JPS62255832A - Mirror scanning type radiation detector - Google Patents

Abstract

PURPOSE:To exactly detect an object to be detected, by constituting the titled detector so that a radiant ray of the object to be detected being within a range extending from a short distance to a long distance is led to a photoelectric transducer, and the photoelectric transducer converts the radiant ray to a signal for detecting the object to be detected. CONSTITUTION:A rotary mirror 36 functions as a scanning mirror for scanning the inside of a range extending from a short distance to a long distance, and a photoelectric element 48 has a function for converting a radiant ray of an object to be detected to a detected object detecting signal. The radiant ray from its object to be detected is reflected by the rotary mirror 36, and thereafter, passes through an objective lens 40, reflected by a mirror 42, forms an image on a slit plate 44, and the radiant ray which has passed through its slit 50 is led to the photoelectric transducer 48 by a relay lens 46. Subsequently, a detected object signal of the photoelectric transducer 48 is inputted to a comparator through an amplifier, and when a level of the examined object signal exceeds a level of a reference signal, it is decided to be a fire, and when the level of the examined object signal is below the level of the reference signal, it is decided not to be a fire.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention detects the amount of emitted light from a test object that exists anywhere from a short distance to a long distance, and determines the test object. The present invention relates to a mirror-scanning radiation detector that can be used.

(Prior art) Fire detectors have conventionally been used as radiation detectors that detect the amount of emitted light from a target that exists anywhere from near to far and determine the target. Are known. This fire detector guides the amount of emitted light from the object to be tested at a predetermined location to a photoelectric conversion element, and determines whether or not the detection signal of the object to be tested as the detection output of the photoelectric conversion element exceeds a standard level. The system is designed to determine whether there is a fire or not.

However, this fire detector detects the presence or absence of a fire by comparing it with a reference level, and the detection output differs depending on whether the target is close or far away, and If you set a reference level at the same time, the detection output of the object to be tested at a distance will be lower than the reference level, and it will not be possible to detect a fire even though there is a fire, and the detection output will be lower than the reference level. If the reference level is also set low, there is a problem that cigarettes or other objects that are not at a close distance may be mistakenly detected as test objects, and if the test object is close or far away. There is a problem that the test object cannot be detected accurately depending on whether the test object is present or not.

(Problems to be Solved by the Invention) Therefore, in Japanese Patent Application Laid-Open No. 186094/1986, based on the fact that there is infrared rays peculiar to fire, the infrared rays can be detected within a range from short to long distances. In order to detect the object to be tested at different positions, slits are formed at predetermined angles in the rotating direction of the rotating disk, and the slit formation locations are shifted in the radial direction to detect different positions of the object. In order to scan an object within the range of
The rotary disk is rotated to pass through slits at different positions to guide the amount of emitted light from the object to be tested to an infrared detection element, and the detection output of this infrared detection element is positionally corrected depending on the slit passing position. We are proposing something that can accurately detect the object to be examined, regardless of whether it is located at a distance or not. However, this Japanese Patent Application Publication No. 59-186
The configuration disclosed in Japanese Patent No. 094 is such that each slit is formed in a rotating disk, and the object to be examined is detected by passing through each slit.

There is a problem that the detection field of view is narrowed.

(Objective of the Invention) The present invention has been made in consideration of the above circumstances, and its purpose is to accurately detect objects from short to long distances without narrowing the detection field of view. The object of the present invention is to provide a mirror scanning type radiation detector capable of detecting radiation.

(Means for solving problems) The features of the mirror scanning radiation detector according to the present invention are as follows.

A scanning mirror sequentially scans the range from near to far, and the emitted light from the object within this range is guided to the photoelectric conversion element, which converts the emitted light detected from near to far. a scanning means that photoelectrically converts the signal and outputs it as a test object detection signal; a correction signal forming means for generating a correction signal corresponding to which position within a range from a short distance to a long distance is being scanned in order to make a determination; and the correction signal and the object detection signal. and determining means for determining the subject based on.

(Function) According to the mirror-scanning radiation detector according to the present invention, emitted light from the object to be examined within a range from a short distance to a long distance is guided to a photoelectric conversion element by scanning of a scanning mirror. The photoelectric conversion element converts the emitted light into an object detection signal. This object detection signal changes sequentially as the object is scanned from a short distance to a long distance. On the other hand, the correction signal forming means cooperates with the test object detection signal to determine whether or not this test object detection signal is obtained by a regular test object. The zero determination means, which generates a correction signal in accordance with a change in the scanning position within a distance range, determines whether or not the object to be examined is normal based on the correction signal and the object detection signal.

(Example) Hereinafter, an example in which a mirror scanning radiation detector according to the present invention is applied to a fire detector will be described with reference to the drawings.

In FIG. 1, reference numeral 10 indicates the main body of a fire detector as a mirror scanning radiation detector. This main body part 10 consists of a housing 12, a support body 14 that rotatably supports this housing 12, and a base part 16 that is fixed to an architectural structure. Housing 2 has hood 1
8, a shaft 20, and a bolt 22 are attached. The support body 14 is formed in a substantially U-shape, and has an insertion hole 24 and an arcuate guide groove 26 formed therein. A shaft 20 fixed to the housing 12 is inserted into the insertion hole 24, and the bolt 22 passes through a guide groove 26 and is screwed onto the housing 12. It is in.

The housing 12 is tilted vertically about a shaft 20 and adjusted, and is held at a predetermined angle with respect to the horizontal direction H by tightening bolts 22 after the adjustment.

The housing 12 is connected to a signal processing circuit to be described later by a cable 28, and the housing 12 includes a protective glass 34 and a rotating mirror 36, as shown in an enlarged view in FIG.
A motor 38 for rotating the motor 38. Objective lens 40, mirror 42, slit plate 44 for limiting the field of view. Relay lens 46, photoelectric conversion element 48. An eyepiece system 52 and the like are housed therein. The rotating mirror 36 functions as a scanning mirror that scans from a short distance to a long distance, and the motor 38, objective lens 40, mirror 42, slit plate 44, relay lens 46, and photoelectric conversion element 48 are Together with the rotating mirror 36, it constitutes a scanning means. Note that the hood 18 serves to prevent the protective glass 34 from getting dirty and also to cut out ambient light.

The photoelectric conversion element 48 has a function of converting the emitted light of the object to be examined within a range from a short distance to a long distance to an object detection signal. The emitted light from the test object is reflected by the rotating mirror 36, passes through the objective lens 40, is reflected by the mirror 42, forms an image on the slit plate 44, and the emitted light that passes through the slit 50 is relayed. The light is guided to a photoelectric conversion element 48 by a lens 46.

Here, the fire detector scans the target in the horizontal direction (angle θ direction) within a range from near distance θ to far distance θ, as shown in FIG. It is now possible to scan the subject in the vertical direction (altitude angle r direction) within the range from short distance r1 to long distance rn, and in Figures 3 and 4, white circles indicate fire detection. The rotating mirror 36 of the main body 10 of the fire detector is shown, and the reference numeral 200 indicates a building structure, and the main body 10 of this fire detector is installed above the building structure 200.

The rotating mirror 36 scans from below to above in the direction of arrow A shown in FIG. 2 by its rotation.

Note that the initial scanning position in the horizontal direction θ is the rotating mirror 3.
It is set by standardizing the eyepiece lens system 52 with the eyepiece 6 rotated. The control signal of the motor 38 and the test object detection signal of the photoelectric conversion element 48 are exchanged with the signal processing circuit via the cable 28. Here, the optical elements housed in the housing 12 including the housing 12 together with the motor 38 constitute a vertical scanning section as a first scanning system.

The base 16 is connected via a cable 30 to a control calculation section 130, which will be described later. This base 16 has a motor 32
is built-in, and a support driving means (not shown) is also built-in. This motor 32 constitutes a part of a second scanning system that rotates the support 14 in the horizontal direction in response to a control signal from the control calculation unit 130, and this second scanning system is a horizontal scanning system that rotates the vertical scanning unit in the horizontal direction. Functions as a scanning section.

The fire detector has a standard level I constant part 1 as shown in Figure 5.
．． OO, the comparator 124 and the control calculation unit 130,
It has a signal processing circuit including an operation section 140 for issuing various commands, a display 150 based on signals from the control calculation section 130, and a memory 160. The reference level setting section 100, together with the control calculation section 130 and the memory 160, cooperates with the test object detection signal to determine whether the test object signal is obtained by a regular test object. Therefore, a correction signal forming means is configured to generate a correction signal corresponding to a scanning position within a range from a short distance to a long distance.

The reference level setting section 100 has a function of setting a reference signal as a correction signal, and includes a clock circuit 112 and a frequency divider 1.
14. It is composed of a counter 116, a D/A converter 118, a buffer 120, and an initial value setting section 122.

The comparator 124, together with the control calculation unit 130, functions as a determining means for determining whether or not the object to be tested is normal based on the correction signal and the object detection signal. The clock circuit 112 forms a pulse with a predetermined period and outputs it to the frequency divider 114, and the frequency divider 114 divides the clock pulse from the clock circuit 112 based on the control signal from the control calculation unit 130, and outputs the pulse to the frequency divider 114. Counter 11 by changing the period
Output towards 6. This periodic change is related to the change in the level of the reference signal.

The initial value setting unit 122 sets an initial value based on the control signal from the control calculation unit 130, and sets the initial value to the counter 1.
16, and the counter 116 starts counting after its initial value is set. The output of counter 116 is D/
It is input to the A converter 118, converted into analog,
The analog signal is input to the comparator 124 as a reference signal via the buffer 12G. Here, this reference signal is used to determine whether or not the object to be tested is a fire, and when the level of the signal to be tested exceeds the level of the reference signal, it is determined that there is a fire. When the level of the signal to be tested is lower than the level of the reference signal, it is determined that there is no fire. The test target signal of the photoelectric conversion element 48 is inputted to the comparator 124 via the amplifier 48a, and is compared with the reference signal from the buffer 120, and the comparison result signal is sent to the control calculation unit 130.
Output to.

The control calculation unit 130 controls the motor 38 of the first scanning system and the motor 32 of the second scanning system, and also controls various circuits based on various information inputted from the operation unit 140, such as the installation status of the fire detector. In addition to outputting control signals to the display device 150
The fire occurrence position signal is displayed in accordance with the output of the comparator 124 and output to the outside via the interface 152.

From the operation unit 140, the horizontal detection direction θ, (i=1.2,
. . . n), the initial value of the reference signal is set to the frequency divider 114.
The frequency division ratio j5 and count increase/decrease information are input according to the installation status of the fire detector, and the control calculation unit 130 stores the frequency division ratio j1 and count increase/decrease information in memory 1 according to the initial value of this reference signal.
60 and read it as necessary to set the initial value KL.
is outputted to the initial value setting section 122, the frequency division ratio j is outputted to the frequency divider 114, and the increase/decrease information of the count is outputted to the counter 116.

Here, the initial value 1 corresponds to the initial level of the reference signal at θ, the frequency division ratio j corresponds to the slope of the level of the reference signal at θ, and the increase/decrease information of the count is based on the reference signal. It consists of an increase command signal that increases the level of the reference signal and a decrease command signal that decreases the level of the reference signal.The details will be explained along with the operation of the fire detector according to the installation situation of the fire detector.

First, the control calculation unit 130 controls the motor 32 so that the housing 12 faces in the θ□ force direction (see FIG. 3).

Next, the control calculation unit 130 rotates the motor 38 and
Scanning is performed from the direction r1, but at this time the memory 16
An initial value of 3 in the direction from 0 to 0, a frequency division ratio j1, and a reduction command signal are output to the initial value setting unit 122, frequency divider 114, and counter 116, respectively.

The counter 116 is set to an initial value of 1, and a signal is generated at the initial level of the reference signal shown in FIG. 6 via the D/A converter 118 and the buffer 120. As the altitude angle increases as the motor 38 rotates, the building structure 20
Although the distance to 0 becomes longer, the count value of the count circuit 116 decreases each time a divided pulse of the frequency divider 114 that divides the clock pulse of the clock circuit 112 is received, and the level of the reference signal decreases. do.

When the altitude angle exceeds the r-y direction, the building structure 200
Since the distance to is shortened again, the control calculation section 130 outputs an increase command signal to the counter 116, and the level of the reference signal becomes high again. The comparator 124 sequentially compares the level of the reference signal and the test object detection signal. When the detection of the 01 direction is completed, the control calculation unit 130 controls the motor 32 so that the housing 12 faces from the θ1 direction to the θ2 direction, and sets the initial value of the 02 direction to 2, the frequency division ratio j2, and the data of count increase/decrease information. Initial value setting section 122
, the frequency divider 114, and the counter 116.

Then, a scan similar to the scan in the 01 direction is performed.

This scanning is repeated until the scanning from the θ direction to the 01 direction is completed, and the first scanning of the entire scanning range in the horizontal and vertical directions is completed.

Here, for example, as shown in FIG. 7, if a cigarette that is different from the regular test object is detected in the r direction, and a fire as a regular test object is detected in the r2 direction, then the 8th As shown in Fig. 9, the level of the reference signal is high, so even if a cigarette is detected at a close distance, the cigarette is prevented from being mistakenly detected as a legitimate test object. In addition, even if the fire that is the official test target is located far away, the level of the reference signal is set low, so the official test target will be mistakenly detected as not being the official test target. This will be prevented.

FIG. 10 is a block circuit diagram showing another embodiment of the correction signal forming means, in which a clock circuit 112, a frequency divider 114
, a memory 180 is provided in place of the initial value setting section 122 and the counter 116, and the memory 180 and D/
The A converter 118 and the buffer 120 constitute a reference level setting section 100, and the memory 18
0, the entire scanning range (θL, i=1, scant, . . . , n:rt, i=1.2
, . . . , n), and during scanning, the control calculation unit 130 sequentially reads out the levels of the reference signals corresponding to the detection direction from the memory 180 and converts them to the D/A converter. After being converted to an analog signal at 118, it is passed through a buffer 120 to a comparator 124.
The comparator 124 compares the detection signal with the object detection signal.

FIG. 11 shows another embodiment of the determination means, in which the correction signal forming means generates a correction signal having an envelope inversely proportional to the square of the distance in order to offset the distance to the object to be examined; The determination means is configured to cancel the change in the detection signal of the object to be tested based on the change in distance, and the memory 160 serving as the correction signal forming means stores a correction value that is inversely proportional to the square of the distance. . Control calculation unit 13
0 has a function of reading out, as a correction signal, a correction value corresponding to the distance to the object to be examined in the detection direction in accordance with the amount of operation of the motor 38 and the motor 32. The object detection signal of the photoelectric conversion element 48 is converted into an analog-to-digital signal by the A/D converter 162 and input to the control calculation section 130 . The control calculation unit 130 multiplies the test object detection signal by a correction value as a coefficient proportional to the square of the distance, cancels the change in the amount of emitted light due to the change in distance, and thereby detects the test object. The purpose is to determine whether or not it is legitimate, and the other configurations are generally the same as those of the previous embodiment, so a detailed explanation thereof will be omitted.

(Effects of the Invention) Since the mirror scanning radiation detector according to the present invention is configured as described above, it is possible to accurately detect a subject within a short to long distance range without narrowing the detection field of view. This effect is achieved.

[Brief explanation of drawings]

FIG. 1 is a side view showing the structure of the main body of a mirror scanning radiation detector according to the present invention, and FIG. 2 is an enlarged perspective view showing the housing of the mirror scanning radiation detector together with its internal structure. Figures 3 and 4 are explanatory diagrams showing the installation status of the mirror scanning radiation detector. Figure 3 is a diagram showing the horizontal installation status, and Figure 4 is the vertical installation status. FIG. 5 is a block circuit diagram of the mirror scanning radiation detector according to the present invention, and FIGS. 6 to 8 are diagrams for explaining the operation of the mirror scanning radiation detector according to the present invention. 6 and 8 are diagrams showing the state in which the level of the reference signal changes as it goes from a short distance to a long distance, and FIG. 9 is a signal comparison diagram for explaining the determination by the determination means of the mirror scanning radiation detector, FIG. 10 is a block circuit diagram showing another embodiment of the correction signal forming means according to the present invention, and FIG. 11 FIG. 6 is a diagram showing still another embodiment of the determination means and correction signal forming means according to the present invention. 10... Main body part, 14... Support body,
36... Rotating mirror, 32, 38... Motor. 40... Objective lens, 48... Photoelectric conversion element, 100... Reference level setting section, 130... Control calculation section. 124...Comparator, 140...Operation unit, 160...Memory. +, -ko...-\ Figure 2 Figure 3 Figure 4

Claims (7)

[Claims] (1) A scan mirror sequentially scans a range from near to far, and emitted light from the object within the range is guided to a photoelectric conversion element, where it is detected from near to far. a scanning means for photoelectrically converting synchrotron radiation and outputting it as a test object detection signal; and a scanning means that cooperates with the test object detection signal to determine whether the test object detection signal is obtained by a regular test object. a correction signal forming means for generating a correction signal corresponding to which position within a range from a short distance to a long distance is being scanned, in order to determine whether or not the object is being scanned; and a determination means for determining the object to be examined based on the detection signal. (2) The scanning mirror is a rotating mirror, and the scanning means includes a vertical scanning section that changes the scanning direction vertically by rotating the rotating mirror, and a vertical scanning section that rotates the vertical scanning section horizontally to change the scanning direction to the horizontal direction. 2. The mirror scanning radiation detector according to claim 1, further comprising a horizontal scanning section for changing the direction of the radiation. (3) A patent characterized in that the correction signal forming means generates a correction signal corresponding to which position within a range from a short distance to a long distance is being scanned in the horizontal direction. A mirror scanning radiation detector according to claim 2. (4) The correction signal forming means generates a correction signal corresponding to which position is being scanned in the vertical direction from a short distance to a long distance. A mirror-scanning radiation detector according to item 2. (5) The determination means includes a reference level setting unit that sequentially changes and sets a reference level based on the correction signal, and a reference level setting unit that sets the reference level by sequentially changing the reference level based on the correction signal, and a reference level setting unit that sets the reference level by sequentially changing the reference level based on the correction signal; and a comparator that sequentially compares each scanning position and determines whether the test object is normal based on whether the level of the test object detection signal exceeds the reference level. A mirror scanning radiation detector according to claim 1, characterized in that: (6) The correction signal forming means generates a correction signal that offsets a change in distance to the test object, and the determination means corrects the test object detection signal based on the correction signal to change the distance. 2. The mirror scanning radiation detector according to claim 1, wherein the mirror scanning radiation detector makes the determination by canceling a change in the detection signal of the object to be detected based on . (7) The mirror scanning radiation detector according to claim 6, wherein the correction signal draws an envelope that is inversely proportional to the square of the distance.