JP3168944B2 - Shutter control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shutter control device for controlling opening and closing of a shutter, and more particularly to a shutter control device for detecting an obstacle at the time of opening and closing and stopping at upper and lower limit positions.

[0002]

2. Description of the Related Art A shutter that is electrically opened and closed is configured to stop opening and closing when the shutter reaches upper and lower limit positions. Specifically, upper and lower limit position detecting means for detecting upper and lower limit positions, and load detecting means for detecting a load applied to the switch when the shutter reaches the upper and lower limit positions are provided. Further, contact with an obstacle at the time of opening and closing the shutter is detected by an obstacle sensing means, and safety control is performed by stopping opening and closing of the shutter.

[0003]

However, as described above, the upper and lower limit position detecting means for detecting the upper and lower limit positions of the shutter and the obstacle detecting means have to be individually provided with respective devices. For example, the upper and lower limit position detecting means is configured to relatively set the upper and lower limit positions of the shutter by connecting a potentiometer to the switch and detecting the number of rotations of the switch, so that when the shutter is loosely wound, etc. There was a problem that the upper and lower limit positions fluctuated.

[0004] The obstacle sensing means is constituted by transmitting a sensing signal from a transmitter to a receiver by operating a sensing switch provided on a seat plate of a shutter when an obstacle comes into contact. The transmitter is provided on a seat plate of a shutter that opens and closes, and is driven by a battery. However, if the battery is worn out or forgets to be replaced, there is a problem that the sensing signal cannot be wirelessly transmitted.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and provides a shutter control device which can easily and inexpensively configure the setting of upper and lower limit positions of a shutter and detection of contact with an obstacle. It is an object.

[0006]

In order to achieve the above-mentioned object, a shutter control device according to the present invention comprises a pair of shutter control devices which are arranged to face each other along an inner surface of a guide rail 2 on a side of a shutter curtain 1 and to which a predetermined voltage is applied. A long switch body 3 in which the resistors 3a and 3b at the location where the pressing force is applied can freely contact and a voltage corresponding to the contact location is output, and the shutter curtain An obstruction sensing means 11 provided on a seat plate 10 at the lower end of the first switch plate 10 and pressing the long switch body 3 at the contact position when an object comes into contact with the seat plate 10; One ends 3a and 3b of a pair of resistors are connected, and voltage values VH and VL corresponding to upper and lower limit positions of the shutter curtain 1 and a detected voltage value obtained when an object comes into contact with the shutter curtain 1 during opening and closing operations. And control means 4 for judging and processing the upper and lower limit positions of the shutter curtain 1 and obstacle detection between these upper and lower limit positions. The control means sets the upper and lower limit positions of the shutter curtain 1. In the setting mode, when the shutter curtain 1 is recognized to be open, the detected voltage value V obtained when the object comes into contact with the object is set and stored as an upper limit voltage value VH. When the shutter curtain is recognized to be closed, The detected voltage value V obtained when the object comes into contact with the object is set and stored as a lower limit voltage value VL, and when opening and closing the shutter curtain 1 in the normal mode, the detected voltage value V is changed from the upper limit voltage value VH to the compensation voltage. Is equal to or higher than the voltage value obtained by subtracting the value Vα (V ≧ VH−V
α), it is determined that the shutter curtain 1 has reached the upper limit position, and when the detected voltage value V is equal to or less than the voltage value obtained by adding the compensation voltage value Vβ to the lower limit voltage value VL (V ≦ VL + Vβ), the shutter curtain 1 is lower limit. Position, and the detected voltage value V is within a range that is smaller than a voltage value obtained by subtracting the compensation voltage value Vα from the upper limit voltage value VH and is larger than a voltage value obtained by adding the compensation voltage value Vβ to the lower limit voltage value VL ( VH−Vα <V <VL
(+ Vβ), it is determined that an obstacle has been touched between these upper and lower positions.

[0007]

Further, a voltage dividing resistor 7 is connected to the long switch body 3 with a predetermined voltage dividing ratio and has the same temperature coefficient as that of the long switch body 3. Alternatively, a configuration may be adopted in which a voltage at a voltage dividing point of the voltage dividing resistor 7 and the long switch body 3 is input.

[0009]

[0010]

[0011]

An elongate switch body 3 is provided on the guide rail 2 of the shutter curtain 1 along the vertical direction, and the obstacle sensing means 11 of the seat plate 10 is used when the operating piece 12a comes into contact with the floor F, or When the operating piece 12b comes into contact with the lintel K of the shutter case, the long switch body 3 at this height is pressed. At the time of this contact, the resistors 3a and 3b inside the long switch body 3 are electrically connected to each other, and a detection voltage value V corresponding to this height position is input to the control means 4. Control means 4
In the setting mode, when the shutter curtain 1 is recognized to be open, the detected voltage value V obtained when the object comes into contact is set and stored as an upper limit voltage value VH. When the shutter curtain is recognized to be closed, when the shutter curtain 1 is recognized to be closed. The obtained detection voltage value V is set and stored as the lower limit voltage value VL. In the normal mode, the detection voltage value V is equal to the lower limit voltage value VL.
If the voltage is equal to or less than the voltage value VL + Vβ obtained by adding the compensation voltage value + Vβ to the shutter curtain, it is determined that the shutter curtain 1 is at the lower limit position. If the detected voltage value V is equal to or higher than the voltage value VH-Vα obtained by adding the compensation voltage value -Vα to the upper limit voltage value VH, it is determined that the shutter curtain 1 is at the upper limit position.
Further, the upper and lower limit positions of the shutter curtain 1 can be detected by comparing the detected voltage value V with the upper and lower limit voltage values VH and VL to which the compensation voltage values -Vα and + Vβ are added. The value of V is within the range of the upper and lower limit voltages (VH-Vα) to which the shutter curtain 1 adds the compensation voltage value.
When <V <VL + Vβ), it can be determined that the obstacle has touched.

[0013]

FIG. 1A is a schematic diagram showing a shutter control device according to the present invention. Shutter curtain 1
On the inner surface of one of the pair of guide rails 2 provided on the side, a long switch body 3 is disposed along the vertical direction.

As shown in FIG. 1 (b), the long switch body 3 has a long flexible tube body having a rectangular cross section having flexibility and made of a synthetic rubber or the like. A pair of resistors 3a and 3b, which are formed in a band shape in the direction and have a unit resistance value, are arranged to face each other. The long switch body 3 is configured such that, when a part in the length direction is pressed, the part is elastically deformed and the resistors 3a and 3b come into contact with each other, and when the pressing force is released. The resistors 3a and 3b are elastically restored and the contact between the resistors 3a and 3b is released. As the long switch body 3, for example, a tape switch is used.

The resistors 3a, 3b of the long switch body 3
Are connected to the control means 4, and the other ends 3ab and 3bb are open. Control means 4
Detects a contact point between the resistors 3a and 3b of the long switch body 3 based on the resistance value output from the long switch body 3. The control unit 4 includes a processing unit 5a including a CPU and the like, a storage unit 5b including a RAM and the like, and an A / D conversion unit 6. The control unit 4 opens and closes a shutter based on opening and closing operations of an operation unit. The stop control of the shutter is performed under the determination condition.

One end 3a of the resistor 3a of the long switch body 3
To a, a power supply 8 of a predetermined voltage is supplied via a voltage dividing resistor 7 having a predetermined specific resistance value. An input terminal 6a of the A / D converter 6 is connected between the voltage dividing resistor 7 and one end 3aa of the resistor 3a of the long switch body 3 (partial voltage division). One end 3ba of the resistor 3b of the long switch body 3 is connected to the input terminal 6b of the A / D converter 6.

As a result, when the long switch body 3 is pressed at a predetermined location and the resistors 3a and 3b come into contact with each other, A
At the input terminals 6a and 6b of the / D converter 6, a voltage value is generated according to the voltage division ratio between the voltage dividing resistor 7 and the long switch body 3. At this time, the resistance value of the long switch body 3 is
The resistance value is the sum of the resistance value corresponding to the length from the one end 3aa to the pressed portion of a and the resistance value corresponding to the length from the pressed portion to the one end 3ba of the resistor 3b.

Since the resistors 3a and 3b are arranged to face each other, the resistors 3a and 3b have the same resistance value. And the resistance value of the long switch body 3 is
One end 3a of each of the resistors 3a and 3b
The resistance value becomes the smallest when the vicinity of a and 3ba is the pressing portion, and becomes the largest resistance value when the vicinity of the other ends 3ab and 3bb of the resistors 3a and 3b is the pressing portion.

The A / D converter 6 A / D converts the input voltage value and outputs it to the control means 4. Processing unit 5a of control means 4
Switches the shutter control between the normal mode and the setting mode. In the setting mode, the voltage value (upper / lower limit position) obtained when the long switch body 3 is pressed is stored in the corresponding setting area of the storage unit 5b after the shutter curtain is moved to the upper / lower limit position when the shutter is installed or the like. .
In the normal mode, a normal opening / closing operation of the shutter curtain after the installation is performed. When the long switch body 3 is pressed at the time of opening / closing, it is compared with the upper / lower limit positions stored in the setting area of the storage unit 5b. To perform safety control of opening and closing operation.

Next, specific means for pressing the long switch body 3 will be described. Seat plate 10 under shutter curtain 1
Is provided with an obstacle sensing means 11. Obstacle sensing means 11 includes operating pieces 12 at the lower and upper portions of seat plate 10, respectively.
a, 12b are provided, and when one of the operating pieces 12a, 12b is operated, the pressing piece 1 on the side of the seat plate 10 is pressed.
3 is a protruding configuration. The operating piece 12a projecting to the lower portion of the seat plate 10 is actuated by coming into contact with an obstacle or the floor surface F when the shutter curtain 1 descends, moves to the inside of the seat plate 10, and is pressed through the internal connecting means 14 inside. Piece 13
To protrude.

The operating piece 12b protruding above the seat plate 10 has
When the shutter curtain 1 is raised, the shutter piece 1 is actuated by coming into contact with an obstacle or the lintel K of the shutter case to move to the inside of the seat plate 10, and the pressing piece 13 is protruded via the internal connecting means 14. The coupling mechanism 14 includes the operating piece 12
It can be constituted by a link mechanism or the like for connecting the pressing pieces 13 with the a and 12b.

Next, the setting operation in the setting mode will be described. First, the shutter curtain 1 is opened and moved while the control unit 4 is in the setting mode. FIG.
When the shutter curtain 1 reaches the upper limit position, as shown in the partial view of FIG.
b contacts the lintel of the shutter case, and the pressing piece 13 presses the long switch body 3.

At this time, the pressing position of the long switch body 3 is as follows.
As shown in the circuit diagram of FIG. 2B, the position is a distance L1 slightly lower than one ends 3aa, 3ba of the resistors 3a, 3b.
A / D converter 6 detects a predetermined upper limit voltage value VH based on a resistance value corresponding to distance L1 from one ends 3aa and 3ba. The processing unit 5a of the control unit 4 recognizes the opening movement of the shutter curtain 1, and stores the obtained upper limit voltage value VH as the upper limit position of the shutter in the corresponding upper limit setting area of the storage unit 5b.

Next, the shutter curtain 1 is closed and moved in this setting mode. As shown in the partial view of FIG. 3A, when the shutter curtain 1 reaches the lower limit position, the operating piece 12a of the obstacle detecting means 11 comes into contact with the floor surface and the pressing piece 1
3 presses the long switch body 3. At this time, the portion where the long switch body 3 is pressed is a position L2 slightly above the other ends 3ab and 3bb of the resistors 3a and 3b as shown in the circuit diagram of FIG. A predetermined lower limit voltage value VL based on a resistance value corresponding to a distance L2 from 3ba is A /
It is detected by the D conversion unit 6. The processing unit 5a of the control means 4
Recognizing the closing movement of the shutter curtain 1,
The lower limit voltage value VL obtained at this time is stored in the corresponding lower limit setting area of the storage unit 5b as the lower limit position of the shutter.

In this way, the upper and lower limit positions of the shutter curtain 1 are set and stored in the storage unit 5b in the setting mode. The obtained upper limit voltage value VH and lower limit voltage value VL due to the pressing of the long switch body 3 are the resistance value by the distances L1 and L2 at which the long switch body 3 is pressed and the specific resistance value of the voltage dividing resistor 7. Is generated by the partial pressure ratio.

FIG. 4 is a flowchart showing the processing contents in the setting mode described above. As shown in the figure, in the specific operation, after the shutter opening / closing operation, the opening / closing drive in the same direction is continued until the stop switch is pressed, and the long switch body 3 reaches the upper / lower limit position. The stop control is performed in response to the pressing of the button. At the same time as the stop, a timer is set, and when a predetermined time T1 has elapsed, the upper and lower limit values VH and VL obtained at this time are set. Then, if there is a stop (reset) operation before the predetermined time T1 elapses, the upper and lower limit values VH and VL are not set and the operation returns to the opening / closing operation wait.

Next, the shutter opening / closing operation in the normal mode will be described. The control means 4 receives the operation of the open switch of the operation unit, drives the switch in the same direction, and opens and moves the shutter curtain 1. When the operating piece 12b of the obstacle sensing means 11 provided on the seat plate 10 comes into contact with the lintel of the shutter case, the pressing piece 13 presses the long switch body 3.

At this time, the A / D converter 6 of the control means 4 obtains the detected voltage value V corresponding to the pressed position of the long switch body 3. The processing unit 5a compares the detected voltage value V with the upper limit voltage value VH set and stored in the storage unit 5b. As a result of the comparison, when the detected voltage value V is equal to or higher than the upper limit voltage value VH (V ≧ VH), it is determined that the shutter curtain 1 has reached the upper limit position, the driving of the switch is stopped, and the shutter is stopped and held at this position. I do. In the determination process at the upper limit position, stop control is executed after confirming that the detected voltage value V is higher than the set lower limit voltage value VL (VL <V).

When the control unit 4 receives the operation of the closing switch of the operation unit, it drives the switch in the same direction to move the shutter curtain 1 closed. When the operating piece 12a of the obstacle sensing means 11 provided on the seat plate 10 comes into contact with the floor, the pressing piece 13 presses the long switch body 3.

At this time, the A / D converter 6 of the control means 4 obtains the detected voltage value V corresponding to the pressed position of the long switch body 3. The processing unit 5a compares the detected voltage value V with the lower limit voltage value VL set and stored in the storage unit 5b. As a result of the comparison, when the detected voltage value V is equal to or lower than the lower limit voltage value VL (VL ≧ V), it is determined that the shutter curtain 1 has reached the lower limit position, the driving of the switch is stopped, and the shutter is stopped and held at this position. . In the determination processing at the lower limit position, stop control is executed after confirming that the detected voltage value V is smaller than the set upper limit voltage value VH (VH> V).

Next, an operation of detecting an obstacle during the opening and closing operation of the shutter curtain 1 will be described. As shown in FIG. 3, when an obstacle is positioned in the moving direction, when the closing switch of the operation unit is operated and the shutter curtain 1 is closed and moved, the obstacle sensing means 11 provided on the seat plate 10 is closed. The operating piece 12b contacts this obstacle, and the pressing piece 13 presses the long switch body 3.

At this time, the A / D converter 6 of the control means 4 obtains the detected voltage value V corresponding to the pressed position of the long switch body 3. The processing unit 5a compares the detected voltage value V with the upper and lower limit voltage values VH and VL set and stored in the storage unit 5b. As a result of the comparison, when the detected voltage value V is smaller than the upper limit voltage value VH and larger than the lower limit voltage value VL (VH>V> VL), the shutter curtain 1 has reached both the upper limit position and the lower limit position. When the obstacle sensing means 11 is operated in the absence state, it is determined that the obstacle has come into contact with the obstacle and the operation of the switch is stopped, and the shutter is stopped at this position, or the operation of the switch is reversed, and the shutter is turned up. I do.

As a result, the shutter curtain 1 is immediately stopped when an obstacle comes into contact, and safety control for setting an abnormal state is executed. At this time, the processing unit 5a may simultaneously output an obstacle signal to the external notification means 9 and notify the operator or the like of the obstacle contact state. Notification means 9
Is notified by a sound such as a buzzer in addition to displaying a lamp, a screen, or the like.

In the above description, the obstacle sensing operation at the time of closing the shutter curtain 1 has been described. However, even during the opening operation, when the operating piece 12a of the obstacle sensing means 11 comes into contact with this obstacle at the time of opening, the pressing piece is pressed. 13 presses the long switch body 3, and at this time, the processing unit 5a performs the comparison processing (V ≧ VH, V ≦ VL), and the shutter curtain 1 does not reach the upper limit position or the lower limit position. At one time, the operation of the switch is stopped, and the shutter is stopped and held at this position.

FIG. 5 is a flowchart showing the contents of processing for opening / closing operation and abnormal state detection in the normal mode. As shown in the drawing, in both the opening operation and the closing operation, the detected voltage value V is compared with the upper limit voltage value VH and the lower limit voltage value VL, and the upper and lower limit positions are detected. When the voltage value V is smaller than the upper limit voltage value VH and larger than the lower limit voltage value VL (VH>V> VL), it is determined that the state is abnormal, that is, the obstacle is in contact. When a stop operation is performed, the shutter immediately stops.

Even if the environmental temperature at the place where the shutter control device is installed changes, even when the stop control at the upper and lower limit positions and the detection of an obstacle at a place other than the upper and lower limit positions are performed. Can be stably controlled. That is, when there is a temperature change, the resistance value of the long switch body 3 fluctuates. At the same time, the resistance value of the voltage dividing resistor 7 also fluctuates. The change rate of the resistance value with respect to the temperature change can be expressed by the following equation: k = (R−Ro) / t, where k is a temperature coefficient and t is t:
Temperature, R: resistance value at that temperature, Ro: a constant by each resistance), and as a result, A
The detection voltage value V input to the / D conversion unit 6 is a value based on the voltage division ratio of the voltage dividing resistor 7 and the long switch body 3, and as a result, is not affected by a temperature change.

In the above embodiment, the processing unit 5a of the control unit 4 stores the upper limit voltage value VH,
The comparison processing of the detected voltage value V is performed based on the lower limit voltage value VL, and the stop at the upper and lower limit positions and the stop at the time of detecting an obstacle are performed. This makes it possible to achieve a configuration that is not affected by the temperature change. However, a physical temporal change of the shutter, for example, a change in the height dimension of the curtain 1 itself, or a sensing operation of the obstacle sensing unit 11 is physically performed. When it changes, accurate stop at the upper and lower limit positions may not be performed. However, even in this case, when an obstacle comes in contact with the shutter during opening and closing, the operating pieces 12a and 12b of the obstacle sensing means 11 operate based on this contact, and the shutter curtain 1 can be controlled to stop.

In order to cope with such a physical change such as a temporal change of the shutter and the long switch, the processing unit 5a determines the upper limit voltage value VH and the lower limit voltage value set in the storage unit 5b as the determination conditions. VL is the compensation voltage value V
Voltage value obtained by adding α and Vβ (VH−Vα, VL + Vβ)
And the detected voltage value V is compared. More specifically, the stop control at the upper limit position is such that the seat plate 10 of the shutter curtain 1 physically contacts the lintel K when the determination condition (V ≧ VH−Vα) is satisfied. When the pressing position of the long switch body 3 is the distance L1
Slightly lower position (lower position by compensation voltage value Vα)
However, this can be determined as the upper limit position and control processing can be performed. Thus, for example, even when the slat curtain portion of the shutter is physically extended (compressed), the shutter curtain 1 can be accurately stopped at the upper limit position.

On the other hand, the stop control at the lower limit position is (V ≦ V
L + Vβ), when the shutter curtain 1 is physically in contact with the floor F, the pressing position of the long switch body 3 is equal to the distance L.
Even in the case of a position slightly higher than 2 (a position higher by the compensation voltage value Vα), this can be determined as the lower limit position and the control processing can be performed. Thus, for example, even when the slat curtain portion of the shutter is physically extended (compressed), the shutter curtain 1 can be accurately stopped at the lower limit position. Thus, the upper limit voltage value VH and the lower limit voltage value V
The voltage values (VH-Vα, VL + Vβ) obtained by adding the compensation voltage values Vα and Vβ to L are set in the setting mode shown in FIG. 4, and the detected voltage values V in the normal mode shown in FIG.
And a stop at the upper and lower limit positions and an abnormal state are detected.

According to the present invention, when the operating piece of the obstacle sensing means comes into contact with an object when the shutter is opened and closed, the pressing piece presses the corresponding long switch body, and the control means changes the obtained detected voltage value. By comparing with the voltage value corresponding to the upper / lower limit position, it is possible to distinguish and determine whether the shutter curtain has reached the upper / lower limit position or the contact with an obstacle. When setting the upper and lower limits, it is possible to easily set different upper and lower limit positions for each shutter simply by actually moving the shutter to the upper and lower limit positions when setting the upper and lower voltage values by switching to the setting mode and setting the shutter. Become like In the normal mode, when the detected voltage value at the time of opening and closing the shutter curtain is equal to or more than the upper limit voltage value obtained by subtracting the compensation voltage value, it is determined that the shutter curtain has reached the upper limit position, and the detected voltage value is added with the compensation voltage value. When the detected voltage value is lower than the upper limit voltage value including the compensation voltage value and larger than the lower limit voltage value, it is determined that the shutter curtain has reached the lower limit position. Since the judgment process has been performed, the upper and lower limit positions and the obstacle contact can be determined only by the voltage value comparison process, and the shutter curtain can be stopped at the upper and lower limit positions even when the shutter curtain is physically expanded and contracted. .

[0041]

In addition, since a voltage dividing resistor having the same temperature coefficient is dividedly connected to the long switch body and detected at a predetermined voltage dividing ratio, even if the environmental temperature fluctuates, the upper and lower limit positions and obstacles are prevented. The contact detection accuracy does not change.

[Brief description of the drawings]

FIG. 1A is a diagram illustrating an embodiment of a shutter control device according to the present invention. (B) is a perspective view showing a long switch body.

FIG. 2A is a diagram illustrating an upper limit position of a shutter.
(B) is a circuit diagram showing an electrical state at the same upper limit position.

FIG. 3A is a diagram illustrating a lower limit position of a shutter.
(B) is a circuit diagram showing an electrical state at the lower limit position.

FIG. 4 is a flowchart showing an operation content in a setting mode of the apparatus.

FIG. 5 is a flowchart showing an operation content of the apparatus in a normal mode.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Shutter curtain, 2 ... Guide rail, 3 ... Long switch body, 3a, 3b ... Resistor, 3aa, 3ba ... One end, 3ab, 3bb ... Other end 4, ... Control means, 5a ... Processing part, 5b ... Storage Part, 6 A / D conversion part, 7 resistor for voltage division, 8 power supply, 9 notification means, 10 seat plate, 11 obstacle detection means, 12a, 12b operating piece, 13 pressing piece,
14: coupling mechanism, K: lintel, F: floor surface.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) E06B 9/56-9/68 G02B 7/36 H03K 17/14

Claims (2)

(57) [Claims] 1. A pair of resistors which are disposed opposite to each other along an inner surface of a guide rail on a side of a shutter curtain and to which a predetermined voltage is applied, and where the resistors receive a pressing force, the two resistors can freely contact each other. A long switch body that outputs a voltage corresponding to the contact point; and a long switch body that is provided on a seat plate at a lower end of the shutter curtain, and that contacts the object when the object comes into contact with the seat plate. Obstacle sensing means for pressing the body, one end of a pair of resistors of the long switch body is connected,
And voltage values that correspond to the lower limit position on the shutter curtain,
Control means for comparing the detected voltage value obtained when an object comes into contact with the shutter curtain during opening / closing operation to determine the upper and lower limit positions of the shutter curtain, and to detect obstacle detection between these upper and lower limit positions. The control means sets upper and lower limit positions of the shutter curtain.
Has a setting mode for setting
When recognizing that the shutter curtain is open, the object touches the object.
Is set as the upper limit voltage value.
Remember, when the shutter curtain is closed, the object
The detected voltage value obtained when contact is made as the lower limit voltage value
When storing and setting the shutter curtain in the normal mode,
Means that the detected voltage value is obtained by subtracting the compensation voltage value from the upper limit voltage value.
The shutter curtain moves to the upper limit
Judgment has been made, the detected voltage value reaches the lower limit voltage value and the compensation voltage
The shutter curtain is at the lower limit when the voltage is less than the voltage value
Position, and the detected voltage value is compensated from the upper limit voltage value.
Compensated to the lower limit voltage value smaller than the voltage value minus the compensation voltage value
When the voltage is within the range greater than the voltage value
It is determined that an obstacle has touched between these upper and lower positions.
Features a shutter control device. 2. A connected with a predetermined division ratio with respect to the elongated switch body comprises a dividing resistor having the same temperature coefficient as the long switch body, said control means, said partial pressure A voltage is input to a resistor and a voltage dividing portion of the long switch body.
1 Symbol placement of the shutter control unit.