JPH02178818A - Power saving circuit and terminal equipment - Google Patents

Abstract

PURPOSE:To minimize the consumption of a power source battery by supplying power to a required part in a handy terminal equipment only at the time of necessity. CONSTITUTION:A handy terminal equipment 10 is provided with an acoustic coupler 12, an LCD display device 14, a membrane type keyboard 16, a key switch 18, a hand-written graphic input pad 20, and a power switch 22, and a base unit 24 has a pedestal 26, a power transmission coil 28, and an optical coupler 30. Power is supplied to each circuit unit only when the operation of this circuit unit is required. Thus, the consumption of the power source battery is minimized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a power saving circuit that suppresses power consumption of a battery-powered electric/electronic circuit such as a handy terminal device, and a terminal device having the power saving function.

[Background Art] With the development of communication technology, small and portable terminal devices and data input devices have come into general use. In addition, with the spread of computer systems, product inventory management,
Computers have come to be used for parcel management work by parcel delivery workers.For example, parcel delivery workers carry around small portable terminal devices and input individual data sequentially into this terminal device and temporarily store it. A possible method is to store the data and later send it all to the host computer or manually.

Such a terminal device requires a large-capacity memory or recording medium (eg, a magnetic disk, etc.) for storing input data, and also requires a communication device, such as an acoustic coupler. Both of these lead to an increase in power consumption.

Furthermore, in recent years, barcodes have become popular, and a management method has come to be used in which barcodes are printed in advance on all products, slips, etc., and the products are managed collectively using the barcodes. In this case, it is necessary to provide the terminal device with a barcode reader.

[Problems to be Solved by the Invention] In small and portable terminal devices, the power source is generally a primary battery or a secondary battery, and due to weight restrictions, it is necessary to suppress power consumption as much as possible. However, as mentioned above, many functions that increase power consumption are increasingly required.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a power saving circuit that can minimize consumption of the power supply battery in such a terminal device, and a terminal device having the power saving function.

[Means for Solving the Problems] In the present invention, the circuit configuration of an electric/electronic device or a terminal device is divided into circuit units for each predetermined function, and each circuit unit is connected to a power supply circuit via an individual switch. . Then, in response to a power switch operation, power is first supplied to a keyboard system circuit unit, and thereafter, power is supplied to a main control circuit unit in response to keyboard input. The main control circuit unit supplies power to the attached circuit unit to perform a predetermined operation as necessary, and shuts off the power supply after the operation is completed.

[Operation] As described above, since the power supply to each circuit unit is limited to the time when the operation of the circuit unit is necessary, consumption of the power supply battery can be minimized. Additionally, even if there is no keyboard operation for a certain period of time, the keyboard circuit unit inquires in advance of the main control circuit unit whether or not the power supply to the main control circuit unit can be cut off, and receives a response indicating that the power supply can be cut off. Since the main control circuit unit and therefore the attached circuit unit are in the middle of operation,
The power supply to them will never be cut off.

[Example] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 2 shows an external perspective view of a handy terminal device to which the present invention is applied. In FIG. 2, numeral 10 is a handy terminal device whose power source is a secondary battery. 12 is an acoustic coupler, 14 is an LCD display device, and 16 is a membrane keyboard, which is provided with a number of key switches 18 and a pad 20 for inputting handwritten figures. 22 is a power switch.

Reference numeral 24 denotes a base unit for supplying power to the secondary battery of the handy terminal device 10 using a magnetic coupling method, and by placing the handy terminal device 10 at a predetermined position on the pedestal 26, the power transmission coil 28 is activated. Power receiving coil of the handy terminal device 10 (not shown)
Electric power is supplied from the base unit 24 to the handy terminal device 10 by the magnetic coupling of these coils. 30 is an optical coupler (a light emitting element and a light receiving element) for communicating with the handy terminal device 10 using light as a communication medium.

The optical coupler 30 (the light receiving element thereof) receives, for example, an optical signal indicating completion of charging from the handy terminal device 10 in addition to the optical communication signal.

FIG. 1 shows a wiring diagram of the power supply system of the terminal device 10 shown in FIG. The same components as in FIG. 2 are given the same reference numerals. 40 is a power supply battery which is a secondary battery, 42 is a base battery.
The power source battery 40 is powered by the power sent from the unit 24.
44 is a power line. The power line 44 includes a backup line that is constantly supplied with power.
The unit 46 is directly connected to the power supply switch 48,
Sub unit 60, main unit 62, display unit 64, barcode reader 66, acoustic communication unit 68 via 50.52, 54, 56.58, respectively.
and optical communication unit 70 are connected.

The backup unit 46 includes a power-on monitoring circuit 72 that monitors the open/close state or operation state of the power switch 22.
．． A backup memory 74 with a memory capacity of about 512 KB or 1,024 KB, and the current time (year, month,
Calendar clock 76 that outputs data (day, hour, minute, second)
Equipped with.

The capacity of the power battery 40 and the power consumption of the backup memory 74 are, for example, such that the backup memory 74 can retain data for approximately 48 hours when the power battery 40 is powering only the backup unit 46. . This is because it is assumed that the data stored in the memory 74 is normally transmitted to the outside within 24 hours, and of course, if it is necessary to store it for a longer period of time,
It's going to change.

The sub-unit 60 controls the keyboard 16 and the keyboard 16, and turns on/off a large number of key switches 18.
It includes a sub-control circuit 78 that converts the off input and the graphic input from the handwritten graphic human power pad 20 into data. The control circuit 78 consists of, for example, an 8-bit one-chip microcomputer. The power supply switch 48 is closed by a close signal from the power-on monitoring circuit 72, and is opened by an open signal from the sub-control circuit 78.

The sub control circuit 78 is connected to the closed power supply switch 48.
The output voltage of the power supply battery 40 is monitored via the power supply line 44 and the power supply line 44, and if the output voltage of the power supply battery 40 decreases to the extent that the long-term operation of the backup unit 46 is impaired, the power supply battery 40 is To reduce consumption,
An open signal is sent to the power supply switch 48 to cut off the power supply to the sub-unit 60. The sub-control circuit 78 also monitors the output voltage of the power battery 40 during charging by the charging circuit 42, and when charging is completed, the terminal device 10 notifies the base unit 24 of the completion of charging, and 40 to stop charging.

The main unit 62 includes a main control circuit 80 that performs various control operations, and a read-only memory (ROM) 8.
2, a random access memory (RAM) 84, a barcode reader 66, and a communication control circuit 86 that controls communication with the acoustic communication unit 68 and the optical communication unit 70.

The main control circuit 80 is composed of, for example, a 16-bit microcomputer, and controls data communication between the display unit 64, the bar code reader 66, the acoustic communication unit 68, and the optical communication unit 70.

The main control circuit 80 also has a data communication path between it and the sub-control circuit 78, and also has a data communication path between it and a display control circuit 88 (to be described later) of the display unit 64, allowing synchronous or asynchronous data communication. are doing.

The ROM 82 stores operating programs and necessary data for the main control circuit 80, and the RAM 84 stores keyboard input data from the sub-unit 60, current date and time data from the calendar clock 76, and the acoustic communication unit 68 and optical communication unit. Communication data for 70 is stored.

Through data communication with the main control circuit 80, the sub control circuit 78 applies an open signal to the switch 50 if there is no problem even if the power to the main unit 50 is cut off, and the switch 5
Release 0. The sub control circuit 78 also has a power supply battery 40
When the output voltage of the main unit 62 is above a predetermined value, there is a predetermined input operation on the keyboard 60, and the main unit 62 needs to operate, a closing signal is applied to the switch 50, and the main unit 62 is activated.

On the other hand, the main control circuit 80 turns on the power supply switch 5 when any of the display unit 64, barcode reader 66, acoustic communication unit 68, and optical communication unit 70 is required.
The corresponding switches 2, 54, 56, and 58 are closed, and when they are no longer required, they are opened. By finely controlling the power supply in this way, the power supply battery 4
It is possible to suppress the consumption of 0 as much as possible.

The display unit 64 includes the LCD display device 14 and a display control circuit 88 that controls the display device 14.
8 displays the data transferred from the main control circuit 80 on the LCD display device 14.

The LCD display device 14 uses a super-twist liquid crystal material with high brightness and a wide viewing angle, and the brightness can be adjusted in eight steps using an electronic volume.

The barcode reader 66 includes a barcode reading circuit, its control circuit, and an external communication circuit. The acoustic communication unit 68 includes an acoustic coupler 12 and a modem (modulator/demodulator). The optical communication unit 70 includes an optical coupler (a light emitting element and a light receiving element) that faces the optical coupler 30 of the base unit 24 when the device 10 is placed on the base unit 24. Optical coupling between the light emitting element of the optical communication unit 70 and the light receiving element of the optical coupler 30 of the base unit 24 notifies the base unit 24 that charging of the power supply battery 40 is complete. The details of these units 66, 68, 70 are not relevant to the content of the present invention, so further explanation will be omitted.

Next, the operation of each part of FIG. 1 from the start of use to the end of use of the handy terminal device 10 will be explained in order. Before use, when the power switch 22 is off, only the backup unit 46 is supplied with power, and the other sub units 60, main unit 62, display unit 64, bar code leader 6
6. Power is not supplied to the acoustic communication unit 68 and the optical communication unit 70. That is, switches 48, 50 .
52, 54, 56, 58 are open.

When power switch 22 is pressed, power-on monitoring circuit 72 detects this and applies a close signal to switch 48, placing sub-unit 60 in a powered state. Sub control circuit 7
8 performs a self-diagnosis including checking the output voltage of the power supply battery 40, and if it is good, it applies a close signal to the power supply switch 50 of the main unit 62, and if it is bad, it applies an open signal to its own power supply switch 48. Apply and cut off the power.

The sub-control circuit 78 also constantly monitors the input state of the keyboard 16, and transfers manual key input or graphic data input to the main control circuit 80 of the main unit 62 via the data communication path 79.

When the switch 50 is closed and the power supply voltage is applied to the main unit 62, the main control circuit 80 first performs handshaking with the sub-control circuit 78 via the communication path 79 based on a fixed procedure. Once handshake can be established, main control circuit 80 performs self-diagnosis such as memory check. If handshake cannot be established, or if main control circuit 80 detects a malfunction during self-diagnosis, sub-control circuit 78 applies an open signal to switch 50 and cuts off power supply to main unit 62. Only when the handshake between the sub-control circuit 78 and the main control circuit 80 is established and the self-diagnosis result of the main control circuit 80 is good, the main control circuit 80 operates according to the main program in the ROM 82, and the handheld terminal All the functions of the device 10 are now available for use. However, the main control circuit 80
is normally in standby mode, which consumes less power.

For example, when some kind of display is to be made, the main control circuit 8
0 enters the active mode by a command from the sub-control circuit 78, applies a close signal to the switch 52, supplies power to the display unit 64, and transfers necessary data to the display control circuit 88. The display control circuit 88 displays necessary information on the LCD display device 14 according to the data.

After displaying for a predetermined period of time, the main control circuit 80 opens the switch 52 to cut off the power supply to the display unit 64 in order to avoid further power consumption.

When there is human input from the keyboard 16, the input data is processed by the sub-control circuit 78 and sent to the signal communication path 79.
It is transferred to the main control circuit 80 via. Prior to this transfer, main control circuit 80 changes from standby mode to active mode in response to a command from sub control circuit 78. The main control circuit 80 stores the data in the RAM 84 according to the contents of the data from the sub-control circuit 78, and stores the data in the display unit 64, barcode reader 66, and acoustic communication unit 68.
and controls the optical communication unit 70.

When the main control circuit 80 wants to operate the barcode reader 66, the acoustic communication unit 68, or the optical communication unit 70, it closes the corresponding switch 54.degree. 56.58 to provide power. And barcode reader 66
, the acoustic communication unit 68 or the optical communication unit 70, data is transferred via the communication control circuit 86.

When the necessary data transfer is completed, the main control circuit 80 applies an open signal to the previously closed switch of the switches 54, 56, and 58 to cut off the power supply. barcode·
Data obtained from reader 66 is stored in RAM 84.

When the terminal device 10 is being charged by the power supply circuit 42 in an office or the like, there is no particular need to save power, so the switches 54, 56, 58 are connected regardless of whether the devices 66, 68, 70 are used or not. may be kept closed at all times. There is no particular need to limit (cut off) the power supply to the communication unit 68, 70, especially during data transfer to the host computer.

If there is no input from the keyboard 16 for a certain period of time, the sub control circuit 78 inquires of the main control circuit 80 as to whether or not the power can be cut off, and in response to a response from the main control circuit 80 indicating that the power can be cut off, sends an open signal to the switch 50. Main unit 6
2. Cut off the power supply. In response to this inquiry, the main control circuit 80 first selects the RAM 84 if it is okay to shut off.
After saving the stored data in the backup memory 74, a signal is sent to the sub-control circuit 78 indicating that it is possible to shut down.

As a result, necessary data is saved and can be restored to the RAM 84 when power is turned on to the main unit 62 later.

In the above embodiment, a backup-only memory 74 is provided separately from the RAM 84, but of course, the RAM 84 or a part thereof is a battery backup memory or a non-volatile memory, and even when the switch 5° is opened, the memory 74 is It may also be possible to eliminate the need for evacuation work. Also, the data that needs to be backed up is not in RAM84, but
The data may be stored in the backup memory 74 all the time, or may be written into the backup memory 74 at the same time as it is written into the RAM 84. This eliminates the need to save data stored in the RAM 84 to the backup memory 74 when the main unit 62 is powered off.

The power switch 22, power-on monitoring circuit 72, and power supply switch 48 in the above embodiment may be modified as shown in FIG. 3 by using a self-holding switch device. The same components as in FIG. 1 are given the same reference numerals.

90 is a self-holding type switch device, 92 is a switch biased by a spring in the opening direction, 94 is an electromagnetic coil that maintains the switch 92 in a closed state when energized, and 96 is a normally open switch.

The switch 96 is connected to bypass the current paths of the switch 92 and the electromagnetic coil 94. When the switch 92 is closed against the spring bias, the switch 92 is held in the closed state by the electromagnetic force of the electromagnetic coil 92. Switch 92 functions as a power switch. If you want to open the switch device 90 from the sub-control circuit 78, switch 96
It is sufficient to apply a short pulse to the terminal for instantaneous closing.

Closing of switch 96 causes switch 92 and coil 9 to close.
No current flows through the current path 4, and the switch 92 becomes open due to the biasing force of the spring. Since switch 96 only closes momentarily, switch device 90 is in an open state and power supply to sub-unit 60 is cut off.

Although the description has been given using a handy terminal device as an example, the present invention can also be applied to battery-powered electric/electronic equipment, such as a portable data-powered device that immediately transmits input data wirelessly.

Switches 48, 50, 5254.5 in the above embodiment
6.58 may be a mechanical switch such as an electromagnetic switch, but a semiconductor switch is preferred from the viewpoint of longevity.

Further, the self-holding type switch device 90 is not limited to the structure shown in the drawings, but may be one that has self-holding properties using a semiconductor circuit.

[Effects of the Invention] As can be easily understood from the above explanation, according to the present invention, power is supplied to the necessary parts only when necessary, so that consumption of the power supply battery can be minimized. Can be done. Therefore, if the battery capacity is the same, it can be used for a longer time without charging.

[Brief explanation of the drawing]

FIG. 1 is a circuit block diagram of a power supply system according to an embodiment of the present invention.
FIG. 2 is an external perspective view of a J"% day terminal device according to an embodiment of the present invention, and FIG. 3 is a circuit block diagram of a modification of FIG. 1 of the power switch portion. 10: Handy terminal device. Terminal device 12: Acoustic coupler
14: LCD display device 16: Membrane keyboard 18: Key switch 20: Handwritten figure input pad 22: Power switch 24: Base unit 2
6: Pedestal 28: Power transmission coil 30: Optical coupler 40:
Power supply battery 42: Charging circuit 44: Power line 46-
Backup unit 48, 50, 52, 54, 5
658: Power supply switch 60: Sub unit
62: Main unit 64: Display unit 64 6
6: Barcode reader 68: Acoustic communication unit 7
0: Optical communication unit 72: Power-on monitoring circuit 74
:Backup memory 76:Calendar clock 78=
Sub control circuit 80: Main control circuit 82: ROM 84
:RAM86: Communication control circuit 88: Display control circuit 9
0: Self-holding switch device

Claims (6)

[Claims] (1) A power supply circuit having a power supply battery, a first unit connected to the power supply circuit through a first switch means, a first unit having a keyboard, and a first unit connected to the power supply circuit through a second switch means; In the electrical/electronic device, the first switch means is closed in response to an operation to turn on the power to the electrical/electronic device, and the first unit is configured to A power saving circuit characterized in that the second switch means is closed in response to a signal input operation. (2) The first unit monitors the output voltage of the power supply circuit, and when the output voltage is equal to or higher than a predetermined value and there is a signal input operation in the signal input means, the second unit monitors the output voltage of the power supply circuit. The power saving circuit according to claim 1, characterized in that the switch means is closed. (3) When there is no signal input operation on the keyboard for a predetermined period of time, the first unit inquires of the second unit whether the power can be cut off, and receives a signal from the second unit indicating that the power can be cut off. According to claim 1 or 2, the first switch means is opened.
The power saving circuit described in section 2). (4) A power supply circuit having a power supply battery, a first unit connected to the power supply circuit through a first switch means, a first unit having a keyboard, and a first unit connected to the power supply circuit through a second switch means; and one or more auxiliary circuit units that are connected to the power supply circuit through separate switch means and controlled by the second unit, and that A terminal device characterized in that the first switch means is closed, and the first unit closes the second switch means in response to a signal input operation on the keyboard. (5) Claim (4) characterized in that the second unit closes the associated switch means only when the function of the attached circuit unit is required.
Terminal device described in section. (6) The terminal device according to claim (4), further comprising data storage means that is constantly supplied with power by the power supply circuit.