JPH10198465A - Power saving mode function loaded device and power saving mode switching method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently consider the consumption of 2nd power source during a period to the time point of switching to a power saving mode state without damaging convenience by detecting whether a selected power source is a 1st power source or the 2nd power source and changing the length of prescribed period corresponding to the detected result. SOLUTION: When there is no key input from an input means 52 for prescribed period, the state of CPU 51 is switched to the power saving mode state operable with minimum power consumption by a power saving mode function. At the power saving mode function, it is detected based on the voltage value of power supply detecting signal fetched from a line 30 whether the source of power supply to the CPU 51 is the power source of solar battery or dry battery and corresponding to this detected result, the count interval of counter provided inside the CPU 51 per count value is set. Based on the set count interval of counter, counting is performed during the period in which there is no information input from the input means and when the count value of counter exceeds a prescribed value, it is discriminated there is no key input for the prescribed period.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has two power supplies for selectively supplying power to processing means for executing a corresponding process based on information input from input means, and inputs information from the input means. The present invention relates to a power saving mode function-equipped device having a power saving mode function and a power saving mode switching method having a power saving mode function for switching the state of a processing unit to a power saving mode state operable with minimum power consumption when there is no predetermined period.

[0002]

2. Description of the Related Art Conventionally, in a device such as a portable information terminal equipped with a CPU and its peripheral devices, power that can operate the CPU and its peripheral devices is generated by energy supplied from the outside, that is, an AC power source, a solar cell, or the like. And a second power supply, such as a dry battery, whose power supply capacity is smaller than the power supply capacity of the first power supply, that is, the power supply capacity is limited, and is connected to the first power supply. Is set to switch from the first power supply to the second power supply when the external energy supply is stopped, and the state of the CPU is minimized when there is no input to the CPU for a predetermined period. It is set to execute a power saving mode function for switching to a power saving mode state operable with power consumption.

[0003] This power saving mode function is, specifically, C
A period during which there is no input to the PU is measured. If the measured period exceeds a preset reference period, it is determined that there is no input to the CPU for a predetermined period, and the state of the CPU can be operated with minimum power consumption. This is a function for switching to the power saving mode state, and this function suppresses a small amount of power consumption.

[0004]

However, in the above-described apparatus having the conventional power saving mode function, when the period during which there is no input to the CPU exceeds a preset reference period, the state of the CPU is changed to the power saving mode state. Since the switching is performed, the period from the time when no input to the CPU occurs to the time when the mode is switched to the power saving mode state is substantially equal between the case where the first power supply is selected and the case where the second power supply is selected, CP
During the period from the time when no input to U occurs to the time when the mode is switched to the power saving mode state, the power consumption when the second power source is selected is the power consumption when the first power source is selected. Almost the same. Therefore, when the second power supply is selected, the power saving mode function that sufficiently considers the consumption of the second power supply during the period from the time when no input to the CPU occurs to the time when the mode is switched to the power saving mode state is provided. Not running.

Therefore, when the second power supply is selected, in order to reduce the consumption of the second power supply during a period from the time when no input to the CPU occurs to the time when the mode is switched to the power saving mode, A method of setting the reference period to be short according to the second power supply is conceivable. However, in this method, the period up to the point of switching to the power saving mode state is shortened.
Even when the first power supply having a sufficient power supply capacity is selected, the frequency of switching to the power saving mode increases, and the usability deteriorates.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a second power saving mode during a period up to the point of switching to a power saving mode state without impairing usability.
It is an object of the present invention to provide a power-saving mode function-equipped device and a power-saving mode switching method capable of executing a power-saving mode function that fully considers power consumption of the power supply.

[0007]

According to the first aspect of the present invention,
Processing means for executing a corresponding process based on the information input from the input means; a first power supply for generating power operable by the processing means with energy supplied from the outside; A second power supply that generates less power than the power supply capacity of the first power supply and that is capable of operating the processing means; and one of the first and second power supplies, and selects one of the selected power supplies. Supply means for supplying power of the power supply to the processing means, and when no information is input from the input means for a predetermined period, the state of the processing means can be operated with minimum power consumption. A power-saving mode function-equipped device having a power-saving mode function for switching to a state, wherein the detecting means detects which one of the selected power supplies is one of the first and second power supplies; In accordance with a detection result of the detecting means, characterized in that a and period changing means for changing the length of the predetermined period.

According to a second aspect of the present invention, in the power saving mode function-equipped apparatus according to the first aspect, the period changing means sets a counting interval per one count value according to a detection result of the detecting means. Means, and counting means for counting during a period when there is no information input from the input means based on the set counting interval, and when the count value of the previous counting means exceeds a predetermined value, It is characterized in that it is determined that there is no information input for a predetermined period, and the state of the processing means is switched to the power saving mode state.

According to a third aspect of the present invention, in the power saving mode function-equipped device according to the second aspect, the counting interval per one count value is set such that the first counting is performed when the first power source is selected. An interval is set, and when the second power source is selected, a second counting interval shorter than the first counting interval is set.

According to a fourth aspect of the present invention, there is provided a processing means for executing a corresponding process based on information input from an input means, and a first means for generating power operable by the processing means by externally supplied energy. And the power supply capacity is smaller than the power supply capacity of the first power supply,
A second power supply for generating power operable by the processing means and one of the first and second power supplies, and supplying the power of the selected one power supply to the processing means; A power supply mode switching method for switching a state of the processing unit to a power saving mode operable with minimum power consumption, wherein the one of the selected power supplies is connected to the second power supply. A detection step of detecting which one of the first and second power supplies is present and outputting a detection result thereof; a period setting step of setting a predetermined period according to the detection result; A switching step of switching the state of the processing unit to the power saving mode state when there is no input for the set predetermined period.

According to a fifth aspect of the present invention, in the power saving mode switching method according to the fourth aspect, the period setting step sets a counting interval per one count value according to the detection result; Counting during a period in which there is no input of information from the input means based on the set counting interval, and inputting information from the input means when the count value of the previous counting means exceeds a predetermined value. Is determined that there is no predetermined period,
The state of the processing means is switched to the power saving mode state.

According to a sixth aspect of the present invention, in the power saving mode switching method according to the fifth aspect, the counting interval per one count value is the first counting interval when the first power supply is selected. And the second counting interval is set to be shorter than the first counting interval when the second power source is selected.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 is a block diagram showing the configuration of a first embodiment of an apparatus having a power saving mode function according to the present invention. In the present embodiment, a portable information terminal will be described as an example of a device equipped with a power saving mode function.

As shown in FIG. 1, the portable information terminal performs processing corresponding to the information inputted from the input means 52, and generates electric power which can be operated by the CPU 51 by light energy supplied from the outside. Solar cell 1
1, the dry battery 12 whose power supply capacity is smaller than the power supply capacity of the solar cell, and which generates power operable by the CPU 51, and when the voltage of the solar cell 11 is equal to or higher than the reference voltage, the power is To the solar cell 11
And a switching circuit 20 for stopping power supply to the line 40 of the solar cell 11 when the voltage of the solar cell 11 becomes lower than the reference voltage.

The switching circuit 20 includes a Zener diode 21 and a backflow prevention diode 22.
And two transistors 23 and 24 and two voltage dividing resistors R1 and R2. When the voltage of the solar cell 11 is equal to or higher than the reference voltage, the power of the solar cell 11 is increased by the transistor 23, the diode 22, and the line. CPU5 through 40
1 is supplied. With the supply to the line 40, a corresponding voltage is applied to the line 30, and the voltage applied to the line 30 is taken into the CPU 51 as a power supply detection signal. On the other hand, when the voltage of the solar cell 11 becomes lower than the reference voltage, the current path between the emitter and the collector of the transistor 23 is cut off, and the power supply to the line 40 of the solar cell 11 is cut off. With the interruption of the power supply to the line 40, the voltage of the line 30 decreases to the reference potential.

As the voltage of the solar cell 11 decreases, the solar cell 1
1 when the power supply to the line 40 is cut off.
2 is a backflow prevention diode 13 and a line 40
After that, the power is supplied to the CPU 51, and the power for the CPU 51 is switched from the solar battery 11 to the dry battery 12. Thus, the power source for the CPU 51 is the solar cell 1
The solar cell 11 is switched to one of the dry cells 12 according to the voltage value of 1, and the CPU 51 is operated by the solar cell 11 or the dry cell 12.

If there is no key input from the input means 52 for a predetermined period, the power saving mode function of the CPU 51 activates the CP.
A power-off process is performed to switch the state of U51 to a power-saving mode in which operation can be performed with minimal power consumption. In the power saving mode function, the power supply source to the CPU 51 is detected based on the voltage value of the power supply detection signal taken in from the line 30 as to which of the solar cell 11 and the dry cell 12 is the power supply. The counting interval per one count value of a counter (not shown) provided inside the CPU 51 is set, and counting is performed during a period in which no information is input from the input means 52 based on the counting interval set by this counter. When the count value of the counter exceeds a predetermined value, it is determined that there is no key input from the input means 51 for a predetermined period, and the power-off process is executed. When information is input from the input unit 51 until the count value of the counter exceeds the predetermined value, key processing is performed on the input key. In the present embodiment, when the power supply source to the CPU 51 is the solar cell 11, the increment of the count value per unit time of the counter is set to 1, and when the power supply source to the CPU 51 is the The predetermined period from the point when there is no key input from the input means 52 to the time when the power-off process is executed is changed according to the power supply source to the CPU 51 by setting the increment of the count value per unit time to 2. I do.

The processing procedure of the power saving mode function will be described with reference to FIGS. 2 and 3. 2 is a flowchart showing a key input process in the power saving mode function-equipped device of FIG. 1, and FIG. 3 is a flowchart showing a timer interrupt process for a power-off process in step S120 of FIG.

When there is no key input from the input means 52 in the key input process, as shown in FIG.
The counter provided inside 51 is reset (step S110).

Next, timer interrupt processing for power-off processing is set (step S120). In the timer interrupt processing for the power-off processing, as shown in FIG.
First, it is determined which of the solar battery 11 and the dry battery 12 is the power supply source to the CPU 51 based on the voltage value of the power detection signal taken from the line 30 (step S210). If the power supply source to the CPU 51 is the solar cell 11, the increment of the count value per unit time of the counter is set to 1, and counting is performed based on the increment of the count value set by this counter (step S220).
On the other hand, when the power supply source to the CPU 51 is the dry battery 12, the increment of the count value per unit time of the counter is set to 2, and counting is performed based on the increment of the count value set by this counter (step). S230).

When the timer interrupt processing for the power-off processing is set, a standby state for waiting for an interrupt is set (step S130). The interrupt includes an interrupt related to key input and chattering processing, and a timer interrupt for power-off processing described above.

Next, the count value of the counter is fetched by a timer interrupt for power-off processing, and it is determined whether or not this count value exceeds a predetermined value (MAX) (step S140). If the count value does not exceed the predetermined value (MAX), it is subsequently determined whether or not a key input has been made (step S150). If a key input has been made, a key for executing a process corresponding to the input key is determined. The process proceeds to step S130. If there is no key input, the process from step S130 is repeated.

On the other hand, when the count value exceeds a predetermined value (MAX), it is determined that there is no key input from the input means 51 for a predetermined period, and a transition to a power-off process is performed.
The state of the CPU 51 is switched to a power saving mode in which operation can be performed with minimum power consumption.

If switching from the solar cell 11 to the dry cell 12 or vice versa is performed in a state where there is no key input from the input means 52, the switching is performed by a timer interrupt processing for power-off processing. Counting is performed based on the increment of the count value.

As described above, when the power supply source to the CPU 51 is the solar cell 11, the increment of the count value per unit time of the counter is set to 1 (step S220).
If the power supply source to the power supply 51 is the dry battery 12, the increment of the count value per unit time of the counter is set to 2 (step S230), so that the operation of the CPU 51 by the dry battery 12 having a limited power supply capacity is performed. Inside, CPU
The period from the point in time when no input to the CPU 51 occurs to the point in time of switching to the power saving mode state is shorter than the period during the operation by the solar cell 11, that is, about half, and from the point in time when no input to the CPU 51 occurs to the power saving mode state. It is possible to execute the power saving mode function in which the power consumption of the dry battery 12 during the period up to the switching point is sufficiently considered.

Conversely, the CPU 5 using the solar cell 11
During the operation from the time when no input to the CPU 51 occurs to the time when the mode is switched to the power saving mode state, the battery 1
2 is about twice as long as the period during the operation by the CPU 2, the CPU 5 using the solar cell 11 having a sufficient power supply capacity.
The frequency of occurrence of switching to the power saving mode during operation 1 is less than that during operation with the dry battery 12 and the usability is not impaired.

Further, when the power supply is switched to the CPU 51 in a state where there is no key input from the input means 52, the counting is performed based on the increment of the count value corresponding to this switching. Meanwhile, the length of the period from the time when no input to the CPU 51 occurs to the time when the mode is switched to the power saving mode can be changed.

In the present embodiment, in order to change the predetermined period from the point when there is no key input from the input means 52 to the time when the power-off process is executed in accordance with the power supply source to the CPU 51, the CPU 51 When the power source of the counter is the solar cell 11, the increment of the count value per unit time of the counter is set to 1, and when the power source to the CPU 51 is the dry cell 12, the increment of the count value of the counter per unit time is set to 1. Although each is set to 2, the increment of the count value per unit time of the counter in each case is not limited to the above value, and the increment of the count value in each case is configured by a combination of other numerical values. It goes without saying that it is possible. In addition, by appropriately selecting the increment of the count value in each case according to the power supply source to the CPU 51, a predetermined period from the time when there is no key input from the input unit 51 to the time when the power-off process is executed is transmitted to the CPU 51. Can be changed according to the power supply source.

Further, in the present embodiment, an example is shown of a combination of a solar cell 11 having a sufficient power supply capacity and a dry battery 12 having a limited power supply capacity.
Needless to say, the same effect can be obtained even when the AC power supply and the secondary battery are combined.

Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 4 is a block diagram showing the configuration of a second embodiment of the device with a power saving mode function according to the present invention.

This embodiment is different from the first embodiment in the configuration of the switching circuit, and the other configuration is the same.

Specifically, the switching circuit 200
As shown in FIG. 4, when the voltage of the solar cell 11 is equal to or higher than the reference voltage, the power is supplied to the line 40, and when the voltage of the solar cell 11 becomes lower than the reference voltage, the solar cell 11
And a circuit for stopping the power supply to the line 40. The circuit includes a phototransistor 20 that is turned on and off by light from an LED (light emitting diode) 201.
2, a voltage dividing resistor R3, and a backflow prevention diode 22. Further, as in the first embodiment, the voltage applied to the line 30 is used as a power detection signal by the CPU.
51.

As described above, the switching circuit 20 is realized by using the combination of the LED 201 and the phototransistor 202.
By configuring 0, the cost of the configuration of the switching circuit 200 can be reduced.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 5 is a block diagram showing a main configuration of a power saving mode function-equipped device according to a third embodiment of the present invention.

The present embodiment differs from the first embodiment in that a predetermined period from the point at which no key input is made from the input means to the time when the power-off processing is executed is performed by a power supply source (power detection C) to change the cycle of the interrupt clock according to the power supply detection signal to change the cycle of the timer interrupt for the power-off process, and C
The same counting interval (same increment value) whether the counter provided inside the PU is a solar cell or a dry cell
It differs in that it is counted by.

More specifically, as shown in FIG. 5, the period of the interrupt clock fetched from outside via the line 31 is changed based on the voltage value of the power supply detection signal output to the line 30 of the switching circuit. A frequency divider 35 for dividing the cycle of the interrupt clock into a half cycle, and an interrupt clock divided by the frequency divider 35 into a half cycle. (1/2 frequency-divided clock) and an interrupt clock (normal clock) output to the line 31 from a selection circuit 36 for selecting according to the voltage value of the power supply detection signal output to the line 30 It is configured.

The selection circuit 36 includes, for example, an inverter 36a receiving a power detection signal, a NAND element 36b receiving the output of the inverter 36a and a normal clock, and a power detection signal and a 1/2 frequency-divided clock. NAN to be input
D element 36c, output of NAND element 36b and NA
NAND element 36d receiving the output of ND element 36c as input
When the power detection signal indicates a solar cell,
The 1/2 frequency-divided clock is output as an interrupt clock from the NAND element 36d to the CPU via the line 32. When the power supply detection signal indicates a dry cell, the normal clock is used as the interrupt clock from the NAND element 36d via the line 32. Output to CPU.

The CPU reads the count value of the counter based on the interrupt clock received via the line 32, and determines whether or not the read count value has exceeded a predetermined value. The read cycle of the counter count value of the counter when the interrupt clock fetched via the line 32 is the normal clock is smaller than the read cycle of the counter count value when the interrupt clock is a 1/2 frequency-divided clock. And double. For example, during the operation of the CPU by the solar cell,
The predetermined period from the point when no input to the CPU occurs to the point when the mode is switched to the power saving mode state is about twice as long as the period during the operation with the dry battery. Therefore, the same effect as that of the first embodiment can be obtained.

[0040]

As described above, according to the power saving mode function-equipped device according to the first aspect, it is detected which one of the selected power supplies is the first or the second power supply. And a period changing unit that changes the length of the predetermined period according to the detection result of the detecting unit, so that the predetermined period can be set according to the selected power supply, and the usability is impaired. In addition, it is possible to execute the power saving mode function in which the consumption of the second power supply during the period up to the point of switching to the power saving mode state is sufficiently considered.

According to the second aspect of the present invention, the period changing means sets the counting interval per one count value according to the detection result of the detecting means, and the set counting interval. Counting means for counting during a period in which there is no information input from the input means based on the input means, and when the count value of the number means exceeds a predetermined value, it is determined that there is no input of information from the input means for a predetermined period. The state of the processing means can be switched to the power saving mode state.

According to the third aspect of the present invention, the counting interval per one count value is set to the first counting interval when the first power supply is selected, and the second counting interval is set when the first power source is selected. Since the second counting interval shorter than the first counting interval is set when the power source is selected, the predetermined period in the case where the second power source is selected is set to the predetermined period in the case where the first power source is selected. The period can be shorter.

According to the power saving mode switching method of the present invention, a detecting step of detecting which one of the selected power supplies is one of the first and second power supplies and outputting the detection result. A period setting step of setting a predetermined period according to the detection result; and a switching step of switching the state of the processing unit to the power saving mode state when there is no input of the information from the input unit for the predetermined period. Thus, the predetermined period according to the selected power source can be set, and the power consumption can be set without giving any consideration to the consumption of the second power source during the period up to the point of switching to the power saving mode state without impairing the usability. A power mode function can be performed.

According to the power saving mode switching method of the fifth aspect, the period setting step includes the step of setting a counting interval per one count value according to the detection result and the input based on the counting interval set by the counting means. Counting during a period when there is no input of information from the means, and when the count value of the number means exceeds a predetermined value, it is determined that there is no input of information from the input means for a predetermined period, and the state of the processing means is determined. Can be switched to the power saving mode state.

According to a sixth aspect of the present invention, in the power saving mode switching method according to the fifth aspect, the counting interval per one count value is the first counting interval when the first power source is selected. And the second counting interval is set to be shorter than the first counting interval when the second power source is selected. Therefore, the predetermined period in the case where the second power source is selected is set to the first counting interval. This can be shorter than the predetermined period when the power supply is selected.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment of a device with a power saving mode function according to the present invention.

FIG. 2 is a flowchart illustrating a key input process in the power saving mode function-equipped device of FIG. 1;

FIG. 3 is a flowchart showing a timer interrupt process for a power-off process in step S120 of FIG. 2;

FIG. 4 is a block diagram showing a configuration of a second embodiment of the device with a power saving mode function according to the present invention.

FIG. 5 is a block diagram illustrating a configuration of a main part of a power saving mode function-equipped device according to a third embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 11 solar cell (first power supply) 12 dry cell (second power supply) 20, 200 switching circuit (supply means) 36 selection circuit 51 CPU (processing means) 52 input means

Claims (6)

[Claims] 1. A processing unit for executing a corresponding process based on information input from an input unit, a first power supply for generating power operable by the processing unit with energy supplied from the outside, and a power supply. Selecting a second power supply whose available capacity is smaller than the available power supply capacity of the first power supply and which generates power operable by the processing means; and one of the first and second power supplies. Supply means for supplying the power of the selected one of the power supplies to the processing means,
When there is no input of information from the input means for a predetermined period,
In a power saving mode function-equipped device having a power saving mode function for switching a state of the processing means to a power saving mode capable of operating with minimum power consumption, the selected one of the power supplies is connected to the first and second power supplies. A power-saving mode function, comprising: a detecting unit for detecting which of the power sources the power supply is provided; and a period changing unit for changing a length of the predetermined period according to a detection result of the detecting unit. apparatus. 2. The method according to claim 1, wherein the period changing unit sets a counting interval per count value in accordance with a detection result of the detecting unit, and inputs information from the input unit based on the set counting interval. Counting means for counting during the absence period,
When the count value of the pre-counter exceeds a predetermined value, it is determined that there is no input of information from the input unit for a predetermined period, and the state of the processing unit is switched to the power saving mode state. 2. A device equipped with a power saving mode function according to 1. 3. The counting interval per one count value is set to a first counting interval when the first power supply is selected, and the count interval is set when the second power supply is selected. 1
3. The device according to claim 2, wherein the second counting interval is set to be shorter than the counting interval. 4. A processing unit for executing a corresponding process based on information input from the input unit, a first power supply for generating power operable by the processing unit by energy supplied from the outside, and a power supply. Selecting a second power supply whose available capacity is smaller than the available power supply capacity of the first power supply and which generates power operable by the processing means; and one of the first and second power supplies. For supplying the power of the selected one of the power supplies to the processing means, and a power saving mode for switching the state of the processing means to a power saving mode operable with minimum power consumption. In the power mode switching method, a detecting step of detecting which one of the selected power supplies is one of the first and second power supplies, and outputting a detection result, Regular And a switching step of switching the state of the processing unit to the power saving mode when there is no input of the information from the input unit for the set predetermined period. Power saving mode switching method. 5. The period setting step includes: setting a counting interval per count value according to the detection result; and inputting no information from the input unit based on the counting interval set by the counting unit. Counting during a period, when the count value of the previous counting unit exceeds a predetermined value, it is determined that there is no input of information from the input unit for a predetermined period, and the state of the processing unit is set to the power saving mode. 5. The method according to claim 4, wherein the state is switched to a state. 6. The count interval per one count value is set to a first count interval when the first power supply is selected, and the count interval is set when the second power supply is selected. 1
6. The method according to claim 5, wherein the second counting interval is set to be shorter than the counting interval.