JPH06149442A - Keyboard unit - Google Patents

Abstract

PURPOSE:To reduce energy consumption in the case of providing dummy keys which are always turned on. CONSTITUTION:Concerning a keyboard unit 17 provided with an MPU 12 and a negative logic OR 16 for sense lines while connecting a decoder 2 for expanding (n) pieces of signal lines (first scan lines) in one direction and (m) pieces of signal lines (prescan lines) in the same direction as the first scan lines into (p) pieces of signal lines (second scan lines) and ten keys 1 provided with a key matrix 6 arranging key contacts at intersection parts between the first/second scan lines and (r) pieces of signal lines (sense lines) in the other direction, a gate 3 is provided for turning all the second scan lines to a key contact ON detection enable state, a SCAN 0 arranging only dummy keys 8a and 8b is turned to a key contact ON detection disable state, SCAN 1-6 are turned to the key contact ON detection enable state, and the MPU 12 is changed from a normal operation mode to a low energy consumption 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 means of a personal computer or a word processor, and more particularly to an option keyboard having a dummy key which is always in an ON state to indicate whether or not the option keyboard device is connected. The present invention relates to a keyboard device suitable for reducing power consumption with the device connected.

[0002]

2. Description of the Related Art A computer such as a personal computer or a word processor has a keyboard device having a number of keys of around 100 keys and is mainly used for inputting numerical values.
In many cases, an optional keyboard device having a number of keys before and after the key (hereinafter referred to as a numeric keypad) can be connected.

FIG. 2 shows a block diagram of a conventional keyboard device and a numeric keypad. In the figure, 11 is a conventional keyboard device, 12 is a microprocessor (hereinafter referred to as MPU) which is a control unit of the keyboard 11, 13 is a key matrix, and is composed of scan lines and sense lines.
A key 7 including a key contact 9 and a diode 10 is arranged at the intersection. Reference numeral 14 is a pull-up resistor, 15 is a conventional numeric keypad, 6 is a key matrix of the numeric keypad 15, and 16 is a negative logic OR. Note that the number of scan lines and sense lines in the key matrix 13 is reduced to simplify the description. Also, the numeric keypad 15
As described in Japanese Patent Application Laid-Open No. 61-165121, by connecting at least one of the intersection points with a diode 10 and keeping it in an ON state at all times (hereinafter, referred to as a dummy key 8), the MPU 12 operates the ten-key 15 It is possible to detect the presence or absence of the connection of.

Normally, the MPU 12 detects ON / OFF of each key contact 9 by checking each sense line input by sequentially setting each scan line to "L" one by one, and detects the data corresponding to the input of the key 7. Is transferred to an unillustrated central processing unit (hereinafter referred to as a main CPU) via an interface signal a.

[0005]

With the widespread use of battery-powered computers in recent years, it has become an important issue to reduce the power consumption of computers. So MP
U12 adopts MPU which has low power consumption mode that keeps power consumption to 1/100 to 1/1000 of normal operation mode by stopping clock oscillation and returns to normal operation mode by external interrupt. , If the MPU12 detects that there is no key input for a predetermined time, or
The MPU 12 is set to the low power consumption mode by a command of the main CPU or the like, and the MPU 12 is pressed by pressing the key 7.
It is conceivable that the MPU 12 is set to the low power consumption mode during the time when there is no key input by making an interruption to the normal operation mode to reduce the power consumption of the keyboard device 11. However, the conventional keyboard device 11 and the numeric keypad 15 have the following problems.

The MPU 12 indicates that no key is input for a predetermined time.
Is detected, or in response to a command from the main CPU or the like, the MPU 12 permits an interrupt and sets all scan lines to a key contact ON detectable state, for example, “L”, and enters a low power consumption mode. When any key 7 is input, the corresponding key contact 9 is turned on, the sense line connected to this key contact 9 becomes "L", and the negative logic OR 16 causes the interrupt signal b to become "L". ", And MPU1
2 is interrupted and the normal operation mode is restored.

Therefore, when the numeric keypad 15 is connected, the dummy key 8 is always in the ON state, so that the MP
Even if the U12 is in the low power consumption mode, the dummy key 8 immediately sets the interrupt signal b to "L" and the MPU 12 is interrupted, so that the normal operation mode is restored, and the low power consumption is actually performed. Cannot be realized.

Further, in the method of shifting to the low power consumption mode by setting only the scan line where the dummy key 8 is arranged to the key contact ON detection disabled state and the other scan lines to the key contact ON detection enabled state, the power consumption can be reduced. Although it becomes possible, even if the key 7 arranged on the same scan line as the dummy key 8 is input, it does not return to the normal operation mode, and the usability deteriorates.

An object of the present invention is, even when a numeric keypad having a dummy key is connected, when the MPU detects that there is no key input for a predetermined time without deteriorating the usability, or by an instruction from the main CPU, An object of the present invention is to provide a keyboard device that can put the MPU in a low power consumption mode while there is no key input.

[0010]

In order to achieve the above object, first, as a first means, the dummy key is arranged on a scan line different from other keys. Next, in order to prevent the number of keys 7 from being reduced by the first means as compared with the conventional ten-key pad, as a second means, among the scan lines other than the dummy keys arranged, A decoder for extending the book to p lines is provided, and a gate for making all the p scan lines extended by the decoder into a key contact-on detectable state is provided. Then, when the MPU enters the low power consumption mode, the scan line on which the dummy key is arranged is set to the key contact on detection disabled state, and the other scan lines are set to the key contact on detection enabled state.

[0011]

In the low power consumption mode, since the scan line in which the dummy key is arranged cannot detect the key contact ON, the dummy key does not interrupt the MPU and return from the low power consumption mode. Therefore, when the MPU detects that there is no key input for a predetermined time, or when there is no key input by an instruction from the main CPU or the like, the MPU can be in the low power consumption mode. Further, since no other keys are arranged on the scan line where the dummy keys are arranged, there is no key that does not return the MPU from the low power consumption mode by key input, and the number of keys is reduced compared to the conventional ten-key pad. Since it does not exist, usability does not decrease.

[0012]

EXAMPLES Examples of the present invention will be described in detail below.

First, FIG. 3 shows a block diagram of an embodiment of a ten-key pad. In the figure, 1 is a numeric keypad according to the present invention,
Reference numeral 2 is a decoder for expanding the three scan lines SCAN1 to SCAN3 to six. Table 1 shows a truth table of the decoder 2.

[0014]

[Table 1]

For SCAN1 to SCAN3, all 3 are "L"
In this case, the negative logic ORs 4a and 4b for bringing all the expanded 6 scan lines to "L" are the diodes for supplying power from the SCAN0 or SCAN1 to the decoder 2 and the negative logic OR3, and 5 is the capacitor, Reference numeral 6 denotes a key matrix, which includes a key 7 at the intersection of the scan line and the sense line, a dummy key 8a indicating whether or not the numeric keypad 1 is connected,
A dummy key 8b indicating that it is the numeric keypad of the present invention is arranged. The key 7 is composed of a key contact 9 and a diode 10, and the dummy keys 8a and 8b are diodes 10.
It consists of only. Further, only the dummy keys 8a and 8b are arranged on the scan line not passing through the decoder 2,
The other keys 7 are arranged on the scan lines extended by the decoder 2.

FIG. 1 shows a block diagram of an embodiment of the keyboard device.

In the figure, the same components as those in FIG. 2 are designated by the same symbols, and their explanations are omitted. Reference numeral 17 is a keyboard device according to the present invention. The numeric keypad 1 has a simplified diagram.

When the MPU 12 detects that there is no key input for a predetermined time, or when it enters a low power consumption mode due to a command from the main CPU or the like, it permits an interrupt and SC
Only AN0 is set to "H", and SCAN1 to SCAN6 are set to "L". As a result, only the scan line in which the dummy keys 8a and 8b are arranged is "H", that is, the key contact ON detection is disabled, and all the other scan lines are "L", that is, the key contact ON detection is enabled. Therefore, SENSE0 and SEN in which the dummy keys 8a and 8b are arranged are
SE2 becomes "L", the interrupt signal b becomes "L" by the negative logic OR 16, and the MPU 12 is not interrupted. Therefore, the MPU 12 can enter the low power consumption mode.

When any one of the keys 7 of the key matrix 6 or the key matrix 13 is input, the key contact 9 corresponding to the key 7 is turned on, and the signal level "L".
Is connected to the sense line via the diode 10, the sense line becomes "L", the interrupt signal b becomes "L" by the negative logic OR 16, the MPU 12 is interrupted, and the normal operation mode is set. Return.

According to this embodiment, by setting SCAN0 to "H", the dummy keys 8a and 8b
Since the interrupt signal b does not become "L", the MPU 12 can be set to the low power consumption mode and the keyboard device 17 can be made low power consumption while there is no key input. Further, the conventional ten-key pad 15 shown in FIG. 2 includes the dummy key 8, and up to 20 keys can be arranged, whereas the ten-key pad 1 according to the present embodiment has the dummy key 8.
Up to 30 keys can be arranged except for a and 8b. Therefore, by arranging the dummy keys 8a and 8b on different scan lines from the other keys 7,
The number of keys is reduced as compared with the conventional numeric keypad 15, and as a result, usability does not deteriorate. Further, in the present embodiment, the connecting portion between the keyboard device 17 and the ten-key pad 1 is the same as the conventional ten-key pad 15. Therefore, the MPU 12 of the keyboard device 17 distinguishes the ten-key pad 1 and the ten-key pad 15 by the presence / absence of the dummy key 8b. Can also be controlled.

In addition to the dummy keys 8a and 8b, when a key for prohibiting the return from the low power consumption mode (hereinafter referred to as a return prohibition key) is provided, the dummy key 8a is used.
And 8b may be arranged on the same scan line. Also, multiple scan lines, such as SCAN0 and SCA
The return prohibition key may be arranged in N4, and when the MPU 12 enters the low power consumption mode, these scan lines may be set to "H", that is, the key contact ON detection disabled state.

In the above embodiments, the case where the dummy key 8 is present has been described. However, when the dummy key 8 is not present, all the scan lines may be set to the key contact ON detectable state, that is, "L". Of course.
Further, the keyboard device 17 and the numeric keypad 1 may be integrated.

[0023]

According to the present invention, even when there is a dummy key which is always on, 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. , The MPU can be set to the low power consumption mode, so that the keyboard device can be reduced in power consumption.

[Brief description of drawings]

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

FIG. 2 is a block diagram of a conventional keyboard device.

FIG. 3 is a block diagram of an embodiment of a numeric keypad according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Numeric keypad using this invention, 2 ... Decoder, 3 ... Negative logic OR, 6 ... Numeric keypad matrix, 7 ... key,
8a and 8b ... Dummy keys, 9 ... Key contacts, 10 ... Diodes, 11 ... Conventional keyboard device, 12 ... MP
U, 13 ... Key matrix of keyboard device, 15 ...
Conventional numeric keypad, 16 ... Negative logic OR, 17 ... Keyboard device using the present invention.

Claims (3)

[Claims] 1. An n number of signal lines in one direction (hereinafter referred to as a first scan line) and m number of signal lines in the same direction as the first scan line (hereinafter referred to as a pre-scan line) are p A decoder extending to one signal line (hereinafter referred to as a second scan line) and an intersection of the first and second scan lines and q signal lines in the other direction (hereinafter referred to as a sense line). A key matrix in which key contacts are arranged, a key contact ON detectable state / key contact ON undetectable state of the first scan line, and only one of the second scan lines via the prescan line In a keyboard device having a control means for controlling the key contact ON detection possible state and the other to a key contact ON detection impossible state, and a negative logic OR of the sense lines, all the second scan lines are in the key contact ON detection detectable state. Gate to The first and second scan lines are all set to a key contact ON detectable state, and the control means is changed from the normal operation mode to the low power consumption mode, and then the key contact ON is detected by the negative logic OR. In this case, the keyboard device is characterized in that the control means is returned to the normal operation mode. 2. In the key matrix, a key contact that is always on and a key that does not return the control means to the normal mode even when turned on are referred to as other key contacts of the first scan line. After arranging the scan lines in different one or more scan lines, setting the scan lines in the key contact on detection disabled state and the other in the key contact on detection enabled state, the control means is changed from the normal operation mode to the low power consumption mode. A keyboard device, wherein when the key contact ON is detected by the negative logic OR, the control means is returned to a normal operation mode. 3. At least one first scan line, m
A pre-scan line is extended to p second scan lines; and a key matrix in which key contacts are arranged at intersections of the first and second scan lines and r sense lines. In the optional keyboard device, in order to enable the control means to confirm whether or not the optional keyboard device is connected or the type of the optional keyboard, etc.
A dummy key) is placed on the first scan line,
An optional keyboard device having no gate other than the dummy key on the first scan line and having a gate for setting all of the second scan lines to a key contact ON detectable state.