JP2009121863A - Radio-controlled clock and reception method of radio-controlled clock - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio-controlled clock capable of avoiding deterioration of a reception state caused by a position relation between a hand and an antenna, receiving stably a communication signal including time information, and displaying an accurate time. <P>SOLUTION: This radio-controlled clock 1 is equipped with: an antenna part 12 into which the communication signal including time information is inputted; a reception processing part 30 for acquiring the time information from the inputted communication signal; a matching part 10 for connecting the antenna part 12 to the reception processing part 30, correcting an impedance difference between the antenna part 12 and the reception processing part 30, and thereby matching the antenna part 12 with the reception processing part 30; a movement 80 for displaying a time based on the acquired time information by circulation of a plurality of hands having conductivity; a hand position detection part 70 for detecting a relative position between at least one of the plurality of hands and the antenna part 12; and an inductor instruction part 65 for instructing to the matching part 10, correction of a difference generated by an impedance of the antenna part 12 fluctuating corresponding to the detected relative position. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a radio timepiece that receives and displays a communication signal including time information and a radio clock receiving method.

  A radio timepiece that receives a time signal transmitted by radio waves and displays accurate time information is a standard radio wave of a long wave band transmitted from a ground base station or a very high frequency wave transmitted from a GPS (Global Positioning System) satellite. In addition to a method for receiving a time signal in a band, in recent years, as described in Patent Document 1 below, for the purpose of mobile communication, radio waves in the ultra-high frequency band transmitted by CDMA (Code Division Multiple Access) modulation are transmitted. A radio timepiece that receives a time signal included in the signal, corrects the time measured by itself, and displays an accurate time has been proposed. Such ultra-short-wave radio waves are widely relayed from various relay stations, so compared to long-wave standard radio waves and radio waves from GPS satellites, in various destinations such as in buildings and underground Is known to be able to receive well. When such a radio-controlled timepiece is applied to an analog radio-controlled timepiece, the antenna for receiving radio waves in the ultra-high frequency band is a dial that eliminates the effects of radio-wave shielding by the exterior case of the analog radio-controlled timepiece. It is arranged on the back side. In such an analog radio-controlled timepiece, the reception state is deteriorated due to the positional relationship between the timepiece hand and the antenna. Therefore, as shown in Patent Document 2, the reception operation is interrupted when the hand comes over the antenna. Analog radio clocks have been proposed.

JP 2000-321383 A JP 2001-166071 A

  However, in the above-described analog radio-controlled timepiece, the reception operation is interrupted depending on the positional relationship between the hands and the antenna. Therefore, reception of radio waves including time information is limited by the time. Therefore, there is a problem that the reception operation is continuously interrupted and the state where the accurate time is not displayed continues.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1]
The radio timepiece according to this application example includes an antenna unit to which a communication signal including time information is input, a reception processing unit that acquires the time information from the input communication signal, and the antenna unit and the reception processing unit. By correcting the difference in impedance, a matching unit that matches and connects the antenna unit and the reception processing unit, and a plurality of conductive hands circulate, thereby displaying a time based on the acquired time information. A display unit that detects, a detection unit that detects a relative position between at least one of the plurality of hands and the antenna unit, and the antenna unit that is generated when impedance of the antenna unit varies according to the detected relative position; An instruction unit that instructs the matching unit to correct the impedance difference of the reception processing unit.

  According to such a configuration, the relative position between the circulating pointer and the antenna unit is detected, and the difference in impedance between the antenna unit and the reception processing unit caused by the impedance of the antenna unit that varies according to the detected relative position is corrected. Since the antenna unit and the reception processing unit are matched, the reception sensitivity of the communication signal is maintained in a stable state. Therefore, since the communication signal input to the antenna unit can be stably received, the time information can be acquired from the communication signal as necessary, and the accurate time can be displayed.

[Application Example 2]
In the radio timepiece according to the application example, the instruction unit may adjust the impedance of the antenna unit to the impedance of the reception processing unit by changing an induction coefficient of the matching unit.

[Application Example 3]
In the radio timepiece according to the application example, the detection unit may detect a relative position with respect to the antenna unit by detecting a position of the circulating pointer.

[Application Example 4]
In the radio-controlled timepiece according to the application example described above, a disk image drawn by turning at least one of the hands may overlap with at least a part of the antenna unit when viewed from the direction in which the display unit is viewed. .

[Application Example 5]
In the radio timepiece according to the application example, the communication signal may be transmitted from a base station by a CDMA communication method.

[Application Example 6]
In the radio timepiece according to the application example, the reception processing unit receives the communication signal, and mixes the received communication signal and the local oscillation signal to obtain an intermediate frequency signal; and A pilot channel signal is acquired from the acquired intermediate frequency signal, and a sync channel signal is acquired from the intermediate frequency signal by synchronizing with the base station with the acquired pilot channel signal, and the acquired sync channel signal A baseband processing unit that extracts time information.

[Application Example 7]
The radio timepiece receiving method according to this application example receives a communication signal including time information at an antenna unit, acquires the time information from the received communication signal at a reception processing unit connected to the antenna unit, and Based on the acquired time information, a method for receiving a radio-controlled timepiece that displays time by rotating a plurality of conductive hands, detecting a relative position between at least one of the plurality of hands and the antenna unit, The impedance of the antenna unit and the reception processing unit is matched by correcting the difference in impedance between the antenna unit and the reception processing unit caused by the impedance of the antenna unit that varies according to the detected relative position. Features.

  According to such a method, the relative position between the circulating pointer and the antenna unit is detected, and the difference in impedance between the antenna unit and the reception processing unit caused by the impedance of the antenna unit that varies according to the detected relative position is corrected. Since the antenna unit and the reception processing unit are matched, the reception sensitivity of the communication signal is maintained in a stable state. Therefore, since the communication signal input to the antenna unit can be stably received, the time information can be acquired from the communication signal as necessary, and the accurate time can be displayed.

  The radio timepiece will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1 is a block diagram showing a functional configuration of a radio timepiece 1 according to the first embodiment of the present invention. As shown in the external view of the radio timepiece 1 in FIG. 2, this radio timepiece 1 is a so-called analog quartz wristwatch, which calculates the time based on the frequency of the crystal resonator and uses the pointer to determine the current time. In addition to the function of displaying, it has a function of receiving radio waves including accurate time information and correcting the displayed time. The radio timepiece 1 includes a matching unit 10, a reception processing unit 30, a control unit 60, a pointer position detection unit 70, and a movement 80.

The matching unit 10 corrects the impedance difference between the antenna unit 12 and the reception processing unit 30 to match and connect the antenna unit 12 and the reception processing unit 30. In the first embodiment, the antenna unit 12 includes a chip antenna 14 (FIG. 2) using a dielectric. In addition, the matching unit 10 includes an inductor variable unit 20 that changes an induction coefficient (inductor) that appears as an induced electromotive force in a winding or the like, and changes the output impedance of the antenna unit 12. The inductor variable unit 20 is configured by connecting coils (22A to 22D) in series. Each of these coils (22A to 22D) has a predetermined inductor, and each of the coils 22B, 22C, and 22D includes switches 24, 26, and 28 that can be short-circuited. These switches 24, 26, and 28 are intermittent in response to an instruction from the inductor instruction unit 65, and the output impedance of the antenna unit 12 is changed by changing the inductor of the inductor variable unit 20 in accordance with the intermittent switch. Is changed.
In the first embodiment, when any of the pointers of the movement 80 is located away from the antenna unit 12 (initial state), the switches 24, 26, and 28 are all disconnected. In this case, since the matching unit 10 has an impedance corresponding to the sum of the inductors of the coils (22A to 22D), the output impedance of the antenna unit 12 and the input impedance to the reception processing unit 30 become equal, and the matching state is maintained. It is configured to lean. Note that the matching method by changing the impedance in the matching unit 10 is not limited to changing the inductor, and a method of matching by changing the capacitance (capacitor) can also be adopted.

The reception processing unit 30 receives a radio signal including time information, and acquires time information from the received radio signal. The reception processing unit 30 includes an RF processing unit 40 and a baseband processing unit 50. The RF processing unit 40 has a function of acquiring an IF signal by mixing a communication signal included in the received radio wave and a local oscillation signal, and includes a low noise amplifier 42, a frequency conversion unit 44, and a local oscillation signal generation unit. 45, an IF band-pass filter 46, and an IF amplifier 48.
The communication signal input to the RF processing unit 40 is amplified by the low noise amplifier 42, sent to the frequency conversion unit 44, and mixed with the local oscillation signal generated by the local oscillation signal generation unit 45. As a result, the time signal included in the communication signal is converted into an IF signal whose frequency is the difference from the frequency of the local oscillation signal (local oscillation frequency). Further, the IF signal is filtered by the IF bandpass filter 46, amplified by the IF amplifier 48, and then output to the baseband processing unit 50.

The baseband processing unit 50 has a function of converting the IF signal output from the RF processing unit 40 into a digital signal and demodulating the digital signal to extract time information, and a baseband demodulation unit 52; A time information extraction unit 54.
The baseband demodulator 52 performs A / D conversion of the IF signal into a digital signal, and then performs CDMA demodulation processing on two digital signals (I signal and Q signal) that are orthogonal in phase to obtain time information. Decrypt data that contains. The time information extraction unit 54 obtains a pilot channel signal from the decoded data and synchronizes with the base station, and then demodulates and demodulates a sync channel signal used to notify time information, system setting information, and the like. The time information is extracted from the sync channel signal. Information regarding the extracted time is sent to the movement 80.
The details of the process of receiving the communication signal including the time information transmitted by the CDMA method and acquiring the time information are not the gist of the present invention, and thus are omitted (for such a method, see, for example, 321383).

The movement 80 includes an hour hand drive unit 82, a minute hand drive unit 84, and a second hand drive unit 86, and as shown in FIG. 2, by driving a metal hour hand 83, a minute hand 85, and a second hand 87, respectively, the current time is set. It is a display unit that displays in an analog manner. The movement 80 obtains a pulse by dividing a predetermined frequency obtained by oscillating a crystal resonator (not shown), and drives each pointer by a step motor and a gear in accordance with the pulse. Further, the currently displayed time is corrected based on the information regarding the time sent from the time information extraction unit 54 at a predetermined interval.
In addition, the chip antenna 14 is disposed at a position in the movement 80 where radio waves can be received satisfactorily. In the first embodiment, the chip antenna 14 is disposed in the vicinity of the back surface of “12” of the dial 88 as shown in FIG. 2 in which the movement 80 is mounted on the radio timepiece 1. In this way, the chip antenna 14 is disposed at a position where a circular image drawn by each of the hands turning around overlaps at least a part of the chip antenna 14 when the movement 80 is viewed from the front. . When any of the hour hand 83, the minute hand 85, and the second hand 87 moves and moves to the vicinity of “12” of the dial 88, the capacitor changes between the pointer approaching “12” and the chip antenna 14. Therefore, the matching relationship between the chip antenna 14 and the reception processing unit 30 is changed, and the matching state is changed to the non-matching state.

The pointer position detection unit 70 includes an hour hand detection unit 72, a minute hand detection unit 74, and a second hand detection unit 76. The pointer position detection unit 70 detects the positions of the hour hand 83, the minute hand 85, and the second hand 87 of the movement 80, respectively. Get relative position information. In the first embodiment, as described above, since the chip antenna 14 is disposed below the “12” of the dial 88, a detection element such as a photosensor is installed in the vicinity of “12” of the dial 88. Alternatively, each pointer position may be detected from a pulse sent to the step motor. Information on the relative position between each pointer detected by the pointer position detection unit 70 and the chip antenna 14 is sent to the inductor instruction unit 65.
The control unit 60 includes an inductor instruction unit 65 and controls each functional unit of the radio timepiece 1. The inductor instruction unit 65 calculates the difference in impedance between the chip antenna 14 and the reception processing unit 30 based on the information on the relative position between each pointer and the chip antenna 14 sent from the pointer position detection unit 70. This difference is caused when the impedance of the chip antenna 14 fluctuates according to the relative position between each pointer and the chip antenna 14. Subsequently, the inductor instruction unit 65 instructs the switches 24, 26, and 28 of the inductor variable unit 20 to be intermittent in order to correct this difference.

  For example, when the hour hand detection unit 72 detects the approach between the hour hand 83 and the chip antenna 14, the inductor instruction unit 65 causes the switch 24 to transition from the unconnected state to the connected state. As a result, since the coil 22B is short-circuited, the inductor of the inductor variable section 20 is reduced by the amount corresponding to the inductor of the coil 22B. Here, since the inductor of the coil 22B is set so as to cancel the increased amount of the capacitor caused by the proximity of the hour hand 83 and the chip antenna 14, the impedance of the fluctuating chip antenna 14 is restored, and the chip antenna 14 and the reception are received. The processing unit 30 returns to the alignment state. The same applies to the minute hand 85 and the second hand 87. As the minute hand 85 and the second hand 87 and the chip antenna 14 approach each other, the coil 22C and the coil 22D are short-circuited, whereby the fluctuation in impedance of the chip antenna 14 is restored. Is done. As a result, even when any pointer approaches the chip antenna 14, the alignment state between the chip antenna 14 and the reception processing unit 30 is substantially maintained.

  In the first embodiment, a change in relative position between the hour hand 83, the minute hand 85, the second hand 87, and the chip antenna 14 is detected. However, since the hour hand 83 is short, it does not reach the chip antenna 14, and since the second hand 87 is thin and has a small area, the impedance variation of the chip antenna 14 is small, so that the hour hand 83 and the second hand 87 are detected. Instead, only a change in the relative position between the minute hand 85 and the chip antenna 14 may be detected. In this case, the hour hand detecting unit 72 and the second hand detecting unit 76 are unnecessary from the configuration of FIG. 1, and the switches 24 and 28 corresponding to the hour hand 83 and the second hand 87 are also unnecessary.

  Although not shown in the drawings, each of the above-described functional units may be realized by an electric circuit, and includes a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, and the like. These hardware and software may be realized in cooperation. Further, at least a part of these functional units may be mounted on an integrated circuit.

Next, FIG. 3 is a flowchart for explaining the flow of processing by the radio timepiece 1. This process is set to be executed every predetermined time or in response to an instruction from the user. First, when this process is executed, the control unit 60 detects the position of the pointer based on the relative position information between the chip antenna 14 and any of the pointers acquired by the pointer position detection unit 70, and It is determined whether or not the pointer is on the chip antenna 14 (step S100). Here, when the pointer position detection unit 70 does not detect any of the pointers and determines that the pointer is not on the chip antenna 14 (No in step S100), the control unit 60 controls each switch 24 with respect to the inductor variable unit 20. , 26, 28 are shifted to the initial state (step S106), all the switches 24, 26, 28 are disconnected, and the process proceeds to step S108.
On the other hand, when the pointer position detection unit 70 detects any of the pointers and determines that there is any of the pointers on the chip antenna 14 (Yes in step S100), the inductor instruction unit 65 responds to the detected pointers. Thus, the switch to be operated is determined from the switches 24, 26, and 28 (step S102). Subsequently, the inductor instruction unit 65 operates the determined switch to change the inductor of the inductor variable unit 20 (step S104), and restores the impedance of the chip antenna 14 that has fluctuated due to the approach of the pointer. As a result, the matching state between the chip antenna 14 and the reception processing unit 30 is maintained.

  Subsequently, the control unit 60 instructs the reception processing unit 30 in which the matching state with the chip antenna 14 is maintained and the reception sensitivity is stable to acquire time information from the received radio wave signal (step S108). . Next, the control unit 60 compares the time information acquired by the reception processing unit 30 with the current time information indicated by the movement 80, and determines whether or not the display time needs to be corrected (step S110). . If it is determined that the display time needs to be corrected (Yes in step S110), the control unit 60 corrects the display time of the movement 80 based on the time information acquired by the reception processing unit 30 ( Step S112), a series of processing ends. Then, it waits for the next reception opportunity. On the other hand, if it is not determined that the display time needs to be corrected (No in step S110), the series of processing ends, and the process waits for the next reception opportunity.

  According to the first embodiment described above, since the hour hand 83, the minute hand 85, and the second hand 87 move around and the positional relationship with the chip antenna 14 changes, impedance variation of the chip antenna 14 can be suppressed. Since the optimum matching state between the chip antenna 14 and the reception processing unit 30 can be maintained, the radio timepiece 1 whose reception sensitivity does not vary according to the position of the pointer can be realized.

(Embodiment 2)
Next, Embodiment 2 of the present invention will be described with reference to FIG. 4 and FIG. In the following description, the same parts as those already described are denoted by the same reference numerals and description thereof is omitted. In the first embodiment, the positional relationship between the hour hand 83, the minute hand 85, the second hand 87, and the chip antenna 14 is detected in two stages depending on the presence or absence of the chip antenna 14, but in the second embodiment, the position is limited to only the minute hand 85. The positional relationship between the minute hand 85 and the chip antenna 14 is divided by the position on the chip antenna 14 and detected in three stages.
4A is an external view of the radio timepiece 1 excluding the dial 88, and FIG. 4B is a block diagram illustrating an outline of a functional configuration of the radio timepiece 1. FIG. As shown in FIG. 4A, the first minute hand detection unit 74 </ b> A and the second minute hand detection unit 74 </ b> B are provided below the chip antenna 14. On the dial 88, the first minute hand detection unit 74A is set to “10.5” (intermediate position between “10” and “11”) to “11” and “1” to “1.5” (“1” and “ The minute hand 85 indicating the intermediate position 2) is detected. Further, the second minute hand detection unit 74B detects the minute hand 85 indicating “10.5” to “1.5” on the dial 88. Here, the area where the chip antenna 14 intersects with the minute hand 85 is “11” to “11” when the minute hand 85 indicates “10.5” to “11” and “1” to “1.5”. It is larger than the case of “1”. Therefore, the fluctuation of the capacitor becomes larger when the minute hand 85 indicates “10.5” to “11” and “1” to “1.5”.

  In addition, as shown in FIG. 4B, the inductor variable section 20 has two coils 22 </ b> C corresponding to the minute hand 85, and a switch 226 that short-circuits one coil 222 and a short-circuit the other coil 224. A switch 228 is provided. The inductor of one coil 222 and the inductor of the other coil 224 correspond to the fluctuation of the capacitor when the area where the chip antenna 14 and the minute hand 85 intersect is large, and the inductor of one coil 222 is the chip antenna 14. And the minute hand 85 are set so as to correspond to the amount of fluctuation of the capacitor when the area where the minute hand 85 intersects is small. These switches 226 and 228 are instructed to be intermittent by the inductor instruction unit 65 according to the detection state of the minute hand 85 by the first minute hand detection unit 74A and the second minute hand detection unit 74B. Impedance fluctuation is suppressed.

  FIG. 5 shows the position of the minute hand 85 and the intermittent state of the switches 226 and 228 of the inductor variable section 20. Among these, FIG. 5A shows the intermittent state of the switch 226, and FIG. 5B shows the intermittent state of the switch 228. As shown in FIGS. 5A and 5B, when the minute hand 85 comes to the position “10.5”, the first minute hand detecting unit 74A detects the minute hand 85, and the switch 226 and the switch 228 are respectively Transition to the connected state causes one coil 222 and the other coil 224 to be short-circuited. When the minute hand 85 comes to the position “11”, the second minute hand detection unit 74B detects the minute hand 85, only the switch 228 is changed to the non-connected state, and the short circuit of the other coil 224 is released. Further, when the minute hand 85 comes to the position “1”, the second minute hand detection unit 74B can no longer detect the minute hand 85, the switch 228 transitions to the connected state again, and one coil 222 and the other coil 224 are Both are short-circuited. When the minute hand 85 comes to the position “1.5”, the first minute hand detection unit 74A can no longer detect the minute hand 85, and the switch 226 and the switch 228 transition to the non-connected state, respectively, And the short circuit of the other coil 224 is cancelled | released.

  According to the second embodiment described above, the positional relationship between the minute hand 85 and the chip antenna 14 is detected in three stages, and the inductor is adjusted in accordance with each stage. be able to.

  Although the embodiment of the present invention has been described with reference to the drawings, the specific configuration is not limited to this embodiment, and includes design changes and the like within a scope not departing from the gist of the present invention. For example, in the second embodiment, the positional relationship between the minute hand 85 and the chip antenna 14 is detected in three stages, but may be detected in four or more stages.

The block diagram which shows the function structure of the radio timepiece which concerns on Embodiment 1 of this invention. 1 is an external view of a radio timepiece according to Embodiment 1 of the present invention. The flowchart explaining the flow of the process by the radio timepiece concerning Embodiment 1 of the present invention. (A) is an external view of the radio timepiece according to the second embodiment of the present invention, and (b) is a block diagram showing an outline of the functional configuration of the radio timepiece according to the second embodiment of the present invention. (A) shows the position of the minute hand and the on / off state of one switch, and (b) shows the position of the minute hand and the on / off state of the other switch.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Radio timepiece, 10 ... Matching part, 12 ... Antenna part, 14 ... Chip antenna, 20 ... Inductor variable part, 22A, 22B, 22C, 22D ... Coil, 24, 26, 28 ... Switch, 30 ... Reception processing part, DESCRIPTION OF SYMBOLS 40 ... RF processing part, 42 ... Low noise amplifier, 44 ... Frequency conversion part, 45 ... Local oscillation signal generation part, 46 ... IF band pass filter, 48 ... IF amplifier, 50 ... Baseband processing part, 52 ... Baseband demodulation part 54 ... Time information extraction unit, 60 ... Control unit, 65 ... Inductor instruction unit, 70 ... Hand position detection unit, 72 ... Hour hand detection unit, 74 ... Minute hand detection unit, 74A ... First minute hand detection unit, 74B ... Second Minute hand detector, 76 ... second hand detector, 80 ... movement, 82 ... hour hand drive, 83 ... hour hand, 84 ... minute hand drive, 85 ... minute hand, 86 ... second hand drive, 87 ... second hand, 88 ... Shaped plate, 222 ... one coil, 224 ... other coil, 226, 228 ... switch.

Claims (7)

An antenna unit to which a communication signal including time information is input;
A reception processing unit that acquires the time information from the input communication signal;
A matching unit that matches and connects the antenna unit and the reception processing unit by correcting a difference in impedance between the antenna unit and the reception processing unit;
A display unit that displays the time based on the acquired time information by rotating a plurality of hands having conductivity,
A detection unit for detecting a relative position between at least one of the plurality of hands and the antenna unit;
An instruction unit for instructing the matching unit to correct a difference in impedance between the antenna unit and the reception processing unit caused by a change in impedance of the antenna unit according to the detected relative position; Radio clock. The radio timepiece according to claim 1,
The radio wave timepiece characterized in that the instruction unit matches the impedance of the antenna unit with the impedance of the reception processing unit by changing an induction coefficient of the matching unit. The radio timepiece according to claim 1,
The radio wave timepiece characterized in that the detection unit detects a relative position with respect to the antenna unit by detecting a position of the circulating pointer. The radio timepiece according to any one of claims 1 to 3,
A radio wave timepiece characterized in that a disk image drawn by rotating at least one of the hands overlaps at least a part of the antenna unit when viewed from the direction in which the display unit is viewed. The radio timepiece according to any one of claims 1 to 4,
The radio timepiece, wherein the communication signal is transmitted from a base station by a CDMA communication method. The radio timepiece according to claim 5,
The reception processing unit
An RF processing unit that receives the communication signal and acquires the intermediate frequency signal by mixing the received communication signal and the local oscillation signal;
A pilot channel signal is acquired from the acquired intermediate frequency signal, and a sync channel signal is acquired from the intermediate frequency signal by synchronizing with the base station with the acquired pilot channel signal, and from the acquired sync channel signal And a baseband processing unit that extracts the time information. A communication signal including time information is received by an antenna unit, and the reception processing unit connected to the antenna unit acquires the time information from the received communication signal. Based on the acquired time information, a plurality of conductive signals are obtained. A method of receiving a radio-controlled timepiece that displays the time by turning the hands of
A relative position between at least one of a plurality of hands and the antenna unit is detected, and a difference in impedance between the antenna unit and the reception processing unit caused by the impedance of the antenna unit that varies according to the detected relative position is corrected. Thus, the radio timepiece receiving method characterized by matching impedances of the antenna unit and the reception processing unit.

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