JPH0647901B2 - Electric blinds - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric blind, and in particular, a plurality of blinds are provided in each of a plurality of zones, and one blind among a plurality of blinds included in each zone. As the base unit, and the remaining blinds as the base unit,
The present invention relates to an electric blind for setting a lower limit of blinds included in each zone or in all zones.

[Prior Art] The setting of the lower limit position of a currently proposed and commercially available electric blind is performed by adjusting a mechanical lower limit switch or the like provided on the lifting shaft. In this system, a cam that moves in the left-right direction by the rotation of the lifting shaft is provided, and the limit switch is operated by the movement of this cam to stop the power supply to the electric motor and stop the descent of the blind.

[Problems to be Solved by the Invention] In the conventional electric blind configured as described above, after the blind is installed at a designated place such as a window frame, the blind is lowered to operate the limit switch at a predetermined position. However, since the head box of the electric blind is usually attached to the upper part of the window, the adjustment work is complicated and it is dangerous because it is located at a high place. In addition, this adjustment is often not completed in one operation, and since it involves the work of actually lowering the blind to check whether the desired position can be set, it takes a long time. .

On the other hand, in some buildings, rooms are divided into zones,
When installing blinds on the windows belonging to each zone,
Depending on the situation, the work for setting the lower limit must be performed individually or zone by zone or as a whole, which is extremely complicated.

Therefore, a main object of the present invention is to provide an electric blind capable of easily setting the lower limit value of the blind individually, zone by zone, and the whole.

[Means for Solving the Problems] The present invention defines one of the blinds in each zone as a master unit and the rest as slave units, and targets the individual zones or all zones, collectively or individually. Further, there are provided a designating unit for outputting a command signal for instructing the setting of the lower limit value of the lowering of the blinds of the master unit and the slave unit, and a receiving unit for receiving the command signal from the commanding unit.

On the other hand, each master unit determines whether or not the command signal received by the receiving unit commands the lower limit value setting of the blind collectively or individually in the corresponding zone; In response to the master unit position detecting means for detecting the current position of the blind of the machine and the master unit determining means, it is determined that the command is an individual or collective lower limit value setting command of the master unit in the zone. , A master unit storage unit that stores the current position of the blind of the master unit detected by the master unit position detection unit as a lower limit value, and a collective lower limit value setting command of the blind in the zone by the master unit determination unit or the zone. A command to output a lower limit value setting command signal to each child device in response to the determination that it is a lower limit value setting command for one of the blinds belonging to the child device. When the command output means and the descent command are given, the motor is rotated until the descent position of the blind of the parent machine detected by the parent machine position detection means matches the lower limit value stored in the parent machine storage means. And a base unit control means for lowering the blind.

On the other hand, each slave unit has a slave unit determination unit that determines whether the command signal output by the command signal output unit of the master unit is a blind lower limit value setting command for the slave unit, and a blind unit for the slave unit. The slave unit position detecting means for detecting the current position of the slave unit and the slave unit determining unit determines the lower limit of the blind blind current position of the slave unit in response to the determination that the lower limit value setting command of the slave unit is determined. When the descent command is given, the descent position of the blind of the child device detected by the child device position detection means matches the lower limit value stored in the child device storage means. And a slave unit control means for rotating the electric motor to lower the blind.

[Operation] In the electric blind according to the present invention, in response to a command to set the lower limit value of the blind of the master unit and the slave unit collectively or individually for each zone or all zones, the master unit issues the command. If the signal commands the setting of the lower limit value of the parent device collectively or in the zone to which the parent device belongs, the current position of the blind of the parent device is stored as the lower limit value. If a command is issued to set the lower limit value collectively or individually to the slaves within the zone to which the master belongs, the command signal is output to the slaves. If each slave unit has a lower limit value setting command for the slave unit, it stores the current position of the blind of the slave unit as the lower limit value. When a lowering command is given from the outside, the master unit and the slave unit rotate the electric motor and lower the blind until the descending position matches the lower limit value stored in each unit.

[Embodiment of the Invention] FIG. 1 is a diagram showing the overall configuration of an embodiment of the present invention, and FIG. 2 is a diagram showing the configuration of each blind shown in FIG.

First, with reference to FIG. 1 and FIG. 2, an external configuration of an embodiment of the present invention will be described. 1n are installed in a predetermined zone 1, the blind 11 is defined as a master unit, and the blinds 12 ... 1n are defined as slave units. The blind 11 of the master unit and the blinds 12 ... 1n of the slave unit are connected by signal lines 1S.

Similarly, the blinds 21, 22, ...
Is installed, the blind 21 is set as the master unit,
The blinds 22 ... 2n are defined as slaves. The signal line 2S is provided between the blinds 21, 22 ... 2n.
Connected by. In addition, for Zone 3 as well,
The blinds 31, 32 ... 3n are installed, the blind 31 is defined as a master unit, and the blinds 32 ... 3n.
Is defined as a child machine. And each blind 3
A signal line 3S connects between 1, 32, ..., 2n. Furthermore, each blind 11, 12, ... 1n, 21, 22 ,.
A power line 5 is wired to n and 31, 32, ... 3n. Further, the light receiving unit 7 is connected to the blinds 11, 21, 31 of each parent device via the signal line 4. A zone controller 6 is provided for instructing the operation of the blinds of each of the above-mentioned parent device and each child device.

In addition, depending on the direction of the windows in the room, for example, the east side is zone 1, the south side is zone 2, and the west side is zone 3 so that blinds are installed or a plurality of windows arranged in a line are blocked. Blinds may be separately provided and the blocks may be divided into zones 1, 2, and 3.

The zone controller 6 is for interlocking the blind groups provided in each zone 1 to 3 for each zone or for all zones, or for instructing rise, stop, descent, opening and closing of slats, or setting of a lower limit value for each zone. It is a command means, and the command signal is transmitted to the light receiving unit 7 as an infrared signal. Then, the zone controller 6 includes a zone 1 key 67, a zone 2 key 68, a zone 3 key 69, an all zone key 70, a ten key 64, an all key 65, a clear key 66, an ascending key 71, a stop key 72, a descending key 73, A set key 74 and slat opening / closing keys 75 and 76 are included.

Zone 1 key 67 to zone 3 key 69 are used to designate zone 1 to zone 3. Although the number of zones is 3 in the example shown in FIG. 1, if the number of zones is to be increased, the number of zone keys may be increased to correspond to each zone. You can reduce the number of zone keys. Further, when only one zone is provided, it is possible to deal with it by using the all zone key 70 described below. All zone keys 7
0 is an instruction to collectively control the blinds included in all zones 1 to 3. When it is not necessary to divide zones 1 to 3, all zones may be set as zone 1, but all zones may be set as targets. In this case, it is not necessary to set the zone.

The ten-key pad 64 is composed of numeric keys 0 to 9 and is provided for inputting a blind device number. The all key 65 is a command switch for interlocking and operating each blind which comprises each zone. Clear key 66 is zone 1 key 67 or zone 3 key 6
This is for clearing and returning to the initial state when the input by the 9 or all zone keys 70 and the ten keys 64 is incorrect. The ascending key 71 is for instructing to raise the blind, the stop key 72 is for instructing to stop the blind, and the descending key 73 is for instructing to descend the blind. The slat opening / closing keys 75 and 76 are for adjusting the angle of the slat. The key 75 is for adjusting the angle so that the slanted surface of the slat faces outward, and the key 76 is for adjusting the angle so that the slanted surface of the slat faces inward. The set key 74 is a key for instructing the start of operations such as raising and lowering of the designated blind.

Next, the configuration of the electric blind will be described with reference to FIG. The power cord 5 is connected to the control unit 40.
The control unit 40 includes a microcomputer, a power supply unit, and the like, and is connected to the geared motor 104 including an electric motor and a reduction gear. Geared motor 104
The rotating shaft of the lifting shaft 1 via the coupling 105
It is connected to 12. Elevating units 106, 107 and 108 are connected to the elevating shaft 112.
Sensors, fault switches (not shown), and upper limit switch 44 built in these lifting units 106, 107, and 108 are connected to the control unit 40 by a wiring member 109. The wiring material 109 also includes wiring to the geared motor 4. Lifting units 106 and 10
8 includes a winding drum 117 and a ladder drum 118,
The elevating unit 107 includes only the ladder drum 118.
One end of a lifting tape (which may be a string-shaped one) 110 is fixed to the winding drum 117. The other end of the lifting tape 110 penetrates the plurality of slats 113 and is fixed to the bottom rail 114.

Then, the winding drum 117 winds or unwinds the lifting tape 110 in accordance with the rotation of the lifting shaft 112, and raises and lowers the slats 113 and the bottom rail 14. Further, one end of the ladder cord 111 is fixed to the ladder drum 118, and the other end of the ladder cord 111 is fixed to the bottom rail 114. Then, the ladder drum 118 rotates with the rotation of the elevating shaft 112, and controls the opening degree of the slat. The bottom rail 114 functions as a weight for descending the blind and a weight for preventing the blind from swaying due to wind or the like after the descent.

Control unit 40, geared motor 104, and lifting unit 10
6, 107 and 108 are covered by a head box 115 that constitutes an outer box. This head box 1
An upper limit switch 44 is provided in the lower part of 15, and this upper limit switch 44 is pressed by the slats 113 to operate when the blind is wound, and detects the upper limit position.

FIG. 3 is a schematic block diagram of the zone controller 6, and FIG. 4 is a block diagram of the control unit 40 included in the electric blind.

Next, with reference to FIG. 3 and FIG. 4, an electrical configuration of one embodiment of the present invention will be described. The zone controller 6, as shown in FIG.
And a power source unit 62 and an infrared light emitting unit 63, and the microcomputer 61 includes a Den key 64, an All key 65, a Clear key 66, a Zone 1 key 67, a Zone 2 key 68,
Zone 3 key 69, All zone key 70, Up key 71,
A stop key 72, a descent key 73, a set key 74, and slat opening / closing keys 75 and 76 are connected. And
The microcomputer 61 creates a command signal according to the input from each of the keys 64 to 76, and the infrared light emitting unit 63
Output as an infrared signal via. The infrared signal generally uses a carrier having a frequency of 38 KHz or the like and is pulse-modulated by a command signal. This carrier may be made by the microcomputer 60, or an oscillator may be provided in the infrared light emitting section 63 to provide the infrared light emitting section 6 with the oscillator.
You may make it in 3. The microcomputer 61 is provided with memories 78 and 79. The memory 78 stores data indicating the designated zone, and the memory 79 stores number data indicating the designated child device. The power supply unit 62 supplies power to the microcomputer 61 and the infrared light emitting unit 63,
Generally, a dry battery is used.

Next, with reference to FIG. 4, the configuration of the control unit 40 incorporated in each blind will be described. The control unit 40 includes a microcomputer 41, and the microcomputer 41 has a RAM 411 built therein. A height detector 421 is connected to the microcomputer 41, and a height encoder 42 is connected to the height detector 421. The height encoder 42 detects the current height of the blind, and the winding drum 117.
And a photo interrupter for detecting the on / off of the slit, and supplies a pulse signal to the height detection unit 421 according to the current height. The height detector 421 converts or pulse-shapes the pulse signal so that the pulse signal can be read by the microcomputer 41.

An angle detector 431 is connected to the microcomputer 41, and an angle encoder 43 is connected to the angle detector 431. The angle encoder 43 detects the angle of the slat, and supplies the detection pulse to the angle detection unit 431. The angle detector 431 processes the pulse signal and supplies it to the microcomputer 41. An upper limit detector 441 is connected to the microcomputer 41, and an upper limit switch 44 is connected to the upper limit detector 441. The upper limit switch 44 detects the upper limit of the blind, and the detection signal is the upper limit detection unit 4
It is given to the microcomputer 41 via 41.

A failure detection unit 451 is connected to the microcomputer 41, and the failure switch 4 is connected to the failure detection unit 451.
5 is connected. The obstacle switch 45 detects an obstacle when the blind is descending, and the detection signal is given to the microcomputer 41 via the obstacle detector 451.

Further, a light receiving unit 7 is connected to the microcomputer 41 via a signal line 4, and a command signal from the zone controller 6 shown in FIG. 3 is input to the microcomputer 41 via the light receiving unit 7. It The light receiving unit 7 receives the infrared signal, demodulates the modulated infrared signal, and gives a command signal to the microcomputer 41 and the connection unit 49. The microcomputer 41 takes in the given command signal, decodes it, and performs various blind operations.

Further, the blinds 12 ... 1n, 22 ... 2n, 3 of the child device
2 ... 3n is provided with a connecting portion 48, and any one of the signal lines 1S, 2S, 3S is connected to the connecting portion 48. Then, the command signal given from any of the signal lines 1S, 2S, 3S is transmitted from the connection section 48 to the transmission data input section 4
It is input to the microcomputer 41 via 81.
Further, the blinds 12 ... 1n, 22 ... 2n, of each slave unit,
A connection portion 49 is provided at 32 ... 3n, and the signal lines 1S, 2S, 3S are also connected to this connection portion 49.
A command signal from the microcomputer 41 is output to the other blind as transmission data via the transmission data output unit 491 to the connection unit 49.

Further, the microcomputer 41 includes a parent / child setting unit 5
0, a device number setting unit 51, a lower limit setting unit 52, and a motor control unit 53 are connected. The parent / child setting unit 50 is for setting whether the corresponding blind is a parent device or a child device. The device number setting unit 51 sets the device number of the blind, but in the case of the master unit, the zone number is set instead of the device number. The lower limit setting unit 52 individually sets the lower limit position of the blind when the lower limit is not set by the zone controller 6. The motor control unit 53 sets the motor 54 for raising, lowering, stopping, or adjusting the slat angle to the normal rotation, reverse rotation, or brake mode based on the output signal from the microcomputer 41. The microcomputer 41, the motor controller 53, and the motor 5
A predetermined power supply voltage is supplied from 4 to the power supply unit 55.

FIG. 5 is a diagram for explaining a code included in the command signal output from the zone controller 6. In FIG. 5, the command code includes a start bit S, a transmission / controller discrimination code R, a zone code Z, a movement code C, a movement auxiliary code Cs, a device code U, a set movement discrimination code K and a parity check code B. The start bit S defines the start of the command code, and the transmission / controller discrimination code R is a signal for transmitting the command code from an arbitrary blind (master device) to another blind (slave device). It is a code for determining whether it is a command signal from the zone controller 6. That is, when the transmission / controller discrimination code R is “1,1”, it indicates that it is a command signal from the zone controller 6, and when it is “0,0”, it is a command signal from the master unit to the slave unit. It is shown that.

The zone code Z is a code of the zone number and all zones. The operation code C is a code that specifies operations such as ascending, stopping, descending, slat angle adjustment, and lower limit value setting. The movement auxiliary code Cs is a code of slat angle data. The equipment code U represents a blind equipment number. Set operation code K
Is a code for determining whether it is a normal command or a setting operation. The parity check code is a code for checking the correctness of the command code.

6A and 6B are flow charts for explaining the operation of the zone controller, FIG. 7 is a flow chart for explaining the lower limit setting operation, and FIG. 8 is a lower limit setting releasing operation. It is a flow figure for explaining.

Next, a specific operation of the embodiment of the present invention will be described with reference to FIGS. First, a general operation will be described. Blinds 11, 21 of the base unit
The parent / child setting unit 50 of the control unit included in each 31 is set to set that each is a master unit, and the blinds 12 ... 1n, 22 ... 2n, 32 ... 3n of the slave units are each slave units. Is set. Furthermore, the device number setting unit 51 is operated to operate the blinds 11, 21, 31 of the parent device.
For each, set the zone number 1 to 3 respectively,
Blind 12 ... 1n, 22 ... 2n, 32 ... 3n
Set the device number for each.

Next, the zone controller 6 is operated. That is, the zone 1 key 67 for designating zone 1 is operated, and then the ten key 64 is operated to input the blind number to be operated. For example, in the 16th blind,
Is input from the numeric keypad 64. Next, when it is desired to raise the blind, the raise key 71 is operated. When the above operation is performed, the microcomputer 61 stores the zone code obtained by the key input of the zone 1 key 67 in the memory 78 and the code input from the ten key 64 in the memory 79. Then, in response to the operation of the up key 71, the microcomputer 61 refers to the memories 78 and 79 and sends a command signal composed of the code shown in FIG.
Sent from. Since the zone code and the device number code are stored in the memories 78 and 79, respectively,
Next, when setting the lower limit value, when the same blind is designated, it is not always necessary to operate the zone 1 key 67 and the ten key 64. The command signal received by the light receiving unit 7 is given to the microcomputer 41 of each parent device. First, the microcomputer 41 checks whether it is a master unit or a slave unit based on the setting of the parent / child setting unit 50. If it is the parent device, it compares its own zone number with the received zone code to check the group to which it belongs. If the zone codes do not match, the following operation is not performed. If the zone codes match, or if they are all zone codes, then a device designation check is performed. Normally, a plurality of child devices belonging to the group are connected to the parent device, and a device number code is set to individually specify these. For example, in zone 1, the master unit is number 1 and the slave units are numbers 12, 13, ... 1n. For example, if the received signal includes the device number code for the child device, the parent device in zone 1 sends a command signal to the child device, and the child device compares the device number with the device number of the child device itself. However, if they match, the signal sent from the master unit to the slave unit is valid. (For example, device codes 12 and 13 are valid.) If the device number code is all codes,
The entire zone can be operated simultaneously regardless of the parent device and the child device.

Next, the operation of the zone controller 6 when setting the lower limit will be described with reference to FIGS. 6A and 6B. First, the zone keys 67 to 7 of the zone controller 6
The blinds for setting the lower limit value are designated by operating 0 and the ten-key pad 64. When any one of the zone keys 67 to 68 is pressed, the microcomputer 61
Stores the zone code corresponding to the key in the memory 78. When the all zone key 70 is pressed, the all zone code is stored in the memory 78. When the device code is input from the ten-key pad 64, the input device code is stored in the memory 79. When the all key 65 is pressed instead of inputting the key code, the all code is stored in the memory 79. When the clear key 66 is pressed, the microcomputer 61 clears the contents stored in the memory 79.

Next, in order to adjust the designated blind to the desired lower limit position, the up key 71 or the down key 73 is operated.
When the ascending key 71 is operated, as shown in FIG. 6B, the microcomputer 61 causes the ascending command signal including the zone code Z stored in the memory 78 and the equipment code U and the ascending code stored in the memory 79. Is modulated into an infrared signal and transmitted. When the down key 73 is operated, as shown in FIG. 6B, the down command signal including the zone code Z stored in the memory 78, the device code U stored in the memory 79, and the down code. Is modulated into an infrared signal and transmitted. When the set key 74 is operated, the set operation command signal including the set operation determination code K and the zone code Z stored in the memory 78 is modulated into an infrared signal and sent out. As a result, the designated blind moves up or down. When the designated blind reaches the desired position, the stop key 7
Operate 2. When the stop key 72 is operated, the microcomputer 61 stops including the zone code Z stored in the memory 78, the device code U stored in the memory 79, and the stop code as shown in FIG. 6B. The command signal is modulated into an infrared signal and transmitted.

Next, in order to set the lower limit value, the stop key 72 and the descent key 73 are simultaneously pressed for a predetermined time. When the pressing of these two keys continues for a certain time, the microcomputer 61 displays the zone code Z stored in the memory 78, the device code U stored in the memory 79 and the lower limit value as shown in FIG. 6B. A lower limit value setting command signal including a setting code is modulated into an infrared signal and transmitted. Also,
To cancel the lower limit set value, the stop key 72 and the up key 71 are pressed simultaneously. When the stop key 72 and the up key 71 are continuously pressed for a certain time, the microcomputer 61 causes the zone code Z stored in the memory 78 and the device code stored in the memory 79 as shown in FIG. 6B. A lower limit set value release command signal including U and a lower limit set value release code is modulated into an infrared signal and transmitted.

The infrared signal transmitted from the zone controller 6 as described above is received by the light receiving unit 7, demodulated and input to the microcomputer 41. Next, the lower limit value setting operation of the electric blind will be described with reference to FIG. The microcomputer 41 of the parent machine decodes the signal from the light receiving unit 7, and first, the transmission / controller discrimination code R
It is determined whether or not it is a signal from the zone controller 6, and if it is a signal from the zone controller 6, then the zone code is read from the device number setting section 51 and it is determined whether or not it matches the zone code Z included in the command signal. To do.
If the zone codes match, it is then determined based on the device code U whether or not the child device is designated. If the child device is designated, the signal line 1S (or 2S, 3
A signal is output to the child device via S). If no cordless handset is specified, no signal is output to the cordless handset. If the zone codes match, the height detection unit 42
The RAM 411 using the detected current height of 1 as the lower limit setting value.
Remember. That is, when the blind is lowered from the position where the microcomputer 41 and the upper limit switch 44 are turned on, it is possible to count the number of pulses output from the photo interrupter included in the height encoder 42 described above to know the lowered height. , The number of pulses is stored as the lower limit set value. After that, even if the blind is raised due to a rise command, the height from the upper limit position can always be known by counting the number of pulses from the photo interrupter. When there is a descending command from the outside, the microcomputer 41 counts the number of pulses from the photo interrupter while performing the descending operation, and stops the descending operation when the detected descending height and the lower limit set value match. .

The slave unit receives a command signal from the master unit, determines that the signal is not from the zone controller 6, and determines that the signal is from the master unit. The device number is read, and it is determined whether or not it matches the device code U included in the command signal. If they match, the current height detected by the height detection unit 421 is stored in the RAM 411 as the lower limit setting value, as in the case of the parent device. The descent control operation in the slave unit is similar to that in the above-described master unit.

Next, referring to FIG. 8, the lower limit set value releasing operation of the electric blind will be described. The microcomputer 41 of the parent machine decodes the signal given from the light receiving unit 7 and recognizes that it is the lower limit set value cancellation signal. Then, by the transmission / controller discrimination code R, the zone controller 6
If it is a signal from the zone controller 6, the zone code is read from the parent / child setting unit 50, and it is determined whether it matches the zone code Z included in the command signal. If the zone codes match, the device code U
Based on, determine whether the child device is specified,
When the child device is designated, the signal is output to the child device through the signal line. If no slave unit is specified, no signal is output to the slave unit. If the zone codes match, the lower limit setting value stored in the RAM 411 is cleared. On the other hand, in the slave unit, when the lower limit set value cancellation signal is given from the master unit and it is determined that it is not the signal from the zone controller 6, and further it is determined that it is the signal from the master unit, the device number The device number is read from the setting unit 51 and the device code U included in the command signal is read.
Determine the match with. If they match, the lower limit setting value stored in the RAM 411 is cleared as in the case of the parent device.

In the above-described embodiment, the zone controller 3 modulates the command signal and outputs it as an infrared signal, and the infrared signal is received by the light receiving section. May be connected to perform data transmission between them.

[Effects of the Invention] As described above, according to the present invention, the blinds of the master unit and the slave unit are arranged for each zone, and according to the command from the command means, targeting each zone or all zones, Since the lower limit position for lowering the blind can be set collectively or individually, the lower limit setting work of the blind can be easily performed in a short time.

[Brief description of drawings]

FIG. 1 is a diagram showing the overall construction of an embodiment of the present invention. FIG. 2 is a diagram showing a configuration of each blind shown in FIG. FIG. 3 is a schematic block diagram of the zone controller shown in FIG. FIG. 4 is a block diagram of a control unit included in the electric blind shown in FIG. FIG. 5 is a diagram for explaining a code included in a command signal output from the zone controller. Figures 6A and 6A
FIG. B is a flow chart for explaining the operation of the zone controller. FIG. 7 is a flow chart for explaining the lower limit set value operation. FIG. 8 is a flow chart for explaining the lower limit set value releasing operation. In the figure, reference numerals 1, 2, and 3 are parent devices, and 12, 13, 2
2, 23, 32 and 33 are slave units, 4 is a signal line, 5 is a power line, 6 is a zone controller, 7 is a light receiving unit, 40 is a control unit, 41 is a microcomputer, 411 is a RAM,
42 is a height encoder, 421 is a height detection unit, 48 and 49 are connection units, 481 is a transmission data input unit, 491 is a transmission data output unit, 50 is a parent / child setting unit, 51 is a device number setting unit, 53 Is a motor control unit, 54 is a motor, 55 is a power supply unit, 61 is a microcomputer, 62 is a power supply unit,
63 is an infrared emitting part, 64 is a numeric keypad, 65 is an all key, 66 is a clear key, 67 is a zone 1 key, 68 is a zone 2 key, 69 is a zone 3 key, 70 is an all zone key, 71 is a rise key, 72 Is a stop key, 73 is a down key, 74 is a set key, 75 and 76 are slat opening / closing keys, 78 and 79 are memories, 1S, 2S and 3S
Indicates a signal line.

Claims (1)

[Claims] 1. A plurality of blinds are provided in each of a plurality of zones, one blind among the plurality of blinds included in each zone is defined as a master unit, and the remaining blinds are defined as slave units, and an electric motor. It is an electric blind that elevates and lowers each blind according to the rotation of each, and commands the setting of the lower limit value of the blind of the master unit or the slave unit collectively or individually for each zone or all zones. Command unit for outputting a command signal for, and a receiving unit for receiving a command signal from the command unit, further, each master unit, the command signal received by the receiving unit, in the corresponding zone Base unit determining means for determining whether or not to command the lower limit setting of the blind collectively or individually, and the blind of the parent unit. A parent device position detecting means for detecting the current position, and the parent device in response to the parent device determining means determining that the lower limit value setting command for the parent device in the zone is set individually or collectively. A master unit storage unit that stores the current position of the blind of the master unit detected by the machine position detection unit as a lower limit value, and a collective blind lower limit value setting command in the zone by the master unit determination unit or belongs to the zone. When it is determined that it is the lower limit value setting command for one of the slave units, the command signal output means for outputting the lower limit value setting command signal to each slave unit and the descent command are given. The electric motor until the lowering position of the blind of the parent machine detected by the parent machine position detection means matches the lower limit value stored in the parent machine storage means. And a slave unit control means for rotating the blind to lower the blind, each of the slave units, the command signal output by the command signal output unit of the master unit is a blind lower limit value setting command to the slave unit. A slave unit determining means for determining whether or not the slave unit position detecting unit for detecting the current position of the blind of the slave unit; and a lower limit value setting command for the slave unit by the slave unit determining unit. In response to the determination, the slave unit storage unit that stores the current blind position of the slave unit as a lower limit value and the slave unit position detection unit that detects the slave unit position when a descent command is given. An electric blind including: a slave unit control unit for rotating the electric motor to lower the blind until the descent position of the blind matches a lower limit value stored in the slave unit storage unit.