JP3128699B2 - Automatic clock correction method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for automatically correcting the display time of a clock using a time signal transmitted via radio waves such as a radio, and more particularly to a method for correcting the display time. It has the characteristic.

[Prior Art] Conventionally, this type of timepiece device generally corrects a display time after confirming that a time signal has been received by an hour sound.

On the other hand, there has also been proposed a method of estimating a point in time of the announcement sound at the stage of the hour and correcting the display at the estimated time to match the occurrence of the hourly sound with the carry of the displayed time ( For example, see JP-A-55-82082.

[Problems to be Solved by the Invention] However, it is not so rare that the sound of 440 Hz which is the notice sound is included in the broadcast, and in order to enable time correction at the stage of confirming the notice sound, It is necessary to accurately detect the announcement sound generation pattern, and the circuit configuration becomes complicated.

The present invention has been made in view of such a problem,
It is an object of the present invention to provide a time adjustment method that can perform an accurate time adjustment that matches a time signal with a relatively simple configuration.

It is still another object of the present invention to provide a time adjustment method capable of performing an optimal adjustment operation in accordance with the time required for adjusting the display time.

Means for Solving the Problems In order to achieve the above object, the present invention corrects the display time to the correction time specified by the notice sound in conjunction with detection of the notice sound constituting the time signal. In addition, when the hourly sound is detected, the corrected time is determined, and when the hourly sound is not detected, the corrected time is returned to the time before the correction.

If the display time reaches the correction time specified by the notice sound before the notice sound is detected, the advance of the display time is stopped until the notice sound is detected within a predetermined time of, for example, about 5 seconds. It is possible to

Further, it is possible to divide the display time into a plurality of sections in accordance with the magnitude of the correction time, and to execute a different correction method for each section. That is, when the correction time is a predetermined minute time shorter than one minute, the display time is corrected before displaying the hour by confirming the advance notice sound, and the corrected time is confirmed after confirming the hour sound. If the correction time is a short time that does not exceed several minutes, the display time is corrected after confirming the hour sound and determining the correction time. Further, if the correction time is a long time exceeding several minutes, the correction time is stored for the first time without correcting the display time, and after the same correction time is confirmed a plurality of times continuously, the display time is not changed. To be modified.

[Operation] With the above-described configuration, the time is adjusted at the stage when the notice sound is confirmed, and the time is displayed in accordance with the hour sound. Further, when the hourly sound is confirmed, the time at which the correction is made is determined. When the hourly sound is not confirmed, the time returns to the time before the correction and waits for the next time correction.

If the correction time comes after the carry of the display time,
By stopping the time display for a predetermined time, the display time is not returned, and the display is performed according to the lapse of time.

Further, when the correction time exceeds several minutes, by checking whether or not the same correction time is detected a plurality of times in succession, in addition to the abnormality of the time signal detection, the abnormality of the clock device itself is detected. Because

[Embodiment] The present invention will be described below based on an example in which the present invention is applied to a clock device provided in a passenger car. However, the present invention is not limited to this. Of course, it can be implemented similarly.

A timepiece device embodying the present invention automatically corrects the time based on a time signal emitted every hour on the first NHK broadcast, and a schematic configuration is shown in FIGS. 1 and 2. As described above, the electronic circuit including the tuner 2 and the control unit 3 is housed in a small case 1 and disposed in a place such as a dashboard that is easy for the driver to see, and a display unit 4 for displaying various times such as time. An operation unit 5 that enables manual operation is provided on the front surface 6 side of the case 1 so as to be exposed.

The tuner 2 selects and detects a medium-wave band AM broadcast from various radio waves input from the antenna 7 for the radio receiver 28 provided in the automobile through the distributor 29 and outputs a predetermined audio signal 8. The tuning frequency is electronically changed in accordance with the control voltage 9 sent from the control unit 3.

The control unit 3 is partially or entirely configured by a program using a so-called “one-chip microcomputer”, and includes a tuning circuit 10 for controlling a tuning operation of the tuner 2.
A timing circuit 11 for controlling various timing operations; a time signal processing circuit 12 for extracting only a time signal from the audio signal 8 output from the tuner 2 and performing predetermined processing; a RAM and a ROM for storing various data And a memory circuit 13 composed of

The tuning circuit 10 detects the detection signal output from the tuner 2
14 and a tuning signal 15 corresponding to the local oscillation frequency, while a control signal 9 is sent from the tuning circuit 10 to the tuner 2 to constitute a predetermined PLL circuit. Further, the memory circuit 13 includes a tuning frequency list 16 in which tuning frequencies are stored and an NHK frequency list 17 in which NHK broadcast frequencies are stored in advance.

The areas provided on the memory circuit 13 for storing the tuning frequency list 16 include I, II, and III as shown in FIG.
And the priorities are set in that order.
Further, for example, the frequencies of, for example, about 10 broadcasting stations can be stored in each of the storage areas (I, II, III) of each set, and the priority order from No. 1 to N in each set is set. , The frequency stored in the (1,1) address of the I group is set as the first priority, and the list 16 of the tuning frequencies sequentially decreasing in priority to the (3, N) number of the III group as indicated by the arrow can be constructed. Has become.

The timing circuit 11 is configured to be constantly connected to a power supply unit 21 composed of a battery provided in an automobile or a specially-provided dry battery or a secondary battery and to be continuously operated, and to operate the crystal oscillator 18 at an oscillation frequency. In addition to the function as an ordinary quartz timepiece serving as a reference, it also serves as a timer for regulating the operation timing in the channel selection circuit 10 described above. That is,
As shown in FIG. 3 (b), in a time storage area 19 set in advance on the memory circuit 13, six-hour display time data 20 of hour, minute, and second manually set via the operation unit 5 are stored for one second. Each time, the current time is specified by adding one at a time, and the data of "hour and minute", which is the upper four digits of the time data 20, is displayed on the display unit 4 by a predetermined display such as a liquid crystal display. It is displayed digitally. Further, when a preset time is reached, a signal is sent from the power supply unit 21 to the switching unit 22 that regulates the timing of power supply to the tuner 2,
Can automatically control the channel selection time.

The time signal processing circuit 12 converts the audio signal 8 output from the tuner 2 into a 440 Hz announcement sound 24 and an 880 Hz hour sound 25 which constitute an NHK time signal 23 as shown in FIG.
Is separated and extracted using a filter, and after determining whether the extracted signal is the time signal 23 or not, when it is confirmed that the signal 23 is the time signal 23, at a predetermined timing described later, the timer circuit 11 A time correction signal 26 is sent.

Next, the time correction operation in the timepiece device having the above-described configuration will be described with reference to the flowcharts shown in FIGS.

First, when a reset switch provided on the operation unit 5 is pressed (step 30), predetermined initial settings are made to the memory circuit 13 or various flags in the control unit 3 (step 31). At that time, the display time data 20 in the time storage area 19 on the memory circuit 13 is also reset to "00:00:00", so that the operation unit 5 is operated to roughly adjust to the current time (step 32).
Then, the process enters a reception frequency family setting process of step 40 described in detail with reference to FIG.

[Family setting process] By the way, as shown in Fig. 8 (a), there are currently 19 NHK first broadcasting stations nationwide that have a high power transmission output and can identify a broadcasting station at that frequency. In addition, a predetermined number of small and medium power stations are provided in a mountainous area or the like where radio waves of the large power station are difficult to reach. Taking the Kyushu area as an example, as shown in Fig. 9, large power stations are set up in Fukuoka, Kumamoto, and Kagoshima, indicated by double circles, so that the radio waves from the three broadcasting stations partially overlap each other. By setting, as shown by the dashed line, the entire Kyushu area is covered by three broadcasting stations, and geographically difficult to reach the radio waves of high power broadcasting stations, for example, each area such as Kitakyushu, Oita, Aso, etc. A broadcasting station with a small transmission power is provided for the supplement. On the other hand, it is a general pattern that a normal driver moves within the service area of the above-mentioned large power station except for a special case such as a long-distance truck driver.

Therefore, in this embodiment, all the NHK first broadcasting stations nationwide are listed, each broadcasting station is assigned an area number starting from No. 1, and the magnitude of the transmission power of each broadcasting station is specifically determined. It is represented by a number or a stage such as large, medium and small. Further, the 19 large power stations mentioned above are assigned area numbers of 1 to 19, and a family of reception frequencies centering on the large power stations is set in advance.
It is stored as a K frequency list 17. For example, FIG. 8 (b) illustrates a family centered on the Fukuoka broadcasting station whose area number is “16”, and FIG. 8 (c) illustrates a family centered on Kumamoto whose area number is “17”. Have been.

In the process starting from step 41 in FIG. 6, prior to time correction, it is estimated which clock the clock is currently located in, which of the above-mentioned families belongs to, and the frequency of the predetermined number of stations is stored in advance in the memory. Storage areas I to II on circuit 13
A channel selection frequency list 16 is stored in I, and, in principle, only the broadcast of the frequency in the stored list 16 is used for time correction.

That is, the tuner 2 is turned on in step 42, and the receiving sensitivity of the tuner 2 is set to the local side having low sensitivity (step 43), and it is tried whether or not the family can be determined in step 60, and step 44 If it is determined that the family cannot be determined in step 45, step 45
・ In step 46, increase the receiving sensitivity and try to determine the family in step 60 again. If the family cannot be determined even when the reception sensitivity is high, it is assumed that the clock is located in a place where radio waves are difficult to reach, such as in a garage.
After a predetermined warning is displayed on the display section 4 of the clock device front face 6 in step 4, the tuner 2 is turned off in step 48 and the processing is terminated.

Conversely, if it is determined in step 44 that the family has been determined normally, it is determined whether there is a family of the same or similar tuning frequency already stored in any of the storage areas I to III. (Step 49), and if not, the family is stored in the storage area with the lowest priority.
For example, when a family is set only in the I area, the family is set in the II area, and when a family is set in all three sets I to III, the selected channel is stored in place of the channel selection family stored in the III area ( After step 50), the tuner 2 is turned off (step 48), and the processing ends.

FIG. 7 is a flowchart for explaining in detail an example of a procedure for determining a family shown in step 60 of FIG. 6, and includes a NHK broadcast pick-up step 70, and a step 80 for selecting a family from a picked-up frequency group. Setting the priority between frequencies within the selected one family 90.

In the NHK broadcast pickup process 70, the tuning frequency in the tuning circuit 10 is set to 522 kHz, which is the lower limit frequency of the medium wave band, in step 71, and then the receiving frequency is increased by a predetermined amount in step 72, and in step 73 If it is determined that the upper limit frequency of the medium wave, for example, 1602 kHz, has not been reached, it is detected in step 74 whether or not a broadcast is received.If any broadcast is received, the frequency is changed in step 75. Compared with the NHK frequency list 17 stored in the memory circuit 13 described above, and when it is confirmed that the broadcast is the first NHK broadcast, it is sequentially stored in a predetermined memory (step 76). When the frequency reaches the upper limit frequency, the process proceeds to step 81. This step 81
Then, if it is confirmed that no NHK broadcast has been received, the operation ends as it is, but if the reception of NHK is confirmed,
A family selection step 80 is performed.

In this step 80, first, in step 82, it is determined whether the number of received stations is one station or a plurality of stations. If only one station is received, whether the station is a high power station shown in FIG. Is determined in step 83. Here, except for the large power station, since a plurality of broadcasting stations are set for the same frequency, it is not possible to judge which broadcasting station is the radio wave only from the frequency value, and thus the family ends without being determined. Conversely, in the case of a large power station,
Store the family number that is the area number (step 8
4) After that, the process enters a priority order determination step 90 described later.

If it is confirmed in step 82 that the number of received stations is 2 or more, all the area numbers to which each frequency belongs are listed in step 85, and if there is only one type of area, the area number is entered in step 86 After storing as the family number determined in step (1), the process enters the priority order determining step 90.

Conversely, if the number of areas listed is plural, the number of stations in each area is compared in step 87, and if the numbers are different, the area containing the largest number of stations is determined as the family (step 88). If the number of stations is the same, the power levels of the large power stations in each area are compared, and the area including stations with higher transmission power is determined as a family (step 89).

[Priority deciding step] This step 90 is for further deciding the priority order between each frequency in the family for one set of the reception frequency families determined as described above. The selected frequency is set as the first priority in the family, and when the number of stations is two or more, in step 92, the higher the transmission power of the corresponding broadcasting station, the higher the priority.

Here, when the number of actually received stations is 2, it is possible to end the processing as it is, but in the present embodiment, 1 is set.
It is assumed that the tuning frequency list for a set is composed of, for example, frequencies for ten stations, and in step 91, the frequencies for the remaining eight stations are mechanically determined. That is, in principle, the transmission power in the frequency group within the determined family is large, and the third to tenth priority frequencies are sequentially determined while making a correction such as not to be shifted to a specific area. And memorize it.

For example, as shown in FIG. 10, 540 (Kitakyushu NHK No. 1 broadcasting station), 720 (KBC broadcasting station), 1197 (RKB broadcasting station) and 160
When a broadcast is received at 2 (Kitakyushu NHK No. 2 Broadcasting Station) kHz, only 540 kHz corresponds to NHK No. 1 Broadcasting.
"40" is stored in step 76 of FIG. However, 540kHz is also used in Miyazaki and Ishigakijima besides Kitakyushu, so the family cannot be determined. Similarly, if only Oita can be received, the family cannot be determined. However, if "Kumamoto" of a large power station or "Aso" of a small power station belonging to only one family is received simultaneously, FIG. From c), the Kumamoto family which is the area number 17 of the family is specified. However, when only "Hita" is received in addition to "Oita", as shown in FIGS. 8 (b) and (c), the family cannot be specified because it belongs to the area numbers 16 and 17 at the same time. Therefore, the transmission power between the large power stations is compared, and the Fukuoka family with the area number of 16 is determined. At this time, since “Oita” has larger power than “Hita”, “Oita” has the first priority and “Hita” has the second priority.
Takes precedence. Furthermore, "Fukuoka", a large power station in the same family, is listed as a third priority.
Small and medium-sized power stations such as "Kitakyushu" continue.

Note that the method of picking up receivable NHK broadcast frequencies is not limited to detecting all receivable broadcast stations as described above, but only detecting frequencies stored in NHK frequency list 17 It is also possible.

When the family of the reception frequency is determined as described above and the frequency group of the tuning frequency list 16 is set on the memory, the process enters a wait loop of step 33 and waits for a correction period.

[Setting of Time Correction Period] That is, the first NHK broadcast is currently performed from 5:00 am to 24:00 as shown in FIG. 4A, and transmission of radio waves is basically stopped from 0:00 to 5:00. In addition, at midnight when broadcasting is stopped, the range of radio waves also increases, and foreign broadcasts of the same frequency as NHK No. 1 broadcast are received, such radio waves may be mistaken for NHK, and the wrong family may be set or the time may be adjusted. There is. Further, there is a possibility that a signal that is the same as or similar to the time signal may be generated during a normal broadcast, and the tuner 2 may be used in order to save power of the power supply unit 21.
Is preferably as short as possible.
Conversely, current clocks generally have an error of one second or less per day, and it is sufficient in principle to correct the time once a day.

Therefore, in this embodiment, at 1:00 am to 4:00 am in one day, the time adjustment process 100 starting from step 101 in FIG.
Does not enter. Further, even at other times, the period during which the tuner 2 is turned on is limited to a certain period before and after every hour, and when it is confirmed that the correction has been performed normally, the broadcast time zone is set. Does not perform the correction operation. For example, immediately after the control unit 3 is reset, there is a possibility that the coarsely set display time is significantly out of order, or that the coarse setting itself has not been performed. Therefore,
In the initial stage in which the time adjustment is not performed by the time signal once, the adjustment period is set to 30 minutes before and after the hour, and if the time is adjusted even once, the adjustment period is set to, for example, around the hour. It is configured to be limited to a short time of about 2 minutes.

Note that the correction period can be limited to about 5 seconds before and after the hour. Conversely, after the correction period is limited, if the time signal is no longer detected during that period, the correction period may be extended.

[Detection of Time Signal] When it is confirmed in step 33 that the time adjustment period has been entered, the operation for detecting the time signal 23 starting from step 101 is started.

First, in step 101, the tuner 2 is turned on with the receiving sensitivity set to the high DX side.
In step 2, as shown by the arrow in FIG. 3 (a), it is checked whether or not there is a reception level of the frequencies stored as the tuning frequency list 16 in the memory circuit 13 in descending order of priority. If the reception level is not detected at all stored frequencies, it is possible that the broadcast itself cannot be received due to entering a room such as a garage, or that the vehicle has moved to a different place than when the family was set, In any case, the time cannot be adjusted as it is, so
Return to the 40 family setting process.

Conversely, if a frequency that can be received by any one of the stations is confirmed in step 102, the process proceeds to step 103 to check whether the time signal 23 can be detected within a predetermined time. The time is adjusted according to the procedure described later in 104. Further, in step 105, it is determined whether or not the family of the reception frequency has already been set. If not, the process returns to step 40, and the setting of the family is tried again. On the other hand, if the frequency is set, the frequency at which the time signal 23 has been successfully received is set as the first priority in the same family, and the family including the frequency is moved to the I area in the three sets of storage areas to select a channel. After storing as the first priority family in the entire list 16, the tuner 2 is turned off in step 107, and the process returns to step 33 to wait for the next correction period.

On the other hand, if the time signal 23 cannot be detected in step 103, the process returns to step 40 unconditionally and attempts to reset the family only when the family has not been determined in step 108. In step 103, the detection of the time signal is executed in step 103, for example, 20
By repeating step 109 about a predetermined number of times, it is confirmed that the setting of the tuning frequency list 16 is inappropriate, and then the process returns to step 40 to reset the family.

[Time correction] By the way, the time signal 23 sent every hour on NHK broadcasting
As shown in FIG. 4 (c), after repeating the 440 Hz notice sound 24 lasting 0.1 second three times at 0.9 second intervals, the 880 Hz hour sound 25 is maintained for about 3 seconds, and the hour sound 25 is repeated. Is configured so that the point in time when it starts is the hour of “00:00:00”. Therefore, if it is set as “00:00:00” exactly one second after the third notice sound 24a is started,
The start of the hour sound 25 and the change of the display on the display unit 4 from “59 minutes to 00 minutes” completely match. However, it is not so rare that the sound of 440 Hz is included in the sound of the broadcast, and simply detecting the sound of 440 Hz causes a large malfunction. Further, it is required that the time signal sound and the time display be accurately linked when the time difference to be corrected is small.

Therefore, in the present embodiment, the correction period is set as shown in FIG.
As shown in the figure, A is divided into three stages of A for 30 seconds before the display time, B for 2 minutes before and after the display time, and C for 30 minutes before and after the display time, and the time adjustment operation is performed in an optimal manner for each stage. .

That is, the period A is often focused on the timing of time correction. Therefore, during this period, if the first and second notice sounds 24 of 440 Hz are sent at an accurate timing before the display time reaches the hour, the third notice sound 24
One second after the moment a is sent, the display time is set to "00:00"
To make the time signal match the time display, while holding the corrected time difference data 20a in the storage area 19a on the memory circuit 13. Conversely, "59 minutes 5
If the 3rd notice sound is not detected even after reaching "9 seconds", instead of keeping the display time at "59 seconds" for about 5 seconds and stopping and keeping the "59 minutes" time display, A time difference from that time to one second after the third notice sound 24a is detected is measured. "00:00:00" one second after the third announcement sound 24a is detected
At the same time, the count-up of the display time 20 is restarted, and the time difference data 20a at that time is saved, so that the time signal 23 and the time display are completely matched. Here, when it is confirmed that the hourly sound 25 is the time signal 23 for two seconds, for example, the display unit 4 displays a message 27 indicating "correction OK".
The operation of correcting the time ends after performing the operation, but if no confirmation is made, the stored time difference data 20 is used.
Using a, the display time 20 is returned to the time before correction.

On the other hand, when the time signal 23 is detected during the period B, the deviation from the display time 20 is relatively large, and it is presumed that much attention is paid to the coincidence with the hour sound 25. Therefore, during this period, when the hourly sound 25 lasts for 2 seconds and the time signal 23 is confirmed, the display time 20
Is set to “00:02”, and the display 27 of “correction OK” is displayed.

Further, when the time signal 23 is detected during the period C, the time difference from the display time 20 is too large, and it is estimated that some abnormality is occurring. Therefore, at the time of the first detection of the time signal 23, the display time data 20 is not corrected, and only the time difference data 20a is stored. When the same time difference is continuously detected again, the display time data 20 Modify 20. However, in such a case, the "hour" display is incorrect because the coarse time adjustment in step 32 is not performed, or the timekeeping function may be abnormal. Call attention to the displayed time.

If the above-mentioned time correction succeeds, for example, twice consecutively, the time correction is not performed until the start of broadcasting the next morning while the display 27 of "correction OK" is maintained, and the tuner 2 is turned on, for example, at 5:02. At the same time, the "OK" display 27 is turned off and the time adjustment operation is restarted.

In addition, the method of determining the family of the reception frequency is not limited to the above-described method.For example, a method of estimating the moving area from all the receiving stations including the commercial broadcast station and determining the family, or, the moving area is targeted. Rather than received
It is also possible to save all the NHK station frequencies into one family. In addition, the NHK frequency list 17 stored in the memory circuit 13 can be directly used for tuning,
The area number in the list 17 can be manually set to determine the family of the selected frequency.

Further, since the cause of the erroneous setting is large at night, the family setting operation may be forcibly stopped after 6:00 pm, for example.

Further, the method of determining the priority within the family may be set in order from the one with the highest actually detected reception level instead of the one with the large transmission output.

It is also possible to provide a function of receiving an emergency broadcast signal, perform a special display such as blinking the display time when the signal is received, or forcibly turn on the radio receiver 28.

Further, by detecting the on / off state of the engine key or the light switch, the operating state of the vehicle is estimated,
Alternatively, it is possible to reduce the consumption of the power supply unit 21 by forcibly restricting the operation period of the tuner 2 by estimating the period in which the vehicle is stopped indoors by separately providing a light detection unit such as CdS. it can.

Further, the train learns the operation pattern of the vehicle, and if it is found that, for example, once entering the garage, often stays for several consecutive days, if the corrective action cannot be performed several times continuously, then several days thereafter It is also possible to forcibly stop the tuning operation. At this time, the tuning operation may be automatically started several days later, but it is also effective to restart the tuning operation only after receiving, for example, an engine start signal. Also, after confirming that the engine has started,
For example, the tuning operation may be performed for a limited period of about one week.

Note that, in the above-described embodiment, the case where the time is adjusted by using the medium-wave band broadcast is exemplified.However, FM broadcast, television broadcast, or satellite broadcast, etc. It is a matter of course that the time signal can be used alone or in combination depending on the situation.

[Effects of the Invention] As described above, the present invention performs a predetermined time adjustment in conjunction with the detection of a notice sound, and then determines the corrected time after confirming the hour sound, thereby achieving a relatively simple configuration. In addition, the time is corrected while maintaining the time display accurately linked to the time signal, and with less malfunction.

Further, the display is not carried forward until the time is adjusted, and the advance of the display time is stopped for a predetermined time, so that the return of the display time is prevented as much as possible, and the display without discomfort is performed.

Also, by implementing a time adjustment method according to the required correction time, there are many advantages such as malfunctions being prevented as much as possible while maintaining the optimal time adjustment operation according to the situation. Having.

[Brief description of the drawings]

1 to 3 show a schematic configuration of a timepiece device embodying the present invention, FIG. 1 is a block diagram showing an example of a circuit configuration, FIG. 2 is a front view, FIG. FIG. 3B is an explanatory diagram showing the configuration of various data storage areas set on the memory circuit. FIGS. 4 (a) to 4 (c) are explanatory diagrams showing a time correction period. 5 to 7 are flowcharts showing the control procedure in the control unit. FIGS. 8 to 10 are explanatory diagrams for determining a tuning list. FIGS. 8 (a) to 8 (c) show an example of a list in which frequencies of NHK broadcasting are classified, and FIG. 9 shows a Kyushu area. Fig. 10 shows an example of the relationship between the reception frequency and the signal strength. 2 ... Tuner, 3 ... Control unit, 4 ... Display unit, 5 ... Operation unit, 10 ... Tuning circuit, 11 ... Time circuit, 12 ... Time signal processing circuit, 13 ... Memory circuit, 16: Tuned frequency list, 17: NHK frequency list, 23: Hourly signal, 24: Notice sound, 25: Hourly sound.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-48-36339 (JP, A) JP-A-50-36644 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) A01N 25/00 A01N 43/52 A01N 43/38 A01N 47/30 A01N 47/48 JICST file (JOIS)

Claims (3)

(57) [Claims] 1. A method for receiving a time signal transmitted in a wireless state and automatically correcting the display time of a clock using the time signal, wherein the time signal is provided at a predetermined constant interval until immediately before the hour. It consists of an announcement sound that repeats twice and an hour sound that starts outputting in response to the hour and lasts for a predetermined time, and is displayed at the correction time specified by the announcement sound in conjunction with the detection of the above-mentioned announcement sound. In addition to correcting the time, when the hourly sound is detected, the corrected time is determined, and when the hourly sound is not detected, the corrected time is returned to the time before the correction. Automatic time correction method. 2. If the display time reaches the correction time specified by the notice sound before the notice sound is detected, the advance of the display time is stopped until the notice sound is detected. Item 1. The automatic time correction method according to Item 1. 3. A method for receiving a time signal transmitted in a wireless state and automatically correcting a display time of a clock using the time signal, wherein the time signal is divided into a plurality according to the magnitude of the correction time for the display time. When the correction time is a predetermined minute time less than 1 minute, the display time is corrected before displaying the hour by confirming the notice sound, the corrected time is confirmed after the confirmation of the hour sound, the correction time is several In the case of a short time that does not exceed the minute, the correct time is confirmed after confirming the hour sound, and the display time is corrected. If the correction time is a long time exceeding several minutes, the display time is corrected first. Automatic time correction method, wherein only the correction time is stored without performing the correction, and the display time is corrected after the same correction time is confirmed a plurality of times in succession.