JPH02176920A - Electronic apparatus - Google Patents

Abstract

PURPOSE:To prevent the power source from being cut off automatically in the case when it is unnecessary by permitting or inhibiting a cut-off control of the power source corresponding to the duration of a prescribed operating state in accordance with a difference of the power source means used for a feed. CONSTITUTION:When a commercial AC power source supply is executed from a power source jack 3, a voltage of a line l3 becomes about 8V, an output of a voltage detector 2 becomes a logical level '1', and when an AC adaptor is not connected to the power source jack 3 and a feed is executed from only a battery 6, the voltage of the line l3 becomes under 6V, and the output of the voltage detector 2 becomes a logical level '0'. A CPU 4 discriminates this logical level, and when the feed is executed from only the battery 6, an auto power-off signal is sent to a power source control part 1, and an auto power-off processing is executed. On the other hand, when a feed is executed from a commercial AC power source, the auto power-off processing is inhibited. In such a way, it does not occur that auto power-off is executed at the time when it is unnecessary.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to electronic equipment, and particularly to power supply control means that automatically cuts off the power to at least a part of the device when a predetermined operating state continues for a predetermined period or more. This relates to the electronic equipment installed.

[Prior Art] Word processors, calculators, and other electronic devices that are powered by various batteries such as solar cells, dry batteries, and rechargeable batteries have been known.

In order to minimize battery consumption in this type of electronic equipment, if a predetermined state continues for a certain period of time, such as when there is no key power, the power supply to parts of the equipment that consume a large amount of power is interrupted, or the equipment A device is known that has a so-called auto power-off function that cuts off the entire power supply.

[Problems to be Solved by the Invention] However, in electronic devices having an auto power-off function as described above, there are no known devices that can be powered from a commercial AC power source via an AC adapter or the like in addition to the built-in battery. However, even in such devices, automatic power-off was performed unconditionally.

Therefore, even though the power is being supplied from a commercial AC power source, if you temporarily leave your seat while processing data using a word processor, etc., and then return to the device, the power will be automatically shut off and you will have to restart the device. There was the inconvenience of having to do it. An object of the present invention is to solve such problems.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides power supply control that automatically cuts off the power to at least a part of the device when a predetermined operating state continues for a predetermined time or more. means for supplying power to a circuit constituting the device from one of the plurality of power supply means; a means for detecting which of the plurality of power supply means is supplying power; A configuration is adopted in which a control means is provided for determining whether or not to cause the control means to execute power cutoff control in accordance with the output of the means.

[Function] According to the above configuration, power cutoff control can be permitted or prohibited depending on the duration of a predetermined operating state depending on the type of power supply means used for power supply.

[Example] Hereinafter, the present invention will be described in detail based on the example shown in the drawings.

FIG. 1 shows the configuration of a power supply section of an electronic device employing the present invention. In this embodiment, the electronic device may be a word processor, a computer, or other various devices. Its power source is provided by both commercial AC power and batteries.

In FIG. 1, reference numeral 3 denotes a power jack to which a DC power supply voltage obtained by transforming and rectifying a commercial AC power supply using an AC adapter (not shown) or the like is supplied.

One terminal of the power jack 3 is connected to the ground potential of the circuit,
The other child terminal is connected to the anode of the diode D1 via the line (Ll). The cathode of the diode D1 is connected to the line 13 on the input side of the power supply control section l.

The power supply control unit 1 has a built-in power supply control circuit consisting of a stabilizing circuit using a switching converter, an analog switch, etc., and stabilizes the power supply input from the line J3 according to the control signal input from the line J6. Output to j4. Line J4 supplies power to each circuit (not shown) inside the device.

The CPU 4 is composed of a microprocessor, etc., and performs power control as described later and control of the entire device, such as processing character and numerical information, etc., according to a program stored in the ROM 4a.The CPU 4 receives power supply from the line 4. .

In the device shown in FIG. 1, power can be supplied not only from a commercial AC power source but also from a built-in (or externally attached) battery 6. The battery 6 is a rechargeable battery in this case, and its + terminal is connected to the line i3 via a line j2, a diode D2, and a resistor R4. One terminal of the battery 6 is grounded.

The anode side of the diode D2 is connected to the battery 6, thereby preventing excessive reverse voltage from being applied to the battery 6.

Further, the resistor R4 is for charging the battery 6, and the current supplied from the power jack 3 is applied to the battery 6 via the resistor R4 to charge it.

Therefore, when power is supplied to the power jack 3, the battery 6 is charged via the resistor R4 during that period, and power is supplied to each circuit of the device via the power control section 1. If the output of an AC adapter or the like is not connected to the power jack 3, the output of the battery 6 will be connected to the line J2. The power is supplied to the line J3 via the diode D2, and power is supplied to each circuit of the device via the power supply control section 1.

In this embodiment, a circuit is provided to detect whether power is being supplied from a commercial AC power supply or only from the battery 6. That is, resistors R1 and R2 connected in series are connected between the line i3 and the ground potential.

The voltage at the connection point between the resistors R1 and R2 is detected via a line j7 by a voltage detector 2 configured using a comparator or the like. Further, a capacitor C is connected between the line j7 and the ground potential in order to control the voltage fluctuation of the line 97 based on a predetermined time constant.

The output of the voltage detector 2 can be processed by the CPU 4, for example, TT.
This is an L level logic signal, and this logic signal is connected to line J5.
is output to the CPU 4 via.

The voltage detector 2 detects the power supply voltage Vcc output by the power supply control section 1.
and line j5 is pulled up via resistor R3.

Next, the operation of the above configuration will be explained.

The power supply from the commercial AC power supply and the charging of the battery 6 or the power supply from the battery are as described above, but which power supply means is supplying power is determined by measuring the divided voltage by the resistors R1 and R2 with the voltage detector 2. This is done by detecting the

The voltage division of resistors R1 and R2 changes depending on the input power supply voltage of line j3. In the device shown in Fig. 1, the voltage supplied to the power jack 3 from an external AC adapter is, for example, 8V.
It is also assumed that the output voltage of the battery 6 is 8V. In this case, assuming that the internal impedance of the external AC adapter is sufficiently low, when power is supplied from battery 6, the input voltage of line J3 will be affected by the internal impedance of battery 6, and will be affected by the voltage drop across diode D2. Usually it will be less than 6v.

Therefore, if the AC adapter is connected to the power jack 3, the voltage of the line J3 will be around 8V, and if the AC adapter is not connected to the power jack 3 and power is being supplied only from the battery 6, then the voltage on the line J3 will be less than 6V. become.

Therefore, when the voltage on line J3 is less than 6V, voltage detector 2 sets logic level 0 on line j5, and when voltage on line j3 exceeds 6V, voltage detector 2 sets logic level 0 on line j5. Resistors R1 and R so as to output 1
By setting the two partial voltage conditions, it is possible to detect which power source is supplying power.

The CPU 4 controls the power supply according to the input logic level of the line j5 according to the procedure shown in FIG. The procedure in Figure 2 is ROM
4a.

The procedure shown in Figure 2 is performed at the timing when a known power-off control should be executed, and the determination as to whether or not to perform this power-off control is made by measuring the time during which there is no key human power using a known timer (not shown). To do something, such as by doing something.

In step S1 of FIG. 2, the CPU 4 checks the output of the voltage detector 2 via the line j5 and determines whether power is being supplied only from the battery 6. power jack 3
If power is being supplied from
It becomes around v, and the output of voltage detector 2 becomes logic level 1.
Further, when the AC adapter is not connected to the power jack 3 and power is supplied only from the battery 6, the voltage of the line J3 becomes less than 6V, and the output of the voltage detector 2 becomes a logic level 0. By determining this logic level, if power is being supplied only from the battery, the process goes to step S2, and if power is being supplied from the AC adapter, the illustrated routine is ended and the normal processing routine is returned.

If power is being supplied only from the battery, step S
At step 2, an auto power off signal is generated. This auto power off signal is a logic level 1 signal input to the power supply control unit 1 via line J6, and this signal causes the power supply control unit 1 to perform auto power off processing in step S4.
In other words, power output to the power line j4 is stopped.

According to the above configuration, it is possible to identify whether power is being supplied using a commercial AC power supply or only with a built-in or external battery, and to determine whether power is being supplied from a commercial AC power supply. Since the automatic power-off process is prohibited in such cases, the automatic power-off process is not performed even though it is not necessary and the user is not forced to perform unnecessary operations as in the conventional case. There is an advantage that it is possible to determine from which power supply means power is being supplied.

In the above, when executing the routine shown in Figure 2, processing such as backing up data has not been described. However, in the case of a word processor, for example, the data being edited is saved to a memory such as a non-volatile ROM, and then the routine shown in Figure 2 is executed. Run the routine. Alternatively, it goes without saying that it is desirable to perform the data saving process as described above immediately before the power-off process in step S2 in FIG.

[Effects of the Invention] As is clear from the above, according to the present invention, an electronic device is provided with a power control means that automatically shuts off the power to at least a part of the device when a predetermined operating state continues for a predetermined time or more. The device is provided with a means for supplying power to a circuit constituting the device from one of the plurality of power supply means, and a means for detecting which of the plurality of power supply means is supplying power, and an output of the detection means is provided. Since a configuration is adopted in which it is determined whether or not to cause the control means to perform power cutoff control according to the power supply means, power cutoff control is performed according to the duration of a predetermined operating state depending on the type of power supply means used for power supply. It is possible to provide an electronic device that is easy to handle without automatically shutting off the power even when it is not necessary as in the past.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the structure of a power supply control section of an electronic device employing the present invention, and FIG. 2 is a flowchart showing a control procedure of the CPU shown in FIG. 1. 1... Power supply control section 2... Voltage detector 3...
Power jack 4...CPU4a...ROM
6...Batteries R1 to R3...Resistance C...
Capacitors D1, D2...diodes

Claims (1)

[Scope of Claims] 1) An electronic device provided with a power supply and control means that automatically shuts off power to at least a part of the device when a predetermined operating state continues for a predetermined time or more, wherein the plurality of power supply means means for supplying power to the circuits constituting the apparatus from any one of the plurality of power supply means; means for detecting which of the plurality of power supply means is supplying power; and power cutoff control by the control means in accordance with the output of the detection means. An electronic device characterized by being provided with a control means for determining whether or not to perform the operation.