EP0682302A2 - Control means for clock synchronised by radio - Google Patents

Abstract

The control device (4) decodes the received radio signals containing the time information and compares the decoded time (t) with the actual time (T) displayed by the clock (5), to allow the latter to be corrected. A defined identification signal is transmitted within the radio signal, for identifying the transmitter or the country or origin, with the correction of the displayed time limited to less than an hour, in dependence on the decoded identification signal, so that the time is not set to the wrong time zone. <IMAGE>

Description

The invention relates to a control device for a clock to be synchronized by radio signals, which has its own drive, with the features specified in the preamble of claim 1.

A control device of the above type is known from DE-OS 40 36 851. A clock is synchronized by receiving and decoding RDS (Radio Data System) signals. Time information is extracted from the decoded signals and used to correct the current time of the clock. In an increasing number of countries, information data are broadcast together with radio broadcasts from broadcasting stations. Among other things, these contain detailed information about the date and time. It is obvious to use this for the synchronization of clocks - for example in motor vehicles. It is problematic, however, that transmitting stations transmit beyond national borders and time zones, that is to say they can possibly also be received where the current time does not match that at the location of the transmitting station. The device according to DE-OS 40 36 851 does not do it justice. When searching for a transmitter that is pleasing to the listener, it can happen that a synchronizable clock is adjusted several times by one or more hours, ie it indicates the wrong time. If a listener prefers to receive a distant foreign station, his watch is constantly wrong.

Another radio controlled clock is known from DE-OS 34 46 724. The problem of correcting the time by an actuator is primarily dealt with here. The starting point are time signals emitted by a long-wave transmitter.

It is an object of the invention to provide a control device which allows the synchronization of the time displayed by free-running clocks with little effort and thereby the above-mentioned. Avoids malfunctions. The time information transmitted with any radio broadcasts should be usable for the exact correction of the time. It should be possible to use the control device worldwide, with an emphasis on user friendliness.

To solve these tasks, the control device of the abovementioned. Kind from the characterizing features of claim 1. Further features emerge from patent claims 2 to 12.

Today, RDS signals from broadcasting stations are transmitted together with radio broadcasts. These signals contain information about the current date and time, but also about the station or its home area. In the future, such signals could also be transmitted using digital transmission systems. After reception by a receiver, the time and identification signals are to be decoded in the control device and extracted from the other signals. If they are not received or not received completely, there is no correction of a free-running clock which can be arranged, for example, in a motor vehicle on the radio or the dashboard. The received identification signal is then compared with identification signals stored in a memory. Depending on the result of the comparison, it is current displayed time of the clock can either be corrected by less than an hour or without a correction value being limited after this time has been compared with the received time signal. The identification signals of the transmitting stations located in the home country or also an identification signal of the home country of the owner of the receiver can be stored in said memory. If a stored identification signal is received, the time can be corrected without limiting the correction value, for example the summer / winter time can also be changed. If it is found in the comparison that the received identification signal is not stored (far-away transmitter is being received), the time can only be corrected by less than an hour, for example a maximum of thirty minutes. Since the time information then transmitted may be incorrect for the location of the recipient, only minutes and seconds are corrected. When traveling abroad (if the receiver is located in a motor vehicle), the memory content can be reprogrammed.

In a slightly different embodiment of the invention, it is also possible to store all or almost all of the identification signals to be received in the memory. The identification signals of the transmitting stations located at the recipient's location must then be marked. The correction value can then be limited depending on whether a marked or an unmarked identification signal has been received. The markings can also be changed.

The correction of the displayed time of the free running clock is done via an adjusting unit. Known possibilities can be used here, the correction value being transmitted from the control device to the actuating unit. The synchronization of quartz clocks with digital or analog display is possible. A symbol on a display unit of the watch can indicate that a correction has been made. If correction of the time is undesirable, the function of the control device should also be able to be switched off. The control device can be an integral part of the receiver or the clock, and the same also applies to the control unit.

The detailed description of the invention is based on an embodiment. The only associated figure shows a program flow diagram to explain the basic mode of operation of the control device.

As the figure shows, radio signals are emitted by a transmitting station 1 (here station XY) which are received by a receiver 2. In the exemplary embodiment, the receiver should be a car radio designed as an RDS receiver 2. The receiver 2 is put into operation or taken out of operation via an on / off switch 3, an associated control device 4 being activated or deactivated at the same time. In terms of circuitry, the control device 4 is connected to a clock 5 or to an actuating unit 6 for the clock 5. The clock 5 is equipped with its own drive, wherein it is preferably designed as a quartz clock. The adjusting unit 6 enables the currently displayed time T to be adjusted in a known manner on the basis of a correction value K. This is necessary because, for example, temperature fluctuations cause the clock 5 to run too slowly or too quickly. The clock 5 can be arranged separately in the motor vehicle or can also be part of the receiver 2.

In addition to a main signal, the radio signals emitted by the transmitting station 1 also contain time signals t and identification signals ID. The time signals t provide information about the day, month and that in encrypted form Year and the exact time. Current information about the hour hh, minute mm and second ss is also provided, which occurs, for example, every full minute. The identification signals ID are also encrypted and provide information about the home area of the transmitting station 1 and / or they identify the transmitting station 1 exactly, for example as station XY. The transmission stations 1 now have different sized transmission areas. There are stations 1 that broadcast locally, regionally, nationally and internationally, which in some cases broadcast across national borders and time zones. The transmitted time information t therefore does not apply to the entire reception area of the individual stations 1. If a program is received, a probe must take place to determine whether a time signal t that is valid or invalid for the reception area is received. This function is guaranteed, among other things, by the control device 4:

gebildet wird. Im Ergebnis liegt der Korrekturwert K vor, der aber unter Umständen noch für ein falsches Empfangsgebiet gilt. Im Arbeitsschritt 4.5 wird das Identifikationssignal ID mit dem Inhalt eines Speichers 7 verglichen. Im Beispiel enthält der Speicher eine Vielzahl zu empfangender Identifikationscodes (Station 1, Station 2 ...) von denen einige durch ein Zeichen (>) markiert sind. Es werden genau die Codes der Sendestationen 1 im Speicher 7 markiert, deren Zeitinformationen t für das Empfangsgebiet richtig sind. Die übrigen, beispielsweise weit entfernten ausländischen Sendestationen, sind unmarkiert. Markierungen können entweder vor der Auslieferung des Systems an einen Kunden installiert werden, oder auch frei vom Kunden selbst programmiert bzw. umprogrammiert werden. Es ist eine hier nicht dargestellte Diagnoseschnittstelle vorgesehen, über die das Programm der Steuereinrichtung 4 ein- und auslesbar ist.After switching on the receiver 2 via the on / off switch 3, the radio signals are transmitted to the control device 4. In a selection step 4.1, a query is made as to whether the control device 4 is in operation, that is to say synchronization of the clock 5 is desired at all. By actuating a switch or button, not shown in detail, the control device 4 can be put out of operation or put back into operation. If the control device 4 is in operation (on), a query is made in a second selection step 4.2 as to whether time signals t and identification signals ID have been transmitted at all. This is necessary because not all of the transmitting stations 1 are yet broadcasting this information together with the radio signals. If the information is included (yes), it is decoded in step 4.3, the time information t being present in the form of hour / minute / second hh / mm / ss and an exact identifier of the transmitting station (XY) and / or a country code. In step 4.4, the radio-transmitted time t is the current time T Clock 5 compared by the difference $\text{K = t - T}$

is formed. The result is the correction value K, which, however, may still apply to an incorrect reception area. In step 4.5, the identification signal ID is compared with the content of a memory 7. In the example, the memory contains a large number of identification codes to be received (station 1, station 2 ...), some of which are marked with a character (>). Precisely the codes of the transmitting stations 1 are marked in the memory 7, the time information t of which is correct for the reception area. The remaining foreign broadcasting stations, for example far away, are unmarked. Markings can either be installed before the system is delivered to a customer, or can be freely programmed or reprogrammed by the customer. A diagnostic interface (not shown here) is provided, via which the program of the control device 4 can be read in and out.

) kann der Korrekturwert K komplett in der Form hh/mm/ss an die Steuereinheit 6 weitergeleitet werden. Die aktuelle angezeigte Zeit T der Uhr 5 ist ggf. um Stunden, Minuten und Sekunden zu verstellen. Ist das empfangene Identifikationssignal ID nicht im Speicher 7 markiert ( $\text{ID = >}$

)oder nicht im Speicher 7 vorhanden, wird vom bisherigen Korrekturwert K im Abschnitt 4.7 die eventuell vorhandene Stundenzahl hh subtrahiert, so daß der neue Korrekturwert K nur noch Minuten mm und Sekunden ss enthält. Dieser Korrekturwert K wird dann an die Stelleinheit 6 übermittelt und zur Korrektur der Zeit T verwendet. Im Maximalfall kann dieser Korrekturwert K dann 59 Minuten und 59 Sekunden betragen. Da es unwahrscheinlich ist, daß die Uhr 5 um annähernd eine Stunde falsch geht, kann nach dem Arbeitsschritt 4.7 noch vorgesehen sein, daß der Korrekturwert K, der sich aus dem Funksignal eines unmarkierten Senders 1 ergibt, auf maximal dreißig Minuten begrenzt wird. Dies ist in der Figur nicht dargestellt. Der Korrekturwert ± K (mm/ ss) wird je nach Vorzeichen auf ± 60/00 ergänzt. Der Ergänzungswert findet dann mit gewechseltem Vorzeichen als Korrekturwert K' Anwendung. Beispielsweise wurde im Schritt 4.7 ein Korrekturwert K = - 54/20 ermittelt. Der Ergänzungswert auf - 60/00 beträgt - 05/40. Zur Korrektur der Uhr 5 fände dann ein Korrekturwert K' = + 05/40 Anwendung, der im Betrag nicht größer als ± 30/00 werden kann.In step 4.6, a program branch takes place, which takes place depending on the result of the comparison in step 4.5. Is the received identification signal ID marked in memory 7 ( $\text{ID =>}$

) the correction value K can be completely passed on to the control unit 6 in the form hh / mm / ss. The current displayed time T of the clock 5 may need to be adjusted by hours, minutes and seconds. If the received identification signal ID is not marked in the memory 7 ( $\text{ID =>}$

) or not available in the memory 7, the possibly existing number of hours hh is subtracted from the previous correction value K in section 4.7, so that the new correction value K only contains minutes mm and seconds ss. This correction value K is then transmitted to the actuating unit 6 and used to correct the time T. In the maximum case, this correction value K can then be 59 minutes and 59 seconds. Since it is unlikely that the clock 5 will go wrong by approximately one hour, it can be done after the work step 4.7 can also be provided that the correction value K, which results from the radio signal of an unmarked transmitter 1, is limited to a maximum of thirty minutes. This is not shown in the figure. The correction value ± K (mm / ss) is expanded to ± 60/00 depending on the sign. The supplementary value is then used with a changed sign as the correction value K '. For example, a correction value K = - 54/20 was determined in step 4.7. The additional value to - 60/00 is - 05/40. A correction value K '= + 05/40 would then be used to correct the clock 5, the amount of which cannot be greater than ± 30/00.

After the transmission of the correction value K (or K '), the clock 5 is adjusted via the setting unit 6, so that it then goes correctly. No more time-consuming reading of operating instructions and programming is necessary to adjust the clock 5. It is sufficient to briefly switch on the receiver 2 to initiate the correction. A correction is briefly signaled by a symbol on the display unit of clock 5. The changeover from summer to winter time and vice versa takes place when receiver 2 receives a home station. When radio signals from far-away transmission stations 1 are received, the current time T of the clock 5 is only corrected in the minute range.

The control device 4 accommodated in the receiver 2 or the clock 5 is to be designed as an extremely space-saving electronic circuit and preferably consists of a decoder, a comparator, the memory 7, a filter and a read / write memory and a data bus. The detailed design of the circuit will not be described in detail here, since there are a large number of technical options.

Claims (12)

Control device (4) for a clock (5) to be synchronized by radio signals with its own drive, wherein - The control device (4) from a transmitting station (1) and received by a receiver (2) received radio signals containing current time signals (t) are fed, - The signals are decoded in the control device (4) and the time signals (t) are extracted, - A current time information (t) resulting from the time signals (t) is compared with the currently displayed time (T) of the free-running clock (5) and the latter is corrected if necessary and - The free-running clock (5) is not corrected if the time signals (t) are not received or are not received exactly, characterized in that - The control device (4) decodes and transmits an identification signal (ID) which is transmitted together with the radio signals and which defines the transmitting station (1) and / or its home country - The currently displayed time (T) of the clock (5) is corrected as a function of the identification signal (ID) by less than an hour or without a correction value (K) being limited. Control device (4) according to claim 1, characterized in that the correction of the currently displayed The time (T) of the clock (5) only takes place without limiting the correction value (K) when radio signals from a vehicle-specific or a local transmitter station (1) are received. Control device (4) according to Claims 1 and 2, characterized in that the free-running clock (5) is a quartz clock (5) with a digital or analog display unit and that the correction of the currently displayed time (T) is carried out via a control device (4 ) connected actuator (6). Control device (4) according to claims 1 to 3, characterized in that a symbol temporarily displayed in the display unit of the clock (5) indicates that the time (T) has been corrected. Control device (4) according to at least one of claims 1 to 4, characterized by a memory unit (7) in which at least one identification signal (ID) is stored. Control device (4) according to Claim 5, characterized in that the decision as to whether a time correction of less than an hour or an unlimited time correction may be made is made as a function of whether the identification signal (ID) stored in the memory unit (7) is received, which can be determined by a comparison operation within the control device (4). Control device (4) according to at least one of Claims 1 to 4, characterized in that approximately all identification signals (ID) to be received are stored in a memory (7), selected ones Identification signals (ID) can be marked in the memory (7). Control device (4) according to Claim 7, characterized in that the decision as to whether a time correction of less than one hour or an unlimited time correction may be made is made depending on whether a marked or an unmarked identification signal (ID) is received, which can be determined by a comparison operation within the control device (4). Control device (4) according to Claims 1 to 8, characterized in that program and memory data can be read in and read out via a diagnostic interface. Control device (4) according to claims 1 to 9, characterized in that it can be switched on or off independently of the receiver (2). Control device (4) according to claims 1 to 10, characterized in that it is an integral part of the receiver (2) or the free-running clock (5). Control device (4) according to at least one of Claims 1 to 11, characterized in that the following main electronic components are provided: a decoder which extracts time signals (t) and identification signals (ID) from radio signals received by the radio receiver (2) and decodes them, - A comparator that the received time information (t) with the current time (T) of the free running Clock (5) and compares a received identification signal (ID) with in one - memory (7) compares stored identification signal (ID), a filter which, upon receipt of certain identification signals (ID), contains the entire time information (t) [or Correction information (K)] and, when other identification signals (ID) are received, trimmed time information (t) [or Correction information (K)] one - Read / write memory feeds as well - A data bus for information exchange between the receiver (2), control device (4), actuating device (6) and clock (5), with one - Diagnostic interface for external data exchange.

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