JP3664568B2 - Movement detection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a movement detection device that detects relative movement between a movement target member and a reference member, such as detection of opening / closing of a shutter installed at a facility entrance / exit.
[0002]
[Prior art]
Conventionally, as shown in FIGS. 6 and 7, a security shutter sensor for detecting the unauthorized opening of a shutter after the door is closed is installed on the opposite side of the retroreflective sheet R to be pasted on the facility-side inner surface of the shutter S in the closed state. And a reflective photoelectric sensor P. When the projection light of the near-infrared light emitted from the projection LED of the photoelectric sensor P is reflected by the reflecting sheet R and enters the receiving part PD, the shutter S is opened by someone who is normal or at night, and the reflecting sheet R When the amount of light incident on the receiving unit PD decreases as a result of movement, an abnormality alarm is issued.
[0003]
In FIG. 7, L is a lens for controlling the light flux, and is drawn as two independent lenses in the figure. However, the projection unit LED and the reception unit PD are separated as shown in this figure, and actually 2 The projection unit LED and the reception unit PD are not limited to those having a single lens, and both the light projection and reception light beams may be controlled by a single lens. The mainstream is a single lens type.
[0004]
[Problems to be solved by the invention]
However, in the shutter sensor described above, an illegal person enters the facility through another small window at night and continuously sticks a belt-like sheet D similar to the reflective sheet R as shown by a dotted line in FIG. If a small work is performed to paste a similar belt-like sheet D without permission, there is a problem that the shutter S can be opened in the manner of an illegal person. This is because the amount of incident light to the receiver PD does not change even when the shutter S is opened without permission by the belt-like sheet D, and no abnormality is detected.
[0005]
The main object of the present invention is to provide a movement detection device that can avoid a situation in which movement detection cannot be performed intentionally without detecting the mechanism of the reflection portion, and can increase security in an application example to a shutter sensor. It is in.
[0006]
[Means for Solving the Problems]
In order to achieve the above-mentioned main object, the invention according to claim 1 is a movement detection device that detects relative movement between two members, as shown in FIG. The coded reflector 1 on the first member side that has a specific code and cannot be recognized externally by the naked eye, and detects whether or not a reflected signal corresponding to the code of the reflector 1 is received And a reflection type sensor 2 on the second member side.
[0007]
In application to the shutter sensor, it is appropriate to provide the coded reflector 1 in the shutter as the first member and the reflective sensor 2 in the facility-side structure as the second member. The reflective sensor 2 may be provided with the coded reflector 1 in the facility-side structure.
[0008]
The code of the coded reflector 1 may be a 3-bit configuration as shown in FIGS. 1 and 2, or a 2-bit simplified version or a 4-bit or higher security version. In addition to the horizontal arrangement, each bit may be arranged in a vertical arrangement, a vertical and horizontal matrix arrangement, an oblique arrangement, an arrangement along the circumference, or the like.
[0009]
The code assigns to each bit, for example, a white reflective portion W having a high reflectance and a black reflective portion B having a low reflectance so as not to be all white or all black. An example is a configuration in which the shields 10 for hiding are stacked. In addition, it is difficult to see the difference in brightness, but using reflective materials with different reflection attributes, that is, different retroreflectance, diffuse reflectance, transmittance, absorption, etc. depending on the difference in internal composition, they are arranged as they are to make a cord structure without a shield. Also good. For convenience of signal processing, encoding is performed using two types of reflection attributes such as black and white. However, encoding may be performed by additionally incorporating other reflection attributes such as third and fourth.
[0010]
The fact that the external recognition by the naked eye of the code is impossible means that there is no confirmation that specifically, which part of the coded reflector 1 is a retroreflective surface and which part is not a retroreflective surface. This means that the reflection attributes of all the parts of the reflecting reflector 1 cannot be seen from the outside. It does not necessarily mean that there is no difference in the colors of the partial parts of the coded reflector 1 or that the section of the area is not known. For example, even if both sides of the coded reflector 1 are a little lighter than the dark black at the center, for an illegal person who is not allowed to experiment, it cannot be confirmed that this light black is indeed a retroreflective surface. The code is still unrecognizable.
[0011]
The reflective sensor 2 is an example of a photoelectric sensor that projects near-infrared rays and receives the reflected light. As shown in FIG. 4, in addition to the parallel system having the number of receiving units 4 (41 to 43) corresponding to the number of bits of the coded reflector 1, the reflected signal of each bit of the coded reflector 1 is converted with a time difference. It is good also as the serial system taken in sequentially.
[0012]
In FIG. 1, the projection unit 3 of the reflection type sensor 2 is omitted, but the projection signal projected from the reflection type sensor 2 is applied to the coded reflector 1. In FIG. 4, the projection unit 3 and the reception unit 4 for each bit control the projection / reception signals with independent lenses as in the relationship of FIG. Both signals may be controlled by a single lens. For downsizing and simplification of the structure, it is excellent to use a single lens to control both signals by bringing projection and reception elements close to each other for each bit. In this case, if there are 3 bits, there are a total of 3 lenses L.
[0013]
In order to reduce the cost of the coded reflector 1 as a whole and to obtain a sufficiently high reliability, the invention according to claim 2 is provided between different reflection attributes of the coded reflector 1 as shown in FIG. Has a lightness difference, and a shield 10 is provided on the front side of the coded reflector 1 to hide the lightness difference. That is, a shield-less material using a reflective material having no brightness difference is excluded here. Except for all white and all black, as exemplified in FIGS. 2 (1) to 2 (6), a structure in which the white reflection part W and the black reflection part B are mixed is a representative example.
[0014]
It should be noted that the difference in appearance color such as white and black is not an important problem, and other color combinations may of course be used. In addition, the black reflecting portion B having a low reflectance may be positively interposed with a black sheet, or may be left with no gaps. Conversely, if the object such as the shutter has a very high retroreflectance, the white-based reflecting portion W can be configured with a gap. Further, in addition to the color classification of two colors, other colors such as the third and fourth colors may be mixed. For example, the colors are classified into three colors of white, black, and gray. The shield 10 typically uses an infrared filter that transmits light such as near infrared light from the reflective sensor 2 but absorbs visible light.
[0015]
The invention according to claim 3 can appropriately cope with the operation of changing the code of the coded reflector 1 according to the user as shown in FIGS. 2 (1) to (6), for example. In order to more thoroughly eliminate code breakthroughs and illegal tricks, as shown in FIG. 4, a code setting unit 5 for arbitrarily setting a code of a reflected signal to be received by the reflective sensor 2 is provided.
[0016]
[Effects of the invention]
In the first aspect of the present invention, as shown in FIG. 1, the coded reflector 1 has a specific code according to partially different reflection attributes, and the code is externally dependent on the naked eye. Since it cannot be recognized and cannot be read, it becomes extremely difficult for an illegal person to imitate the coded reflector 1 and impersonate a belt-like sheet or the like. Even if a random belt-like sheet or the like is continuously attached to the coded reflector 1, if the relative position between the coded reflector 1 and the reflective sensor 2 is shifted, a reflected signal corresponding to the code of the coded reflector 1 is generated. Since it is not received, the reflection type sensor 2 detects the movement without missing and cannot cheat the detection by the sensor 2. Therefore, it is possible to eliminate the intentional interference of the reflective sensor 2 and to sufficiently increase the security in the application example to the shutter sensor.
[0017]
In the invention according to claim 2, as shown in FIGS. 1 and 2, it is possible to easily and inexpensively realize an array having different reflection attributes due to the difference in brightness, and the code based on the difference in brightness by combining with the shield 10 on the front side. Can be prevented, the cost for coding as a whole can be reduced, and the reliability can be sufficiently high.
[0018]
According to the third aspect of the invention, the code to be properly received can be set by the code setting unit 5 shown in FIG. 4 in correspondence with various codes of the coded reflector 1 shown in FIG. For this reason, it is possible to use various codes according to the user, and it is possible to more reliably eliminate code breakthroughs and illegal tricks compared to the case of using only one code.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1, the coded reflector 1 is attached to the facility-side upper inner surface of the shutter in the closed state by adhesion or the like, and the reflective sensor 2 is installed on the facility-side structure so as to face this. This relationship is the same as in FIG.
[0020]
The coded reflector 1 includes a white reflector W or a black reflector B assigned to each of all 3 bits, and a shield 10 that is integrally bonded to the front side. In the case of 3 bits, as shown in FIG. 2, except for all white and all black, 6 kinds of codes can be used with 2 to the power of 3 minus 2. In the case of 4 bits, 14 codes with 2 to the power of 4 minus 2 can be used.
[0021]
The white-based reflective portion W has a higher retroreflectance than the black-based reflective portion B. For example, a united sparklight reflective film is a preferred example. As shown in FIG. 3, this is a thin film formed of a transparent surface resin layer WF on the incident side, a glass bead WB layer having a diameter of several tens of microns using a bead hold resin WH as a binder, and an aluminum vapor deposition layer on the back side. The coating reflective layer WR is provided, and good retroreflection characteristics can be obtained.
[0022]
The shield 10 is composed of an infrared filter, for example, a near-infrared transmission filter R2805 or IR2880 of the technalite series manufactured by Chuchu Plastic Industry Co., Ltd. These are black sheets in appearance and absorb visible light and transmit 90% or more of near infrared rays having a wavelength of 700 nm (R2805) or 800 nm (IR2880) or more.
[0023]
In addition, by disperse | dying the dye which permeate | transmits only near-infrared rays, such as a black type | system | group, in the glass bead WB in FIG. 3, it is a retroreflective sheet from the exterior, while keeping a retroreflectivity still high level. The structure cannot be determined. For this reason, an infrared filter can be made unnecessary and a shield-less structure can be obtained.
[0024]
The reflective sensor 2 is a photoelectric sensor that projects near-infrared rays and receives reflected light. As shown in FIG. 4, the projection unit 3 that projects near-infrared rays toward the coded reflector 1, coded. A receiving unit 4 that receives a reflected signal from the reflector 1, a code setting unit 5 that sets a code to be received in correspondence with the coded reflector 1, and a determination unit that checks whether the actual received code matches the set code 6, the alarm output part 7 and the power supply part 8 are comprised.
[0025]
A specific circuit of the reflective sensor 2 is shown in FIG. The projection unit 3 is driven and coded by a gate logic type oscillation circuit 31 in which gates G1 and G2, resistors R1 and R2, and a capacitor C1 are combined, transistors TR1 and TR2, and drive circuits 32 having resistors R3 and R4. Three near-infrared light emitting elements IRLED1 to IRLED1 for projecting near-infrared rays onto each bit of the reflector 1 are provided.
[0026]
The receiving unit 4 includes three identical parallel receiving circuits 41 to 43 each having light receiving elements PD1 to PD3 each formed of a photodiode corresponding to each bit of the coded reflector 1. The light incident signals to the light receiving elements PD1 to PD2 are amplified in two stages by the operational amplifiers IC1 and IC2, and then compared with the reference potential of the reference voltage setting circuit having the fixed resistors R5 and R6 and the variable resistor VR1, and output from the operational amplifier IC3. In addition, a high level, that is, a logic “1”, or a low level, that is, a logic “0”, is output in accordance with the difference in reflected incident light between the white-based reflecting portion W and the black-based reflecting portion B. R7 to R17 are fixed resistors, VR2 is a variable resistor, and C2 to C5 are capacitors.
[0027]
The code setting unit 5 sets each bit to logic “1” or “0” according to the code scheduled to be received. Three pulls to the logic “1” are made corresponding to the 3-bit code. It has up resistors R18-R20 and three pull-down switches SW1-SW3 to logic "0".
[0028]
In the determination unit 6, the outputs of the final stage operational amplifiers IC3 of the reception circuits 41 to 43 are synchronized with the outputs of the oscillation circuit 31 by AND gates G3 to G5, and then the first input of the determination element IC4 including the comparator 74HC85 and the like. Input to the parts XA, XB, XC. The set values of the respective bits by the code setting unit 5 are input to the second input units YA, YB, YC. When the first input and the second input coincide with each other, that is, when XA = YA, XB = YB, and XC = YC, the output X = Yout is set to logic “1”. In other cases, the logic is “0”.
[0029]
The alarm output unit 7 includes a monostable multivibrator (hereinafter referred to as one-shot) IC5 such as 74HC123, relay circuits Ry and D1, and driver circuits R21 and TR3 thereof. The output of the determination element IC4 is synchronized with the output of the oscillation circuit 31 by the AND gate G6 and then input to the B1 input of the one-shot IC5. The set time of the time constant circuits R22 and C6 is set longer than the oscillation cycle of the oscillation circuit 31.
[0030]
If the received code matches the setting code and the trigger is continuously input to the B1 input, the output QC1 is maintained at logic “0”, the transistor TR3 is off, the relay Ry is not excited, and no alarm is issued. . On the other hand, if the received code and the setting code do not match and the trigger to the B1 input is lost, the output QC1 changes to logic “1”, and the relay Ry is energized to generate an alarm. When an alarm is output, a buzzer or a lamp is driven or a security company is notified via a communication line. In addition to the alarm output terminal that interposes the make contact of the relay Ry, a tamper output terminal that interposes the break contact of the relay Ry is provided to enhance convenience.
[0031]
The power supply unit 8 includes a full-wave rectifier DB1, smoothing capacitors C7 and C8, a three-terminal regulator IC6 for 5 volts, and a noise killer capacitor C9. The 5 volt power supply VCC is taken out. Needless to say, the 5-volt power supply VCC is a so-called C-MOS or TTL high level, ie, logic “1”, and the ground G is the same low level, ie, logic “0”.
[0032]
The operation will be described taking the coded reflector 1 shown in FIG. 1 as an example. The light receiving elements PD1 and PD3 corresponding to the white reflection parts W and W at both ends are sufficiently incident with retroreflective light, while the light receiving element PD2 corresponding to the central black reflection part B is almost incident. There is no. That is, when the received signal is represented by a logical level, it is “1” “0” “1”. The setting code by the code setting unit 5 is also set to “1”, “0”, and “1”, and the signal level of each bit matches, so that no alarm is issued and the shutter is kept closed.
[0033]
If the shutter is opened without permission at night or the like, the coded reflector 1 moves upward and comes out of the front of the reflective sensor 2, so that the retroreflected light from the white-colored reflectors W and W is incident. Therefore, the received light signals “1”, “0”, and “1” can no longer be obtained. Accordingly, the received code and the setting code cannot be matched, and an alarm is output.
[0034]
It is extremely difficult for an illegal person to see through the code of the coded reflector 1, and even if a strip sheet having the same width as that of the coded reflector 1 is continuously pasted, a regular code is received by the reflective sensor 2. Since the code cannot be matched, an alarm is issued when the shutter is opened. Therefore, safety can be sufficiently increased.
[0035]
In addition to the shutter sensor, the present invention is naturally applicable to door / window opening / closing sensors, etc. In addition, the present invention can be applied to a movement detector in all cases where an object can move relative to a reference member. Applicable.
[Brief description of the drawings]
FIG. 1 is a perspective view of a main part of a movement detection device according to the present invention.
FIG. 2 is an explanatory diagram of variations when the coded reflector 1 is 3 bits.
FIG. 3 is a cross-sectional view of a white-based reflector in the coded reflector 1;
4 is a block diagram of a reflective photoelectric sensor 2. FIG.
FIG. 5 is a circuit diagram of the reflective photoelectric sensor 2;
FIG. 6 is an explanatory diagram of the prior art taking a shutter sensor as an example.
FIG. 7 is a plan view of the main part of the prior art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1; Coded reflector 10; Shield 2; Reflective sensor 5; Code setting part

Claims (3)

In a movement detection device that detects relative movement by interposing between two members, the first member side has a specific code according to partially different reflection attributes, and the external recognition by the naked eye of this code is impossible It comprises a coded reflector (1) and a reflection sensor (2) on the second member side for detecting whether or not a reflected signal corresponding to the code of the reflector (1) is received. To move. 2. The light reflector according to claim 1, wherein there is a brightness difference between different reflection attributes of the coded reflector (1), and a shield (10) is provided on the front side of the coded reflector (1) to hide the brightness difference. Movement detection device. The movement detecting device according to claim 1 or 2, further comprising a code setting unit (5) for arbitrarily setting a code of a reflected signal to be received by the reflective sensor (2).

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