JPH08263473A - Input device - Google Patents

Abstract

(57) [Abstract] [Purpose] A sleep function is provided in an input device used in personal computers to reduce power consumption.
Do not place a time burden on the central processing unit in the power management work. According to the present invention, an input means for inputting a character symbol or the like, a power supply means for supplying electric power to the input means, and a power supply means for supplying power to the input means when there is no input by the input means for a predetermined time. And a power supply control means for controlling the supply to stop and to return to the original supply state when there is an input from the input means in the stopped state. According to the present invention, the power management of the input device itself can be finely performed without lowering the processing speed on the main body side, which contributes to the reduction of power consumption of the entire system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an input device for portable information terminal equipment and the like.

[0002]

2. Description of the Related Art In recent years, information terminal devices such as personal computers have been downsized due to the progress of high-density mounting technology of electronic parts.

Due to the miniaturization of the information terminal equipment, portable information terminal equipment intended for carrying is also attracting attention as a product forming a new market.

Although a keyboard device is generally used as an input device of the portable information terminal device, since a commercially available keyboard device consumes a large amount of current, power management is indispensable for extending the battery life. .

A conventional keyboard device will be described below. FIG. 3 is a hardware block diagram of a keyboard unit and a power management circuit according to a conventional technique.

A keyboard section 1 including a key panel, a main body section 2 including a central processing unit (CPU) 3 and a power management circuit 4 are connected by a signal line 6 and a power supply line 7.

The power management circuit 4 is controlled by the central processing unit 3 through the bus line 5.

[0008]

However, in the above configuration, if the power management of the keyboard device is attempted in detail, the load on the central processing unit 3 increases and the processing speed of the entire system decreases. Had.

The present invention has been made to solve the above problems, and
An object of the present invention is to provide an input device that does not burden the central processing unit by the power management process.

[0010]

SUMMARY OF THE INVENTION The present invention provides an input means for inputting characters and symbols, a power supply means for supplying electric power to the input means, and an input means for inputting power when there is no input for a predetermined time. Power supply control means for stopping the supply of electric power from the power supply means and for returning to the original supply state when there is an input from the input means in the stopped state.

[0011]

With the above structure, the power management of the keyboard device can be finely executed without imposing a burden on the central processing unit of the main body.

[0012]

EXAMPLES The present invention will be described in detail below with reference to examples.

FIG. 1 is a hardware block diagram of an input device according to an embodiment of the present invention. A key panel 10 for inputting a key inside an input means (keyboard section) 8 and a central processing unit (C) for controlling according to a code stored in a ROM 12 in which a program code is stored.
PU) 11, an oscillation circuit 13 that supplies a clock to the central processing unit 11, a clock circuit 14 that measures time,
An interrupt generation circuit 15 for generating an interrupt to the central processing unit 11 when input to the key panel, a switch 17 for turning on / off the power supply line, and a power supply control means (switch control circuit) for controlling the switch 17. )
16 and a power supply unit (backup battery 18) for supplying power to the central processing unit and the like.

The central processing unit 11 controls various circuits through the bus line 22. In addition, power is supplied from the backup battery 18 to various circuits through the backup power supply line 21.

The main body 9 and the keyboard 8 are connected to the power line 1
9 and the signal line 20. FIG. 2 is a software block diagram of the input device according to the embodiment of the present invention.

After the power of the main body is turned on (step 1), the central processing unit 11 initializes various circuits (step 2), and the switch control circuit 16 turns on the switch 17 of the power supply line 19 (step 1). Step 3).

If the clock circuit 14 measures the time up to a fixed time (step 4), an input is made to the key panel 10 within the fixed time, and the central processing unit 11 detects an interrupt from the interrupt generating circuit 15. (Step 5),
The clock circuit 14 measures the time again.

If the central processing unit 11 does not detect the interrupt from the interrupt generating circuit 15 even after the elapse of a certain time, the switch control circuit 16 turns off the switch 17 of the power supply line 19 (step 6). Switch 17
Stops the power supply to the keyboard device.

The central processing unit 11 is then connected to the key panel 1
This state is held until 0 is input (step 7).

[0020]

As described above, according to the present invention, the power management of the input device itself can be finely performed without lowering the processing speed on the main body side, which contributes to the reduction of the power consumption of the entire system. it can.

[Brief description of drawings]

FIG. 1 is a hardware block diagram of an input device according to an embodiment of the present invention.

FIG. 2 is a software block diagram of the input device according to the embodiment of the present invention.

FIG. 3 is a hardware block diagram of a keyboard unit according to a conventional technique.

[Explanation of symbols]

 1 keyboard part 2 main body part 3 central processing unit 4 power management circuit 5 bus line 6 signal line 7 power supply line 8 keyboard part 9 main body part 10 key panel 11 central processing unit 12 ROM 13 oscillator circuit 14 timing circuit 15 interrupt generation circuit 16 switch control circuit 17 switch 18 backup battery 19 power supply line 20 signal line 21 backup power supply line 22 bus line

Claims (1)

[Claims] 1. Input means for inputting characters and symbols, power supply means for supplying electric power to the input means, and input from the power supply means to the input means when there is no input by the input means for a predetermined time. An input means comprising: a power supply control means for stopping the supply of electric power and, when there is an input from the input means in the stopped state, controlling so as to return to the original supply state.