JP2010139369A - Radio controlled timepiece and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio controlled timepiece and a method for manufacturing the same in which the time required for correcting the time is shortened. <P>SOLUTION: The radio controlled timepiece 1 capable of correcting the timed time based on a time signal at least includes: a radio wave receiving system 11 for receiving radio waves containing the time signal; a microcomputer 14 for controlling a resonance frequency of the radio wave receiving system 11; and a storage part 15 for storing, as a reference value table 151 of control voltages to be output by the microcomputer 14, a relationship of the resonance frequency of the radio wave receiving system 11 in association with the control voltage output by the microcomputer 14. The microcomputer 14 outputs the control voltage in association with the resonance frequency to be received by the radio wave receiving system 11 by referring to the reference value table 151 stored in the storage part 15. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a radio-controlled timepiece that receives a radio signal including a standard time signal and corrects the time, and a manufacturing method thereof.

  For example, a standard time radio signal transmitted at a frequency of 60 kHz from a standard radio wave transmission station installed in Saga Prefecture, or a standard time radio signal transmitted at a frequency of 40 kHz from a standard radio wave transmission station installed in Fukushima Prefecture, A radio-controlled timepiece that corrects the time based on the standard time radio signal is known (for example, see Patent Document 1).

  However, since the standard radio wave transmission station described above is generally located at a location away from the city center and transmits a standard time radio wave signal with a relatively low transmission output of about 50 kW, for example, two standard radio wave transmission stations In a radio-controlled timepiece installed in an urban area away from the city, the reception time of the standard time radio signal is weak, so that the time may not be adjusted appropriately depending on the location.

Therefore, after receiving the standard time radio signal, or when the standard time radio signal cannot be received, it receives radio waves such as radio broadcasts that contain the time signal around every hour and corrects the time based on the time signal. There has been proposed an automatic correction timepiece for performing (see, for example, Patent Document 2).
JP 2002-267775 A JP 2006-38579 A

  Since the standard time radio signal is transmitted every minute, for example, the time can be adjusted in a relatively short time. On the other hand, time signals based on radio waves such as radio broadcasts are transmitted only every hour, so that time adjustment takes longer than when standard time radio signals are received and time adjustment is performed. There is a profit.

  An object of the present invention is to provide a radio-controlled timepiece that can shorten the time required for time correction and a method for manufacturing the same.

  The radio-controlled timepiece of the present invention is a radio-controlled timepiece that can correct the time measured based on a time signal, and at least a receiving unit that receives a radio signal including the time information and a resonance frequency of the receiving unit are controlled. A control unit that outputs a control voltage for the control unit, and a correspondence relationship between the resonance frequency of the receiving unit and the control voltage output by the control unit is stored as a reference value table of the control voltage to be output by the control unit The control unit refers to the reference value table stored in the storage unit, and outputs a control voltage corresponding to the resonance frequency to be received by the reception unit.

  Preferably, the storage unit stores, as an offset value from a reference value of the reference value table, a value at which the reception sensitivity of the receiving unit is maximized corresponding to the resonance frequency, and the control unit stores the storage With reference to the offset value corresponding to the resonance frequency to be received stored in the unit, the reception frequency is corrected so that the reception frequency becomes the offset value.

  Preferably, the radio-controlled timepiece has a display unit that displays the reception frequency of the reception unit, and the control unit corrects the reception frequency of the reception unit after outputting the control voltage. A start display for starting correction of the reception frequency is displayed on the display unit, and after the start display is displayed on the display unit, the offset value is displayed on the display unit.

  Preferably, the radio-controlled timepiece has a sound emitting unit that demodulates a radio signal including at least the time information received by the receiving unit and emits a sound according to the demodulated audio signal.

  Preferably, the radio-controlled timepiece has a transmission unit that transmits a reference radio signal of a reference frequency, and the control unit receives the reference radio signal transmitted from the transmission unit when the reception unit receives the reference radio signal. The measured resonance frequency having the highest reception sensitivity is stored in the storage unit as the offset value.

  Preferably, the radio-controlled timepiece includes a time correction unit that corrects the time measurement based on the first time information or the second time information, and the reception unit includes a first time information including the first time information. 1 radio wave signal and the second radio wave signal including the second time information can be received, and the time correction unit is configured to receive the first radio signal when the reception unit fails to receive the first radio signal. Based on the second time information when the reception unit has been successfully received, the time measurement time of the time measurement unit is corrected.

  The method of manufacturing a radio-controlled timepiece according to the present invention includes a step of transmitting a radio signal of a predetermined frequency, a step of varying a control voltage of a control unit that controls a resonance frequency of a receiving unit that receives the radio signal, and the receiving unit Storing the value having the highest reception sensitivity in the storage unit as a reference value table of the control voltage to be output by the control unit.

  Preferably, the method for manufacturing the radio-controlled timepiece includes a step of transmitting a reference radio signal of a reference frequency, and a resonance frequency having the highest reception sensitivity when the receiving unit receives the radio signal of the reference frequency. And storing it in the storage unit as an offset value.

  According to the present invention, the time required for time correction can be shortened.

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

[Configuration example of signal processing system of radio-controlled timepiece 1]
FIG. 1 is a schematic block diagram showing a configuration example of a signal processing system 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.

  1 includes a radio wave reception system 11, an audio output circuit 12, a speaker (SP) 13, a microcomputer 14, a storage unit 15, a display unit 16, an operation unit 17, an internal clock 18, an AM modulated wave. The generator 19 and the loop antenna 191 are included.

  The radio wave receiving system 11 corresponds to the receiving unit of the present invention. The microcomputer 14 corresponds to the control unit and the time correction unit of the present invention. The audio output circuit 12 and the speaker 13 correspond to the sound emitting unit of the present invention. The AM modulated wave generator 19 and the loop antenna 191 correspond to the transmission unit of the present invention.

  The radio-controlled timepiece 1 has a time correction function for correcting the time measured by the internal clock 18 and an AM broadcast reception function for listening to AM (Amplitude Modulation) broadcasts.

  In the time correction function, the radio-controlled timepiece 1 has a first time correction mode and a second time correction mode. The first time adjustment mode is included in the standard time radio wave (first radio signal including the first time information) operated by the National Institute of Information and Communications Technology (NICT). In this mode, the time is corrected based on the received time signal. The second time adjustment mode is included in NHK (Japan Broadcasting Corporation) first broadcast radio wave (radio signal including time information, second radio signal including second time information) which is one of AM broadcast radio waves. In this mode, the time is corrected based on the time signal.

  The radio-controlled timepiece 1 first tries to correct the time in the first time-correction mode. However, depending on where the radio-controlled timepiece 1 is installed, there may be cases where the standard time radio wave cannot be received. In this case, the radio-controlled timepiece 1 automatically switches the time adjustment mode from the first time adjustment mode to the second time adjustment mode, and performs time adjustment in the second time adjustment mode. The user can also manually switch the time adjustment mode to the first or second time adjustment mode.

  The frequency band of AM broadcast radio waves is 525 kHz to 1605 kHz, and the frequency of standard time radio waves is 40 kHz or 60 kHz. The frequency of the NHK first broadcast radio wave is 594 kHz in Tokyo and varies depending on the region. The NHK second broadcast radio wave may be used instead of the NHK first broadcast radio wave.

  Thus, since the radio-controlled timepiece 1 has an AM broadcast receiving function, the following effects can be obtained.

  First, AM radio broadcasting has a wide broadcast coverage area, and its transmission output is larger than the transmission output of standard time radio waves. Secondly, electronic devices such as home appliances are designed to satisfy the standards related to noise in a frequency band in which radio broadcasting is generally performed, and therefore have excellent reception sensitivity of AM radio broadcasting.

  For this reason, it becomes easy to receive the AM broadcast radio wave regardless of the installation location of the radio-controlled timepiece 1. Even when the reception of the standard time radio wave fails, the AM broadcast radio wave can be received to correct the time.

  By the way, when AM broadcast radio waves cannot be received, the time cannot be corrected. In order to avoid such a situation, it is necessary to check whether or not the AM broadcast radio wave can be received in advance and then install the radio wave correction watch 1 in a place where the AM broadcast radio wave can be received.

  Therefore, the radio-controlled timepiece 1 has an AM broadcast radio wave reception determination function that can easily determine whether or not AM broadcast radio waves can be received. When executing the AM broadcast reception determination function, the radio wave correction timepiece 1 causes the speaker 13 to output the AM broadcast. If the user installs the radio correction clock 1 at a place where the user can listen to the AM broadcast, the radio correction clock 1 can receive the AM broadcast radio wave.

  At this time, the radio-controlled timepiece 1 has a fine adjustment mode in order to facilitate the selection of AM broadcasting. The radio-controlled timepiece 1 is preset with a predetermined broadcast station frequency. When the fine adjustment mode is executed, the AM broadcast wave of the preset broadcast station can be quickly received by simply pressing the up switch 172 or the down switch 173. In this embodiment, the preset frequency of the broadcasting station is 594 kHz of the NHK first broadcast radio wave, but a desired frequency of the broadcasting station can be preset.

  The radio wave reception system 11 receives AM broadcast radio waves at a set reception frequency based on the control of the microcomputer 14. Then, the radio wave reception system 11 demodulates the AM broadcast radio wave and outputs it to the audio output circuit 12 as an audio signal. When the radio wave reception system 11 receives an AM broadcast radio wave and a standard time radio wave including a time signal, the radio wave reception system 11 performs a process to be described later and outputs the processed data to the microcomputer 14.

  The audio output circuit 12 adjusts the audio level or the like for the audio signal input from the radio wave reception system 11 based on the control of the microcomputer 14, and then outputs this to the speaker 13.

  The speaker (SP) 13 receives an audio signal from the audio output circuit 12 and emits a sound wave corresponding to the audio signal.

  The microcomputer 14 supervises the overall operation of the radio-controlled timepiece 1. That is, the microcomputer 14 performs reception control of the radio wave reception system 11, audio control of the audio output circuit 12, access to the storage unit 15, display control of the display unit 16, time correction of the internal clock 18, and the like.

  In particular, when performing time adjustment in the second time adjustment mode, the microcomputer 14 refers to the reference value table 151 stored in the storage unit 15 and determines the control voltage CTL corresponding to the frequency to be received as the control voltage. The data is output to the generation circuit 1104.

  At this time, in order to correct an error of the control voltage CTL caused by individual differences of analog circuits constituting the radio wave reception system 11, the microcomputer 14 refers to the offset value 152 and performs control corrected based on the offset value 152. The voltage CTL is output to the control voltage generation circuit 1104.

  In addition, the microcomputer 14 monitors the success or failure of the time adjustment in the first time adjustment mode, and if the microcomputer 14 detects a time adjustment failure in the first time adjustment mode, the microcomputer 14 sets the time adjustment mode to the second time adjustment mode. Switch to mode.

  In this embodiment, the storage unit 15 is configured by a flash memory. The storage unit 15 can also be composed of other nonvolatile storage devices or volatile storage devices. The storage unit 15 stores a reference value table 151 and an offset value 152. In addition, the storage unit 15 stores data related to preset broadcast station frequencies, various data such as programs necessary for processing performed by the microcomputer 14, alarm time, and melody. Details of the reference value table 151 and the offset value 152 will be described later.

  In the present embodiment, the display unit 16 is composed of an LCD (Liquid Crystal Display) panel. For example, the display unit 16 may be configured by an organic EL (Organic Electro Luminescence) display. The display unit 16 performs display according to the display control signal of the microcomputer 14.

  The operation unit 17 includes, for example, a reset switch 171, an up switch 172, a down switch 173, and a confirmation switch 174. These switches 171 to 174 employ push switches that are switched from off to on when the switches are pressed.

The reset switch 171 is turned on when various states of the microcomputer 14 are reset (returned) to the initial state. The reset switch 171 is turned on, for example, when the AM broadcast radio wave reception determining function is used.

  The up switch 172 and the down switch 173 are turned on, for example, when an alarm time is set or when the AM broadcast wave reception determination function is used. When the AM broadcast radio wave reception determination function is executed, the reception frequency can be increased by turning on the up switch 172. Conversely, the reception frequency can be lowered by turning on the down switch 173.

  The confirmation switch 174 is turned on to determine the alarm time or reception frequency set by operating the up switch 172 or the down switch 173.

  The internal clock 18 measures time based on an oscillation circuit (not shown). Specifically, the internal clock 18 includes, for example, a year information counter, a month information counter, a day information counter, a day information counter, an hour counter that counts hour information, a minute counter that counts minute information, and a second counter that counts second information. Have

  A loop antenna 191 is connected to the AM modulated wave generator 19. The AM modulated wave generator 19 functions as a jig used in the design process or adjustment process of the radio wave correction timepiece 1. Therefore, the AM modulated wave generator 19 operates alone and is electrically disconnected from the microcomputer 14 and the like. The AM modulation wave generator 19 transmits a carrier wave having a predetermined frequency in the design process or adjustment process of the radio wave correction timepiece 1.

[Detailed configuration example of the radio wave receiving system 11]
A detailed configuration example of the radio wave reception system 11 will be described.
FIG. 2 is a block diagram showing a specific example of the radio wave receiving system according to the embodiment of the present invention.
The radio wave reception system 11 illustrated in FIG. 2 includes a broadcast radio wave reception unit 111 and a standard radio wave reception unit 112.

[Broadcast radio wave receiver 111]
The broadcast radio wave receiving unit 111 will be described.
The broadcast radio wave reception unit 111 includes an antenna ANT1, a tuning circuit 1101, a frequency conversion circuit 1102, a local oscillation circuit 1103, a control voltage generation circuit 1104, an intermediate frequency amplification circuit 1105, a detection circuit 1106, a time signal detection circuit 1107, and a low-pass filter (LPF). 1108.

  The broadcast radio wave reception unit 111 receives an AM broadcast radio wave including a time signal with the antenna ANT1, and outputs a signal indicating the reception result to the microcomputer 14. For example, the time signal includes a time signal included at every hour on the hour.

  The antenna ANT1 is composed of, for example, a ferrite bar antenna. In the present embodiment, the antenna ANT1 is shared with the antenna ANT2 of the standard radio wave receiver 112. Thus, the standard time radio wave and the AM broadcast radio wave can be received using the common ferrite bar antenna.

  The tuning circuit 1101 is constituted by, for example, a capacitor or a coil. Tuning circuit 1101 tunes to a frequency set by signal S 1104 input from control voltage generation circuit 1104. Then, the tuning circuit 1101 outputs a signal S1101 having a set tuning frequency from the AM broadcast radio wave received by the antenna ANT1 to the frequency conversion circuit 1102.

  The frequency conversion circuit 1102 subjects the signal S1101 input from the tuning circuit 1101 to frequency conversion processing based on the signal S1103 input from the local oscillation circuit 1103. Then, the frequency conversion circuit 1102 outputs the signal subjected to the frequency conversion process to the intermediate frequency amplification circuit 1105 as an intermediate frequency signal S1102.

  The local oscillation circuit 1103 oscillates at a frequency corresponding to the signal S1104 input from the control voltage generation circuit 1104. Then, the local oscillation circuit 1103 outputs the transmitted frequency signal S1103 to the frequency conversion circuit 1102.

  In the present embodiment, the frequency conversion circuit 1102 mixes the signal S1101 and the signal S1103 to generate an intermediate frequency signal S1102 having a frequency of 455 Hz, and outputs this to the intermediate frequency amplification circuit 1105. The local oscillation circuit 1103 generates a signal S1103 having a frequency that generates the above-described intermediate frequency signal S1102 under the control of the microcomputer 14.

  The control voltage generation circuit 1104 has a function of controlling the frequency. The control voltage generation circuit 1104 generates a signal S1104 having a predetermined frequency based on the control voltage CTL output from the microcomputer 14 and outputs the signal S1104 to the local oscillation circuit 1103. In this way, the microcomputer 14 directly controls the control voltage generation circuit 1104, whereby the oscillation frequency of the local oscillation circuit 1103 is varied.

  The intermediate frequency amplifier circuit 1105 is configured by, for example, an automatic gain control circuit (AGC). The intermediate frequency amplification circuit 1105 amplifies the level of the signal S1102 input from the frequency conversion circuit 1102 so as to have a set level, and outputs the amplified signal as a signal S1105 to the detection circuit 1106.

  The intermediate frequency amplifier circuit 1105 outputs, for example, a carrier level detection signal S1105a serving as an index indicating the magnitude of the signal S1102 to the microcomputer 14. Specifically, the intermediate frequency amplification circuit 1105 generates the carrier level detection signal Sagc based on the AGC control voltage when the signal S1102 is amplified to have a set magnitude. That is, the carrier level detection signal Sagc indicates the degree of amplification by the automatic gain control circuit.

  The detection circuit 1106 detects the signal S1105 output from the intermediate frequency amplification circuit 1105, and outputs this as a signal S1106 to the time signal detection circuit 1107. At this time, the detection circuit 1106 performs detection by, for example, square detection, envelope detection, or the like.

  The time signal detection circuit 1107 detects a time signal based on the signal S1106 input from the detection circuit 1106. Then, the time signal detection circuit 1107 outputs a signal S1107 indicating the detection result to the low-pass filter 1108. The time signal detection circuit 1107 detects, for example, the rising edge (see FIG. 4) of the level of the time signal, sets the detection result to the signal S1107, and outputs this to the low-pass filter 1108.

  The low-pass filter 1108 removes the high frequency component of the signal S1107 input from the time signal detection circuit 1107, and outputs this to the microcomputer 14 as the signal S1108.

[Specific examples of time signals included in AM broadcast radio waves]
Here, the time signal included in the AM broadcast radio wave will be described.
FIG. 3 is a diagram illustrating an example of a time signal included in an AM broadcast radio wave received by the radio-controlled timepiece according to the embodiment of the present invention.

  The AM broadcast radio wave transmitted from the radio broadcast station includes a time signal d shown in FIG. 3 near every hour on the hour (00:00). Specifically, for example, a warning signal (pulse signal) p having a frequency of 440 Hz is AM-modulated at 57 seconds, 58 seconds, and 59 seconds.

  At every hour on the hour (00:00), a preset frequency, for example, an 880 Hz hour signal (attenuation signal) d is AM-modulated. For example, the rising times T57, T58, T59, and T00 of the pulse signal p and the attenuation signal d are synchronized in seconds. As shown in FIG. 3, the time signal (normal time signal) d includes a time signal d having a predetermined frequency (for example, 880 Hz) for a predetermined time Td (for example, about 1 to 3 seconds).

  By the way, the transmission format of the time signal d indicating the hour on the hour (00:00) is defined for each broadcasting station. Generally, the frequency of the time signal is 880 Hz, but depending on other broadcasting stations, a time signal having a frequency of 522.3 Hz or 1047 Hz is also transmitted. The warning signal (pre-signal) is also defined for each broadcasting station. Some broadcasting stations transmit only the time signal d shown in FIG. 3 without transmitting the warning signal.

  FIG. 4 is a diagram for explaining a time signal received by the radio-controlled timepiece according to the embodiment of the present invention. In FIG. 4, the horizontal axis represents time, and the vertical axis represents the signal level.

  (AM) The prescribed time Td of the time signal included in the broadcast radio wave is prescribed for each broadcasting station. The level of the time signal d rises at the hour (T00), for example, as shown in FIG. In the case of the time signal d1, the level of the time signal d is attenuated in about 1 second, in the case of the time signal d2, it is attenuated in about 2 seconds, and in the case of the time signal d3, it is about 3 seconds. Decreases with degree. That is, as shown in FIG. 4, the prescribed times Td1 to Td3 of the time signals d1 to d3 differ depending on the broadcasting station.

[Detailed configuration example of hourly signal detection circuit 1107]
A detailed configuration example of the time signal detection circuit 1107 will be described.
FIG. 5 is a block diagram showing a detailed configuration example of the time signal detection circuit according to the embodiment of the present invention.

  A time signal detection circuit 1107 illustrated in FIG. 5 includes a filter 11071 and a signal processing circuit 11072.

  The filter 11071 extracts a signal having a frequency corresponding to the time signal, for example, a signal of 594 kHz, from the signal S1106 output from the detection circuit 1106, and outputs this as a signal S11071 to the signal processing circuit 11072.

  The signal processing circuit 11072 receives the signal S11071, performs predetermined signal processing, and outputs a signal S1107 indicating the processing result to the microcomputer 14 via the low-pass filter 1108. Specifically, for example, the signal S11071 is received, the rising edge of the signal level is detected, and the detection result is output to the microcomputer 14 as the signal S1107.

[Standard radio wave receiver 112]
The standard radio wave receiver 112 illustrated in FIG. 2 will be described.
The standard radio wave receiver 112 includes an antenna ANT2, a standard radio wave receiver circuit 1121, and a low-pass filter 1122.

  The standard radio wave receiving unit 112 receives the standard time radio wave by the antenna ANT2, and outputs a signal indicating the reception result to the microcomputer 14. As described above, the antenna ANT2 is shared with the antenna ANT1.

  More specifically, the standard radio wave receiving circuit 1121 includes, for example, an RF amplifier, a detection circuit, a waveform shaping circuit, etc. (not shown). The standard radio wave receiving circuit 1121 receives standard time radio waves via the antenna ANT2 at the initial stage. The standard radio wave reception circuit 1121 performs amplification processing, detection processing, and the like on the received standard time radio wave, and outputs a standard time signal as a processing result to the low-pass filter 1122 as a signal S1121.

  The low-pass filter 1122 removes the high frequency component of the signal S1121 input from the standard radio wave receiving circuit 1121, and outputs this to the microcomputer 14 as the signal S1122.

  At the initial stage, the microcomputer 14 determines the time measured by the internal clock 18 based on a signal S1122 indicating a standard time radio signal (also referred to as a time code) input from the standard time radio signal reception circuit 1121 via the low-pass filter 1122. Correct it.

[Specific examples of standard time radio signals]
Here, a specific example of the standard time radio wave will be described.
FIG. 6 is a diagram for explaining standard time radio waves received by the standard radio wave receiving circuit according to the embodiment of the present invention.

  Japanese standard time radio waves are operated under the National Institute of Information and Communications Technology, and there are standard radio wave transmission stations that transmit standard time radio waves with a frequency of 40 kHz and standard radio wave transmission stations that transmit standard radio waves with a frequency of 60 kHz. It has been.

  The standard time radio signal is modulated such that the level of the pulse is switched at least every second of the standard time, for example. The standard time radio signal is modulated based on a signal defined according to any of minute information, hour information, date information, leap second information, or summer time information in the standard time.

  For example, the standard time radio wave received by the radio wave reception system 11 is sent in a form as shown in FIG.

  Specifically, the time code is composed of three types of signal patterns of 1, 0 and P. The time code is distinguished by a 100% amplitude period width in one signal pattern of 1 sec, and 1, 0 and P are 500 ms, 800 ms and 200 ms, respectively. The modulation method is amplitude modulation with a maximum value of 100% and a minimum value of 10%.

  When the reception state is good, as shown in FIG. 6B, the standard radio wave receiving unit 112 outputs a pulse signal corresponding to the standard time radio wave to the low-pass filter 1122 as a signal S1121.

  For example, the signal S1121 includes a high level corresponding to the first level and a low level corresponding to the second level. The microcomputer 14 performs reception state evaluation processing based on the high level, the low level, the falling edge ed1 from the high level to the low level, and the rising edge ed2 from the low level to the high level. When the edge ed1 and the edge ed2 are not distinguished, this is simply referred to as the edge ed.

Next, transmission data of standard time radio waves will be described.
FIGS. 7A and 7B are diagrams showing an example of the time code of the standard time radio signal. FIG. 7A shows a format other than 15 minutes and 45 minutes per hour. FIG. 7B shows a format of 15 minutes and 45 minutes per hour.

  The transmission information is the accumulated date from minutes, hours, and January 1st. The time data is transmitted at 1 bit / sec. One frame is one frame, and information on the accumulated date from the above-mentioned minute / hour / January 1 is provided as a BCD code in this frame.

  The transmitted data includes a marker called P code in addition to 0 · 1. There are several P codes in one frame, and appear at the minute (0 seconds), 9 seconds, 19 seconds, 29 seconds, 39 seconds, 49 seconds, and 59 seconds. This P code appears continuously only once at 59 seconds and 0 seconds in one frame, and the position where this P code appears continuously becomes the minute position. That is, the time data such as minute / hour data is determined in the frame with reference to the minute position, so that the time data cannot be extracted unless the minute position is detected.

[Overall configuration of radio-controlled watch 1]
An example of the overall configuration of the radio-controlled timepiece 1 will be described.
8A and 8B are diagrams showing an example of the appearance of the radio-controlled timepiece according to the embodiment of the present invention. FIG. 8A is a front view of the radio-controlled timepiece 1. FIG. 8B is a rear view of the radio-controlled timepiece 1.

  In the radio-controlled timepiece 1 illustrated in FIG. 8A, a display unit 16 and an operation unit 17 are provided on the front surface of the housing 100. Specifically, an up switch 172 and a down switch 173 are provided side by side in the center of the housing 100, and a confirmation switch 174 is provided below the up switch 172.

  As illustrated in FIG. 8B, a housing portion 113 and a plurality of hole portions 114 are provided on the back surface of the housing 100. Specifically, a plurality of holes 114 for emitting sound output from the speaker 13 (see FIG. 1) to the outside of the housing 100 are provided near the center of the housing 100. A housing portion 113 for housing an internal battery 115 for driving the internal timepiece 18 (see FIG. 1) and a reset switch 171 is provided at the bottom of the housing 100.

  The storage unit 113 is formed in a substantially rectangular shape when viewed from the back surface of the housing 100, and is formed in a concave shape with respect to the surface of the housing 100. The storage unit 113 is closed by a back cover (not shown) so that the user does not touch the internal battery 115 and the reset switch 171 carelessly.

[Configuration Example of Display Unit 16]
A configuration example of the display unit 16 will be described.
FIG. 9 is a diagram illustrating a specific example of the display unit illustrated in FIG. 8.

  An LCD panel 161 is attached to the display unit 16 shown in FIG. The LCD panel 161 is configured to be able to digitally display hours, minutes, seconds, month / day, day of week, alarm time, reception frequency, error code, and the like. These displays are controlled by display control signals output from the microcomputer 14.

  Specifically, the hour / minute display unit DPA1 digitally displays a reception frequency, an error code, and the like in addition to the hour information and the minute information. Since the display of the hour and minute and the reception frequency is required to be more visible than the display of other information, the hour and minute display unit DPA1 is assigned to occupy most of the display area of the LCD panel 161.

  The second display unit DPA2 displays second information and is assigned to the right of the hour / minute display unit DPA1. The month / day display unit DPA3 displays month information and day information, and is assigned to the lower part of the display area. The day of the week display unit DPA4 displays the day of the week. The alarm time display unit DPA5 displays the alarm time. The day-of-week display unit DPA4 and the alarm time display unit DPA5 are assigned to be aligned with the month / day display unit DPA3 at the bottom of the display area.

[Manufacturing process of radio-controlled watch 1]
As described above, when the time correction in the first time adjustment mode using the standard time radio wave cannot be performed, the radio time correction watch 1 corrects the time in the second time correction mode using the AM broadcast radio wave broadcasting. It is characterized by performing.

  When the first time correction mode using the standard time radio wave is used, it is known that the frequency of the time signal to be received is either 40 kHz or 60 kHz. It is easy to design or adjust the standard radio wave receiver 112 so that the reception sensitivity of the standard radio wave receiver 112 (see FIG. 2) is the best.

  On the other hand, when the second time adjustment mode using AM broadcast radio waves is used, the frequency of the time signal to be received varies from region to region, and due to individual differences in products, broadcast radio waves in the manufacturing process. It is difficult to design or adjust the broadcast wave receiving unit 111 so that the receiving sensitivity of the receiving unit 111 (see FIG. 2) is the best in any region.

  Therefore, the microcomputer 14 refers to the reference value table 151 stored in the storage unit 15 and the offset value 152 as appropriate, and outputs a suitable control voltage CTL to the control voltage generation circuit 1104 (see FIG. 2). Thus, the tuning frequency of the tuning circuit 1101 is controlled.

  Hereinafter, the manufacturing process of the radio-controlled timepiece 1 will be described with a focus on the portion necessary for executing the second time correction mode.

[Design process]
The manufacturing process of the radio-controlled timepiece 1 is divided into a design process for manufacturing the reference value table 151 and an adjustment process for manufacturing the offset value 152 and fine-tuning the reception frequency etc. before product shipment. . First, the design process will be described with reference to FIGS.

FIG. 10 is a flowchart showing an example of the design process according to the embodiment of the present invention.
11 and 12 are schematic block diagrams showing examples of circuit boards in the design process according to the embodiment of the present invention.

(Step ST11: Formation of circuit board A and installation of measuring equipment)
In step ST11 illustrated in FIG. 10, the circuit board A is formed and a measuring instrument is installed.

  In the design process, the reference value table 151 is manufactured. Since the reference value table 151 is commonly used for each product, a circuit board for design process is used separately from the circuit board used for the product. In addition, the frequency of the NHK first broadcast radio wave is preset.

  Specifically, as shown in FIG. 11, an antenna ANT1, a broadcast radio wave receiver 111, an audio output circuit 12, a speaker 13, and a microcomputer 14 are formed on a circuit board A for design process. Further, the AM modulation wave generator 19 connected to the loop antenna 191 is independently formed on the circuit board A.

  In order to measure the control voltage CTL output from the microcomputer 14 to the control voltage generation circuit 1104 of the broadcast radio wave receiver 111, the probe of the voltmeter 21 is connected to the signal line to which the microcomputer 14 and the audio output circuit 12 are connected. Connect to L1.

(Step ST12: Transmission of carrier wave using AM modulated wave generator 19)
As shown in FIG. 10, the AM modulation wave generator 19 is caused to transmit a carrier wave (radio wave signal) of 594 kHz, which is the frequency of the NHK first broadcast radio wave (Tokyo), for example. As a result, the broadcast radio wave receiver 111 receives the 594 kHz carrier wave transmitted by the AM modulated wave generator 19.

(Step ST13: Measurement of control voltage CTL)
Next, the microcomputer 14 varies the control voltage CTL that can be output to the control voltage generation circuit 1104 step by step, and sequentially measures the control voltage CTL displayed on the voltmeter 21.

  The microcomputer 14 can be controlled by PWM (Pulse Width Modulation). The range of the control voltage CTL that can be output by the microcomputer 14 is, for example, about 0.0 V to 6.0 V. The control voltage CTL that can be varied in one step is, for example, about 0.1V.

(Step ST14: Formation of circuit board B and installation of measuring equipment)
Next, as shown in FIG. 12, the antenna ANT1, the broadcast radio wave receiver 111, the audio output circuit 12, and the speaker 13 are formed on the circuit board B for the design process. Similarly to the circuit board A, the AM modulation wave generator 19 connected to the loop antenna 191 is also independently formed on the circuit board B.

  In order to measure the voltage waveform of the audio signal output from the audio output circuit 12 to the speaker 13, as shown in FIG. 12, the probe of the oscilloscope 22 is connected to the signal line to which the audio output circuit 12 and the speaker 13 are connected. Connect to L2.

  Further, the constant voltage source 23 is connected to the control voltage generation circuit 1104 in order to directly control the control voltage generation circuit 1104.

(Step ST15: Transmission of carrier wave using AM modulated wave generator 19)
Similarly to step ST12, the AM modulated wave generator 19 is caused to transmit a carrier wave of 594 kHz, which is the frequency of the NHK first broadcast radio wave (Tokyo), for example. The broadcast radio wave receiver 111 receives the 594 kHz carrier wave transmitted from the AM modulated wave generator 19.

(Step ST16: Measurement of the reception frequency with the best reception sensitivity)
The output voltage of the constant voltage source 23 is varied from, for example, about 0.0 V to 6.0 V, for example, in increments of 0.1 V, and the tuning circuit 1101 (see FIG. 2) is tuned. At this time, the oscilloscope 22 is used to observe the waveform of the audio signal output from the audio output circuit 12, and the reception frequency f with the best reception sensitivity is measured.

(Step ST17: Writing of the reference value table 151 to the storage unit 15)
From the measurement result in step ST13 and the measurement result in step ST16, the relationship between the control voltage CTL to be output to the control voltage generation circuit 1104 and the reception frequency f of the broadcast radio wave receiver 111 can be obtained. Then, this relationship is separately written in the storage unit 15 as a reference value table 151. Here, an example of the reference value table 151 will be described with reference to FIG.

FIG. 13 is a diagram showing an example of a reference value table according to the embodiment of the present invention.
The horizontal axis illustrated in FIG. 13 indicates the reception frequency f. The vertical axis represents the control voltage CTL. FIG. 13 also shows the measurement results when the AM modulated wave generator 19 transmits a carrier wave of another frequency.

  As shown in FIG. 13, the reception frequency f and the control voltage CTL are in a substantially proportional relationship. That is, the higher the frequency to be received, the higher the control voltage CTL to be output to the control voltage generation circuit 1104.

  Through the above steps ST11 to ST17, the frequency 594 kHz is preset. In the case of receiving an AM broadcast radio wave having a frequency of 594 kHz exemplified in this example, the control voltage CTL to be output to the control voltage generation circuit 1104 may be set to about 3.3V.

  Specifically, when the radio-controlled timepiece 1 receives AM broadcast radio waves having a preset frequency of 594 kHz, the microcomputer 14 refers to the reference value table 151 and controls about 3.3 V corresponding to this frequency. The voltage CTL is output to the control voltage generation circuit 1104.

  As a result, the sharpness of the tuning circuit 1101 increases, and the broadcast radio wave receiver 111 can obtain the highest reception sensitivity. As described above, the microcomputer 14 only needs to output the control voltage CTL corresponding to the reception frequency to the control voltage generation circuit 1104 with reference to the reference value table 151, so that a PLL (Phase-locked loop) circuit or a variable capacitor can be used. It is possible to easily select a channel without using the above. Furthermore, stable reception is possible.

[Adjustment process]
Next, the adjustment process will be described. As described above, the microcomputer 14 can easily select a channel by referring to the reference value table 151 and outputting the control voltage CTL corresponding to the frequency to be received to the control voltage generation circuit 1104.

  However, actually, the broadcast radio wave receiving unit 111 has many parts constituted by analog circuits, and there are individual differences of products. For this reason, even if the reception area of the AM broadcast radio wave is the same, the maximum reception sensitivity may not be obtained.

  Therefore, a deviation value from the reference value table 151 of the control voltage CTL corresponding to the frequency to be received is obtained, and this is set as an offset value. The control voltage CTL can be corrected by setting the control voltage CTL to this offset value.

  However, the value of this deviation is caused by individual differences in the analog circuit, and is substantially constant for all frequencies in the same product. For this reason, it is not necessary to obtain a deviation value for every reception frequency, and it is sufficient that the broadcast radio wave reception unit 111 obtains a deviation value from the reception frequency when a carrier wave having a reference frequency is received.

Hereinafter, the adjustment process will be described with reference to FIGS. 14 and 15.
FIG. 14 is a schematic block diagram showing an example of a circuit board in the adjustment process according to the embodiment of the present invention.
FIG. 15 is a flowchart illustrating an example of the adjustment process according to the embodiment of the present invention.

(Step ST21: Switch to inspection mode)
As illustrated in FIG. 14, the radio-controlled timepiece 1A in a semi-finished state as a product is configured in the same manner as the radio-controlled timepiece 1 illustrated in FIG. 1, but only the reference value table 151 is stored in the storage unit 15. It is remembered.
First, the probe of the oscilloscope 22 is connected to the signal line L2.

  Next, the inspection mode for correcting the deviation of the values in the reference value table 151 is switched on. The inspection mode is switched by, for example, a selector switch (not shown) on the circuit board 1A.

(Step ST22: Output of control voltage CTL by microcomputer 14)
For example, the microcomputer 14 outputs a 1 MHz PWM to the control voltage generation circuit 1104.

(Step ST23: Transmission of carrier wave of reference frequency)
For example, a 1 MHz carrier wave (reference radio signal) serving as a reference frequency is transmitted to the AM modulation wave generator 19. The broadcast radio wave receiver 111 receives the 1 MHz carrier wave transmitted by the AM modulated wave generator 19. The reference frequency can be suitably set, for example, 594 kHz.

(Step ST24: Adjustment of reception frequency)
The microcomputer 14 refers to the reference value table 151 stored in the storage unit 15 and outputs a control voltage CTL corresponding to a frequency of 1 MHz to the control voltage generation circuit 1104.

  At this time, the up switch 172 or the down switch 173 of the operation unit 17 is pressed to adjust the reception frequency of the broadcast radio wave reception unit 111.

(Step ST25: Measurement of the reception frequency with the best reception sensitivity)
While adjusting the reception frequency of the broadcast radio wave reception unit 111, the oscilloscope 22 is used to observe the waveform of the audio signal output from the audio output circuit 12, and the reception frequency f with the highest reception sensitivity is measured.

(Step ST26: Determination of offset value)
When the reception frequency f with the best reception sensitivity is measured in step ST25, the confirmation switch 174 is pressed. As a result, a deviation value of the control voltage CTL from the reception frequency corresponding to 1 MHz in the reference value table 151, that is, an offset value is determined.

  FIG. 16 is a diagram illustrating an example of the offset value according to the embodiment of the present invention. The horizontal axis shown in FIG. 16 indicates the reception frequency f. The vertical axis represents the control voltage CTL.

The offset value determined in step ST26 is substantially the same value for other reception frequencies. Thereby, the relationship between the corrected reception frequency f and the control voltage CTL is corrected as shown in FIG.
The offset value is stored in the storage unit 15 as the offset value 152 (see FIG. 1) under the control of the microcomputer 14.

  In the future, when performing time correction using the second time correction mode, the microcomputer 14 refers to the reference value table 151 stored in the storage unit 15 and controls the control voltage CTL corresponding to the frequency to be received. Is read.

  Next, the microcomputer 14 refers to the offset value 152 stored in the storage unit 15 and sets the control voltage CTL to the offset value 152. Then, the microcomputer 14 outputs the control voltage CTL corrected based on the offset value 152 to the control voltage generation circuit 1104. Thereby, the value of deviation due to individual differences between products is corrected, and the reception sensitivity of the broadcast radio wave receiver 111 can be improved.

[Example of operation of radio wave correction watch 1]
An operation example of the radio-controlled timepiece 1 centering on the time correction function will be described.
FIG. 17 is a flowchart showing an operation example of the radio-controlled timepiece according to the embodiment of the present invention.

  It is assumed that the time has arrived on time and a standard time radio wave has been transmitted. As shown in FIG. 17, when the standard radio wave reception circuit 1121 of the radio wave reception system 11 receives a time signal included in the standard time radio wave, the radio wave correction watch 1 corrects the time in the first time correction mode ( Step ST31).

  The microcomputer 14 monitors the success or failure of the time adjustment in the first time adjustment mode. When the microcomputer 14 detects the success of the time adjustment in the first time adjustment mode (YES in step ST32), the time adjustment in the first time adjustment mode ends.

  On the other hand, when the microcomputer 14 detects a time adjustment failure in the first time adjustment mode (NO in step ST32), the radio-controlled timepiece 1 changes the time adjustment mode from the first time adjustment mode to the second time adjustment mode. Is switched to the time correction mode, and the time is corrected in the second time correction mode (step ST33).

  At this time, the microcomputer 14 reads the control voltage CTL corresponding to the frequency to be received with reference to the reference value table 151 stored in the storage unit 15.

  Next, the microcomputer 14 refers to the offset value 152 stored in the storage unit 15 and sets the control voltage CTL to the offset value 152. Then, the microcomputer 14 outputs the control voltage CTL corrected based on the offset value 152 to the control voltage generation circuit 1104. Thereby, the time adjustment in the second time adjustment mode is completed.

[AM broadcast radio wave reception discrimination function]
As described above, when the AM broadcast cannot be received, the time adjustment itself cannot be performed. For this reason, it is necessary to install the radio-controlled timepiece 1 after confirming whether or not AM broadcasting can be received in advance. Hereinafter, an AM broadcast radio wave reception determination function for determining whether or not AM broadcast radio waves can be received will be described.

  FIG. 18 is a flowchart for explaining an AM broadcast reception determination function according to the embodiment of the present invention.

  The user removes a back cover (not shown) installed on the back surface (see FIG. 8) of the housing 100, and presses the reset switch 171 inside the hole 114 (step ST41).

  The microcomputer 14 reads the control voltage CTL corresponding to the frequency to be received by referring to the reference value table 151 stored in the storage unit 15.

  Next, the microcomputer 14 refers to the offset value 152 stored in the storage unit 15 and sets the control voltage CTL to the offset value 152. Then, the microcomputer 14 outputs the control voltage CTL corrected based on the offset value 152 to the control voltage generation circuit 1104.

  At this stage, the frequency of the preset broadcast station (for example, NHK first broadcast radio wave (Tokyo)) is set to the frequency to be received. Thereby, the preset reception frequency of the broadcasting station is displayed on the display unit 16.

  Next, the user preferably presses the up switch 172 or the down switch 173 to set the reception frequency of the AM broadcast radio wave in the area where the radio correction clock 1 is installed (step ST42).

  After setting the AM broadcast radio wave reception frequency, the user presses the confirmation switch 174 (step ST43). By this operation, the fine adjustment mode is executed. At this time, “0” indicating that the fine adjustment mode has been executed is displayed on the display unit 16, and the AM broadcast of the reception frequency is output from the speaker 13.

  The user preferably presses up switch 172 or down switch 173 and finely adjusts the reception frequency so that the sound output from speaker 13 can be clearly heard (step ST44). At this time, the display unit 16 displays an offset value such as “+10 kHz” or “−10 kHz”, for example.

  If the user can listen to the AM broadcast clearly (YES in step ST45), it means that the current installation location of the radio-controlled timepiece 1 is good. Therefore, the radio-controlled timepiece 1 can perform time correction using AM broadcast radio waves at the current installation location (step ST46).

  On the other hand, if the user cannot hear the AM broadcast clearly (NO in step ST45), the installation location of the radio-controlled timepiece 1 is changed (step ST47), and until the AM broadcast can be heard clearly, steps ST41 to ST41 are performed. Repeat ST45.

  As described above, according to the present embodiment, the time required for time correction can be shortened. The microcomputer 14 refers to the reference value table 151 and outputs the control voltage CTL corresponding to the reception frequency to the control voltage generation circuit 1104. Therefore, easy tuning and stable reception are possible.

  The processing performed by the microcomputer 14 is processed by software, but part or all of the processing can be performed by hardware. In the present embodiment, a digital method using the LCD panel 161 is used for displaying the time and reception frequency, but an analog method using a pointer can also be used for displaying the time. However, the display of the reception frequency is preferably a digital method.

  The radio wave receiving system 11 may be configured to receive FM broadcasting. The AM radio broadcasting station received by the radio wave receiving system 11 is not limited to the above-described form.

  The radio-controlled timepiece according to the present invention can be mounted on various electronic devices such as a surveillance camera, a consumer camcorder, and a personal computer.

FIG. 1 is a schematic block diagram showing a configuration example of a signal processing system of a radio-controlled timepiece according to an embodiment of the present invention. FIG. 2 is a block diagram showing a specific example of the radio wave receiving system according to the embodiment of the present invention. FIG. 3 is a diagram illustrating an example of a time signal included in an AM broadcast radio wave received by the radio-controlled timepiece according to the embodiment of the invention. FIG. 4 is a diagram for explaining a time signal received by the radio-controlled timepiece according to the embodiment of the present invention. FIG. 5 is a block diagram showing a detailed configuration example of the time signal detection circuit according to the embodiment of the present invention. FIG. 6 is a diagram for explaining standard time radio waves received by the standard radio wave receiving circuit according to the embodiment of the present invention. FIGS. 7A and 7B are diagrams showing an example of the time code of the standard time radio signal. 8A and 8B are diagrams showing an example of the appearance of the radio-controlled timepiece according to the embodiment of the present invention. FIG. 9 is a diagram illustrating a specific example of the display unit illustrated in FIG. 8. FIG. 10 is a flowchart showing an example of the design process according to the embodiment of the present invention. FIG. 11 is a schematic block diagram showing an example of a circuit board in the design process according to the embodiment of the present invention. FIG. 12 is a schematic block diagram showing an example of a circuit board in the design process according to the embodiment of the present invention. FIG. 13 is a diagram showing an example of a reference value table according to the embodiment of the present invention. FIG. 14 is a schematic block diagram showing an example of a circuit board in the adjustment process according to the embodiment of the present invention. FIG. 15 is a flowchart illustrating an example of the adjustment process according to the embodiment of the present invention. FIG. 16 is a diagram illustrating an example of the offset value according to the embodiment of the present invention. FIG. 17 is a flowchart showing an operation example of the radio-controlled timepiece according to the embodiment of the present invention. FIG. 18 is a flowchart for explaining an AM broadcast reception determination function according to the embodiment of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Radio correction clock, ANT1, ANT2 ... Antenna, 11 ... Radio wave receiving system, 12 ... Audio output circuit, 13 ... Speaker, 14 ... Microcomputer, 15 ... Memory | storage part, 16 ... Display part, 17 ... Operation part, 18 ... Internal clock, 19 ... AM modulated wave generator, 100 ... casing, 111 ... broadcast radio wave receiving unit, 112 ... standard radio wave receiving unit, 113 ... storage unit, 114 ... hole, 115 ... internal battery, 151 ... reference value table , 152 ... Offset value, 161 ... LCD panel, 171 ... Reset switch, 172 ... Up switch, 173 ... Down switch, 174 ... Confirm switch, 191 ... Loop antenna, 1101 ... Tuning circuit, 1102 ... Frequency conversion circuit, 1103 ... Local Oscillator circuit, 1104... Control voltage generation circuit, 1105... Intermediate frequency amplifier circuit, 1106. Hourly detection circuit, 1108,1122 ... low-pass filter, 1121 ... standard radio wave receiving circuit, 11071 ... filter, 11072 ... signal processing circuit

Claims (8)

A radio-controlled timepiece that can correct the time based on time information,
At least a receiving unit that receives a radio signal including the time information;
A control unit that outputs a control voltage for controlling the resonance frequency of the receiving unit;
A storage unit that stores a correspondence relationship between the resonance frequency of the reception unit and the control voltage output by the control unit as a reference value table of a control voltage to be output by the control unit;
The control unit
A radio-controlled timepiece that outputs a control voltage corresponding to a resonance frequency to be received by the receiving unit with reference to the reference value table stored in the storage unit. The storage unit
Store the value at which the receiving sensitivity of the receiving unit is maximized corresponding to the resonance frequency as an offset value from the reference value of the reference value table,
The control unit
The radio wave correction timepiece according to claim 1, wherein the reception frequency is corrected so that the reception frequency becomes the offset value with reference to the offset value corresponding to the resonance frequency to be received stored in the storage unit. A display unit for displaying the reception frequency of the reception unit;
The control unit
When correcting the reception frequency of the reception unit after the output of the control voltage, a start display to start correction of the reception frequency is displayed on the display unit, and after the start display of the display unit is displayed. The radio-controlled timepiece according to claim 2, wherein the offset value is displayed on the display unit. The radio-controlled timepiece according to any one of claims 1 to 3, further comprising: a sound emitting unit that demodulates a radio signal including at least the time information received by the receiving unit and emits a sound according to the demodulated audio signal. . Having a transmitter that transmits a reference radio signal of a reference frequency;
The control unit
5. When the receiving unit receives the reference radio wave signal transmitted by the transmitting unit, the measured resonance frequency with the highest reception sensitivity is stored in the storage unit as the offset value. 5. The radio-controlled watch described in Kaichi. A time correction unit that corrects the time measurement based on the first time information or the second time information;
The receiver is
A first radio signal including the first time information and a second radio signal including the second time information can be received;
The time correction part
The time counting time is corrected based on the second time information when the receiving unit succeeds in reception when the receiving unit fails to receive the first radio wave signal. Radio wave correction clock of mention. A method of manufacturing a radio-controlled timepiece that can correct the time based on time information,
Transmitting a radio signal of a predetermined frequency;
Varying the control voltage of the control unit that controls the resonance frequency of the receiving unit that receives the radio signal;
Storing a value having the highest reception sensitivity of the receiving unit in a storage unit as a reference value table of a control voltage to be output by the control unit. Transmitting a reference radio signal of a reference frequency;
The method of manufacturing a radio-controlled timepiece according to claim 7, further comprising: storing the resonance frequency having the highest reception sensitivity in the storage unit as an offset value when the reception unit receives the radio signal of the reference frequency.

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