JPH0766061B2 - Accident prevention device for automatic doors - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is an automatic opening / closing system that automatically opens and closes like an automatic opening / closing door of a train or an elevator, and may cause a person or an object to be caught when closing. The present invention relates to a door accident prevention device.

[Prior Art] FIG. 6 is a structural diagram of a conventional accident prevention device for an automatic door. In the figure, (55) is the body of the automatic door, (6
(0) is a movable part that can be pushed to the left in the figure by an object that is pinched when the door is closed, (61a) is a movable part (6
(61b) (61c) are electrodes, (62a) (62b) are wirings connected to electrodes (61b) (61c), and (63) is electrodes (61b) (61c). A supporting base that supports the (64) is attached between the supporting base (63) and the movable part (60), a spring applied to the movable part (60), and (65) a wiring (62a) (62b). The detection device is connected to the electrodes (61b) and (61c) via the electrodes.

Regarding the conventional accident prevention device with such a configuration,
Next, the operation will be described. FIG. 6 shows a state in which an object is not caught in the automatic door. In this state, the movable part (60) is pushed out from the main body (55) to the right in the figure by the spring (64), and the electrodes (61a) (61b) (61
c) are in electrical non-contact with each other and the detector (6
5) does not output the pinching signal. When the pinching signal is not output, the operation of the automatic opening / closing door in the closing direction proceeds as it is under the control of the logic device (not shown), and no alarm is issued.

However, as shown in FIG. 7, when the object (3b) is sandwiched by the automatic opening / closing door, the main body (55) moves due to the closing operation of the automatic opening / closing door. A force is applied to (60), and the movable part (60) is pushed to the left in the figure. Therefore, the spring (64) is compressed and the electrodes (61a) (61b) (61c) are in electrical contact with each other, and the wiring (62a), the electrodes (61b) (61a) (61c) and the wiring (62b). ), The detection current of the detection device (65) flows, and a pinching signal is output from the detection device (65).
In response to the pinching signal, the logic device has a body (55).
Is operated in the opening direction and an alarm is issued.

[Problems to be Solved by the Invention] A conventional automatic door-opening door accident prevention device is configured to detect pinching of an object by contact of contacts as described above, and to prevent malfunction, play Since it is necessary to take up a large space, there is a problem that it does not respond correctly to the pinching of small objects such as umbrellas and children's limbs. Further, the contact has a problem that a contact failure easily occurs as an electrical mechanical component.

Due to such poor contact, the detection device does not function normally,
If an elevator, train, etc. that has the automatic opening / closing door starts running while the above-mentioned objects and people are sandwiched between the automatic opening / closing doors, there are many problems that may cause a serious accident. It was

The present invention has been made to solve the above problems, and an object of the present invention is to provide a highly reliable automatic door-opening accident prevention device capable of correctly responding to pinching of a small object. To aim.

[Means for Solving the Problems] An accident prevention device for an automatic disclosure door according to the present invention includes: a first optical path including an installation position of a rail installed on a bottom portion of the automatic disclosure door from a light projecting device; For example, the light is converged and emitted below the size of the object to be detected, and the light in the first optical path and the light in the second optical path formed by the reflection of the object existing in the first optical path are respectively received. A device for detecting whether or not an object exists on the first optical path by receiving light by the device, converting it into an electric signal, and performing arithmetic processing on the electric signal of the light receiving device by a signal processing circuit. The first logic signal and the second logic signal indicating the incident level of the light with respect to the light receiving device are generated.

[Operation] The light projecting device according to the present invention converges and emits light in the first optical path including the installation position of the rail at a size equal to or smaller than the size of the object to be detected, thereby detecting whether or not there is an object on the light receiving device side. A distinguishable signal light is made incident, and the first and second
By determining the magnitude relation between the signal lights and the signal level through the optical path, the first and second logic signals indicating whether the door operation is normal can be obtained.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a structural diagram showing an outline of an automatic opening / closing door in an accident prevention device for an automatic opening / closing door.

In FIG. 1, (3) is the bottom of the automatic door.
A rail that guides the door is installed here. It is preferable that the rail be provided with a drainage hole so that water that hinders the reflection of the signal light does not collect. Furthermore, the bottom part (3) is not made of polished metal, glass, synthetic resin or the like that strongly reflects light from a specific angle, but is made of matte white paint or the like to have an appropriate light reflectance, Moreover, it is preferable that it is not easily polluted by mud.

(51) is a floodlighting device placed above the automatic door
Reference numeral (52) is a light receiving device, which is juxtaposed with the light projecting device (51) on the upper part of the automatic opening / closing door, emitted from the light projecting device (51), and reflected from the bottom part (3) (4). To receive.
(54) is the upper part of the automatic opening / closing door, that is, the ceiling, and (55) is the main body of the automatic opening / closing door.

FIG. 2 is a layout diagram more specifically showing the layout of the respective parts shown in FIG. In the light projecting device (51), (1) is a light projecting element, which emits pulsed light by blinking.
(2) is a light collecting lens that collects the light emitted from the light projecting element (1). Reference numeral (3a) is a reflector which reflects the signal light (4a) incident from the light collecting lens (2). here,
The rail arranged on the bottom portion (3) of the main body (55) functions as a reflection plate (3a).

In the light receiving device (52), a light collecting device (5) collects light by entering the light of the light collecting lens (2) reflected by the object (3b) (showing the case where it exists in the optical path of the signal light (4a)). Optical lens,
Reference numeral (6) is a light receiving element block, which is emitted from the light projecting element (1) and passes through the light collecting lens (2), the reflecting plate (3a), and the light collecting lens (5), that is, a signal of a light path. The light is emitted from the anode cell (light receiving element) (7a) on the semiconductor layer (6a) that receives the light (4a) and the light projecting element (1),
Receiving the light of the second optical path, that is, the signal light (4b) through the light collecting lens (2), the object (3b) (in the case where it exists in the light path of the signal light (4a)), and the light collecting lens (5). And an anode cell (light receiving element) (7b) on the semiconductor layer (6b).

In FIG. 3, the anode cells (7a) and (7b) in the light receiving element block (6) are juxtaposed, and the periphery thereof is composed of a guard (6c). Most of the spots of the signal light (4a) are incident on the circular region of the anode cell (7a) indicated by hatching in the figure, and the rest are incident on the circular region of the anode cell (7b). As shown in FIG. 2, the signal light (4
When the object (3b) is present in the optical path of a), the spot of the signal light (4b) is incident on the circular area of the anode cell (7b), most of which is shaded in the figure, in the same way. And the rest is incident on the circular area of the anode cell (7a).

FIG. 4 is a circuit diagram of the light receiving device (52) shown in FIG. 2 and a circuit of the signal processing circuit (10) connected to the device and having a function of logarithmically compressing the photocurrents of the anode cells (7a) and (7b). It is a figure. As shown, the light receiving device (52) is a light receiving device (52a).
And a light receiving device (52b).

The anode cell (7a) which forms the light receiving device (52a) and the anode cell (7b) which forms the light receiving device (52b) convert the signal lights (4a) and (4b) into electrical signals (9a) and (4a), respectively. 9b) and input to buffer amplifiers (10a) and (10b). The buffer amplifiers (10a) and (10b) respectively amplify the signals (9a) and (9b) and input them to the differential inputs of the operational amplifier (12) via the resistors (13a) and (13c), respectively.

The output terminal of the operational amplifier (12) is connected to the first input of the operational amplifier (12) via the resistor (13b). Operational amplifier (1
The second input of 2) is a reference voltage source (14) via a resistor (13d).
Connected to the positive terminal of. Since the operational amplifier (12) constitutes a differential amplifier together with the resistors (13a) to (13d), the output corresponding to the differential voltage of the signal input through the resistors (13a) and (13c). Is supplied to the output end (18d) connected to the output end. The voltage at the output terminal (18d) has a value related to the photovoltaic current ratio between the anode cells (7a) and (7b), from the light receiving device (52) to the reflector (3a) or object (3b). Is supplied to a logic circuit (not shown) as distance information.

An alarm device having the same structure as the alarm device (65) shown in FIG. 6 is connected to the output side of the logic circuit (not shown).

The positive terminal of the reference voltage source (14) is connected to the first input of the comparator (15a) via the resistor (17a), and its second input is connected to the buffer amplifier (10b). The positive terminal of the reference voltage source (14) is connected to the first input of the comparator (15b) via the resistor (17b), and its second input is connected to the output terminal (18d). The output terminal (18d) is connected to the first input of the comparator (15c). Furthermore,
The first inputs of the comparators (15a) and (15b) are connected to the constant current sources (16a) and (16b), respectively, and
The second input of c) is connected to a constant current (16c) and is connected to a constant current source (16b) via resistors (17c) and (17b).

Here, the current values of the constant current sources (16a) (16b) and (16c), the resistance values of the resistors (17a) (17b) and (17c), and the voltage value of the reference voltage source (14) are predetermined values. Set to. Therefore, the comparators (15b) and (15c) compare the reference voltage set by the current values of the constant current sources (16b) and (16c) with the voltage value of the output terminal (18d), and the result is the second value. The object (3c) shown in the figure is output from the output terminals (18b) and (18c) as a first logic signal indicating "present" or "absent" within a predetermined distance range, and the logic circuit (not shown). Supply). Similarly, the comparator (15
a) compares the reference voltage set by the constant current source (16a) and the voltage of the output terminal (11b) of the buffer amplifier (10b) to the anode cell (7b) and outputs a signal light of a predetermined level or more. A second logic signal indicating whether or not (4b) is incident is output from the output end (18a) and supplied to a logic circuit (not shown).

FIG. 5 is a circuit diagram showing a circuit of the light receiving device (52a) shown in FIG. Since the light receiving device (52b) has the same configuration as the light receiving device (52a), only the light receiving device (52a) will be described here. In FIG. 5, the anode cell (7
The cathode of a) is connected to the power supply potential point Vcc, and the anode of which is connected to the ground via the load resistance (33).
(34) is a low frequency attenuation capacitor connected between the anode of this light receiving element and the base of the current amplification transistor (19), and (35) is a bias voltage supplied to the base, and the power supply potential point Vcc and current amplification An npn transistor for base bias connected between the base of the transistor (19),
Reference numeral (36) is a first current mirror circuit composed of a pair of pnp transistors (21) and (22). The emitters of both pnp transistors are connected to the power supply potential point Vcc and their bases are commonly connected. The base and collector of the transistor (21) are connected to the collector of the amplification transistor (19), and the collector of the other pnp transistor (22) is connected to the anode of the logarithmic compression diode (23), and the pnp transistor (21) ( 22) emitter area ratio
The current value flowing through the pnp transistor (22) is configured to be 1: n, and the current value flowing through the pnp transistor (21) is n times as large. (37) is the pnp transistor (2
1) connected in parallel to the second constant current source (27) constant current I ₂₇
A first constant current source through which a larger constant current I ₃₇ flows, which is composed of, for example, a transistor. (38)
Is an npn transistor whose base is connected to the base of the logarithmic compression diode (24) to form a current mirror circuit, and is set so that a current value equal to that of the logarithmic compression diode (24) flows. (39) is a second current mirror circuit composed of a pair of pnp transistors (40) and (41). The emitters of both pnp transistors are connected to the power supply potential point Vcc and their bases are commonly connected. pnp
The base and collector of the transistor (40) are connected to the collector of the npn transistor (38). (42) is 1
The third composed of a pair of npn transistors (43) (44)
In the current mirror circuit, the emitters of both transistors are grounded and the bases are commonly connected, and one of the base and collector is connected to the collector of the pnp transistor (41), and the current value flowing in the npn transistor (44) is The emitter area ratios of the pnp transistors (40) (41) and the npn transistors (43) (44) are set so that the current value flowing through the pnp transistor (40) is multiplied by m. Reference numeral (46) is a fourth current mirror circuit composed of a pair of npn transistors (47) and (48). The emitters of both npn transistors are grounded and their bases are commonly connected.
The base and collector of 7) are the above pnp transistors (44)
Second constant current source (45) connected to the collector of
Is connected to the power supply potential point Vcc via the, and the collector of the other transistor (48) is connected to the emitter of the current amplification transistor (19), and both transistors (47) (48)
Are set so that equal currents are applied to them. (Four
9) is a fourth constant current source connected between the anode of the logarithmic compression diode (23) and the ground.

The operation of the accident prevention device for an automatically opening and closing door of the present invention having the above-described configuration will be described below. First, when the automatic opening / closing door starts the closing operation, the automatic opening / closing door accident prevention apparatus starts the following distance measuring operation under the control of a logic device (not shown).

Normal, that is, when the object of the automatic opening / closing door is not pinched and neither the objects (3b) and (3c) exist in the optical path of the signal light (4a) as shown in Fig. 2, distance measurement is performed. When the operation is started, the signal light (4
(a) is reflected by the bottom portion (3) (FIG. 1) of the main body (55) and is incident on the light receiving device (52). This signal light (4a)
Is hardly incident on the anode cell (7b) of the light receiving element block (6). Therefore, a larger photovoltaic current flows in the anode cell (7a) than in the anode cell (7b).
In this state, the logical signal including the distance information corresponding to the distance 1 between the reflection plate (3a) and the light receiving device (52) and the incident level information is transmitted through the output terminal (18a) to the output terminal (18c). Are supplied to a logic device (not shown). This logic device determines from the logic state of these information that the automatic door is operating normally, continues the closing operation of the automatic door, and of course does not activate the alarm device. Further, the logic device repeats the above-described distance measurement processing at predetermined time intervals for the outputs of the output end (18b) and the output terminal (18c) until the closing operation of the automatic opening / closing door is completed.

On the other hand, when there is an abnormality, that is, when the object (3b) enters between the light collecting lens (2) and the object (3c) as shown in the figure, the signal light (4b) reflected by the object (3b) is Most of the light is incident on the anode cell (7b) of the light receiving element block (6) through the light collecting lens (5). Therefore, in such a state, the anode cell (7b) is connected to the anode cell (7b).
A larger current than a) flows. Logic device (not shown)
Determines that the object (3b) is sandwiched by the automatic opening / closing door from the logical output state of the output end (18b) and the output terminal (18c), and interrupts the closing operation of the closing door by itself. Activate the alarm device to generate an alarm. afterwards,
Absence of an object (3b) within a predetermined time
When judged from the logical output states of b) and (18c), the closing operation of the automatic opening / closing door is restarted and completed. If it is determined that the object (3b) is present even after a lapse of a predetermined time, the closing operation is switched to the opening operation.

Further, when an object (3c) having a high reflectance like metal enters between the light collecting lens (2) and the reflector (3a) as shown in the figure, the signal light (4a) is reflected by the object (3c). Then, it becomes a signal light (4c) and does not reach the light receiving device (52). Therefore, no signal light (4a) or (4b) is incident on any of the anode cells (7a) and (7b), and no photocurrent is generated in the anode cells (7a) and (7b).
For this reason, the logic device (not shown) has output terminals (18a) (1
8b) and (18c) are logically judged to activate the alarm device to generate an alarm, and the signal levels of the signal lights (4a) and (4b) are below a predetermined value. Since it is determined, a warning is generated and this is latched.

Next, the operation of distance measurement will be described. Referring to FIG. 2, since the distance between the light projecting element (1) and the light receiving element block (6), that is, the base line length is constant, the light projecting angle of the light projecting element (1) and the light receiving element are determined. When the light receiving angle of the block (6) is clear, the distance to the reflector (3a) or the object (3b) can be calculated. Therefore, if the projection angle is perpendicular to the baseline length, the signal light (4
The signal light (4b) from a) or the object (3b) is imaged on the anode cells (7a) and (7b) via the light collecting lens (5) as shown in FIG. Reflector on top (3a)
Or it moves according to the distance to the object (3b). Thus calculating the ratio I ₇ a / I ₇ b or I ₇ b / I ₇ a between the photovoltaic current (I7b) photovoltaic current (I7a) an anode cell (7b) of the anode cell (7a) To do. These ratios are distance information that is not affected by the reflectance of the objects (3b) and (3c). Since the light receiving devices (52a) and (52b) have the same configuration, if the gain is A and the logarithmic compression constant is K, the signals (9a) and (9b) are output from the buffer amplitude units (10a) and (10b). Can be shown as V ₁₁ a = KlnAI ₇ a and V ₁₁ b = KlnAI ₇ b.

Since the operational amplifier (12) and the resistors (13a) to (13d) form a differential amplifier, the voltage of the reference voltage source (14) is changed to V ₁₄ ,
If the value of the resistors (13a) to (13d) is R, the output end (18
The voltage of d) can be expressed as V ₁₈ d = V ₁₄ + {V ₁₁ bV ₁₁ a}. Therefore, V ₁₈ d = V ₁₄ + KlnI ₇ b / I ₇ a is obtained, and a voltage corresponding to the distance is obtained with the reference voltage V ₁₄ as the center. The voltage V ₁₈ d is compared by comparators (15b) and (15c) having as inputs a comparison reference voltage corresponding to a predetermined distance, and is supplied to a logic circuit (not shown) via output terminals (18b) and (18c). .

Next, the operation of the light receiving device (52a) having the above configuration will be described. First, pulsed signal light (4b) reflected from the object (7b) to be measured on the anode cell (7a)
Will be described when no light is incident, that is, when there is no signal.

Now, assuming that the initial current flowing through the logarithmic compression diodes (23) (24) is I ₂₃ , pnp of the first current mirror circuit (36) is
The current flowing through the transistor (22) is I ₂₃ + I ₄₉ , and pnp
The current flowing through the transistor (21) is 1 / n {I ₂₃ + I ₄₉ }. Therefore, a current of I ₃₇ + 1 / n {I ₂₃ + I ₄₉ } flows into the collector of the current amplification transistor (19). A current I ₂₃ equal to the initial current flows through the transistor (38) and is multiplied by m by the second and third current mirror circuits (39) (42). Therefore, a current of mI ₂₃ flows through the npn transistor (44) of the third current mirror circuit (42). And the npn of the fourth current mirror circuit (46)
Since a current of I ₄₅ -mI ₂₃ flows through the transistor (47), a current of I ₄₅ -mI ₂₃ also flows through the npn transistor (48). Therefore, the free current flowing from the emitter of the current amplification transistor (19) is I ₂₇ + I ₄₅ -mI ₂₃ . In the current amplification transistor (19), the base current can be almost ignored and the collector current and the emitter current match. Therefore, in order to satisfy I ₃₇ + 1 / n {I ₂₃ + I ₄₉ } = I ₂₇ + I ₄₅ -mI ₂₃ , the area ratio m, n of the current mirror circuit and the first to fourth constant current sources are set. Constant current value I of (37) (27) (45) (49)
Set ₃₇ , I ₂₇ , I ₄₅ , and I ₄₉ . Therefore, the initial current I ₂₃ of the logarithmic compression diodes (23) and (24) can be set by the above constants, so that it can be set arbitrarily and has a large design margin.

Next, the mechanism by which the initial current I ₂₃ flows through the logarithmic compression diodes (23) and (24) when there is no signal will be described. Now
If no current flows through the logarithmic compression diodes (23) (24), the transistor (38) becomes non-conductive, so that the npn transistor (44) of the third current mirror circuit (42) also becomes non-conductive. A current equal to the constant current I ₄₅ flowing through the second constant current power supply (45) flows through the npn transistors (47) (48) of the fourth current mirror circuit (46). Then, the current of I ₄₅ + I ₂₇ -I ₃₇ flows through the pnp transistor (21) of the first current mirror circuit (36), and the current of n {I ₄₅ + I ₂₇ -I ₃₇ } of pnp transistor (22) changes. An electric current flows. Since this n {I ₄₅ + I ₂₇ -I ₃₇ } is larger than the constant current I ₄₉ flowing through the fourth constant current source (49), the logarithmic compression logarithmic diodes (23) (24) have n {I ₄₅ + I _{37 27} -I ₃₇ } -I ₄₉ current flows in and stabilizes at the initial current I ₂₃ . On the other hand, the compression diode (23) (24) large current I _'23 from the initial current I ₂₃ in to and flows, npn of the third current mirror circuit (42)
The current flowing through the transistor (44) becomes mI ′ ₂₃ . Npn transistor if this mI _'23 is greater than the constant current of the third constant current source (45) fourth current mirror circuit (46) (47) (48) becomes non-conductive. Since the constant current I _{37 of} the first constant current source (37) is larger than the second constant current source I ₂₇ , the pnp transistors (21) (22) of the first current mirror (36) are also in the emergency state. Then, the current value flowing into the logarithmic compression diode (23) (24) decreases and the initial current
It stabilizes at I ₂₃ .

As is clear from the above, the logarithmic compression diode (23)
The initial current I ₂₃ flowing through (24) is determined by the first to fourth current mirror circuits and the first to fourth current sources, and becomes a stable constant current with little influence of temperature change.

In addition, when external light, for example, light having a substantially constant intensity such as sunlight or low-frequency light such as a fluorescent lamp enters the light-receiving element (7), direct current or low-frequency light is applied to the anode cell (7a). Even if a photocurrent is generated, the low-frequency attenuating capacitor (34) blocks the transmission to the base of the current amplification transistor (19), which adversely affects the operation of the light receiving device (52a). Absent.

On the other hand, when the pulsed signal light (4b) reflected from the object (3b) is incident on the light receiving element (7a), the pulsed signal light (4b) causes the anode cell (7a) to be pulsed. A photocurrent I _{L7 of} is generated. This pulsed photocurrent I
_L7 is a load resistor (33) and a low frequency attenuation capacitor (3
It flows into the base of the current amplification transistor (19) via 4) and is multiplied by _hFE19 and flows into the bypass capacitor (20). At this time, the first and second constant current sources (37) (27)
The constant current of is set to be sufficiently large with respect to the value _{obtained by} multiplying the starting flow flowing into the base of the current amplification transistor (19) by h _FE19 . Therefore, the potential fluctuation of the voltage between the base and emitter of the current amplification transistor (19) is very small,
The fluctuation of the voltage across the load resistor (33) is also very small, and the pulsed photocurrent I in the light receiving element (7)
Almost all _L7 flows to the base of the current amplification transistor (19). Then, the above-mentioned photocurrent I _L7 multiplied by h _FE19 flows into the bypass capacitor (20), so that this h _FE19
・ The current equivalent to I _L7 is the first current mirror circuit (3
It flows into the pnp transistor (21) of 6), and _{nhFE19I L7} flows into the pnp transistor (22). As a result, a current of I ₂₆ + n · h _FE19 · I _L7 flows through the anti-compression diodes (23) (24), and the output terminal receives the pulsed photocurrent I _L7 of the light receiving element (7). A compression voltage corresponding to the width is displayed.

In the light receiving device (52a) configured as described above,
The anode potential of the logarithmic compression diode (23), which is hardly affected by the low-frequency attenuator such as a fluorescent lamp, by the low-frequency attenuation capacitor (34), and the initial current flowing through the logarithmic compression diode (23) is obtained. I ₂₃ is determined by the first to fourth current mirror circuits (36) (39) (42) (46) and the first to fourth constant current sources (37) (27) (45) (49). Therefore, it is possible to obtain a highly accurate one in which the anode potential of the logarithmic compression diode (23) is unlikely to be affected by temperature fluctuations, disturbances and the like.

In the above embodiment, the case where the pulse light is emitted from the light projecting element and the logic device periodically reads the output of the light receiving device to make a logical judgment has been described. It controls to emit intermittently modulated light, receives such intermittently modulated light on the light receiving side, converts it to an electrical signal, and then detects and integrates it to obtain a continuous distance measurement signal. Alternatively, the same effect as that of the above embodiment can be obtained.

Further, in the above embodiment, the case where the pair of light projecting devices and the light receiving devices are arranged at the upper part of the automatic opening / closing door and the positions where the automatic opening / closing doors on both sides are closed has been described. The device may be arranged to perform the object detection stepwise. Further, the light projecting device and the light receiving device may be arranged above the tip of the moving automatic opening / closing door to be configured so as to continuously detect an object while using the rail at the bottom as a reflecting surface while moving. It has the same effect as the example.

As described above, according to the present invention, the distance measurement processing is performed on the light receiving side,
The light receiving level is determined and the results of these processes are logically determined, and the spot width of the signal light is set by the light collecting lens to be narrower than the width of a thin object such as an umbrella. It is possible to detect even such objects correctly, and it is possible to fully identify the pinch of the automatic opening / closing door even if there are people or objects approaching the automatic opening / closing door. This has the effect of increasing the reliability of abnormality detection related to the operation of the door.

Further, according to the present invention, the light-receiving level is determined on the light-receiving side, and, for example, when mud or dirt adheres to the rails of the automatic doors and the light reflectance is below a predetermined level, the The effect is that it can be dealt with by switching to a logical signal indicating the state. Further, according to the present invention,
Since the optical means is used for detecting the abnormality related to the operation of the automatic opening / closing door, the problem of electrical contact failure can be eliminated, and the size of the device can be easily reduced.

[Brief description of drawings]

FIG. 1 is a structural view of an accident prevention device for an automatic opening / closing door according to an embodiment of the present invention, FIG. 2 is a layout view showing details of the accident prevention device for an automatic opening / closing door shown in FIG. 1, and FIG. Is a plan view showing the arrangement of the anode cells, FIG. 4 is a circuit diagram showing a light receiving device and a signal processing circuit for logarithmically compressing the photocurrent signals of the anode cells, and FIG. 5 is a circuit diagram showing the light receiving device. 6
FIG. 7 is a structural view showing a conventional accident prevention device for an automatic door. In the figure, (2) and (5) are light collecting lenses, (3) is a bottom portion (rail), (7a) and (7b) are anode cells (light receiving elements), (10) is a signal processing circuit, and (15a) ( 15b) (15c)
Is a comparator, (51) is a projector, (52) (52a) (5
2b) is a light receiving device. The same reference numerals in the drawings indicate the same or corresponding parts.

Claims (5)

[Claims] 1. An accident prevention device for an automatic door that automatically opens and closes by being guided by a rail installed at the bottom of the automatic door, and emits to a first optical path including the installation position of the rail. And a light receiving device for respectively receiving the light of the first optical path and the light of the second optical path formed by reflection of an object existing in the first optical path and converting the light into an electrical signal. A first logic signal indicating whether or not an object is present on the first optical path by the arithmetic processing of the electric signal of the light receiving device and a second indicating the incident level of the light with respect to the light receiving device. And a signal processing circuit for generating a logic signal of the automatic opening / closing door accident prevention device. 2. The light-receiving device is arranged in parallel with a light-collecting lens that collects each of the incident light beams of the first and second optical paths, and the light-collecting lens is arranged side by side on the extension of the first and second optical paths. A pair of light receiving elements for respectively receiving the respective transmitted light and converting the received light into an electric signal.
The automatic door-opening door accident prevention device described in the item. 3. The automatic opening / closing system according to claim 1 or 2, wherein the signal processing circuit has a plurality of comparators for performing arithmetic processing on electric signals of the light receiving device. Door accident prevention device. 4. The accident of an automatic opening / closing door according to claim 1, wherein the light projecting device converges and emits light at a size equal to or smaller than the size of an object to be detected. Prevention device. 5. The light projecting device and the light receiving device are arranged at least in a pair on the upper part of the automatic opening / closing door, and a space between the upper part and the bottom part of the automatic opening / closing door is included in the first optical path. The automatic door-opening door accident prevention device according to any one of claims 1 to 4, wherein: