JP2010218025A - Key input device and clock - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a key input device capable of detecting a large number of key inputs by a small number of input ports, and to provide a clock capable of properly performing time correction. <P>SOLUTION: The key input device (2) includes a plurality of key switches (SW1-SW4), and a key scanning part (11) performing key scanning. The plurality of key switches are grouped into a plurality of groups (GP1, GP2) forming one group by at least one key switch. The key scanning part starts the key scanning by a first key operation performed by the use of one of the key switches as a trigger, detects the key switch performed by the first key operation by the key scanning, and thereafter, detects the key switches performed by a continuous key operation including a second key operation while sequentially changing over the group to be performed by the key scanning in a key scanning period until the continuous key operation including the second key operation is completed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a key input device that detects a large number of key inputs with a few input ports, and a timepiece having the key input device.

  A microcomputer or the like is provided with an input port for detecting a key input. When the number of key switches to be used is larger than the number of input ports, it is common to form a key matrix and perform a key scan to detect key switches that have been keyed (Patent Document 1). ~ 3).

JP-A-11-242552 JP 2005-346550 A JP 2008-269104 A

Key input devices as disclosed in Patent Documents 1 to 3 are used in all electronic devices, and radio-controlled timepieces are no exception.
Many radio-controlled timepieces perform time correction based on a time signal included in a standard time radio wave operated by the National Institute of Information and Communications Technology (NICT).

In a radio-controlled timepiece, time correction is often performed automatically. In the key input devices disclosed in Patent Documents 1 to 3, since a pulse signal is used during key scanning, for example, when a key switch for setting an alarm time is operated while receiving a standard time radio wave, The reception sensitivity may decrease due to the pulse signal.
In this case, the standard time radio wave cannot be normally received, and the time is not properly adjusted.

  An object of the present invention is to provide a key input device capable of detecting a large number of key inputs with a few input ports and a timepiece capable of appropriately performing time adjustment.

  The key input device of the present invention includes a plurality of key switches, and a key scanning unit that performs a key scan to detect on / off of the key switch in which the key operation is performed among the plurality of key switches. The plurality of key switches are grouped into a plurality of groups forming one group by at least one key switch, and the key scan unit performs the first key operation performed using any one of the key switches. Triggered by the key scan, the key scan from which the first key operation has been performed is detected by the key scan until the continuous key operation including the second key operation is completed. During the period, consecutive key operations including the second key operation were performed while sequentially switching the groups to be scanned. Respectively detect the over switch.

  Preferably, the plurality of key switches are grouped into a plurality of groups forming one group by two key switches.

  Preferably, each group has a detection node for detecting on or off of each key switch commonly connected to one end of each key switch, and the key scanning unit includes The signal level of the detection node is monitored, and if the signal level is the first level, it is detected that any one of the key switches connected to the detection node is on, and the signal level is When the level is two, it is detected that any one of the key switches connected to the detection node is off.

  Preferably, each group includes a supply node connected in common to the other end of each key switch and supplied with the signal, and the key scan unit is configured to perform the key scan during the key scan period. The signal is supplied to the supply node of each group while alternately switching the signal level to the first level or the second level for each group to be performed.

  Preferably, the key scan unit supplies the first level signal to the supply node of each group outside the key scan period.

  The timepiece of the present invention has a time correction function for correcting the time of the internal clock, and a key input device for performing key operations related to at least the time correction. The key input device includes a plurality of key switches, and the plurality of key switches. A key scanning unit that performs key scanning to detect on / off of a key switch that has been operated by a key operation, and the plurality of key switches form a group by at least one key switch. The key scan unit starts the key scan using the first key operation performed by using any one of the key switches as a trigger, and the first key operation. After the key switch that has been operated is detected by the above key scan, the key sequence until the continuous key operation including the second key operation is completed. The catcher down period, while sequentially switching the groups to be the key scan, detect each key switch successive key operation is performed including the second key operation.

  According to the present invention, it is possible to detect a large number of key inputs with a small number of input ports and perform time correction appropriately.

FIG. 1 is a schematic block diagram showing a configuration example of a radio-controlled timepiece according to an embodiment of the present invention. FIG. 2 is an equivalent circuit diagram showing a configuration example of the key input device according to the embodiment of the present invention. 3A to 3F are timing charts showing an operation example of key scanning according to the embodiment of the present invention. FIG. 4 is a flowchart showing an example of a key scanning method according to the embodiment of the present invention. FIG. 5 is an equivalent circuit diagram showing a configuration example of a key input device according to a modification of the embodiment of the present invention. FIG. 6 is a flowchart illustrating an example of a key scanning method according to a modification of the embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Configuration example of radio-controlled clock 1]
FIG. 1 is a schematic block diagram showing a configuration example of a radio-controlled timepiece according to an embodiment of the present invention. However, only the main part of the signal processing system of the radio-controlled timepiece 1 is shown in FIG.

As shown in FIG. 1, the radio-controlled timepiece 1 includes a key switch group 10, a microcomputer 11 as a key scanning unit, a long wave receiving circuit 12, a standard radio wave receiving circuit 13, an internal clock 14, a display unit 15, and an audio output unit. 16, a speaker 161, and a memory 17.
The key input device 2 includes a key switch group 10 and a microcomputer 11.

The radio-controlled timepiece 1 has a time correction function for correcting the time measured by the internal clock 14.
When correcting the time, the radio-controlled timepiece 1 corrects the time based on a time signal included in the standard time radio wave operated by the National Institute of Information and Communications Technology.
In addition, the radio-controlled timepiece 1 has, for example, an alarm function and a snooze function.

  The key switch group 10 includes, for example, a forced reception key switch for causing the long wave reception circuit 12 to receive a standard time radio wave and correcting the time of the internal clock 14, a manual time adjustment key switch for manually adjusting the time, an alarm An alarm key switch for setting time, a snooze key switch for a snooze function, a reset key switch, an up key switch, and a down key switch are provided.

  The microcomputer 11 performs a key scan, detects a key switch that has been operated by a key (specifically, pressed), and performs processing according to the detected key switch.

However, the microcomputer 11 performs the following key scan.
Specifically, the microcomputer 11 shifts to the standby mode in preparation for the start of the key scan during a period when the key switch is not operated.
When any one of the key switches is pressed, the microcomputer 11 shifts from the standby mode to the key scan mode with the press of the key switch as a trigger, and starts the key scan.
Then, after detecting the key switch, the microcomputer 11 performs the key scan for each group while sequentially switching the group to be scanned for a period until the continuous key operation is completed.

For example, when the forced reception key switch is pressed, the microcomputer 11 detects the pressing of the forced reception key switch, causes the long wave reception circuit 12 to receive the standard time radio wave, and causes the internal clock 14 to correct the time measurement.
In addition, the microcomputer 11 performs reception control of the standard radio wave reception circuit 13, time correction of the internal clock 14, display control of the display unit 15, audio control of the audio output unit 16, access to the memory 17, and the like.

  The long wave receiving circuit 12 includes, for example, an RF amplifier, a detection circuit, a waveform shaping circuit, etc. (not shown). The long wave receiving circuit 12 receives the standard time radio wave S1 using the antenna ANT1. Then, the long wave receiving circuit 12 performs amplification processing, detection processing, and the like on the received standard time radio wave S1, and outputs a standard time signal S2 as a processing result to the microcomputer 11.

  The standard radio wave receiving circuit 13 includes, for example, an RF amplifier, a detection circuit, a waveform shaping circuit, etc. (not shown). The standard radio wave receiving circuit 13 receives an AM (Amplitude Modulation) radio broadcast radio wave S3 using the antenna ANT2. Then, the standard radio wave receiving circuit 13 demodulates the AM radio broadcast radio wave S3 and outputs it to the microcomputer 11 as an AM signal S4.

The internal clock 14 measures the time based on an oscillation circuit (not shown). Specifically, the internal clock 14 includes, for example, a year information counter, a month information counter, a day information counter, a day information counter, a hour counter that counts hour information, a minute counter that counts minute information, and a second that counts second information. Has a counter.
The internal clock 14 corrects the time measurement based on the standard time signal S2 received by the microcomputer 11.

The display unit 15 includes, for example, an LCD (Liquid Crystal Display) panel, an organic EL (Organic Electro Luminescence) display, or the like.
Needless to say, the display unit 15 may be formed of an analog clock board. The display unit 15 performs display according to the display control signal S5 of the microcomputer 11.

  The audio output unit 16 performs processing such as D / A conversion and volume adjustment on the digital audio signal S <b> 6 input from the microcomputer 11, and outputs this to the speaker 161. The audio signal S6 is an audio signal such as AM broadcast or alarm sound.

  The memory 17 is composed of, for example, a nonvolatile storage device or a volatile storage device. The memory 17 stores various data such as a program, alarm time, and melody necessary for the microcomputer 11 to perform key scanning.

[Configuration Example of Key Input Device 2]
A configuration example of the key input device 2 will be described with reference to FIG.
FIG. 2 is an equivalent circuit diagram showing a configuration example of the key input device according to the embodiment of the present invention.

As described above, the key switch group 10 has a plurality of key switches, but in order to clarify the explanation, it is assumed that the key switch group 10 includes four key switches.
Specifically, as illustrated in FIG. 2, the key switch group 10 includes four key switches SW1 to SW4.
As an example, push switches are employed for the key switches SW1 to SW4. The key switches SW1 to SW4 are assumed to be a forced reception key switch, a manual time adjustment key switch, an alarm key switch, and a snooze key switch, respectively.

The microcomputer 11 has two input ports PI1 and PI2 and two output ports PO1 and PO2 in order to detect key inputs from the key switches SW1 to SW4.
Inside the microcomputer 11, an input unit 111 connected to the input ports PI1 and PI2 and an output unit 112 connected to the output ports PO1 and PO2 are provided.

As shown in FIG. 2, the key switches SW1 and SW3 are connected in parallel so as to form a group GP1.
Specifically, the terminal C11 of the key switch SW1 and the terminal C31 of the key switch SW3 are connected to the common node ND1. The terminal C12 of the key switch SW1 and the terminal C32 of the key switch SW3 are connected to the common node ND3.

Similarly, the key switches SW2 and SW4 are also connected in parallel so as to form the group GP2.
Specifically, the terminal C21 of the key switch SW2 and the terminal C41 of the key switch SW4 are connected to the common node ND2. The terminal C22 of the key switch SW2 and the terminal C42 of the key switch SW4 are connected to the common node ND4.

The node ND1 is connected to the input port PI1 of the input unit 111. The node ND1 functions as a detection node for detecting on / off of the key switch SW1 or SW3.
The node ND2 is connected to the input port PI2 of the input unit 111. The node ND2 functions as a detection node for detecting on / off of the key switch SW2 or SW4.

The node ND3 is connected to the output port PO1 of the output unit 112. The node ND3 functions as a supply node for the output unit 112 to supply the detection signal Chk1.
The node ND4 is connected to the output port PO2 of the output unit 112. The node ND4 functions as a supply node for the output unit 112 to supply the detection signal Chk2.

A resistor R1 is inserted between the node ND3 and the terminal C32 of the key switch SW3. Similarly, a resistor R2 is inserted between the node ND4 and the terminal C42 of the key switch SW4. Further, a resistor R3 is inserted between the output port PO2 and the node ND4.
These resistors R1 to R3 are provided to detect a pressed key switch. The resistors R1 to R3 have resistance values that can be detected.

The input unit 111 monitors the voltage level input to the input ports PI1 and PI2, that is, the potentials of the nodes ND1 and ND2, and detects the potentials of the nodes ND1 and ND2, thereby pressing the SW1 to SW4. One key switch is detected (detection process).
In the detection process, it is assumed that the input unit 111 detects the pressing of the key switch SW1. In this case, the microcomputer 11 receives the detection result of the input unit 111, causes the long wave reception circuit 12 to receive the standard time radio wave, and causes the internal clock 14 to correct the time measurement.

The output unit 112 outputs an H level (high level) detection signal Chk1 or an L level (low level) detection signal Chk1 to the output port PO1, that is, the node ND3.
Further, the output unit 112 outputs an H level detection signal Chk2 or an L level detection signal Chk2 to the output port PO2, that is, the node ND4.
These detection signals Chk1 and Chk2 are signals for detecting a pressed key switch.

  When the key input device 2 adopts such a connection form, it is possible to detect more key inputs than the number of input / output ports.

[Details of Detection Processing by Input Unit 111]
Here, an example of detection processing by the input unit 111 will be described with reference to FIG. However, in the following description, it is assumed that two or more key switches are not pressed simultaneously.

  (1) When the output unit 112 supplies the detection signal Chk1 at the H level to the node ND3 and supplies the detection signal Chk2 at the H level to the node ND4.

(1-1) When the key switch SW1 is pressed, the terminals C11 and C12 are connected, and the potential VND1 of the node ND1 becomes H level.
When the potential VND1 of the node ND1 is at the H level, the input unit 111 detects pressing of the key switch SW1.

(1-2) When the key switch SW3 is pressed, the terminals C31 and C32 are connected, and the potential VND1 of the node ND1 becomes the potential H1 that is lowered from the H level by the voltage drop of the resistor R1.
The input unit 111 detects pressing of the key switch SW3 when the potential VND1 of the node ND1 is the potential H1.

(1-3) When the key switch SW2 is pressed, the terminals C21 and C22 are connected, and the potential VND2 of the node ND2 becomes the potential H2 that is lowered from the H level by the voltage drop of the resistor R3.
When the potential VND1 of the node ND1 is the potential H2, the input unit 111 detects pressing of the key switch SW2.

(1-4) When the key switch SW4 is pressed, the terminal C41 and the terminal C42 are connected, and the potential VND2 of the node ND2 becomes the potential H3 that is lowered from the H level by the voltage drop between the resistors R2 and R3.
When the potential VND2 of the node ND2 is the potential H3, the input unit 111 detects pressing of the key switch SW4.

(1-5) The potential of the node to which the key switch not pressed is connected is, for example, the ground potential or L level.
Therefore, the input unit 111 does not detect pressing of any key switch when the potential of the node ND1 is the ground potential or the L level. The same applies when the potential of the node ND2 is the ground potential or L level.

  (2) The output unit 112 supplies the H level detection signal Chk1 to the node ND3 and supplies the node ND4 to the L level detection signal Chk2.

(2-1) When the key switch SW1 is pressed, as in the case of (1-1), the input unit 111 detects the pressing of the key switch SW1.
(2-2) When the key switch SW3 is pressed, as in the case of (1-2), the input unit 111 detects the pressing of the key switch SW3.
(2-3) When the key switch SW2 or the key switch SW4 is pressed, since the potential of the node ND4 is at L level, the potentials of the nodes ND1 and ND2 are also at L level or ground potential.
Therefore, the input unit 111 does not detect pressing of the key switch SW2 or the key switch SW4.

  (3) The output unit 112 supplies the L level detection signal Chk1 to the node ND3 and supplies the node ND4 to the H level detection signal Chk2.

(3-1) When the key switch SW2 is pressed, as in the case of (1-3), the input unit 111 detects the pressing of the key switch SW2.
(3-2) When the key switch SW4 is pressed, as in the case of (1-4), the input unit 111 detects the pressing of the key switch SW4.
(3-3) When the key switch SW1 or the key switch SW3 is pressed, since the potential of the node ND3 is L level, the potentials of the nodes ND1 and ND2 are also L level or ground potential.
Therefore, the input unit 111 does not detect pressing of the key switch SW1 or the key switch SW3.

As described above, the output unit 112 outputs an H level detection signal to the node ND3 or the node ND4 of the group to be key scanned for the group to be key scanned.
On the other hand, the output unit 112 outputs the L level detection signal to the node ND3 or the node ND4 of the group not performing the key scan for the group not performing the key scan.
Then, the input unit 111 detects on / off of the key switches SW1 to SW4 based on the potential of the node ND1 or the node ND2, and detects the pressed key switch.

[Key scan operation example]
Hereinafter, an example of the key scanning operation will be described with reference to FIG.
3A to 3F are timing charts showing an operation example of key scanning according to the embodiment of the present invention.
3A shows the voltage level of the detection signal Chk1, and FIG. 3B shows the voltage level of the detection signal Chk2.
3C to 3F show ON / OFF of the key switches SW1 to SW4, respectively.

(~ Time t1: standby mode)
First, the microcomputer 11 shifts to the standby mode in preparation for the start of the key scan during a period when the key switch is not operated.
At this time, the output unit 112 supplies the H level detection signal Chk1 to the node ND3 as illustrated in FIG. 3A, and the H level detection signal Chk2 as illustrated in FIG. 3B. This is supplied to the node ND4.

(Time t1 to time t2: Start of key scan)
For example, as illustrated in FIG. 3D, it is assumed that the key switch SW2 is pressed during a period from time t1 to time t2.
At time t1, the microcomputer 11 shifts from the standby mode to the key scan mode triggered by pressing of the key switch SW2, and starts key scanning.
At this time, since the detection signal Chk1 at the H level is supplied to the node ND3 and the detection signal Chk2 at the L level is supplied to the node ND4, the input unit 111 has the key switch as described in (1-3). The pressing of SW2 is detected.

(Time t2 to time t3: key scan of group GP1)
After the input unit 111 detects that the key switch SW2 is pressed, the microcomputer 11 performs a key scan of the group GP1.
From time t2 to time t3, the output unit 112 supplies an H level detection signal Chk1 to the node ND3 as illustrated in FIG. 3A, and supplies the node ND4 to the node ND4 as illustrated in FIG. 3B. This is supplied to the L level detection signal Chk2.
At this time, since no key switch is pressed, the input unit 111 does not detect any key switch.

(Time t3 to time t4: Key scan of group GP2)
Next, the microcomputer 11 performs a key scan of the group GP2.
For example, as illustrated in FIG. 3D, it is assumed that the key switch SW2 is pressed during a period from time t3 to time t4.
From time t3 to time t4, the output unit 112 supplies the detection signal Chk1 at the L level to the node ND3 as illustrated in FIG. 3A, and supplies the node ND4 to the node ND4 as illustrated in FIG. 3B. This is supplied to the H level detection signal Chk2.
At this time, as described in (3-1), the input unit 111 detects pressing of the key switch SW2.

  Thus, the key scan in which the key scan of the group GP1 and the group GP2 is one cycle is completed.

(Time t4 to time t6: Key scan)
Again, the microcomputer 11 performs the key scan in the order of the group GP1 and the group GP2.
However, it is assumed that no key operation is performed after time t4.
In this case, as described in (1-5), since no key switch is pressed, the input unit 111 does not detect any key switch.

(Time t6-: Key scan stop)
If any key switch is not pressed during one cycle of key scan from time t4 to time t6, the microcomputer 11 stops the key scan.
After the key scan stops, the microcomputer 11 shifts from the key scan mode to the standby mode to prepare for the next key scan.
At this time, the output unit 112 supplies the H level detection signal Chk1 to the node ND3 as illustrated in FIG. 3A, and the H level detection signal Chk2 as illustrated in FIG. 3B. This is supplied to the node ND4.

[Key scan method]
The key scanning method will be described with reference to FIG.
FIG. 4 is a flowchart showing an example of a key scanning method according to the embodiment of the present invention.

  As shown in FIG. 4, in order to enter the standby mode, the output unit 112 supplies an H level detection signal Chk1 to the node ND3 and supplies an H level detection signal Chk2 to the node ND4 (ST11).

When any one of the four key switches SW1 to SW4 is pressed (YES in ST12), the microcomputer 11 switches from the standby mode to the key scan mode using the pressed key switch as a trigger. Migrate and start key scan.
On the other hand, if no key switch is pressed (NO in ST12), the standby mode is entered, so that the process in step ST11 is resumed.

After the key scan is started, the input unit 111 detects the key-key switch pressed in step ST12 (ST13).
After the key-key switch pressed in step ST13 is detected, the microcomputer 11 performs a key scan of the group GP1 (ST14).
At this time, the output unit 112 supplies the detection signal Chk1 at the H level to the node ND3 and supplies the detection signal Chk2 at the L level to the node ND4.
In the key scan of the group GP1, the input unit 111 detects pressing of the key switch SW1 or the key switch SW3 (ST15).

Next, the microcomputer 11 performs a key scan of the group GP2 (ST16).
At this time, the output unit 112 supplies the L level detection signal Chk1 to the node ND3, and supplies the node ND4 to the H level detection signal Chk2.
In the key scan of the group GP2, the input unit 111 detects a key operation of the key switch SW2 or the key switch SW4 (ST17).

Thereafter, when the key operation is continuously performed (NO in ST18), the processes in steps ST14 to ST17 are performed again.
On the other hand, when the operation of the key key switch is completed (YES in ST18), specifically, when none of the key switches is pressed during one-cycle key scan (ST14 to ST17), the microcomputer 11 stops the key scan. To do.
Thereafter, in order to shift from the key scan mode to the standby mode, the process of step ST11 is performed.

As described above, during the period when the key switch is not operated, the microcomputer 11 shifts to the standby mode in preparation for the start of the key scan.
Thereafter, when any one of the key switches is pressed, the microcomputer 11 starts key scanning with the pressing of the key switch as a trigger.
The microcomputer 11 detects the pressed key switch and then performs key scan in units of groups while alternately switching the group to be scanned to the group GP1 or group GP2 until the continuous key operation is completed. I do.

  As described above, since it is not necessary to perform a key scan during a period when the key switch is not pressed, even if the long wave reception circuit 12 receives the standard time radio wave S1 during this period, the detection signal (for example, the standard time signal) It is possible to prevent a decrease in reception sensitivity due to S2).

[Modification of Key Input Device 2]
In the key input device 2 described above, the case where the key switch group 10 is configured by four key switches SW1 to SW4 is taken as an example. Hereinafter, as a modification, an example in which the key switch group 10 includes six key switches SW1 to SW6 will be described. Note that differences from the above-described embodiment will be described.

FIG. 5 is an equivalent circuit diagram showing a configuration example of a key input device according to a modification of the embodiment of the present invention.
As shown in FIG. 5, in the key input device 2a, the key switch group 10a includes a key switch SW5 and a key switch SW6 in addition to the key switches SW1 to SW4.
The microcomputer 11a has three input ports PI1 to PI3 and three output ports PO1 to PO3 in order to detect key inputs of the key switches SW1 to SW6.

The key switches SW5 and SW6 are connected in parallel to each other so as to form a group GP3.
Specifically, the terminal C51 of the key switch SW5 and the terminal C61 of the key switch SW6 are connected to the common node ND5. The terminal C52 of the key switch SW5 and the terminal C62 of the key switch SW6 are connected to the common node ND6.

The node ND5 is connected to the input port PI3 of the input unit 111a. The node ND5 functions as a node for detecting on / off of the key switch SW5 or SW6.
The node ND6 is connected to the output port PO3 of the output unit 112a. The node ND6 functions as a node for the output unit 112a to supply the detection signal Chk3.

A resistor R4 is inserted between the node ND6 and the terminal C62 of the key switch SW6. Similarly, a resistor R5 is inserted between the output port PO3 and the node ND6.
These resistors R4 and R5 are provided to detect the pressed key switch (SW5 or SW6). The resistors R4 and R5 have resistance values that can be detected.

[Key Scan Method in Modification]
A key scanning method in the modification will be described with reference to FIG.
FIG. 6 is a flowchart illustrating an example of a key scanning method according to a modification of the embodiment of the present invention.

  As shown in FIG. 6, in order to enter the standby mode, the output unit 112a supplies an H level detection signal Chk1 to the node ND3, an H level detection signal Chk2 to the node ND4, and an H level detection signal. Chk3 is supplied to the node ND6 (ST21).

If any one of the six key switches SW1 to SW6 is pressed (YES in ST22), the key scan is started, and the input unit 111a is pressed in step ST22. Is detected (ST23).
On the other hand, when none of the key switches is pressed (NO in ST22), the process of step ST21 is resumed to enter the standby mode.

After the key switch pressed in step ST23 is detected, the microcomputer 11a performs a key scan of the group GP1 (ST24).
At this time, the output unit 112a supplies the node ND3 with the H level detection signal Chk1, supplies the node ND4 with the L level detection signal Chk2, and supplies the node ND6 with the L level detection signal Chk3.

In the key scan of the group GP1, the depression of the key switch SW1 or the key switch SW3 is detected (ST25), and the microcomputer 11a performs the key scan of the group GP2 (ST26).
At this time, the output unit 112a supplies the node ND3 with the L level detection signal Chk1, supplies the node ND4 with the H level detection signal Chk2, and supplies the node ND6 with the L level detection signal Chk3.

In the key scan of the group GP2, the depression of the key switch SW2 or the key switch SW4 is detected (ST27), and the microcomputer 11a performs the key scan of the group GP3 (ST28).
At this time, the output unit 112a supplies the node ND3 with the L level detection signal Chk1, supplies the node ND4 with the L level detection signal Chk2, and supplies the node ND6 with the H level detection signal Chk3.
In the key scan of the group GP3, the input unit 111a detects a key operation of the key switch SW5 or the key switch SW6 (ST29).

Thereafter, when the key operation is continuously performed (NO in ST210), the processes in steps ST23 to ST29 are performed again.
On the other hand, when the operation of the key key switch is completed (YES in ST210), the microcomputer 11a stops the key scan.
Thereafter, in order to shift from the key scan mode to the standby mode, the process of step ST21 is performed.

In this way, the key switch group 10a can also be configured with six key switches SW1 to SW6.
Also in this case, since it is not necessary to perform a key scan during a period when the key switch is not pressed, even if a standard time radio wave is received during this period, it is possible to prevent a decrease in reception sensitivity due to the detection signal. it can.

If the above-described embodiment and its modification are further applied, the key switch group can be constituted by eight or more key switches.
The number of key switches need not be even. For example, the key switch group may be composed of three key switches. In this case, one key switch forms one group, and two key switches form one group, and the method described in steps ST11 to ST18 can be applied.

In the above-described embodiment and its modification, a radio wave correction clock is taken as an example of a clock. However, the clock of the present invention performs time correction based on AM broadcast radio waves such as NHK (Japan Broadcasting Corporation) first broadcast radio waves. A radio-controlled clock or a clock without an automatic time correction function may be used.
The key input device of the present invention can also be applied to various electronic devices such as a radio, a timer, a stopwatch, and a bug detector.

  DESCRIPTION OF SYMBOLS 1 ... Radio wave correction clock 2, 2a ... Key input device 10, 10a ... Key switch group 11, 11a ... Microcomputer, 12 ... Long wave receiving circuit, 13 ... Standard radio wave receiving circuit, 14 ... Internal clock, 15 ... Display 16: Audio output unit, 17: Memory, 111, 111a ... Input unit, 112, 112a ... Output unit, 161 ... Speaker, ANT1, ANT2 ... Antenna, ND1-ND6 ... Node, PI1-PI3 ... Input port, PO1 ~ PO3 ... Output port, SW1 ~ SW6 ... Key switch

Claims (6)

Multiple key switches,
A key scan unit that performs a key scan to detect on / off of a key switch that has been operated by a key among the plurality of key switches, and
The above key switches
Grouped into a plurality of groups forming one group by at least one key switch,
The key scan part
Triggered by the first key operation performed using any one of the key switches, the key scan is started,
After the key switch on which the first key operation has been performed is detected by the key scan, the group to be scanned by the key is selected during the key scan period until the continuous key operation including the second key operation is completed. A key input device that detects each key switch in which a continuous key operation including the second key operation is performed while sequentially switching. The above key switches
The key input device according to claim 1, wherein the key input device is grouped into a plurality of groups forming one group by two key switches. Each of the above groups
A detection node for detecting ON or OFF of each key switch connected in common to one end of each key switch;
The key scan part
Monitor the signal level of the detection nodes of each group,
When the signal level is the first level, it is detected that any one key switch connected to the detection node is on;
The key input device according to claim 1, wherein when the signal level is a second level, it is detected that any one of the key switches connected to the detection node is off. Each of the above groups
A supply node connected in common to the other ends of the key switches and supplied with the signal;
The key scan part
2. The signal is supplied to the supply node of each group while alternately switching the signal level to the first level or the second level for each group to be key-scanned during the key scan period. 4. The key input device according to any one of 3 to 3. The key scan part
5. The key input device according to claim 1, wherein the first level signal is supplied to the supply node of each group outside the key scan period. 6. A time correction function for correcting the time of the internal clock,
At least a key input device that performs key operations related to the time correction, and
The key input device
Multiple key switches,
A key scan unit that performs a key scan to detect on / off of a key switch that has been operated by a key among the plurality of key switches, and
The above key switches
Grouped into a plurality of groups forming one group by at least one key switch,
The key scan part
Triggered by the first key operation performed using any one of the key switches, the key scan is started,
After the key switch on which the first key operation has been performed is detected by the key scan, the group to be scanned by the key is selected during the key scan period until the continuous key operation including the second key operation is completed. A timepiece that detects each key switch in which successive key operations including the second key operation are performed while sequentially switching.

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