JPH0580913A - Keyboard device - Google Patents

Abstract

PURPOSE:To place a control part in low power consumption mode while there is no key input even when a dummy key indicating whether or not an option board is connected or when a setting part for the kind of a keyboard is ON. CONSTITUTION:The dummy key 9 and setting part 10 are arranged at a SCAN 4 as an SCAN line different from other key contacts 14 and when an MPU2 is placed in low power consumption mode, only the SCAN 4 is set to high impedance and other SCN lines are held at an 'L' level. Since the SCN 4 has the high impedance, so a SENSE line is held at the 'L' level by the dummy key 9 or setting part 10 and an interruption signal (b) goes up to an 'H' level so that the MPU 2 is never interrupted. When there is a key input, a key contact 14 is made, the SENSE line goes down to the 'L' level, and the interruption signal (b) rises to the 'H' level to interrupt the MPU 2, which returns to its normal operation mode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a keyboard device which is an input device such as a computer, and more particularly to a keyboard device suitable for reducing power consumption.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram of a conventional keyboard device. In FIG. 2, a keyboard device 12 includes a microprocessor (hereinafter, referred to as MPU) 2 which is a control unit, and the MPU 2 serves as a central processing unit (hereinafter, referred to as main CPU) on the computer main body side (not shown) by an interface signal a. It is connected and receives and transmits data related to key input and a command for shifting to a low power consumption mode (hereinafter, simply referred to as a command). Key matrix 3
Is composed of a SCAN line and a SENSE line, and a key contact 14 and a diode 15 are provided at the intersection. Reference numeral 6 is a pull-up resistor, 13 is an optional keyboard such as a numeric keypad, and 8 is a key matrix of the optional keyboard 13. The key matrix 3 and the key matrix 8 are SCAN lines and S
The number of ENSE lines is reduced. As described in Japanese Patent Application Laid-Open No. 61-165121, this keyboard device 12 has at least one of the intersections of the option keyboard 13 connected by a diode 15 so as to be always in an ON state (hereinafter referred to as a dummy key 9). ), This M
The PU 2 can detect whether or not the optional keyboard 13 is connected.

Further, as described in Japanese Patent Application Laid-Open No. 57-159328, a predetermined part of the intersection of the key matrix 3 is used as a setting section 10, and the setting section 10 is always in an off state or connected by a diode 15. Then, the MPU 2 can identify the type of the keyboard by keeping the MPU 2 always on.

[0004]

In the recent MPU, the power consumption is suppressed to 1/100 to 1/1000 of the normal operation mode by stopping the clock oscillation, and the normal operation mode is generated by an external interrupt. There is a low power consumption type that returns to. Such an MPU is used to reduce the power consumption of the keyboard device. However, by using this low power consumption type MPU, when the MPU 2 detects that there is no key input for a predetermined time, or when there is no key input by the main CPU command or the like, the MPU 2 is set to the low power consumption mode. Every time, MPU2 by key input
Even if an interrupt is made to return to the normal operation mode, the conventional keyboard device 12 has the following problems.

When the MPU 2 enters the low power consumption mode, the MPU 2 permits an interrupt and sets all the SCAN lines to a key contact ON detectable state, for example, "L" level. When any one of the keys is input, the corresponding key contact 14 is turned on, the SENSE line connected to this key contact 14 becomes the “L” level, and the negative logic OR gate 11 outputs the interrupt signal b. The level becomes "H", the MPU 2 is interrupted, and the normal operation mode is restored.

However, the dummy key 9 or the setting unit 10
Is on, even if the MPU2 is in the low power consumption mode, the dummy key 9 or the setting unit 10 immediately sets the interrupt signal b to the “H” level, and the MPU2 is interrupted. However, the power consumption cannot actually be reduced.

An object of the present invention is to provide a function even when the dummy key 9 or the setting section 10 is in the ON state, when the MPU detects that there is no key input for a predetermined time, or when there is no key input due to a command from the main CPU or the like. It is to provide a keyboard device capable of setting the MPU in a low power consumption mode.

[0008]

In order to achieve the above object, in the first invention, the dummy key and the setting section are
Of the AN wires, the SCAN wires are arranged on one or more SCAN wires different from other key contacts, and when the MPU enters the low power consumption mode, this SCAN wire is in the key contact ON detection disabled state,
For example, I set it to high impedance.

Further, in the second invention, the dummy key and the setting section are arranged on one or more SENSE lines of the SENSE line which are different from other key contacts, and the SE
The NSE line is not input to the negative logic OR gate.

[0010]

In the first invention, in the low power consumption mode,
Since the SCAN line on which the dummy key and the setting section are arranged has a high impedance, the connected SENSE line does not go to "L" level and the interrupt signal b does not go to "H" level even if the key contact is on. Therefore, the MPU is not interrupted by the dummy key or the setting unit,
While there is no key input, the MPU can be kept in the low power consumption mode, and the power consumption of the keyboard device can be reduced.

Further, in the second invention, since the SENSE line in which the dummy key and the setting section are arranged is not input to the negative logic OR gate, the SENSE line connected when the key contact is turned on is set to the "L" level. However, the interrupt signal b does not go to "H" level. Therefore, the MPU is not interrupted by the dummy key or the setting unit,
While there is no key input, the MPU can be kept in the low power consumption mode, and the power consumption of the keyboard device can be reduced.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a keyboard device according to a first embodiment of the present invention. In FIG. 1, 1 is a keyboard device, and 7 is an optional keyboard device. Hereinafter, the same components as those in FIG. 5 are designated by the same reference numerals, and the description thereof will be omitted. The dummy key 9 and the setting unit 10 are arranged on the same SCAN line, SCAN 4, and the other keys are S.
It is arranged other than CAN4. The MPU 2 is an MPU that enters a low power consumption mode, permits interrupts, sets only SCAN 4 to high impedance, and sets all other SCAN lines to “L” level. Since SCAN4 has high impedance, the dummy key 9 and the setting unit 10 are connected to the S
The ENSE0 is never set to the "L" level by the dummy key 9 or the setting unit 10. Therefore, while there is no key input, the interrupt signal b is at "L" level, and the MPU 2 is not interrupted. Therefore, the MPU 2 can enter the low power consumption mode.

When a key is input, the key contact 14 corresponding to that key is turned on, the SCAN line of the "L" level and the SENSE line are connected through the diode 15, and this SENSE line is the "L" level. And the negative logic OR gate 11 sets the interrupt signal b to the “H” level,
2 is interrupted and the normal operation mode is restored.

According to the present embodiment, since the dummy key 9 or the setting unit 10 does not cause the interrupt signal b to go to the "H" level by setting the SCAN 4 to a high impedance state, the MPU 2 is turned on while there is no key input. The low power consumption mode can be set.

In addition to the dummy key 9 and the setting unit 10, when setting a return prohibition key, the same SCAN line as the dummy key 9 and the setting unit 10, SCAN in this embodiment is used.
4 may be arranged. In addition, as shown in FIG.
A plurality of N lines are used to arrange the dummy key 9, the setting unit 10 and the return prohibition key, and when the MPU 2 enters the low power consumption mode, these SCAN lines, SC in this embodiment, are used.
A configuration in which AN4 and SCAN3 have high impedance may be used.

FIG. 3 is a block diagram of a keyboard device according to a second embodiment of the present invention. In this embodiment, the dummy key 9 and the setting unit 10 are set to the same SENSE line SENS.
It is located at E0, and other keys are located other than SENSE0. When entering the low power consumption mode, the MPU 2 permits interrupts and sets all SCAN lines to "L" level. As a result, the SE having the dummy key 9 and the setting unit 10 connected thereto
NSE0 becomes "L" level, but negative logic OR gate 1
Since it is not input to 1, the interrupt signal b remains at "L" level. Therefore, since the MPU 2 is not interrupted, the MPU 2 can be in the low power consumption mode while there is no key input.

When a key is input, the key contact 14 corresponding to that key is turned on, and the "L" level SCAN line and the SENSE line are connected through the diode 15, and this SENSE line is at the "L" level. become. Since the key contact 14 is connected to other than SENSE0, the negative logic OR gate 11 sets the interrupt signal b to the “H” level, and the MPU
2 is interrupted and the normal operation mode is restored.

According to the present embodiment, the SENSE line connecting the dummy key 9 and the setting unit 10 does not cause the interrupt signal b to go to the "H" level, so that the MPU 2 is set in the low power consumption mode while there is no key input. Can be

In addition to the dummy key 9 and the setting section 10, when setting the above-mentioned return prohibition key, the dummy key 9
And the same SENSE line as the setting unit 10, SEN in this example
It may be placed at SE0. Also, as shown in FIG.
Dummy key 9 and setting unit 1 using multiple ENSE lines
0 and the return prohibition key are arranged, and these SENS
Other than the E line, in this embodiment, SENSE2 and SENSE
Of course, it does not matter if 0 is not input to the negative logic OR gate.

[0020]

According to the present invention, even when the dummy key or the setting section is in the ON state, the control section has low power consumption when there is no key input or when there is no key input due to an instruction from the main CPU. Since the keyboard device can be set in the mode, the power consumption of the keyboard device can be reduced.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a keyboard device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a keyboard device according to a modification of the first embodiment.

FIG. 3 is a configuration diagram of a keyboard device according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram of a keyboard device according to a modification of the second embodiment.

FIG. 5 is a configuration diagram of a conventional keyboard device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Keyboard device, 2 ... MPU, 3, 8 ... Key matrix, 4 ... Key contact, 5 ... Diode, 7 ... Optional keyboard device, 9 ... Dummy key, 10 ... Setting part,
11 ... Negative logic OR circuit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kaaki Nomura 7-1-1 Higashi Narashino, Narashino City, Chiba Prefecture Hitachi Systems Design and Development Center

Claims (2)

[Claims] 1. A key matrix in which key contacts are arranged at intersections between signal lines in one direction (hereinafter referred to as SCAN lines) and signal lines in the other direction (hereinafter referred to as SENSE line) arranged in a matrix. And a control unit for controlling the key contact on detection possible state / key contact on detection impossible state of the SCAN line, and the SEN for the key contact on.
An OR circuit for the SE line is provided, and the SCAN line is set to a key contact ON detectable state, and the control unit is changed from the normal operation mode to the low power consumption mode. Then, the OR circuit detects the key contact ON. In this case, in a keyboard device for returning the control unit to the normal operation mode, a key contact that is always on and a key (hereinafter referred to as a return prohibition key) contact that does not return the control unit to the normal operation mode even when turned on. , SCAN lines are arranged on one or a plurality of SCAN lines different from other key contacts, and the SCAN lines are set to a key contact ON detection disabled state,
A keyboard device characterized in that another SCAN line is set to a key contact ON detectable state, and the control section is changed from a normal operation mode to a low power consumption mode. 2. An SC of signal lines arranged in a matrix.
A key matrix in which key contacts are arranged at the intersections of the AN line and the SENSE line, a control unit for controlling the SCAN line key contact ON detection possible state / key contact ON detection undetectable state, and the SENSE line for the key contact ON OR of
Circuit, and when the SCAN line is set to a key contact-on detectable state and the control unit is changed from a normal operation mode to a low power consumption mode and then the key contact is detected by the OR circuit, the control is performed. In the keyboard device for returning the unit to the normal operation mode, one or a plurality of S contacts different from the other key contacts in the SENSE line are used as the key contacts and the recovery prohibition key contacts that are always on.
A keyboard device arranged on the ENSE line, and the SENSE line is not input to the OR circuit.