JP2000267741A - Power source device and electronic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power source device for sharply reducing the total power consumption in the product life of equipment by reducing the power consumption in the waiting state of an electronic equipment for office business more than a conventional manner, and an electronic equipment equipped with this power source device. SOLUTION: A power source control circuit 13 in the power source device 10 is provided with a function for detecting a saving energy mode signal from a control substrate 20 in equipment, and while the saving energy mode signal is detected, a battery 12 is held in a discharged state by a charging/discharging switching circuit 13c, and a power is supplied from the battery 12 to a load in the electronic equipment. Also, even when the saving energy mode signal is detected, the discharging of the battery 12 is stopped by the charging/ discharging switching circuit 13c when the residual power stored in the battery 12 is decreased, and the power source is switched to a converter 11. Also, when any power is not obtained from a commercial power source 30, a power is supplied from the battery 12 to the load in the electronic equipment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for reducing the power consumption of an electronic device supplied with electric power from a commercial power supply, and more particularly to a power supply circuit technique for reducing power consumption during standby.

[0002]

2. Description of the Related Art Office electronic devices, such as facsimile machines, copiers, and printers, have an operation detection unit to reduce power consumption when the device is not used for a predetermined period of time even when the power is turned on. A state in which the power supply to most of the devices is cut off except for a minimum necessary portion such as a reception detection unit, a human sensor unit, and an interface unit with the host device, that is, a transition to an energy saving mode and a standby state.

[0003]

However, conventional office electronic devices always convert power (such as AC / DC conversion and voltage conversion) from a commercial power supply (AC power supply) and supply it to an internal load even during standby. In addition, since the power conversion efficiency during standby is significantly inferior to that during operation, the power consumption is so large that it cannot be ignored even during standby. Therefore, in a device in which the ratio of the standby time to the product life (total power-on time) is relatively large, the amount of power consumption in the standby is determined by the total power consumption in the product life of the device. Will be affected. Therefore, an object of the present invention is to provide a power supply that can significantly reduce the total power consumption during the product life of the device by reducing the power consumption during standby of office electronic devices and the like compared to the past. It is an object of the present invention to provide a device and an electronic device provided with the device.

[0004]

In order to solve the above-mentioned problems, the invention according to claim 1 relates to a power supply device which is provided internally or externally in an electronic device which operates by obtaining electric power from a commercial power supply. A converter for converting power from a commercial power supply into a load in an electronic device (a circuit on a control board, an image forming unit for forming an image by an electrophotographic process, a communication unit, and the like), and the converter And a rechargeable battery (a nickel-metal hydride battery, a lithium ion battery, etc.) for storing power from the converter. The converter and the battery are connected in parallel to the load, and when the power consumption by the load is large, Supplying power from the converter to the load;
When the power consumption of the load is small, power is supplied from the battery to the load. According to a second aspect of the present invention, in the power supply device according to the first aspect, the remaining amount of the power stored in the battery is monitored, and when the remaining amount is equal to or less than a predetermined amount, the converter sends the load to the load. And has a function of supplying power to the The invention described in claim 3 is the invention according to claim 1 or 2
Wherein the power supply device has a function of supplying power from the battery to the load when power cannot be obtained from the commercial power supply.

According to a fourth aspect of the present invention, there is provided an electronic apparatus provided with a power supply for obtaining power from a commercial power supply, wherein the power supply supplies power from the commercial power supply to a load in the electronic equipment. And a rechargeable battery that stores power from the converter, and the converter and the battery are connected in parallel to the load, and when the power consumption by the load is large, The power is supplied from the converter to the load, and the power is supplied from the battery to the load when the power consumption of the load is small. According to a fifth aspect of the present invention, in the electronic device according to the fourth aspect, the electric device generates a predetermined signal indicating that the electronic device is in a standby state in an energy saving mode, and the power supply device is configured to output the predetermined signal. It has a function of detecting a signal, and supplies power to the load from the battery while detecting the predetermined signal. Also, in the electronic device according to claim 4 or 5, the power supply device monitors the remaining amount of power stored in the battery, and when the remaining amount is equal to or less than a predetermined amount, the power converter monitors the converter. It is preferable that the battery has a function of supplying power to the load from the power supply and a function of supplying power from the battery to the load when power cannot be obtained from the commercial power supply.

[0006]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a circuit block diagram of a power supply device and a peripheral portion showing an example of an embodiment of the present invention. In the figure, reference numeral 10 denotes a power supply device according to the present invention,
Reference numeral 20 denotes a control board for office electronic devices such as a facsimile, a copying machine, and a printer in which the power supply device 10 is built. For example, in the case of a copying machine, the control board 20 includes an automatic document feeder (ADF) for automatically feeding a document, a scanner for reading a document image, an image forming unit for forming an image by an electrophotographic process, and various types of an image forming unit. It has a control circuit that controls all the operating elements of the electronic device, such as a paper feed unit that selectively feeds transfer paper of a size and a paper discharge mechanism that discharges copied recording paper. In addition, the control board 20 has an energy saving control circuit. Even when the main power is turned on, if the device is not used for a predetermined time or more, the operation detection unit is provided to reduce power consumption. Control is performed in a state in which the power supply to most of the devices is cut off except for the minimum necessary parts such as the reception detection unit, the human sensor unit, and the interface unit with the host device, that is, the operation shifts to the energy saving mode and waits. When the mode is shifted to the energy saving mode, a predetermined signal indicating that the device is currently on standby (hereinafter, this signal is referred to as an energy saving mode signal) is issued from the energy saving control circuit on the control board 20.

[0007] The power supply device 10 supplies electric power from the commercial power supply 30 to a load in the electronic device (a circuit on the control board 20, an automatic document feeder, a scanner, an image forming unit, a paper feeder, a paper discharge mechanism, Converter 11 as an original power supply device for converting the power to be supplied to various sensors, a rechargeable battery 12 for storing power from the converter 11, and a power supply according to an energy saving mode signal from the control board 20. A power supply control circuit 13 for controlling the device 10 is provided. The converter 11 includes an AC / DC conversion circuit for full-wave rectifying an input (AC voltage) from the commercial power supply 30 to a DC voltage, and a voltage for stabilizing the DC voltage after the full-wave rectification and supplying the DC voltage to the control board 20 and the like. A stabilizing circuit. As the battery 12, a battery (secondary battery) having a high power density such as a lithium ion battery is used. The converter 11 and the battery 12 are connected in parallel to a load in an electronic device such as the control board 20. The power supply control circuit 13 includes a battery charging circuit 13 that charges the battery 12 with power from the converter 11.
a, a battery capacity monitoring circuit 13b for monitoring the remaining amount of power stored in the battery 12, and the like, and a charge / discharge switching circuit 13c for switching charging / discharging of the battery 12. The power supply control circuit 13 has a function of detecting an energy saving mode signal. While detecting the energy saving mode signal, the battery 12 is held in a discharged state by the charge / discharge switching circuit 13c. Control to supply power to the load in the device. Also, even when the energy saving mode signal is detected, if the remaining amount of power stored in the battery 12 is small, the charge / discharge switching circuit 13c stops discharging the battery 12 and switches the power supply to the converter 11. Control such as switching is also performed. In addition, control is performed to supply power from the battery 12 to a load in the electronic device when power cannot be obtained from the commercial power supply 30.

The operation of this embodiment will be described.
Turning on (turning on) the power of the electronic device, that is, the power supply device 10
Is activated, the electronic device is first activated by the electric power from the converter 11 and performs an initialization process. Thereafter, if there is an access from the user within a certain period of time, the electronic device maintains the normal operation state using the converter 11 as a power supply, but if there is no access from the user for a certain period of time, the electronic device shifts to the energy saving mode. To enter the standby state. At this time, an energy-saving mode signal is issued from the energy-saving control circuit on the control board 20 of the electronic device, and is sent to the power supply control circuit 13 of the power supply device 10. The power supply control circuit 13 detects the energy saving mode signal, switches the battery 12 to the discharged state by the charge / discharge switching circuit 13c, and switches the converter 11
To stop. Thus, power supply from the battery 12 to the load in the electronic device is started. While power is being supplied from the battery 12, the power consumption from the commercial power supply 30 is approximately 0 W (watt). Thereafter, when the battery 12 is depleted and the remaining amount (or voltage) of the power stored in the battery 12 falls below a predetermined value, this is detected by the battery capacity monitoring circuit 13b. Then, immediately, the power supply control circuit 13
The converter 11 is restored (activated), and the power supply route is changed from the battery 12 to the converter 11. Then, at the same time when the converter 11 returns, the battery 12 is switched to the charged state by the charge / discharge switching circuit 13c until the charging of the battery 12 is completed.
The converter 11 is in charge of power supply during standby. Battery 12
Is fully charged, this is detected by the battery capacity monitoring circuit 13b. Then, the power supply control circuit 13 switches the battery 12 to the discharge state by the charge / discharge switching circuit 13c, and also stops the converter 11 to cause the battery 12 to be in charge of power supply during standby.

As described above, the energy-saving mode signal emitted when the electronic device enters the standby state is monitored, and when the energy-saving mode signal is not detected, the converter 11 is used as a power source, and when the energy-saving mode signal is detected. Since the power supply device 10 is configured to use the battery 12 as a power source as much as possible, the power consumption of the electronic device during standby can be significantly reduced as compared with the related art. The power conversion efficiency of the converter 11 is greatly deteriorated during standby because the load in the electronic device is light during standby, but the power conversion efficiency is reduced by stopping the converter 11 during standby as described above. This is because power waste resulting from low efficiency can be largely eliminated. Also, the power supply device 10 is provided with a function of self-diagnosis of the remaining battery level, and the converter 1 is provided inside the power supply device 10.
1 and the battery 12 are automatically switched to be used as a power supply, so that the power consumption can be reduced in the most effective manner and power saving can be achieved. In addition, when the electronic device is operated by the user's access and the energy saving mode signal is not output, the converter 11 is immediately activated and the power supply from the battery 12 is cut off. Can be prevented.

Further, since the battery 12 is provided as a secondary circuit in parallel with the converter 11 which is the original power supply circuit, when the battery 12 becomes abnormal, or when the battery 12 has a durable life. In the event of a failure, do not use the path on the battery 12 side so as not to impair the performance and safety of the equipment.
Power can be supplied from the converter 11 as in the conventional case. When removing the battery 12 for battery replacement or the like, it is possible to work without stopping the device. Also,
Battery 1 when power cannot be obtained from commercial power supply 30
Since power can be supplied to the load in the electronic device from the device 2, the device can be used as long as the power of the battery 12 remains even during a power failure. Conventionally, this type of electronic equipment is equipped with an input smoothing electrolytic capacitor and the like, and by using power of this capacity, it is possible to reduce the power consumption by 10 to 5 times.
Although the equipment stoppage at the time of the instantaneous power failure of about 0 ms was prevented, according to the present invention, it is possible to prevent the equipment from being stopped not only by the instantaneous power failure but also by a long-time power failure such as 10 minutes to 1 hour. become. Also, even if the power cord is disconnected from the commercial power supply 30, the battery 12 can be operated for a while using the power supply, so that the portable device can be moved while maintaining the usable state as in the portable device. Will be able to do that. Note that the power supply device or the electronic device of the present invention can also be realized by adding the battery 12 and the power supply control circuit 13 to an existing power supply device (converter) built in the electronic device.

[0011]

As described above, according to the first and fourth aspects of the present invention, a converter for converting power from a commercial power supply to a load in an electronic device, and a power from the converter. A rechargeable battery that stores the power and the parallel connection of the converter and the battery to the load, and when the power consumption by the load is large, supplying power from the converter to the load, When the power consumption of the electronic device is small, the power is supplied from the battery to the load, so that the power consumption during standby of the electronic device can be significantly reduced compared to the conventional device. Total power consumption over the life can be significantly reduced. According to the second aspect of the present invention, in the first aspect, a function of monitoring the remaining amount of the battery is provided, and the converter and the battery are automatically switched inside the power supply device to be used as a power supply. With the configuration, power consumption can be reduced in the most effective manner, and labor saving can be achieved. According to the third aspect of the present invention, in the first or second aspect, power is supplied from the battery to the load when power cannot be obtained from a commercial power supply. Also, the device can be used as long as the battery power remains. According to a fifth aspect of the present invention, in the fourth aspect, a predetermined signal emitted when the electronic device is in a standby state is monitored, and when the signal is not detected, the converter is used as a power supply, By configuring the power supply device to use the battery as a power supply when the signal is detected, it is possible to reliably reduce the power consumption of the electronic device during standby.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram of a power supply device and a peripheral portion showing an example of an embodiment of the present invention.

[Explanation of symbols]

10: power supply device, 20: control board, 30: commercial power supply, 1
1: converter, 12: battery, 13: power supply control circuit, 13
a: Battery charging circuit, 13b: Battery capacity monitoring circuit, 13
c: Charge / discharge switching circuit

Claims (5)

[Claims] 1. A converter for converting electric power from a commercial power supply to a load in an electronic device, and a rechargeable battery for storing electric power from the converter. When connected in parallel with the load, the converter supplies power to the load when the power consumption by the load is large, and supplies the power from the battery to the load when the power consumption of the load is small. A power supply device characterized by being configured as described above. 2. A function of monitoring a remaining amount of electric power stored in the battery and supplying power from the converter to the load when the remaining amount is equal to or less than a predetermined amount. Item 7. The power supply according to Item 1. 3. The power supply device according to claim 1, further comprising a function of supplying power from the battery to the load when power cannot be obtained from the commercial power supply. 4. An electronic device including a power supply device for obtaining power from a commercial power supply, wherein the power supply device converts the power from the commercial power supply to a load in the electronic device, and a converter for converting the power from the commercial power supply to a load in the electronic device. A rechargeable battery that stores power from the converter, and the converter and the battery are connected in parallel to the load, and when the power consumption by the load is large, power is supplied from the converter to the load. The electronic apparatus is configured to supply power when the power consumption of the load is small and to supply power from the battery to the load. 5. The electric device generates a predetermined signal indicating that the electric device is in a standby mode in an energy saving mode, and the power supply device has a function of detecting the predetermined signal. The electronic device according to claim 4, wherein power is supplied from the battery to the load during the detection.