JP2010019566A - Time receiving device and time correcting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a time receiving device for performing high-accuracy time adjustment even at a facility or place where a communication network such as the Internet is not available. <P>SOLUTION: The time receiving device includes: a transmission control means 211 which controls a communication means and transmits a command code for reporting that time correction is to be performed to another apparatus at a communication timing of 1 occurring at predetermined time intervals, and stores the time of the time measurement means 214 at that transmission time; a reception control means which controls the communication means 220 and receives time data transmitted from the other apparatus at a communication timing later by a prescribed time interval than the communication timing of 1; and a time correction means which reads the time of the time measurement means in reception of the time data by the reception control means, determines whether or not correction of the time of the time measurement means is required based on the stored time and the predetermined time interval, and corrects the time of the time measurement means by using the received time data when necessary. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a time adjustment technique in an electronic device provided with a time receiver and a time measuring means, and more particularly to a technique suitable for use in an electronic wristwatch having a wireless communication function such as Bluetooth.

  The electronic timepiece has a built-in oscillation circuit having a vibrator such as a crystal vibrator and has a timekeeping function. However, a time shift occurs due to variations in the oscillation frequency. Therefore, a radio timepiece is provided that has an antenna and receives a radio signal (time standard radio wave) including time information to correct the time. However, radio timepieces (including wristwatches) have a problem that the time correction function does not work when they are placed indoors where radio waves do not reach, especially in underground facilities.

In recent years, there are an increasing number of electronic devices that require highly accurate time information in order to perform high-speed processing with high accuracy. For this reason, various time adjustment techniques have been proposed for electronic devices that hold time information internally (see, for example, Patent Document 1).
JP 2007-163330 A

  The invention described in Patent Document 1 sends time information from a server to a client device in a system in which a server having a reference internal clock and a client device are communicably connected via a communication path. Time adjustment is performed. Under the assumption that the communication times of the forward path and the backward path are the same, the present invention has created a response including time T1 when the client device requests time, T2 when the server receives the request, and the server including time information. Assuming that the time is T3 and the time when the response is received by the client device is T4, the time lag of the clock in the client device is calculated and corrected by {(T2-T1) + (T3-T4)} / 2. ing.

  According to the invention of the prior application, although there is an advantage that the time can be set with relatively high accuracy, there is a problem that the time cannot be set unless the facility or place has an infrastructure such as the Internet.

  Further, although the Bluetooth standard that is assumed to be used as a wireless communication means in the embodiment of the present invention also defines the method of time synchronization, the time synchronization in the Bluetooth standard is simply performed by the transmission side (master) on the reception side (master). The time is transmitted to the slave (slave) and the receiver sets the clock. When automatic retransmission is performed due to a communication failure, there is a problem that the communication delay time becomes long and the accuracy of time adjustment decreases.

  The present invention has been made paying attention to the above problems, and an object of the present invention is to provide a time receiving apparatus capable of highly accurate time setting even in a facility or place without a communication network such as the Internet.

  Another object of the present invention is to enable highly accurate time adjustment even when time data is sent using a communication standard such as Bluetooth in which automatic retransmission is performed in the event of a communication error. The object is to provide a time receiver.

In order to achieve the above object, the invention described in claim 1 of the present application is
A timing means for timing based on an internal clock signal;
A time receiving device comprising a communication means for communicating with other devices at a predetermined time interval,
Transmission control means for controlling the communication means to transmit a command code notifying other devices of time correction at the communication timing of one of the predetermined time intervals;
A reception control means for controlling the communication means to receive time data sent from the other device at a communication timing after the communication timing of the one;
Time correction means for correcting the time of the time measuring means based on the time data received by the reception control means and the predetermined time interval;
It is characterized by having.

According to a second aspect of the present invention, in the time receiving device according to the first aspect,
The time correction means includes
A time difference between the time of the time counting unit when the command code is transmitted and the time of the time measuring unit when the reception control unit receives the time data is obtained, and this time difference is determined from a predetermined specific time. The time correction is performed only when the time is smaller than the specific time.

The invention according to claim 3 is the time receiving device according to claim 2,
The specific time is larger than one predetermined time interval and smaller than two intervals.

According to a fourth aspect of the present invention, in the time receiving device according to any one of the first to third aspects,
The communication means is a wireless communication means.

The invention according to claim 5 is the time receiving device according to claim 4,
The communication by the wireless communication means is communication according to the Bluetooth standard.

The invention according to claim 6 is the time receiving device according to claim 5,
The wireless communication means is a wireless communication means provided in a slave side device in Bluetooth communication.

The invention according to claim 7 is the time receiving device according to any one of claims 1 to 6,
The other device is an electronic device that holds a current time inside.

The invention according to claim 8 is the time receiving device according to claim 7,
The other device includes a wireless communication unit of a system different from the communication unit, and acquires and holds the current time by the wireless communication unit.

The invention according to claim 9 is the time reception device according to claim 8,
The other device is a mobile phone.

The invention according to claim 10 is:
A timing means for timing based on an internal clock signal;
A time correction method in a time receiving device comprising a communication means for communicating with other devices at a predetermined time interval,
A step of transmitting a command code for controlling the communication means and notifying other devices to correct the time at one communication timing of the predetermined time interval;
A receiving step of controlling the communication means and receiving time data sent from the other device at a communication timing later than the one communication timing;
A time correcting step for correcting the time of the time measuring means based on the time data received in the receiving step and the predetermined time interval;
It is characterized by including.

The invention according to claim 11 is the time correction method of the time receiver according to claim 10,
The time correction step includes
A time difference between the time of the time measuring unit when the command code is transmitted to the other device at the communication timing of the first time by the communication unit and the time of the time measuring unit when the time data is received in the receiving step. A calculation step to be obtained;
A determination step for determining whether or not the time difference obtained in this calculation step is smaller than a predetermined time;
A time correction control step for executing the time correction only when it is determined in this determination step that the time difference is smaller than a predetermined time.
It is characterized by including.

The invention according to claim 12 is the time correction method of the time receiver according to claim 11,
The specific time is larger than one interval of the predetermined time intervals and smaller than 2 intervals.

  ADVANTAGE OF THE INVENTION According to this invention, the time receiver which can carry out a highly accurate time-setting can be implement | achieved also in the facilities and places without a communication network, such as the internet.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings. In the following description, a case where the time receiving device according to the present invention is a wristwatch will be described as an example, but embodiments to which the present invention can be applied are not limited thereto.

  In recent years, with the development and popularization of mobile phones, high-function mobile phone services have been provided, and one of them is providing high-accuracy time information from a base station as a server to a mobile phone as a terminal. There is a service that always sends. In addition to the original communication functions of mobile phones such as telephone calls and data communication, the communication function using infrared rays and the specifications of short-distance wireless communication of about 10 m using a frequency band of 2.4 GHz to 2.48 GHz are specified. Mobile phones equipped with a communication function according to the Bluetooth standard are provided.

The Bluetooth standard wireless communication system is a packet communication system that transmits a predetermined amount of data with a header, and includes asynchronous communication (ACL: Asynchronous Connectionless) having a retransmission function and packet transmission at a predetermined cycle without a retransmission function. Two communication modes of synchronous communication (SCO: Synchronous Connection Oriented) for transmission are provided, and transmission and reception are performed in time division.
In Bluetooth communication, a clock signal (hereinafter simply referred to as a clock) is synchronized between a master device and a slave device, and a communication connection is established, based on a 3.2 kHz clock signal called a Bluetooth clock. Packet data is exchanged at a period twice that of 3.2 kHz (625 μs).

This embodiment uses a mobile phone having a short-range communication function such as Bluetooth that has high-accuracy time information and has a constant transmission / reception interval. As shown in FIG. 1, time adjustment of a wristwatch that is difficult to hold time information can be performed by sending time information from the mobile phone 100 to the wristwatch 200 by short-range communication.
FIG. 2 is a block diagram showing a part of each internal system of the mobile phone 100 and the wristwatch 200 in the present embodiment.

  As shown in FIG. 2, a mobile phone 100 includes a control unit 110 including a microprocessor (so-called microcomputer) that controls the entire system, and a Bluetooth communication device (hereinafter referred to as a wireless IC) having a communication function according to the Bluetooth standard. ) And the like, and the control unit 110 and the communication processing unit 120 are connected by a serial bus. Similarly, the wristwatch 200 includes a control unit 210 that controls the entire system and a communication processing unit 220.

  In addition to the control unit 110 and the communication processing unit 120, the mobile phone 100 includes peripheral devices such as a GSM or WCDM standard wireless communication processing unit, a liquid crystal display unit, a speaker, and a numeric keypad that provide a call function inherent to the device. However, since they are not directly related to the present invention, illustration and description are omitted. On the other hand, the wristwatch 200 includes a clock module for displaying time in addition to the control unit 210 and the communication processing unit 220, but illustration and description thereof are omitted. In addition, since the configurations of the control unit 210 and the communication processing unit 220 of the wristwatch 200 in this embodiment are the same as those of the mobile phone 100, only the control unit 110 and the communication processing unit 120 will be described for the hardware configuration. Description of the configuration of the control unit 210 and the communication processing unit 220 will be omitted.

  As shown in FIG. 2, the communication processing unit 120 (Bluetooth communication device) includes an up-conversion function, modulation function, amplification function, reception signal amplification function, demodulation function, down-conversion function, etc. A high-frequency signal processing unit (RF unit) 121 that transmits and receives data via the ANT, and processes the data transmitted and received by the high-frequency signal processing unit 121 in accordance with the Bluetooth communication protocol, and the communication connection state between the communication partner devices A link controller 122 is provided that establishes and analyzes, decodes, and reconstructs packets. The structure of the packet to be transmitted is defined by the Bluetooth standard, and is a sequence that indicates data for synchronization, an area for receiving the address of the transmission partner, parameters for managing packet types and communication links, and packet order. It consists of a packet header area for entering a number and the like, a payload area for entering data to be transmitted and an error correction code.

  The communication processing unit 120 includes a transmission buffer 123 that temporarily stores transmission data, a reception buffer 124 that temporarily stores reception data, and an interface unit that exchanges signals between the link controller 122 and the control unit 110. 125 and the like. When the reception data is taken into the reception buffer 124, a reception interrupt signal is generated to the control unit 110, and the control unit 110 starts processing the reception data by interruption.

  The control unit 110 includes a microprocessor (CPU) 111, a ROM 112 including a nonvolatile memory for storing a control program, a RAM 113 including a volatile memory for providing a work area for the CPU and temporarily storing processing data, The timer unit 114 generates a clock φ and performs timing processing, and an interface unit 115 that exchanges signals with the communication processing unit 120.

  Serial communication between the control unit 110 and the communication processing unit 120 is performed by sending a command code and data in synchronization with a clock signal. When data is transmitted from the communication processing unit 120 to the control unit 110, the interruption signal INT is used. In FIG. 2, each of the control unit 110 and the communication processing unit 120 is configured as one semiconductor integrated circuit (IC), but may be configured by a plurality of semiconductor integrated circuits.

  Here, the wireless connection by Bluetooth communication will be briefly described. In Bluetooth communication, one device serves as a master and the other device operates as a slave, and transmission / reception is performed at a constant period T0 (625 μs). When establishing a connection, first, the master (device A) creates a packet from the data in the transmission buffer 123 and transmits it to the slave (device B). At this time, if the transmission buffer is empty, a packet with an empty data area is sent. If the sequence number of the previously received packet is wrong, the previously transmitted data is retransmitted.

On the other hand, the slave checks the sequence number and error correction code when receiving a packet including its own address, and stores the data in the reception buffer 224 if the data is correct. The same applies to the case of transmitting data from the slave side.
Next, in the embodiment of FIGS. 1 and 2, the watch 200 as the slave (device B) requests time information from the mobile phone 100 as the master (device A), and the time of the clock in the slave is stored in the master. A procedure for adjusting to the time of the clock will be described.

  The control unit 210 of the wristwatch 200 (device B) reads the time Tb1 from the time measuring unit (clock) 214 and stores it in the RAM 213. Then, the “time adjustment start” command code is written as data in the transmission buffer 223 in the communication processing unit (wireless IC) 220. Then, the communication processing unit 220 transmits a packet containing data in the transmission buffer 223 to the mobile phone 100 (device A) at the next connection timing.

  Then, the communication processing unit (wireless IC) 120 of the mobile phone 100 receives and checks the packet, and stores the received data in the reception buffer 124 if the data is correct. When the reception data is stored in the reception buffer 124, an interrupt is issued to the control unit 110, and the control unit 110 reads the data from the reception buffer 124 and decodes it. In this case, since the received data is a “time adjustment start” command code, the time Ta is read from its own clock unit (clock) 114 and the time data is stored in the transmission buffer 123 in the communication processing unit (wireless IC) 120. Write Ta. Thereafter, the communication processing unit 120 transmits a packet containing the time data of the transmission buffer 123 to the wristwatch 200 (device B) at the next connection timing.

  The communication processing unit (wireless IC) 220 of the wristwatch 200 receives the packet and checks it. If the data is correct, the received data is stored in the reception buffer 224. When the reception data is stored in the reception buffer 224, an interrupt is issued to the control unit 210, and the control unit 210 receives the time data Tb1 stored in the RAM 213 and the current time Tb2 from the time measuring unit (clock) 214. And the time data Ta received from the reception buffer 224 are read out.

  Then, it is determined whether or not the relationship of Tb2 ≦ TB1 + 2T0, that is, Tb2−Tb1 ≦ 2T0 is satisfied. When the relationship is satisfied, the time of the time measuring unit 214 is corrected to Ta + T0. Here, T0 is a communication cycle (625 μs in Bluetooth). On the other hand, when Tb2 ≦ Tb1 + 2T0 is not satisfied, it is determined that the connection has failed, and the process is terminated without correcting the time of the clock B (time measuring unit 214). Note that 2T0 in the above relational expression is not limited thereto, and may be any value as long as it is greater than T0 and equal to or less than 2T0. In Bluetooth communication, since the communication cycle is fixed, the success / failure of the connection can be determined with such settings.

FIG. 3 shows an example of timing when the time adjustment is successful. The time Tb1 read from the watch B (timer 214) of the wristwatch 200 (device B) at the timing t1 is written in the transmission buffer B (223), and transmitted to the mobile phone 100 (device A) at the timing t2. Are taken into the reception buffer A (124). Then, the time Ta read from the clock A (timer 114) at the timing t2 ′ is written to the transmission buffer A (123), and transmitted to the wristwatch 200 (device B) at the timing t3 later by T0 than t2. The data is taken into the reception buffer B (224).
At this time, the time Tb2 is read from the clock B (timer 214) and compared with the time data Tb1 in the RAM. In this case, since transmission / reception is completed in one cycle, Tb2 ≦ Tb1 + 2T0 is satisfied. Therefore, the time is corrected by changing the time of the clock B (time measuring unit 214) to Ta + T0. In this case, by correcting the time to the time obtained by adding T0 to Ta, the time is corrected in consideration of the delay due to communication, so that the correct time can be corrected.

  FIG. 4 and FIG. 5 show examples of timing when the time adjustment fails. 4 shows a case where transmission from the cellular phone 100 (device A) to the wristwatch 200 (device B) fails at timing t3, and FIG. 5 shows a case where transmission from the wristwatch 200 (device B) to the cellular phone at timing t3 ′ is performed. The case where transmission to 100 (apparatus A) fails is shown.

  In any case, the cellular phone 100 (device A) attempts to retransmit the time data Ta at a timing t4 that is later by T0 than t3. Even if the retransmission succeeds, in this case, Tb2 ≦ Tb1 + 2T0 is not satisfied, and the wristwatch 200 (device B) that has received the time data Ta does not correct the time of the clock B (timer 214). For this reason, correction to an error time is avoided, and the time accuracy of the watch 200 (device B) is improved over a long span.

  A cellular phone can always hold time information with high accuracy by using a time reception service from a base station. In addition, since the mobile phone (master device) cannot be used where radio waves do not reach, the user always tries to place or carry the mobile phone where radio waves can reach, so the time information held inside is accurate. The watch (slave device) is configured to receive the time information from the mobile phone by short-range wireless communication different from the wireless communication for the original call. By doing so, it is possible to improve the accuracy of the time information inside the wristwatch in combination with the ability to receive time information without time lag accompanying transmission and reception as described above.

  Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above embodiments, and various modifications can be made. For example, in the above-described embodiment, the case where the wireless communication according to the Bluetooth standard is used as the communication between the mobile phone and the wristwatch has been described. It is not limited, and a wired communication method may be used instead of wireless communication. By adopting the wireless communication system, handling (preparation) of the device at the time adjustment becomes easy. In general, a mobile phone may be treated as a concept that does not include PHS (Personal Handy-phone System), but the mobile phone in the present invention is a concept that includes what is called PHS.

  In the above description, an example in which the present invention is applied to a wristwatch having a Bluetooth communication function has been shown. However, the present invention is not limited to this, and an electronic device having a communication function for periodically transmitting and receiving in synchronization with each other is shown. Any device may be used. For example, the time receiving device may be a stationary watch such as a stationary type, or a small radio or the like.

It is the schematic which shows suitable embodiment of this invention. It is a block diagram which shows a part of each internal system of a mobile telephone and a wristwatch in one Embodiment of this invention. It is a time chart which shows the example of a successful transmission / reception of the time information between the mobile telephone and a wristwatch in embodiment. It is a time chart which shows the example of failure of transmission / reception of the time information between the mobile phone and the wristwatch in the embodiment. It is a time chart which shows the other example of failure of time information transmission / reception between the mobile telephone and a wristwatch in embodiment.

Explanation of symbols

100 Cellular Phone 110 Control Unit 111 Microprocessor (CPU)
112 ROM (nonvolatile memory)
113 RAM (volatile memory)
114 Timing unit 115 Interface unit 120 Communication processing unit 121 High-frequency signal processing unit (RF unit)
122 Link Controller 123 Transmission Buffer 124 Reception Buffer 125 Interface Unit 200 Wristwatch 210 Control Unit 211 Microprocessor (CPU)
212 ROM (nonvolatile memory)
213 RAM (volatile memory)
214 Timing unit 215 Interface unit 220 Communication processing unit 221 High-frequency signal processing unit (RF unit)
222 Link controller 223 Transmission buffer 224 Reception buffer 225 Interface unit

Claims (12)

A timing means for timing based on an internal clock signal;
A time receiving device comprising a communication means for communicating with other devices at a predetermined time interval,
Transmission control means for controlling the communication means to transmit a command code notifying other devices of time correction at the communication timing of one of the predetermined time intervals;
A reception control means for controlling the communication means to receive time data sent from the other device at a communication timing after the communication timing of the one;
Time correction means for correcting the time of the time measuring means based on the time data received by the reception control means and the predetermined time interval;
A time receiving device comprising: The time correction means includes
A time difference between the time of the time counting unit when the command code is transmitted and the time of the time measuring unit when the reception control unit receives the time data is obtained, and this time difference is determined from a predetermined specific time. 2. The time receiving apparatus according to claim 1, wherein the time correction is executed only when the time is smaller than the specific time.   The time receiving apparatus according to claim 2, wherein the specific time is larger than one interval of the predetermined time intervals and smaller than 2 intervals.   The time receiving apparatus according to claim 1, wherein the communication unit is a wireless communication unit.   The time receiving apparatus according to claim 4, wherein the communication by the wireless communication means is communication according to a Bluetooth standard.   The time receiving apparatus according to claim 5, wherein the wireless communication means is a wireless communication means provided in a slave side device in Bluetooth communication.   The time receiver according to claim 1, wherein the other device is an electronic device that holds a current time therein.   The time receiver according to claim 7, wherein the other device includes a wireless communication unit having a different system from the communication unit, and acquires and holds the current time by the wireless communication unit.   The time receiver according to claim 8, wherein the other device is a mobile phone. A timing means for timing based on an internal clock signal;
A time correction method in a time receiving device comprising a communication means for communicating with other devices at a predetermined time interval,
A step of transmitting a command code for controlling the communication means and notifying other devices to correct the time at one communication timing of the predetermined time interval;
A receiving step of controlling the communication means and receiving time data sent from the other device at a communication timing later than the one communication timing;
A time correcting step for correcting the time of the time measuring means based on the time data received in the receiving step and the predetermined time interval;
The time correction method in the time receiver characterized by including. The time correction step includes
A time difference between the time of the time measuring unit when the command code is transmitted to the other device at the communication timing of the first time by the communication unit and the time of the time measuring unit when the time data is received in the receiving step. A calculation step to be obtained;
A determination step for determining whether or not the time difference obtained in this calculation step is smaller than a predetermined time;
A time correction control step for executing the time correction only when it is determined in this determination step that the time difference is smaller than a predetermined time.
The time correction method in the time receiver according to claim 10, comprising:   12. The time correction method in the time receiving apparatus according to claim 11, wherein the specific time is larger than one interval of the predetermined time intervals and smaller than 2 intervals.

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