JP2004208458A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To further reduce the power consumption of a display and operating device for a hot water supply system. <P>SOLUTION: The operation display device 120 comprises a control circuit 128 which causes a drive circuit 125 to display the image on a display unit 121 on power supplied from a power circuit 112, a cutoff circuit 123 for cutting off the power circuits 112 and 122 from each other, and a power switch 124a operated by the user to turn on/off the power supply. The control circuit 128 is supplied with power from the power circuit 112. When the power switch 124a is operated to turn off power supply, the control circuit 128 controls and causes the cutoff circuit 123 to cut off the power circuits 112 and 122 from each other. Thus, when the power switch 124a is operated to turn off power supply, the power circuits 112 and 122 are cut off from each other, and power supply from the power circuit 112 to the power circuit 122 is interrupted. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a display device that displays an image when power is supplied from an external power supply device.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a hot water supply system including a hot water supply unit that is installed outdoors to generate hot water by burning fuel gas and a remote control (display device) that is set in a room such as a kitchen and remotely controls the hot water supply unit by a user's operation is known. It has been proposed (for example, see Patent Document 1).
[0003]
Here, the remote control is operated by a user to operate the operation mode, set the target temperature, and the like, an operation switch, a display unit that displays various types of character information, and the like, and an external power supply device built in the hot water supply unit. And a control circuit for supplying power from the power supply circuit and displaying character information and the like on a display unit.
[0004]
In this device, when an operation for performing the power saving mode is performed on the operation switch during standby, the control circuit executes the power saving mode and stops the display on the display unit. I have to. As a result, in the power saving mode, the display unit does not perform display, so that power saving can be achieved.
[0005]
[Patent Document 1]
JP-A-11-316565
[Problems to be solved by the invention]
However, even if the power saving mode is executed in the above-described remote controller, the display unit does not perform any display, and the control circuit continues to be supplied with power from the power supply circuit. Therefore, even in the power saving mode, the power is continuously consumed by the control circuit and eventually the power supply circuit.
[0007]
The present invention has been made in view of the above circumstances, and has as its object to provide a display device capable of further reducing power consumption.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, a display unit (121), a power supply circuit (122) that is supplied with power from an external power supply device (112) and outputs power, A display device which is supplied with power from a power supply circuit and displays an image on a display unit. The display device includes a cutoff circuit (123) for cutting off between an external power supply device and a power supply circuit; And a power switch (124a) that is operated to supply power from a power supply circuit so that when the power switch is operated to turn off the power supply, the power supply circuit shuts off the external power supply device and the power supply circuit. And a control circuit (128) for controlling the cutoff circuit.
[0009]
Thus, when the power switch is operated to turn off the power, the connection between the external power supply and the power supply circuit is cut off, so that power is not supplied from the external power supply to the power supply circuit. As a result, even if the power switch is operated to turn off the power, it is possible to prevent the power circuit, and eventually the control circuit, from continuing to consume power, thereby achieving further power saving.
[0010]
According to the invention described in claim 2, the power switch outputs a switch signal based on the power supplied from the external power supply device when the power switch is operated by the user to turn off / on the power. When the switch is operated to turn on the power, a shutoff circuit connects between the external power supply and the power supply circuit based on a switch signal output from the power switch and causes the power supply circuit to start supplying power to the control circuit. Wherein the control circuit controls the shutoff circuit so as to maintain the connection between the external power supply device and the power supply circuit when power supply from the power supply circuit is started.
[0011]
Thus, even when the power supply circuit is not supplied with power from the external power supply, when the power switch is operated to turn on the power, the connection between the external power supply and the power supply circuit is maintained, and the control circuit is switched from the power supply circuit to the control circuit. Power supply can be started.
[0012]
More specifically, when the control circuit determines that the power switch has been operated to turn off the power based on the switch signal output from the power switch, the control circuit determines whether the external power supply has been turned off. The cutoff circuit may be controlled so as to cut off between the device and the power supply circuit.
[0013]
Further, as in the invention according to claim 4, a voltage dividing circuit (126) for dividing the voltage of the switch signal output from the power switch is provided, and the control circuit includes a voltage dividing circuit output from the voltage dividing circuit. Based on the signal, it may be determined that the power switch has been operated to turn off the power.
[0014]
According to the fifth aspect of the present invention, the shutoff circuit has a detection unit for detecting a power-on signal output to turn on the power from the external power supply device, and based on the power-on signal detected by the detection unit, It is characterized by connecting between the external power supply device and the power supply circuit.
[0015]
Thus, by supplying a power-on signal from the external power supply device, power supply can be started from the power supply circuit to the control circuit and the like.
[0016]
Specifically, as in the invention according to claim 6, the power-on signal is a voltage change signal indicating a voltage change of a power supply voltage output from the external power supply device. A differentiating circuit for detection may be used.
[0017]
In addition, like the invention according to claim 7, the display device according to any one of claims 1 to 6 may be a display device applied to a hot water supply system that supplies hot water.
[0018]
Incidentally, reference numerals in parentheses of the above-mentioned units are examples showing the correspondence with specific units described in the embodiments described later.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
(1st Embodiment)
FIG. 1 shows a schematic diagram of an embodiment of a hot water supply system to which the display device according to the present invention is applied.
[0020]
The hot water supply system includes a hot water supply device 100, an electronic control device 110 (external device), and an operation display device (display device) 120. The hot water supply device 100 includes a heat pump unit 10 for heating water for hot water supply. And a hot water storage unit 20.
[0021]
The heat pump unit 10 causes the high-pressure refrigerant compressed by the electric compressor 11 to flow into the high-pressure side heat exchanger 12, where the high-pressure refrigerant and the hot water exchange heat to heat the hot water. The high-pressure refrigerant after heat radiation that has passed through 12 is then decompressed to a low pressure state by the decompression device 13. This low-pressure refrigerant absorbs heat from the atmosphere or the like in the evaporator 14 and evaporates, and then is sucked into the electric compressor 11 and compressed again.
[0022]
The hot water storage tank unit 20 has a hot water storage tank 21, and the hot water storage tank 21 receives hot hot water heated by the high-pressure side heat exchanger 12 of the heat pump unit 10 from the upper inlet / outlet thereof, and stores the hot water. Hot water is supplied to the bathtub from the entrance. The hot water flowing out of the lower outlet of the hot water storage tank 21 flows into the high-pressure side heat exchanger 12 of the heat pump unit 11 by the electric pump 17. Further, the hot-water storage tank 21 is configured to flow from a water supply stopcock 19c from a water tap. Reference numerals 19a and 19b in FIG. 1 indicate a water stop valve and a water stop valve with a check valve.
[0023]
Next, an electric circuit configuration of the hot water supply system will be described with reference to FIGS. FIG. 2 is a block diagram illustrating a schematic electric circuit configuration of the hot water supply system, and FIG. 3 is an electric circuit diagram illustrating a specific configuration of a cutoff circuit, a switch input circuit, and the like of the operation display device 120.
[0024]
The electronic control unit 110 includes a control circuit 111. The control circuit 111 detects a temperature detected by the tank internal hot water temperature sensors 22a to 22c, a detected temperature of the water discharge temperature sensor 16a, a detected pressure of the pressure sensor 16b, and an operation display. The electric compressor 11, the electric blower 14a, the electric pump 17, and the like are controlled so that the hot water temperature in the hot water storage tank 21 approaches the hot water target temperature based on the target temperature and the like set by the device 120.
[0025]
The outflow temperature sensor 16a detects the temperature of the water flowing out of the water-refrigerant heat exchanger 12, and the pressure sensor 16b detects the pressure of the refrigerant flowing out of the water-refrigerant heat exchanger 12 in the heat pump unit 10. Things. The in-tank hot water temperature sensors 22a to 22c are attached in order from the upper side to the lower side on the outer surface of the hot water storage tank 21, and detect the hot water temperature in the hot water storage tank 21, respectively. The electric blower 14 a blows outside air toward the evaporator 14.
[0026]
The electronic control unit 110 includes a power supply circuit 112 (external power supply circuit) and a communication circuit 113. The power supply circuit 112 is based on an AC voltage (for example, 200 V) input from a commercial power supply, and has a It generates a low voltage of 5V or DC. The low voltage of 5 V is output to the control circuit 111 and the communication circuit 113. Thus, the control circuit 111 and the communication circuit 113 are supplied with power from the power supply circuit 112.
[0027]
Further, in order to supply power from the power supply circuit 112 to the operation display device 120, a power supply voltage of 12V is output to the operation display device 120 through the electric wire 200a. Note that reference numeral 200b in FIG. 2 denotes a ground line, which is connected between the electronic control device 110 and the operation display device 120.
[0028]
The communication circuit 113 superimposes a downstream communication signal on the power supply voltage of 12 V applied to the electric wire 200 a and transmits the signal to the communication circuit 127. The downstream communication signal is composed of a plurality of rows of pulse signals, and is a signal indicating the detected temperature, detected pressure, and the like of the sensors 16a, 16b, 22a to 22c. Further, the communication circuit 113 receives the upstream communication signal superimposed on the power supply voltage of 12 V applied to the electric wire 200a. The upstream communication signal is composed of a plurality of rows of pulse signals, and is a signal indicating a hot water target temperature or the like.
[0029]
The operation display device 120 is for displaying characters such as a hot water target temperature and an error code and setting the target temperature. As shown in FIG. 2, the display unit 121, the power supply circuit 122, the cutoff circuit 123, the power supply It comprises a switch 124a, a temperature setting switch 124b, a drive circuit 125, a switch input circuit 126, a communication circuit 127, and a control circuit 128.
[0030]
The display unit 121 is, for example, a liquid crystal display panel that displays characters such as a target hot water temperature and an error code. The power supply circuit 122 is applied from the power supply circuit 112 of the electronic control device 110 via the electric wire 200a. The power supply voltage (for example, 12 V) is reduced to generate a reduced voltage (5 V). The reduced voltage is supplied to the control circuit 128 and the like.
[0031]
The cutoff circuit 123 performs one of connection and cutoff between the power supply circuit 112 and the power supply circuit 122 of the electronic control device 110. More specifically, as shown in FIG. 3, the cutoff circuit 123 includes transistors 130 and 131, a current-limiting resistor 132, and diodes 133 and 134 for backflow prevention.
[0032]
The transistor 130 is a PNP transistor provided between the power supply circuits 112 and 122, and is driven by the transistor 131 to perform one of connection and disconnection between the power supply circuits 112 and 122. The transistor 131 is connected between the transistor 130 and the ground, and drives the transistor 130 based on a control signal input from the control circuit 128 through the diode 133. Further, the transistor 131 can also drive the transistor 130 by a switch signal input from the power switch 124a through the diode 133.
[0033]
The power switch 124a is a normally open switch disposed between the electric wire 200a and the diode 133 of the cutoff circuit 123, and is operated by the user to turn off / on the power (hereinafter, referred to as power off / on operation). Then, the connection between the electric wire 200a and the diode 133 of the cutoff circuit 123 is made. Thus, when the power switch 124a is turned on / off, the switch signal can be output based on the DC 12V power supplied from the power circuit 112 through the electric wire 200a.
[0034]
As shown in FIG. 3, the switch input circuit 126 includes resistance elements 135 and 136 connected in series between the common connection terminal 137 and the ground. The common connection terminal 137 is a common connection terminal between the power switch 124a and the diode 133. Then, the resistance elements 135 and 136 divide the switch signal output from the common connection terminal 137 and output the divided signal from the common connection terminal 138 to the control circuit 128. The common connection terminal 138 is a common connection terminal between the resistance elements 135 and 136.
[0035]
The temperature setting switch 124b shown in FIG. 2 is operated by the user to set the hot water target temperature, and outputs an operation signal indicating the hot water target temperature to the control circuit 128. The drive circuit 125 is controlled by the control circuit 128 to cause the display unit 121 to display the hot water target temperature, the error code, and the like as characters. Further, the communication circuit 127 superimposes an upstream communication signal on the power supply voltage applied to the electric wire 200a and transmits the superimposed communication signal to the communication circuit 113, and also transmits a downstream communication signal superimposed on the power supply voltage applied to the electric wire 200a. To receive.
[0036]
As will be described later, the control circuit 128 causes the drive circuit 125 to display the target hot water temperature, an error code, and the like on the display unit 121, and controls the cutoff circuit 123 based on a switch signal output from the power switch 124a.
[0037]
Next, the operation of the operation display device 120, which is a feature of the hot water supply system of the present embodiment, will be described.
[0038]
First, when power is supplied to the hot water supply system for the first time or when power is supplied again from the power OFF state, the user presses the power switch 124a as a power on operation.
[0039]
Accordingly, the power switch 124a outputs a switch signal based on the DC 12V power supplied from the power circuit 112 through the electric wire 200a. This switch signal is input to the base terminal of the transistor 131 via the diode 133 of the cutoff circuit 123, so that the transistor 131 is turned on. Therefore, a base current flows from the base terminal of the transistor 130 to the ground through the transistor 131, so that the transistor 130 is turned on. As a result, the cutoff circuit 123 starts the connection between the power supply circuits 112 and 122.
[0040]
Here, the power supply circuit 122 starts supplying power to the control circuit 128 based on the power supply voltage applied from the power supply circuit 112 via the electric wire 200a. Accordingly, when power supply from the power supply circuit 122 is started, the control circuit 128 continuously outputs a high-level control signal to the base terminal of the transistor 131 through the diode 134.
[0041]
Therefore, even when the user presses down the power switch 124a, the ON state of the transistors 130 and 131 and the connection state between the power supply circuits 112 and 122 can be maintained. Thus, the state in which the power is supplied from the power supply circuit 122 to the control circuit 128, that is, the power-on state can be maintained only by the user pressing the power switch 124a once.
[0042]
In such a power-on state, the control circuit 128 causes the drive circuit 125 to display the hot water target temperature on the display unit 121 based on an operation signal output from the temperature setting switch 124b, and to perform communication indicating the hot water target temperature. A signal is output to the communication circuit 127, the occurrence of an error is determined based on the downlink communication signal input from the communication circuit 127, and a code of the determination error is displayed on the display unit 121 by the drive circuit 125. I do.
[0043]
Next, the power switch 124a is pressed by the user for turning off the power as a power-off operation.
[0044]
Accordingly, the power switch 124a outputs a switch signal based on the DC 12V power supplied from the power circuit 112 through the electric wire 200a. Since the switch signal is divided by the resistance elements 135 and 136, a divided voltage signal is generated from the common connection terminal 138. Here, when the voltage level of the divided signal exceeds a predetermined level, the control circuit 128 determines that the power switch 124a has been turned off.
[0045]
Accordingly, the control circuit 128 causes the communication circuit 127 to transmit a power-off notification signal to the communication circuit 113. Therefore, the communication circuit 127 superimposes the power-off notification signal on the power supply voltage applied to the electric wire 200a. . The power-off notification signal indicates that although the control circuit 128 itself shifts to the power-off state, the power-off is not caused by a failure.
[0046]
Further, since the control circuit 128 outputs a low-level control signal to the base terminal of the transistor 131 through the diode 134, the transistor 130 is turned off. Therefore, the transistor 131 is also turned off, so that the power supply circuits 112 and 122 are shut off. As a result, the state can be shifted to a state in which the power supply from the power supply circuit 122 to the control circuit 136 is stopped, that is, a power-off state, just by pressing the power switch 124a by the user.
[0047]
Hereinafter, the operation and effect of the present embodiment will be described. In the operation display device 120, a display unit 121, a power supply circuit 122 that is supplied with power from a power supply circuit 112 (external power supply device) of the electronic control device and outputs power, and a drive circuit 125 based on the power supplied from the power supply circuit 112. A control circuit 128 for displaying an image on the display unit 121, a shutoff circuit 123 for shutting off between the power supply circuits 112 and 122, and a power switch 124a operated by a user to turn off / on the power; The control circuit 128 is supplied with power from the power supply circuit 112 and controls the shutoff circuit 123 so as to cut off between the power supply circuits 112 and 122 when the power switch 124a is operated to turn off the power.
[0048]
Thus, when the power switch 124a is operated to turn off the power, the power supply circuits 112 and 122 are shut off, so that power is not supplied from the power supply circuit 112 to the power supply circuit 122. Accordingly, even if the power switch 124a is operated to turn off the power, it is possible to prevent the power circuit 122 and the control circuit 128 from continuing to consume power, and to further reduce power consumption.
[0049]
(2nd Embodiment)
In the above embodiment, the power is turned on by operating the power switch 124a. In addition, in the second embodiment, the power of the operation display device 120 is controlled by remote control from the electronic control device 110. Indicates what is turned on. FIG. 4 shows the configuration of the operation display device 120 and the electronic control device 110 in this case.
[0050]
As shown in FIG. 4, the operation display device 120 of the present embodiment has a detection circuit 150 including a differentiating circuit 141 and a current-limiting resistance element 140 added to the cutoff circuit 123 of the operation display device 120 shown in FIG. Things. The detection means 150 detects a power-on signal output from the power supply circuit (external power supply) 112 to turn on the power. The differentiating circuit 141 and the resistance element 140 are connected to the electric wire 200 a and the PNP transistor 131. It is connected in series with the base terminal. As the differentiating circuit 141, a capacitor is used.
[0051]
Further, the power supply circuit 112 of the electronic control device 110 of the present embodiment includes a constant voltage circuit 112a and a transistor 112b. The constant voltage circuit 112a is connected to a commercial power source similarly to the electronic control device 110 of the above embodiment. A power supply voltage of 12 V DC or a low voltage of 5 V DC is generated based on the input AC voltage.
[0052]
The transistor 112b is disposed between the constant voltage circuit 112a and the electric wire 200a, and is controlled by the control circuit 111 to perform one of connection and disconnection between the constant voltage circuit 112a and the electric wire 200a.
[0053]
In the present embodiment configured as described above, the control circuit 111 turns off the transistor 112b (ON → OFF). For this reason, since the connection between the constant voltage circuit 112a and the electric wire 200a is cut off, the power supply from the power supply circuit 112 of the electronic control device 110 to the power supply circuit 122 of the operation display device 120 is stopped, and the power supply is turned off.
[0054]
Next, when the control circuit 111 turns on the transistor 112b (OFF → ON), the power supply voltage generated from the power supply circuit 112 changes so as to rise from a low level.
[0055]
When a voltage change signal (power-on signal) indicating such a change in the power supply voltage is input to the differentiating circuit 141 via the resistance element 140 through the electric wire 200a, the voltage changing signal is transmitted from the differentiating circuit 141 to the base of the transistor 131. It will be input to the terminal. As a result, the differentiating circuit 141 detects a voltage change signal indicating a change in the power supply voltage and outputs it to the transistor 131.
[0056]
Accordingly, as in the above-described embodiment, the transistors 131 and 130 are turned on, so that the cutoff circuit 123 starts the connection between the power supply circuits 112 and 122, and the power supply circuit 122 receives the input via the electric wire 200a. The power supply to the control circuit 136 is started based on the supplied power supply voltage. Accordingly, the control circuit 136 maintains the ON state of the transistor 131, and furthermore, the power-ON state in which power is supplied from the power supply circuit 122 to the control circuit 136.
[0057]
(Other embodiments)
In each of the embodiments described above, the display device is applied to the display operation device 120 of the hot water supply system that supplies hot water, but may be applied to the operation display device (remote control) of the air conditioning system. .
[0058]
In each of the above-described embodiments, the hot water supply system is a heat pump type. However, the present invention is not limited to this, and a hot water supply system that generates hot water by burning fuel gas may be used.
[0059]
In the above embodiments, the transistor 112b and the transistors 131 and 130 use bipolar transistors such as PNP and NPN as described above. However, various transistors such as field effect transistors may be used. Good.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a schematic configuration of a hot water supply system according to a first embodiment of the present invention.
FIG. 2 is a block diagram showing a schematic electric circuit configuration of the hot water supply system of FIG.
FIG. 3 is an electric circuit diagram showing a specific configuration of the operation display device of FIG. 1;
FIG. 4 is an electric circuit diagram showing an electric circuit configuration of an operation display device of a hot water supply system according to a second embodiment of the present invention.
[Explanation of symbols]
11 ... electric compressor, 16a ... water temperature sensor, 16b ... pressure sensor,
14a: electric blower, 17: electric pump,
22a to 22c: tank hot water temperature sensor,
110: electronic control device, 111: control circuit, 112: power supply circuit,
113: communication circuit, 120: operation display device, 121: display unit,
122: power supply circuit, 123: cutoff circuit, 124a: power switch,
124b: temperature setting switch, 125: drive circuit,
126: switch input circuit, 127: communication circuit, 128: control circuit.

Claims (7)

A display unit (121);
A power supply circuit (122) that is supplied with power from an external power supply device (112) and outputs power;
A display device that is supplied with power from the power supply circuit and displays an image on the display unit,
An interruption circuit (123) for interrupting between the external power supply device and the power supply circuit;
A power switch (124a) operated by a user to turn off / on the power;
A control circuit for controlling the shutoff circuit so as to shut off the connection between the external power supply device and the power supply circuit when power is supplied from the power supply circuit and the power switch is operated to turn off the power supply; And a display device comprising: The power switch outputs a switch signal based on power supplied from the external power supply device when the power switch is operated for power off / on by a user.
When the power switch is operated to turn on the power, the shutoff circuit connects the external power supply and the power supply circuit based on a switch signal output from the power switch and performs the control by the power supply circuit. To start supplying power to the circuit,
The power supply circuit according to claim 1, wherein the control circuit controls the shutoff circuit so as to maintain a connection between the external power supply device and the power supply circuit when power supply from the power supply circuit is started. 2. The display device according to 1. When the control circuit determines that the power switch has been operated to turn off the power based on a switch signal output from the power switch, the control circuit disconnects the external power device and the power circuit. The display device according to claim 2, wherein the display device controls the cutoff circuit. A voltage dividing circuit (126) for dividing a voltage of a switch signal output from the power switch,
4. The display device according to claim 3, wherein the control circuit determines that the power switch has been operated to turn off the power, based on a divided voltage signal output from the voltage dividing circuit. 5. The shutoff circuit has a detecting unit that detects a power-on signal output to turn on the power from the external power device, and based on the power-on signal detected by the detecting unit, the external power device The display device according to claim 1, wherein a connection is made between power supply circuits. The power-on signal is a voltage change signal indicating a voltage change of a power supply voltage output from the external power supply,
The display device according to claim 5, wherein the detection means is a differentiating circuit that detects the voltage change signal. The display device according to any one of claims 1 to 6 is applied to a hot water supply system that supplies hot water.

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