologram - Google Patents

Abstract

PURPOSE:To enlarge a detecting range by using hologram in optical parts, bidirectionally transmitting an infrared ray through the optical parts, diffracting the infrared ray with a constant diffracting angle at the time of transmission and forming a cone-shaped detecting area with the revolution of the optical parts. CONSTITUTION:An infrared ray beam 22A to transmit through a hologram disk 23 is diffracted and outgoing as outgoing beams 22b and 22c. These outgoing beams 22b and 22c are reflected on indoor constituting objects and incident to the hologram disk 23 as a diffused light 22d. Then, the light is diffracted again, condensed by a condenser lens 23 as a diffracted light 23A and incident to a photo-detecting element 25 as an incident light 24A. The photo-detecting element 25 outputs an electric signal to correspond to the light quantity of the incident light 24A. Then, the output of the photo-detecting element is caused to be numerical values by an A/D converter 27 and successively stored to a newest indoor data storing part 28. The hologram disk 23 is monotonously revolved and driven by a motor driving part 32 and a motor 33. Thus, the outgoing beams 22b and 22c also turn around the inside of a room so as to draw the surface of a cone respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an intruder detector having an infrared radiation source and an infrared receiving element.

[Conventional technology]

FIG. 2 shows the configuration of a conventional intruder detector, in which 1 is a pulse modulation signal generation circuit that generates a pulse modulation signal, and in response to this pulse modulation signal, a radiation source driver 2 drives an infrared radiation source 3.
The infrared rays (near infrared light, etc.) emitted from the infrared radiation source 3 are radiated via the radiation layer optical component 4 to indoor components such as floors, walls, desks, and lockers. This emitted light 5 hits the indoor components and is reflected, becoming scattered light 6. This scattered light 6 is received by a light receiving element 8 via a light receiving optical component 7, and the light receiving element 8 outputs an electric signal according to the amount of light received. This signal is passed through a detector 9 and an amplifier 10 to a comparison/judgment processing section 1.
2 is input. On the other hand, the unmanned detected amount storage section 11 stores the unmanned detected amount, that is, the output of the amplifier 10 when unmanned, and the comparison judgment processing section 12 stores the output of the amplifier 10 and the output of the unmanned detected amount storage section 11. When the deviation exceeds a certain value, it is determined that there is an intruder, and an intruder alarm S is output.

[Problem to be solved by the invention]

The conventional intruder detector described above is generally installed on the ceiling or wall, and the detection area is fixed to a part of the room such as an irradiation spot on the floor or wall or a space through which the emitted light passes. On the other hand, in rooms where there are multiple places that can be penetrated, such as doors and windows, a wide detection area is required, and in order to satisfy this requirement, the number of detectors must be increased, which increases the installation cost of the detectors. There were issues such as increased operating costs.

Therefore, in order to minimize the number of detectors installed indoors, it was necessary to widen the detection area of the detector, and it was considered to drive the infrared radiation source 3 and the light receiving element 8 in rotation. . However, in this case, the signal lines for the radiation source 3 and the light receiving element 8 also rotate, resulting in a problem that the signal lines are twisted or torn. For this reason, it was necessary to devise a mechanical configuration to prevent the signal line from rotating, but this made the configuration complicated and increased electrical noise, making it impractical. It is also conceivable to rotate the optical components 4 and 7 such as lenses and lenses, and in this case, the directions of radiation and light reception are changed by rotating the optical components 4 and 7. As a result, there is no need to rotate the radiation aI3 and the light receiving element 8,
The signal line will not be twisted or torn (
Become. However, in order to accommodate the rotating optical component 4.7 in a compact detector, it is not possible to increase the light receiving area of the optical component 4.7, and the minute scattered light 6
It became difficult to receive more light. For this reason, it became difficult to detect changes in the intensity of the scattered light 60, and it became difficult to distinguish between when no one was present and when an intruder was present.

Further, since the optical components 4.7 rotate, it becomes difficult to maintain a constant optical path connecting the radiation 113 and the optical component 4, or the light receiving element 8 and the optical component 7. As described above, conventional intruder detectors have a problem in that the directions of radiation and light reception cannot be easily changed, making it difficult to widen the detection area.

This invention was made to solve the above-mentioned problems; the optical component can serve as both the radiation side and the incident side, the optical component can be easily rotated, and the detection range can be expanded with a compact configuration. The purpose is to obtain an intruder detector that can be expanded.

[Means to solve the problem]

An intruder detector according to the present invention includes an optical component using a hologram that transmits infrared radiation and scattered light at a constant diffraction angle, a rotation drive means for rotationally driving the optical component, and a scattered light transmitted through the optical component. A storage means for storing the amount of light received in each direction of the optical component as the latest indoor data, a storage means for storing the amount of light received when unattended as the unattended indoor data, and an intruder alarm according to the difference between the two data. A comparison judgment processing means for outputting the information is provided.

[For production]

The optical component in this invention uses a hologram, and infrared rays pass through the optical component in both directions, and are diffracted at a certain diffraction angle during transmission, and a conical detection area is formed by rotation of the optical component.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. 1st
The figure shows the configuration of an intruder detector according to this embodiment, and shows 21
is a laser drive unit that drives the laser diode 22 with a pulse modulation signal, and the laser diode 22 emits an infrared beam 22A. A hologram disk 23 receives the infrared beam 22A, and is an optical component using a hologram that transmits emitted light and scattered light in both directions at a constant diffraction angle. 24 is a condenser lens that condenses the light transmitted through the hologram disk 23, 25 is a light receiving element that receives the focused light, 26 is an analog signal processing unit that processes the output of the light receiving element 25, and 27 is an analog signal Processing section 26
28 is the latest indoor data storage unit that stores the output of the A/D converter 27; 29
3 is an unmanned room data storage unit that stores unmanned room data, that is, the latest indoor data when there is no intruder; 30 is a comparison judgment processing unit that compares the unmanned room data with the latest indoor data; 31 is a rotation reference direction of the hologram disk 23; 32 is a motor drive unit that drives a motor 33, and the motor 33 detects the hologram disk 23.
is driven to rotate with its central axis as the rotation axis.

Next, the operation of the above configuration will be explained. The laser diode 22 driven by the pulse modulation signal generated by the laser drive section 21 emits an infrared beam 22A, which is incident on the hologram disk 23. The infrared beam 22A that has passed through the hologram disk 23 is diffracted at a diffraction angle determined by the conditions at the time of hologram production, and output beams 22b and 2 exit the detector.
It is emitted as 2C. This output beam 22b, 22
The light c hits the indoor components and is reflected, enters the hologram disk 23 as scattered light 22d, is diffracted again, is focused by the condenser lens 23 as diffracted light 23A, and enters the light receiving element 25 as incident light 24A. . Light receiving element 25
outputs an electric signal according to the amount of incident light 24A, and this electric signal is amplified and sampled and held in the analog signal processing section 26, then digitized by the A/D converter 27, and stored in the latest indoor data storage section 28. are stored sequentially. on the other hand,
The hologram disk 23 is driven to rotate monotonically by the motor drive unit 32 and the motor 33, and therefore the emitted beams 22b and 22c also orbit inside the room so as to draw conical surfaces, respectively. The rotation reference direction of the hologram disk 23 is detected by the photo ink clubter 31 detecting a microhole provided in the hologram disk 23, and at this time, the direction in which the emitted beams 22b and 22c are facing is determined as the indoor reference direction ( By rotating the hologram disk 23 in this way, digitized data for each direction, such as every 0.1 degree, is obtained, and this digitized data is sequentially stored in the latest indoor data storage unit 2. By storing the latest indoor data, the latest indoor data is generated, and the data in the latest indoor data storage section 28 is updated every - period. Furthermore, the latest indoor data when there is no intruder is copied and stored in the unmanned indoor data storage section 29. The comparison/judgment processing unit 3o compares the unmanned indoor data and the latest indoor data, for example, every 0.1 degree rotational direction, and if a difference of more than a predetermined value is detected between the two, it is determined that there is an intruder. and outputs an intruder alarm S.

Figure 3 (al, (bl) shows how the directions of the outgoing beams 22b, 22c change when the hologram 23 is rotated, and the directions of the outgoing beams 22b, 22C are the same as those of the infrared beam 22.
Incidence position 2 when A enters the hologram disk 23
It shows that it changes continuously in 3B. Note that the small arrow in the center of the hologram disk 23 is drawn for convenience to indicate that the hologram disk 23 is rotating.

FIG. 4 shows a timing chart showing that the infrared beam 22A is pulse-modulated, an example of the received scattered light intensity and its numerical data, (al is the infrared beam 22A)
The intensity of A, the peak) indicates the received light intensity of the scattered light 22d, and (C1 indicates numerical data of this received light intensity).

Further, FIG. 5 shows experimental data according to this example, in which (a) shows the unmanned indoor data stored in the unmanned indoor data storage section 29, and the horizontal axis indicates the direction of rotation (0 to 360
(degrees), and the vertical axis is the received scattered light intensity (the numerical value is the detection voltage value V). (b) shows the latest indoor data when there is a person in the detection area, and the arrow part shows the case when there is no person. It turns out that there is a person because the outputs are different. (C) shows the difference between the unoccupied indoor data and the latest indoor data, indicating that a person is moving within the detection area. th is the difference between both data when it is determined that there is an intruder.

〔Effect of the invention〕

As described above, according to the present invention, a hologram is used as an optical component, and infrared rays transmitted through this optical component are diffracted. Therefore, the conical bark detection area is formed by rotating the optical component, and a wide range of detection area can be obtained. In addition, the optical components only need to be rotated monotonously, and the entire surface can be used effectively as both the infrared radiation side and the light receiving side, and the optical system and its rotation mechanism can be constructed easily and inexpensively. In addition, a relatively large light-receiving area can be obtained, and the optical path does not fluctuate due to the rotation of optical components, making it possible to obtain a reliable detector. Furthermore, since the rotation direction of the optical component can be detected, the direction in which the intruder is present can be detected, and by recording this, the movement of the intruder can also be detected, making it possible to more accurately identify the intruder. Detection can be performed.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an intruder detector according to the present invention, Fig. 2 is a block diagram of a conventional intruder detector, and Fig. 3 is a diagram showing how the direction of the emitted beam changes when the hologram disk according to the present invention is rotated. FIG. 4 is a timing chart showing the operation of each part according to the present invention, and FIG. 5 is a data diagram obtained by the intruder detector of the present invention. 21... Laser drive unit, 22... Laser diode, 23... Hologram disk, 24... Condensing lens, 25... Light receiving element, 28... Latest indoor data storage unit, 29... - Unmanned room data storage unit, 30... Comparison judgment processing unit, 32... Motor drive unit, 33... Motor. Figure (b)

Claims (1)

[Claims] an infrared radiation source that emits pulse-modulated infrared radiation;
This infrared radiation is transmitted at a certain diffraction angle, and the transmitted infrared radiation hits indoor components and reflected scattered light is transmitted at a certain diffraction angle. A light-receiving element for receiving scattered light, a rotational drive means for rotationally driving the optical component, an up-to-date indoor data storage means for sequentially storing the amount of light received by the light-receiving element in each direction of the optical component as the latest indoor data; An unmanned room data storage means that stores the amount of light received by the light receiving element in each direction of the optical component as unmanned room data, and a comparison judgment process that compares the latest indoor data with the unmanned room data and outputs an intruder alarm according to the difference. An intruder detector using a hologram, characterized in that it is equipped with a means.