JP2006322812A - Radio-controlled clock - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio-controlled clock capable of attaining power saving by elongating a battery lifetime as long as possible, when using a battery as a power source. <P>SOLUTION: It is determined whether a detected voltage value V of the battery is below a prescribed voltage value V1 or not (S2). When the detected voltage value V is not below the prescribed voltage value V1 as a result of determination, a receiving period for receiving a standard radio wave intermittently by a receiving circuit is set at T1 (S3), and the receiving circuit performs intermittent reception of the standard radio wave with the receiving period T1 (S4). Also, when the detected voltage value V is below the prescribed voltage value V1, the receiving period is set at T2 (T1<T2) (S5), and the receiving circuit performs intermittent reception of the standard radio wave with the receiving period T2 (S6). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a radio timepiece that receives a standard radio wave including time data and can correct (correct) the time based on the received time data.

In this type of radio-controlled timepiece, the receiving circuit is generally operated intermittently in order to reduce power consumption.
In addition, as a conventional radio clock, a receiver that receives standard radio waves intermittently, a clock using a crystal oscillation circuit, and an internal time signal that is counted by the clock using a standard time signal superimposed on the standard radio The time control unit calculates the deviation between the internal time signal and the standard time signal, stores the deviation, and stores the internal time signal when the standard radio wave cannot be received. Is known (for example, see Patent Document 1).

Thus, since the conventional radio timepiece receives the standard radio wave intermittently, the power consumption can be reduced.
However, in the conventional radio-controlled timepiece, the intermittent reception interval of the standard radio wave is fixed. Therefore, when a battery is used as a power source, the life of the battery cannot be extended as much as possible. There was a desire for a solution.
Japanese Patent Laid-Open No. 2004-340749

  In view of the above points, an object of the present invention is to provide a radio timepiece capable of realizing power saving by extending the life of a battery as much as possible when using the battery as a power source. is there.

In order to solve the above problems and achieve the object of the present invention, each invention has the following configuration.
That is, in the first invention, the received standard time data is received by the receiving circuit, the time data generated by the time measuring circuit is corrected based on the received standard time data, and the battery is used as the power source. In the radio timepiece, a voltage detection circuit for detecting the voltage of the battery is provided, and the reception cycle when the reception circuit receives intermittently in response to a decrease in the detection voltage value of the voltage detection circuit is increased. .

  According to a second aspect of the present invention, there is provided a radio-controlled timepiece that uses a battery as a power source, and receives a standard time data transmitted intermittently, a clock circuit that generates time data, and the receiver circuit receives the standard time data. A correction unit that corrects time data generated by the time measuring circuit based on standard time data, a voltage detection circuit that detects the voltage of the battery, and the reception circuit according to a decrease in the detection voltage value of the voltage detection circuit And a reception control unit that operates the reception circuit so that the reception cycle becomes longer.

In a third aspect based on the second aspect, the reception control unit operates the reception circuit so that the reception cycle of the reception circuit gradually increases in response to a decrease in the detection voltage value of the voltage detection circuit. I tried to make it.
In a fourth aspect based on the second aspect, the reception control unit compares the detection voltage value of the voltage detection circuit with a predetermined value, and when the detection voltage becomes equal to or lower than the predetermined value, the reception circuit Is changed to a predetermined value longer than the current value.

According to a fifth aspect of the present invention, in the fourth aspect, the display unit further includes a display unit that displays the time data corrected by the correction unit, and a display indicator that instructs display of the display unit. After changing the reception cycle of the receiving circuit, time data is displayed when there is a display instruction from the display indicator.
According to the present invention having such a configuration, when a battery is used as a power source, power saving can be realized by extending the life of the battery as much as possible.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The configuration of the radio timepiece of the present invention will be described with reference to the block diagram of FIG.
As shown in FIG. 1, the radio timepiece according to this embodiment includes a receiving circuit 1, a CPU 2, a timer circuit 3, a display unit 4, a voltage detection circuit 5, and a power supply circuit 6, and a battery as a power source. 7 is used to drive each part.

An antenna 8 is connected to the receiving circuit 1. The antenna 8 receives a standard radio wave including standard time data (time code) transmitted and outputs an electrical signal corresponding to the standard radio wave to the receiving circuit 1.
The receiving circuit 1 operates in accordance with an instruction from the CPU 2, selects a specific frequency signal from the electric signal from the antenna 8, extracts (decodes) standard time data from the selected specific frequency signal, and extracts this. This standard time data is output to the CPU 2. The receiving circuit 1 performs intermittent reception as described later under the control of the CPU 2.

The CPU 2 controls each unit as will be described later, and performs determination and processing as shown in FIG. The CPU 2 includes a memory (not shown), and the memory includes a RAM and a ROM.
Here, the RAM is a readable / writable memory used for work or the like when the CPU 2 performs later-described determination and processing. The ROM is a read-only memory in which a program in which the CPU 2 controls each unit and a program (procedure) in which the CPU performs determination and processing described later are stored in advance.

The timer circuit 3 counts signals from a crystal oscillator (not shown) to generate current time data (year, month, day, hour, minute, second data). The current time data generated by the timer circuit 3 is corrected using the standard time data received by the receiving circuit 1.
The display unit 4 displays time data generated by the time measuring circuit 3 and includes a liquid crystal display.

The voltage detection circuit 5 detects the voltage of the battery 7, and the detected voltage value is supplied to the CPU 2.
The power supply circuit 6 is intended to stabilize the voltage of the battery 7, and each part is driven by the output voltage of the power supply circuit 6. That is, the output voltage of the power supply circuit 6 is supplied to the receiving circuit 1, the CPU 2, the time measuring circuit 3, the display unit 4, and the voltage detection circuit 5.

The battery 7 may be either a primary battery that cannot be charged or a secondary battery that can be charged and used repeatedly. This embodiment is particularly effective when the battery is a primary battery.
Next, a first operation example of the embodiment having such a configuration will be described with reference to the flowchart of FIG.
In this embodiment, when the operation of the radio timepiece is started by using the battery 7, the voltage detection circuit 5 detects the voltage of the battery 7.

The CPU 2 takes in the detected voltage V (step S1), and determines whether or not the detected voltage value V is equal to or less than a predetermined value V1 (step S2).
As a result of the determination, if the detected voltage value V is not less than or equal to the predetermined value V1 (step S2: NO), the CPU 2 sets the reception cycle when the reception circuit 1 intermittently receives the standard radio wave (standard time data) as T1. (Step S3). Then, the CPU 2 controls the receiving circuit 1 to perform intermittent reception of the standard radio wave at the set reception cycle T1 (step S4). Then, it returns to step S1.

Accordingly, when the time has not passed since the start of use of the battery 7, the receiving circuit 1 performs intermittent reception of the standard radio wave with a relatively short reception cycle T1.
On the other hand, as a result of the determination, when the detected voltage value V is equal to or lower than the predetermined voltage value V1 (step S2: YES), the CPU 2 sets the reception cycle when the receiving circuit 1 intermittently receives the standard radio wave to T2. Set (step S5). Here, T1 <T2. Then, the CPU 2 controls the receiving circuit 1 to perform intermittent reception of the standard radio wave at the set reception cycle T2 (step S6). Then, it returns to step S1.

Therefore, when a considerable amount of time has elapsed since the start of use of the battery 7, the reception circuit 1 performs intermittent reception of standard radio waves with a relatively long reception cycle T2.
Next, a second operation example of the embodiment having such a configuration will be described with reference to FIG.
In the first operation example, the detection voltage value V of the battery 7 is compared with the predetermined value V1, and when V is equal to or higher than V1, the reception cycle of the receiving circuit 1 is set to T1, and when V is equal to or lower than V1. The receiving cycle of the receiving circuit 1 is set to T2.

However, in this second operation example, for example, three predetermined values V1, V2, and V3 are provided, the detected voltage value V of the battery 7 is compared with these, and the reception circuit 1 of the receiving circuit 1 is compared according to the result of this comparison. The reception period is set to T1, T2, T3, and T4 as follows.
That is, when V ≧ V1, the reception cycle is set to T1.
Further, when V1 ≧ V ≧ V2, the reception cycle is set to T2.

Further, when V2 ≧ V ≧ V3, the reception cycle is set to T3.
Further, when V ≦ V3, the reception cycle is set to T4.
These relationships are illustrated in FIG.
Here, V1 to V3 have a relationship of V1>V2> V3, for example, V1 = 1.3 [V], V2 = 1.1 [V], and V1 = 1.0 [V]. T1 to T4 have a relationship of T1 <T2 <T3 <T4.

Accordingly, in this case, the reception cycle of the reception circuit 1 gradually becomes longer in accordance with a decrease in the power supply voltage of the power supply 7, and the reception circuit 1 is standardized at any one of the set reception cycles T1 to T4. You will receive radio waves.
In this way, it is possible to receive the standard radio wave by finely changing the reception cycle of the reception circuit 1 according to the voltage drop of the battery 7.

As described above, according to this embodiment, when a battery is used as a power source, power saving can be realized by extending the life of the battery as much as possible.
In the first operation example, the CPU 2 compares the detection voltage value V of the battery 7 with the predetermined value V1, and when V is equal to or lower than V1, the reception cycle of the reception circuit 1 is set to T2, which is longer than T1. I set it. In this case, the display unit 4 may display the time data when the user operates the display indicator to give a display instruction. Here, the display indicator may be provided in a part of the display unit 4.

  In this way, when the voltage of the battery 7 drops below a predetermined value, the operation of the display unit 4 can be operated only when display is necessary, so that the battery life can be extended as much as possible. it can.

It is a block diagram which shows the structure of embodiment of this invention. It is a flowchart which shows the 1st operation example of embodiment. It is a figure explaining the 2nd operation example of embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Reception circuit, 2 ... CPU, 3 ... Time measuring circuit, 4 ... Display part, 5 ... Voltage detection circuit, 6 ... Power supply circuit, 7 ... Battery

Claims (5)

In the radio timepiece that receives the standard time data transmitted by the receiving circuit, corrects the time data generated by the time measuring circuit based on the received standard time data, and uses a battery as a power source,
A voltage detection circuit for detecting the voltage of the battery;
A radio timepiece characterized in that the reception cycle when the reception circuit receives intermittently in response to a decrease in the detection voltage value of the voltage detection circuit is lengthened. A radio-controlled timepiece that uses batteries as its power source,
A receiving circuit for intermittently receiving standard time data transmitted;
A clock circuit for generating time data;
A correction unit for correcting time data generated by the timekeeping circuit based on standard time data received by the receiving circuit;
A voltage detection circuit for detecting a voltage of the battery;
A reception control unit that operates the reception circuit so that the reception cycle of the reception circuit becomes longer in accordance with a decrease in the detection voltage value of the voltage detection circuit;
A radio-controlled timepiece characterized by comprising:   The said reception control part operates the said receiving circuit so that the receiving period of the said receiving circuit may become long gradually according to the fall of the detection voltage value of the said voltage detecting circuit. Radio clock.   The reception control unit compares a detection voltage value of the voltage detection circuit with a predetermined value, and sets the reception cycle of the reception circuit to a predetermined value longer than a current value when the detection voltage becomes equal to or lower than the predetermined value. The radio timepiece according to claim 2, wherein the radio timepiece is changed. A display unit for displaying time data corrected by the correction unit;
A display indicator for instructing display of the display unit,
5. The radio wave according to claim 4, wherein the display unit displays time data when there is a display instruction from the display indicator after the reception cycle of the reception circuit is changed. clock.

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