JPH10268986A - Information equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide information equipment with which a power source can be miniaturized by attaining power saving at the time of maximum power consumption even in case of general-purpose information equipment. SOLUTION: Concerning the information equipment provided with a power consumption reducing means, this equipment is provided with a power measuring circuit 3 for measuring power consumed in the equipment and discriminating whether the measured power consumption exceeds a prescribed value or not and a power consumption reduction control part 4 for performing prescribed power consumption reduction control when it is discriminated by the power measuring circuit the power consumption exceeds this prescribed value and a signal (a) is outputted. Besides, the power consumption reduction control part 4 is constituted so as to perform control for lowering the operating clock rate of CPU as one of prescribed power consumption reduction control.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information device having a power consumption reducing means such as a portable information device and a personal computer, and more particularly to an information device capable of reducing the size of a power supply at the time of maximum power consumption.

[0002]

2. Description of the Related Art In a portable information device driven by a battery, various power savings have been made in order to extend an operable time without replacing a battery. Also, in stationary information devices such as personal computers and copiers, power savings have been made for the purpose of saving power and reducing the size of power supplies. In particular, in order to reduce the size of the power supply, it is necessary to save power when the power consumption is maximized. The electrophotographic apparatus (copier) disclosed in Japanese Patent Application Laid-Open No. 1-282570 is intended to reduce the size of a power supply from the above viewpoint, and when an image forming rotation operation that maximizes power consumption is performed, The surface temperature of the photoconductor is maintained at a predetermined temperature by power supply from a storage battery instead of the main power supply. In addition, power is supplied from the main power supply to the storage battery during a period in which the power consumption is low, whereby the maximum power consumption of the main power supply can be reduced and the size can be reduced.

[0003]

However, the means of supplying power from the storage battery at the time of maximum power consumption and reducing the size of the power supply is a measure for reducing the size of the power supply in a small device such as a portable information device or a personal computer. However, since a storage battery is required instead of the structure, an effective effect cannot be obtained in keeping the size of the device small.
The conventional technique disclosed in Japanese Patent Application Publication No. 0-205 has a problem in that it is not possible to cope with general-purpose information equipment in which the power consumption is uncertain under what circumstances. The object of the present invention is to
It is an object of the present invention to solve the above-mentioned problems of the prior art and to provide an information device capable of reducing power consumption at the time of maximum power consumption and reducing the size of a power supply even for a general-purpose information device.

[0004]

According to the first aspect of the present invention, there is provided an information apparatus having a power consumption reducing means for measuring the power consumed in the apparatus. A measuring unit, a power consumption determining unit that determines whether the power consumption measured by the power consumption measuring unit exceeds a predetermined value, and the power consumption determining unit determines that the power consumption exceeds the predetermined value. Power reduction control means for performing predetermined power consumption reduction control. Further, in the invention described in claim 2, in the above, the power reduction control means is configured to perform control for lowering the operation clock rate of the CPU as one of the predetermined power consumption reduction controls. According to a third aspect of the present invention, in the first aspect of the invention, as one of the predetermined power consumption reduction controls, the power reduction control means is configured to generate an interrupt to the CPU. According to a fourth aspect of the present invention, there is provided a liquid crystal display device and a backlight thereof.
In addition, in the information device provided with the power consumption reduction means, the power reduction control means is configured to perform control for lowering the luminance of the backlight as one of the predetermined power consumption reduction controls.

[0005]

According to the first aspect of the present invention, when the power consumption exceeds a predetermined value, the power consumption is controlled to be reduced. In the invention according to claim 2,
When the power consumption exceeds a predetermined value, the power consumption is reduced due to a decrease in the operation clock of the CPU. According to the third aspect of the invention, when the power consumption exceeds a predetermined value, the CPU is interrupted, and the CPU can shift to a low power consumption mode such as an idle state. According to the fourth aspect of the present invention, when the power consumption exceeds a predetermined value, the power consumption is reduced by lowering the brightness of the backlight.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on an embodiment shown in the drawings. FIG. 1 shows the first embodiment of the present invention.
FIG. 2 is a configuration block diagram of an information device showing an example of the embodiment. As illustrated, the information device of this embodiment includes an operation unit 1 including a CPU, a display device, a storage device, and the like for performing various information processing and the like, a power supply unit 2 for supplying power to the operation unit 1 and the like,
A resistor R provided on a power supply line for supplying power from the power supply unit 2 to the operation unit 1 and the like; a power measurement circuit 3 for detecting a voltage across the resistor R to measure power consumption;
And a power consumption reduction control unit 4 that performs control to reduce the power consumption in the operation unit 1 when the signal a is output when a power consumption exceeding a predetermined value is detected. The power consumption measuring means in the claims is a resistor R
And the power measuring circuit 3, and the power consumption determining means indicates the power measuring circuit 3. Further, the power reduction control means in the claims indicates the power consumption reduction control unit 4.

FIG. 2 shows how the power consumption (vertical axis) of such information equipment varies with time (horizontal axis). Hereinafter, the operation of this embodiment will be described with reference to FIGS. In the example shown in FIG. 2, the standard operation continues until time T1, and although the power consumption fluctuates, the power consumption is small. Therefore, the voltage drop at both ends of the resistor R provided on the power supply line is small, the power measurement circuit 3 determines that the value of the voltage drop is within the predetermined value, and does not output the signal a to the power consumption reduction unit 4. . However, at time T1, when the power consumption increases due to the activation of a motor in a device in the operation unit 1, for example, a hard disk device, the power supplied from the power source 2 to the operation unit 1 increases, and the resistance R The voltage drop at both ends increases. As a result, the power measurement circuit 3 detects the voltage drop, determines that the power consumption has exceeded the predetermined value at T2 when the power consumption reaches the predetermined value x, and outputs a signal a from the comparator in the power measurement circuit 3.

FIG. 3 shows a comparator 5 in the power measuring circuit 3. When the analog voltage b generated from the voltage drop (detection voltage) at the resistor R and indicating the power consumption at that time becomes larger than the analog voltage c indicating the predetermined value x, the signal a is output. . 1 and 2
When the signal a is given to the power consumption reduction control unit 4, the power consumption reduction control unit 4
The operation unit 1 is controlled so that a predetermined portion in the operation unit 1 enters the low power consumption mode. Thus, at time T3, a predetermined portion of the operation unit 1 is switched to the low power consumption mode, the power consumption gradually rises, reaches the maximum value y, and then goes down (decreases). Incidentally, in the case of the prior art not having the means as in this embodiment, as shown by the dotted line,
The maximum reaches z. After that, power consumption decreases,
When the power consumption becomes smaller than the predetermined value x at the time T4, the signal a output from the power measurement circuit 3 stops being output (for example, LOW level). Cancel power mode.

FIG. 4 shows an example in which the CPU 8 included in the operation unit 1 is set to the low power consumption mode. As shown in the figure, a clock control unit 6 and a clock generation unit 7 are provided in the power consumption reduction control unit 4. When the signal a is output from the power measurement circuit 3, the clock control unit 6 is output from the clock generation unit 7. The clock generation unit 7 is controlled so that the cycle of the clock is longer, that is, the clock rate is reduced. Since the power consumption of the CPU composed of a semiconductor is proportional to the operation clock rate, the clock output from the clock generator 7 is given to the CPU 8 as shown in FIG.
By lowering the operating clock rate of U8, CP
It is possible to reduce the power consumption of U8. According to this embodiment, since the maximum power consumption of the power supply unit 2 can be designed as y (see FIG. 2), the power supply unit can be reduced in size by the decrease in the maximum power consumption.

FIG. 5 is a block diagram showing a configuration of a main part of an information device according to a second embodiment. The information device of this embodiment includes a liquid crystal display device 9 and a backlight 10 attached to the liquid crystal display device 9 in the operation unit 1, and a backlight control unit 11 for driving the backlight 10 in the power consumption reduction control unit 4.
Is provided. The other configuration is the same as the configuration block diagram shown in FIG. In such an information device, when a device such as a hard disk device (not shown) included in the operation unit 1 is driven and power consumption increases, a resistance provided on a power supply line between the operation unit 1 and the power supply 2 is increased. The voltage drop across R increases, and signal a is output from power measurement circuit 3. At this time, the backlight control unit 11 included in the power consumption reduction control unit 4 lowers the drive voltage supplied to the backlight 10 of the drive unit 1 and lowers the brightness of the backlight 10.
Thus, also in the information device of this embodiment, the maximum power consumption can be reduced, and the power supply unit can be downsized.

FIG. 6 is a block diagram showing a configuration of a main part of an information device according to a third embodiment. The information device of this embodiment includes a CPU 8 in the operation unit 1 and an interrupt generation unit 12 and an interrupt control unit 13 in the power consumption reduction control unit 4. The other configuration is the same as the configuration block diagram shown in FIG. In such an information device, when a device such as a hard disk device (not shown) included in the operation unit 1 is driven and power consumption increases, a resistance provided on a power supply line between the operation unit 1 and the power supply 2 is increased. The voltage drop across R increases, and signal a is output from power measurement circuit 3. At that time, the interrupt generation unit 12 of the power consumption reduction control unit 4 generates a predetermined interrupt signal, and thereby the interrupt control unit 13 controls the interrupt to the CPU 8. Thus, C
The PU 8 shifts to a low power consumption mode such as an idle state. It is to be noted that a configuration is also possible in which the power consumption reduction control described in each embodiment is combined and simultaneously performed.

[0012]

As described above, according to the present invention,
According to the first aspect of the present invention, when the power consumption exceeds a predetermined value, the power consumption is controlled so as to be reduced, so that the maximum power consumption is reduced. Can be downsized. Claim 2
In the described invention, when power consumption exceeds a predetermined value, CP
The power consumption is reduced by lowering the operating clock rate of U. In the invention according to claim 3, when the power consumption exceeds a predetermined value, the CPU is set to an idle state or the like to reduce the power consumption. According to the present invention, when the power consumption exceeds a predetermined value, the power consumption is reduced by lowering the brightness of the backlight, so that the effects of claim 1 can be easily realized.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram of an information device showing a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of an information device showing a first embodiment of the present invention.

FIG. 3 is a circuit diagram of a main part of an information device showing a first embodiment of the present invention.

FIG. 4 is a configuration block diagram of a main part of an information device showing a first embodiment of the present invention.

FIG. 5 is a configuration block diagram of a main part of an information device showing a second embodiment of the present invention.

FIG. 6 is a configuration block diagram of a main part of an information device showing a third embodiment of the present invention.

[Explanation of symbols]

1 ··· Operation unit, 2 ··· Power supply unit, 3 ··· Power measurement circuit, 4 ··· Power consumption reduction control unit, 5 ··· Comparator, 6 ··· Clock control unit, 7 ··· Clock Generating unit, 8 CPU, 9 Liquid crystal display device, 10
・ Backlight, 11 ... Backlight control unit, 13
... Interrupt control unit

Claims (4)

[Claims] 1. An information device provided with a power consumption reducing means, a power consumption measuring means for measuring power consumed in the equipment, and whether the power consumption measured by the power consumption measuring means exceeds a predetermined value. Power consumption determining means for determining whether the power consumption has exceeded the predetermined value, and power reduction control means for performing predetermined power consumption reduction control when the power consumption determining means determines that the power consumption has exceeded the predetermined value. Information equipment. 2. The information apparatus according to claim 1, wherein the power reduction control means is configured to perform control for lowering the operation clock rate of the CPU as one of the predetermined power consumption reduction controls. machine. 3. The information device according to claim 1, wherein the power reduction control means is configured to generate an interrupt to the CPU as one of the predetermined power consumption reduction controls. 4. In an information device provided with a liquid crystal display device and its backlight and provided with power consumption reduction means, control for lowering the brightness of the backlight is performed as one of predetermined power consumption reduction controls. An information device comprising power reduction control means.