JPH11215697A - Power controller and scanner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the power consumption at sleep of a cordless apparatus, by making a power controller cut a switch under specified conditions, and connect the switch when it has detected a trigger signal, thereby enabling a DC-DC converter to be supplied with power from a current source. SOLUTION: In case that there is no change for a certain time in the signal inputted into the specified terminal of a system controller 1 or a power controller 7, the power controller 7 cuts off a switch 8 to put it in sleep condition, whereby power ceases to be supplied to a DC-DC converter 4, the system controller 1, and each device 10. When a push button or the like is pushed by a user and a trigger signal is sent to the power controller 7 from a trigger transmitter 5 and a one-chip microcomputer detects a voltage change, it calls off the sleep condition and connects the switch 8, and the system controller 1 and each device 10 are supplied with power. As a result, the consumption of power can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device for a cordless device using a rechargeable battery or a dry battery, and more particularly to a power supply device for a cordless device equipped with a power saving function that suppresses power consumption when not used for a certain period of time. Related to the device. Also, the present invention relates to a cordless scanner equipped with a power saving function that can use both a power supplied from a facsimile or the like and a power supplied by a rechargeable battery held inside.

[0002]

2. Description of the Related Art Cordless devices that use rechargeable batteries or dry batteries, such as cordless scanners and notebook computers, automatically turn off the power if left unattended for a certain period of time so that they can operate for a long time. Some have a power saving function that minimizes consumption. During operation of the power saving function (hereinafter referred to as “sleep state” or “sleep state”), when the normal trigger signal is received, it returns to the original state, and the portion for detecting the trigger signal is always energized. ing.

An example of a conventional power control device mounted on a cordless device having a power saving function will be described with reference to a block diagram shown in FIG. In the figure, the solid line indicates the flow of power supply, and the broken line indicates the flow of signals. The power supply of the cordless device is supplied to the DC-DC converter 4 from the interface 3 or the rechargeable battery 2 for receiving an external power supply converted from a 100 V commercial power supply to a direct current, for example, and is converted to a predetermined voltage (for example, 5 V). 1 and each device 10 (arrows A1, A2).

A rechargeable battery 2 and an interface 3
A diode 6 is provided on the output side to prevent a backflow of current to both when an external power supply is connected.

[0005] The system control unit 1 having received the power supply of the predetermined voltage controls the voltage of the DC-DC converter 4 and the power supply to each device 10 (arrow C) and controls each device 10. (Arrows D1 and D2), when there is no change in a predetermined signal input to the system control unit 1 for a certain period of time, the system control unit 1 and each device 10 enter a sleep state to minimize power consumption.

When the user presses a push button switch or the like when the system is in sleep mode and a trigger signal is transmitted from the trigger transmission unit 5 to the system control unit 1, the system control unit 1 and each device 10 return from the sleep state to the original state. The power consumption is reduced when the power switch is forgotten to be turned off, and when the rechargeable battery is used without using an external power supply, the operating time of the rechargeable battery is prevented from decreasing. It is supposed to. Therefore, at the time of sleep, it is necessary to supply power to at least the portion that monitors and detects the trigger signal.

Next, FIG. 2 shows a configuration example of a facsimile apparatus 40 and a cordless scanner 41 for the facsimile apparatus. In FIG. 2, the cordless scanner 4
1 is driven by the power of an external power supply supplied from the rechargeable battery 32 or the facsimile machine 40 through the connection connector 43 and the connection connector 42 (the interface 3 in FIG. 1), and the system of the cordless scanner 41 is operated by inputting the power key 35. Power is supplied to the whole, and a reading key 36 is provided to notify the system of the start of image reading by the user.

When an image is read by the cordless scanner 41, when a reading key 36 is input by the user, a reading light source (not shown) is turned on to wait for the main body of the cordless scanner 41 to move. A light receiving element (not shown) such as an image sensor is moved on the desired image while irradiating light on the desired image and irradiating light on the desired image.
, And image data is read by performing image processing based on information from an encoder (not shown) that detects the amount of movement of the cordless scanner 41.

As described above, the cordless scanner 41 is also provided with a power saving function, and if no operation is performed for a certain period of time, the system goes into a sleep state and power consumption is suppressed.

[0010]

In FIG. 1, a power saving function (sleep function) is provided for all devices 10 controlled by the system control unit 1 when the system is in a sleep state.
Are not added, so that individual devices 10
Focusing on, the device 10 which is not in the sleep state
There was wasted power consumption. Further, in order to supply power only to the monitoring portion of the trigger signal and put all the other devices 10 into the sleep state, a method is provided in which a switch is provided at a connection portion of the device 10 having no power saving function, and this switch is controlled by the system control unit 1. However, the circuit becomes complicated and causes an increase in cost.

Further, it is necessary to supply power to the system control unit 1 in order to monitor the trigger signal during sleep of the system. However, the DC-DC converter 4 consumes a large amount of power during sleep due to a large current loss. Was.

In the cordless scanner 41,
The light source was turned on even when the image was not read until the main body of the cordless scanner 41 was placed on the desired image after the reading key 36 was input and the movement was started, and wasteful power was consumed. .

An object of the present invention is to provide a power control device capable of extending the operating time of a rechargeable battery or a dry battery by reducing power consumption during sleep of a cordless device.

Further, the present invention provides a scanner capable of reducing power consumption by mounting the power control device and further reducing power consumption by turning on a reading light source only while the main body is moving. With the goal.

[0015]

In order to achieve the above object, a power control apparatus according to the present invention comprises a current source comprising a rechargeable battery or a dry battery, and a power source having a predetermined voltage from the current source.
A C-DC converter and the DC-DC converter
A switch for opening and closing a current supplied to the converter, a power control unit for controlling the DC-DC converter and the switch, and a trigger transmission unit for transmitting a trigger signal to the power control unit; Is supplied from the input side of the switch, disconnects the switch when a predetermined condition is satisfied, monitors the trigger signal, and connects the switch when the trigger signal is detected to connect the switch to the DC-DC converter from the current source. Power can be supplied.

According to this configuration, the power converted to a predetermined voltage from the rechargeable battery or the dry battery via the DC-DC converter is supplied to the system controller of the cordless device and other devices, so that the cordless device can be used, and the power control can be performed. When there is no signal change at a predetermined terminal of the unit or the system control unit for a certain period of time, the power control unit cuts off the switch on the path from the rechargeable battery or the dry battery to the DC-DC converter and puts the power control unit into a sleep state. Monitor the trigger signal. At this time, the power control unit is supplied with power from the rechargeable battery or the dry cell, but the power is not supplied to the DC-DC converter, so that power is not supplied to the system control unit and other devices. When a trigger signal is transmitted from the trigger transmission unit by the user, the power control unit is released from the sleep state and the switch is connected to supply power to the DC-DC converter, the system control unit, and other devices. become.

Further, the power control device of the present invention comprises a first current source comprising a rechargeable battery or a dry battery, an interface capable of receiving power from an external second current source, the first current source or the first A DC-DC converter for obtaining a power supply of a predetermined voltage from the second current source; a switch for opening and closing a current supplied from the first current source or the second current source to the DC-DC converter; A power control unit that controls the DC converter and the switch, and a trigger transmission unit that transmits a trigger signal to the power control unit, wherein the power control unit is supplied with power from an input side of the switch, and when a predetermined condition is satisfied, The switch is disconnected and the trigger signal is monitored. When the trigger signal is detected, the switch is connected to connect the switch to the first current source or the second current source. Thereby enabling power to the DC-DC converter.

According to this configuration, when power can be supplied from the DC power source or the like converted from the commercial AC power source to the power control device through the interface, the power is converted from the interface or a rechargeable battery or a dry battery to a predetermined voltage through the DC-DC converter. The supplied power is supplied to the system control unit and other devices of the cordless device, the cordless device becomes usable, and when there is no signal change at a predetermined terminal of the power control unit or the system control unit for a predetermined time, the power control unit D from interface or rechargeable battery or dry cell
The switch in the middle of the path leading to the C-DC converter is turned off, and the power control unit enters a sleep state to monitor the trigger signal. At this time, the power control unit is supplied with power from the interface or the rechargeable battery or the dry cell, but the DC-
Since no power is supplied to the DC converter, no power is supplied to the system control unit and other devices. When a trigger signal is transmitted from the trigger transmission unit by the user, the power control unit is released from the sleep state and the switch is connected to supply power to the DC-DC converter, the system control unit, and other devices. become.

Further, in the power control device according to the present invention, a trigger signal is transmitted to the power control unit when the second current source is connected.

According to this configuration, when power is supplied from the DC power source or the like converted from the commercial AC power source to the power control device through the interface while the power control device is in the sleep state and the switch is turned off, a trigger signal is generated. The information is transmitted to the power control unit and the sleep state is released.

According to the present invention, there is provided a scanner for reading an image by moving a main body, comprising the power control device, a light emitting means for reading an image, and a detecting means for detecting the movement of the main body. The light emitting means emits light when the movement of the main body is detected.

According to this configuration, the light source for image reading does not emit light only by inputting the image reading key provided on the scanner, but emits light when the movement of the scanner body starts thereafter.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. FIG. 3 is a block diagram showing the cordless device 21 and the power control device 20. The same members as those in the conventional example are denoted by the same reference numerals, a broken line indicates a signal flow, and a solid line indicates a power supply flow. According to the figure, the power supplied to the DC-DC converter 4 via the switch 8 from the interface 3 or the rechargeable battery 2 capable of receiving an external power is converted into a predetermined voltage and supplied to the system control unit 1 and each device 10. (Arrows A1, A
2).

The power controller 7 composed of a one-chip microcomputer or the like has an interface 3 or a rechargeable battery 2.
The power is supplied from the power supply through the regulator 9, and the one-chip microcomputer does not need the regulator 9 particularly because the movable voltage range is large. However, when an unexpectedly large voltage is applied to the power control unit 7, It is provided for step-down so as not to destroy the one-chip microcomputer.

When a signal input to a predetermined terminal of the system control unit 1 or the power control unit 7 does not change for a predetermined time,
The power control unit 7 turns off the switch 8 and enters a sleep state, so that power is not supplied to the DC-DC converter 4, the system control unit 1, and each device 10.

When a push button switch or the like is pressed by a user and a trigger signal is transmitted from the trigger transmission unit 5 to the key-on wake-up terminal of the one-chip microcomputer of the power control unit 7 and the one-chip microcomputer detects a voltage change, one chip The microcomputer releases the sleep state and connects the switch 8. Thereby, the system control unit 1 and each device 10
Will be supplied with power.

As described above, when the system is in the sleep state, the power only needs to be supplied to the portion for monitoring the trigger signal of the power control unit 7, so that the DC-DC converter 4 having a large current loss or a device having no power saving function The power consumption can be reduced because the power to the power supply is cut off.

The same effect can also be obtained in a cordless device in which the rechargeable battery is charged by a separate charger without the interface 3 for connecting an external power supply. The same effect can be obtained in a device using a dry battery instead of the rechargeable battery 2.

When an external power supply is connected, it is better not to supply power from the rechargeable battery 2 and to charge the rechargeable battery 2 immediately when the external power supply is removed. This is desirable because cordless devices can be driven by electric power.

An embodiment of the present invention will be described in more detail with reference to FIG. FIG. 4 is a block diagram of the cordless scanner 41 for the facsimile apparatus 40 as described above and shown in FIG. In FIG. 4, a broken line indicates a signal flow, and a solid line indicates a power supply flow.
The flow of power supplied from the output side of the converter 34 to each device is omitted.

According to the figure, the interface 33 or NiCd receiving power from the facsimile
Diode 36 and switch 3 from rechargeable battery 32 such as a battery
8, the power supplied to the DC-DC converter 34 is converted into a predetermined voltage and supplied to each device. DC
The DC converter 34 is divided into a step-up unit 34a and a step-down unit 34b, and since the NiCd battery has a variation of about 4.0 to 5.8V, the voltage is adjusted to a predetermined voltage of 5V by the step-down unit 34b after the step-up unit 34a has stepped up the voltage. Have been.

The rechargeable battery 32 is charged from the booster 34a, and the charge control circuit 61 controls whether to charge quickly or to charge after discharging. Power is supplied from a rechargeable battery 32 or an external power supply directly through a regulator 39 to a power control unit 37 composed of a one-chip microcomputer. When the read key 36 is not operated for a certain period of time, the power control unit 37 cuts off a switch 38 to perform one-chip operation. The microcomputer enters the sleep state and monitors the trigger signal.
When the switch 38 is turned off, power is not supplied to devices other than the power control unit 37, and the entire system is in a sleep state.

When the system is in the sleep state, the power key 3
When 5 or the read key 36 is input, a trigger signal is detected at the key-on wake-up terminal of the one-chip microcomputer, the sleep state of the one-chip microcomputer is released, and the switch 38 is connected. As a result, power is supplied to each device, and the cordless scanner 41 can be used.

When the reading key 36 is input, the reading light source 58 is turned on by the system control unit 31. When the user moves the cordless scanner 41 on a desired image, the reflected light of the light source 58 is received by the light receiving element. The image data is read by detecting the moving amount of the cordless scanner 41 by the encoder 60.

The image data signal is amplified by an amplifier 57, converted into a digital signal by an AD converter 56, and subjected to image processing by a system controller 31. At the time of image processing, processing such as image compression is also performed to transmit image data to the facsimile apparatus 40, a buffer 51 for temporarily storing image data, a memory 52 for compressing and storing data in the buffer 51, and a memory for image processing. 55 or the like is used. When the image processing is performed, the image data is transmitted to the facsimile device 40 via infrared communication or a communication cable. In the case of communication using a communication cable, the user needs to input a transmission command after connecting the communication cable.

A CPU 54 is used for various operations, and a system control program is stored in a system ROM 53 and executed by the system control unit 31.

According to such a configuration, when the system of the cordless scanner 41 is in the sleep state, only the power for monitoring the input of the power key 35 or the reading key 36 is consumed, so that the device such as the system control unit 31 or the memory is used. Power is not supplied to the power supply, and power consumption can be reduced as compared with the related art.

Next, when the user uses the rechargeable battery without connecting the external power source and the system is in the sleep state and the user connects the external power source, the user immediately starts reading the image. Since it is considered that the rechargeable battery 32 is charged, it is desirable that the sleep state be automatically released.
For this purpose, when an external power supply is connected to the interface 33, for example, a trigger signal may be transmitted to the key-on wake-up terminal of the one-chip microcomputer (arrow E), and a circuit as shown in FIG. Can be configured.

When an external power supply is not connected, the power supply terminal 33a of the interface 33 has a so-called low voltage of 0V.
In this state, no base current flows through the transistor 71. At this time, the power supply terminal 37a of the one-chip microcomputer of the power control unit 37 is in a so-called High state of 3 V, for example, and the transistor 71 is in a high impedance state, so that the voltage drop of the resistor 72 is small and the key-on wake-up terminal 37b is in the High state. .

When an external power supply is connected, the interface 3
When the third power supply terminal 33a goes high, a base current flows and the transistor 71 has a low impedance, so that the voltage drop across the resistor 72 is large and the key-on wake-up terminal 37b goes low, so that it can be detected as a trigger signal. Become.

At this time, the trigger signal is always transmitted when the external power supply is connected, and the system does not enter the sleep state. However, if the rising of the voltage of the key-on wake-up terminal 37b is detected, the system is kept constant even when the external power supply is connected. If the time reading key 36 is not operated, the system can be put to sleep.

When the external power of the cordless scanner 41 is received from the facsimile apparatus 40 by the interface 33, the facsimile apparatus 40 is not connected to the cordless scanner 41 by the interface 33 (connectors 42 and 43). If the power supply terminal of the connection connector 43 is set to a high voltage, there is a danger since the connection connector 43 on the side is exposed.

Therefore, as shown in the block diagram of FIG. 6, a terminal on the interface 33 for detecting that the cordless scanner 41 has been connected through the interface 33 (connectors 42 and 43) (generally referred to as a "φR terminal"). (81), the facsimile machine 40
The power supply to the power supply terminal on the interface 33 is turned on on the side (82), and then when communication is performed through the interface 33, a command for communication is transmitted / received (83) to prevent breakage due to a short circuit. Danger can be avoided.

In FIGS. 3 and 4, even if the power key 35 of the cordless scanner 41 of this embodiment is turned off, the system enters a sleep state and consumes a small amount of power. For this purpose, for example, a power switch may be separately provided on the input side of the regulator 39 so that the power can be completely shut off.

Although the present embodiment has been described using a cordless scanner for facsimile, the present invention is not limited to this. For example, a scanner device for a personal computer, a notebook computer, a video camera,
The present invention can be applied to all devices having a power saving function using a rechargeable battery such as a cordless iron or a dry battery.

Next, in the facsimile cordless scanner shown in FIGS. 2 and 4, in order to read the information of each point of the two-dimensional image, it is necessary to simultaneously detect the image information by the light receiving element and the moving amount of the main body. The amount of movement of the main body can be detected by the encoder,
The encoder measures the distance according to the movement of the main body, and can recognize the aspect ratio of the image.

As described above, when the image reading light source 58 is turned on when the reading key 36 is input by the user, the reading is performed until the cordless scanner 41 is placed at the desired start position and moved. Power for turning on the light source 58 is wasted. Therefore, the power can be used without waste by turning on the light source 58 after the encoder 60 detects that the cordless scanner 41 has started moving.

[0048]

According to the first aspect of the invention, the power consumption of the cordless device during sleep can be reduced, and the operating time of the rechargeable battery or the dry battery can be extended.

According to the second aspect of the present invention, since the power of the rechargeable battery or the dry battery is not consumed when the external power source taken from the commercial power source is used together, the operating time of the rechargeable battery or the dry battery can be extended. Become.

According to the third aspect of the present invention, when an external power supply is connected to the interface while the system is in the sleep state, the sleep state is automatically released, so that it is not necessary to input a trigger signal of the cordless apparatus and the operation of the cordless apparatus can be performed. Can be easier.

According to the fourth aspect of the present invention, the light source for reading is turned on when the reading of the cordless scanner is started, so that wasteful power consumption can be prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a conventional power control device.

FIG. 2 is a configuration diagram of a facsimile apparatus with a cordless scanner.

FIG. 3 is a block diagram showing a power control device of the present invention.

FIG. 4 is a block diagram of the cordless scanner of the present invention.

FIG. 5 is a circuit diagram for detecting an external power supply of the cordless scanner of the present invention.

FIG. 6 is a flowchart when the cordless scanner according to the present invention is connected to an interface.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 System control part 2, 32 Rechargeable battery 3, 33 Interface 4, 34 DC-DC converter 5 Trigger transmission part 6 Diode 7, 37 Power control part (one chip microcomputer) 8, 38 Switch 9, 39 Regulator 20 Power supply device 21 Cordless device 35 Power key 36 Reading key 40 Facsimile device 41 Cordless scanner 42, 43 Connector

Claims (4)

[Claims] A current source comprising a rechargeable battery or a dry battery;
A DC-DC converter for obtaining a power supply of a predetermined voltage from the current source; a switch for opening and closing a current supplied from the current source to the DC-DC converter;
A power control unit that controls a converter and the switch;
A trigger transmission unit for transmitting a trigger signal to the power control unit, wherein the power control unit is supplied with power from an input side of the switch, disconnects the switch when a predetermined condition is satisfied, monitors the trigger signal, and monitors the trigger signal. When a signal is detected, the switch is connected and the DC-
A power control device capable of supplying power to a DC converter. 2. A first current source comprising a rechargeable battery or a dry battery, an interface capable of receiving power from an external second current source, and a predetermined current from the first current source or the second current source. A DC-DC converter for obtaining a voltage power supply, a switch for opening and closing a current supplied from the first current source or the second current source to the DC-DC converter, the DC-DC converter and the switch, And a trigger transmission unit that transmits a trigger signal to the power control unit.The power control unit is supplied with power from an input side of the switch, and disconnects the switch when a predetermined condition is satisfied. A trigger signal is monitored, and when the trigger signal is detected, the switch is connected to connect the DC-current from the first current source or the second current source.
A power control device capable of supplying power to a DC converter. 3. The power control device according to claim 2, wherein a trigger signal is transmitted to the power control unit when the second current source is connected. 4. A power control device according to claim 1, wherein the scanner reads the image by moving the main body, and a light emitting unit for reading the image.
Detecting means for detecting movement of the main body, wherein the light emitting means emits light when the movement of the main body is detected by the detecting means.