Patent Publication Number: US-7715283-B2

Title: Method for recording information, in particular audio signals, received via radio, in particular broadcast radio

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application is a divisional of prior U.S. application Ser. No. 10/453,443 filed Jun. 2, 2003 now U.S. Pat. No. 7,561,495, and claimed priority to German Application No. DE 102 25624.1 filed Jun. 7, 2002, all of which are incorporated herein by reference. 

   BACKGROUND INFORMATION 
   Broadcast radio receivers in the form of car radios having a traffic message recording function are known, in which audio signals received via broadcast radio, here in the form of spoken traffic messages, are stored in an audio signal memory of the device in response to a traffic message identifier that accompanies the traffic reports and is also broadcast by radio. When its capacity is exceeded as a result of newly received traffic messages, the memory of the device is regularly overwritten by the latest messages. The currently stored traffic messages can be recalled when desired by the user and reproduced acoustically. 
   Particularly from the field of home entertainment electronics, recording devices are known by which (audio) signals received via broadcast, for example radio or television broadcast, can be recorded from the current program. 
   SUMMARY OF THE INVENTION 
   The method according to the present invention has the advantage over the related art that even when the playback of an audio signal which interests the user or the transmission of information has already begun, the user can nevertheless completely record the entire audio signal unit or information unit, for example, the complete piece of music which has already been partially played back. 
   For this purpose, according to the present invention, there is a buffer memory (also referred to below as the first memory), into which all information received, in particular audio signals, is regularly written; when the recording capacity of the buffer memory is exceeded, its content is overwritten by newly received information, beginning with the oldest stored signals. The memory capacity of the buffer memory is advantageously designed so that it is possible to record at least a segment of a received signal, in particular an audio signal, in particular a music signal, to enable the user to judge whether the audio signals just received and played back are of particular interest to him/her and hence worth storing. According to the present invention, at a record command the content of the buffer memory is transferred into a memory (referred to below as the second memory) and thus stored for later playback. 
   According to an advantageous refinement of the present invention, the information signals of the same information unit which are received by radio following the recorded information, in particular audio signals, in particular of the same piece of music, are saved to the second memory, preferably at memory locations following the first segment of information. Thus a complete information unit, in particular an audio signal unit, in particular a complete piece of music, is available in the second memory to be recalled for subsequent repeated playback. 
   In an advantageous embodiment of a radio receiver for carrying out the method, for short-term temporary storage of the information signal received by radio, in particular an audio signal, the receiver uses a buffer, which is needed for error correction in conjunction with a playback device for disk-shaped recording media (CD, DVD, . . . ) that is integrated into the radio receiver. A buffer of this type (shock proof memory) typically has sufficient recording capacity for buffering the information signal received by radio, in particular an audio signal, according to the present invention. Moreover, the buffer is not needed for disk playback (CD, DVD, . . . ) in radio playback mode, in particular broadcast radio playback mode, and can thus be co-utilized advantageously for other purposes. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows a schematic diagram of the part of a car radio important to the present invention, as an example of a system for carrying out the method according to the present invention. 
       FIG. 2  shows a schematic depiction of the process of recording an audio signal received via radio. 
       FIG. 3  shows a detailed schematic depiction of the process of recording an audio signal received via radio. 
       FIG. 4  shows the view of a front cover of a car radio for carrying out the method according to the present invention. 
       FIG. 5  shows a detailed schematic depiction of the process of recording an audio signal received via radio according to an alternative exemplary embodiment of the present invention. 
   

   DETAILED DESCRIPTION 
     FIG. 1  shows a schematic diagram of a radio receiver  1  for carrying out the method of the present invention, using the example of a car radio that is designed to receive frequency modulated radio signals in the VHF frequency band. The modulation content of these VHF broadcast signals regularly includes radio program signals intended for acoustic playback, i.e. audio signals, including pieces of music. 
   A mixture of VHF reception signals receivable at the receiving location, that are present at a receiving antenna  18 , is conducted to a receiving section  10  of the car radio. In a manner already known and therefore not explained in greater detail here, receiving section  10  has the circuitry for selecting and demodulating a particular one of the receivable VHF reception signals. Accordingly, modulation content  101  of the selected and demodulated VHF reception signal, i.e. the actual radio program, is present at the output of receiving section  10 . 
   Continuously received radio program  101  is recorded in a first memory (also buffer memory)  13  in a radio playback mode described below. First memory  13  preferably has limited storage capacity, so that it can store an audio signal segment of 30 seconds in length, for example. In addition, first memory  13  is designed so that in the event that its storage capacity is completely exhausted by stored audio signals, the oldest of the recorded signals are overwritten by newly received audio signals. Consequently, at any given moment of observation the audio signals received in the last 30 seconds are stored in first memory  13 . 
   According to a particularly advantageous embodiment of the present invention, in a broadcast playback mode in which the received radio program is played back through speakers connected to the car radio, a “shock proof memory” is used as first memory  13 . The “shock proof memory” is a buffer memory for temporary storage of audio signals read from an audio signal medium in disk format, for example a compact disk (CD) or digital versatile disk (DVD) or the like. Such a recorded data medium in disk format and the associated reading device is widely used in present-day car radios, and is marked with the reference symbol  17  in  FIG. 1 . As is generally known, disk reading devices are sensitive to shock; as a result of shocks to the reading devices, errors occur in reading the disk media, which result in audibly deficient audio signals. For that reason, an earlier patent application which is commonly assigned provided that audio signals  171  be read out at a higher speed than required for playback, and that the resulting data surplus be buffered for the purpose of error correction. The storage capacity of the “shock proof memory” used for that purpose is normally in the range of some tens of seconds, for example 30 seconds. 
   In a broadcast playback mode, continuously received radio program  101  is played back through a source selector switch  11  as playback signal  111  through a playback device  12 . For this purpose, in a manner already known and therefore not explained in greater detail here, playback device  12  has the necessary means for volume adjustment and amplification and for influencing the sound of playback signal  111  if appropriate, as well as attached speakers for converting playback signal  111  to a sound event. Source selector switch  11  is switched among various playback modes by a control unit  16  of the car radio that includes control elements, using a source selection signal  165 . In the present case, for example, provision is made for CD or DVD playback (corrected CD or DVD audio signal  172 , if appropriate), broadcast playback mode (radio program signal  101 ), or playback of audio signals  151  recorded in a second memory  15 , for example a multi-media card (MMC). 
   Depending on the desired playback mode, source selector switch  11  routes one of the forenamed audio signals, radio  101 , MMC  151  or CD  172 , as directed by source selector signal  165 , to the input of playback device  12  as playback signal  111  for playback. 
   The above-described radio receiver also has a recording function, described in greater detail below, for recording audio signals received via radio on another recording medium, for example an MMC, which is represented in the figure by second memory  15 . 
   Received audio signal (radio program signal)  101  is conducted for this purpose through a release switch  14  to second memory  15 . Release switch  14  is actuated by control unit  16 ; after a record command is initiated by the user through control unit  16 , a release signal  162  connects release switch  14  through to convey received audio signal  101  to second memory  15 . In addition, a copy signal  161  initiated by the record command causes memory content  102  of first memory  13 , i.e. the segment of audio signal  101  written to first memory  13 , to be output to second memory  15 . Finally, a transfer signal  163  to second memory  15 , issued by the control unit in response to the record command, causes content  102  of first memory  13  to be transferred to second memory  15  and also currently received audio signal  101  to be recorded at memory locations in second memory  15  following the content transferred from the first memory. Consequently, content  102  of first memory  13  and immediately thereafter, currently received audio signal  101  is written first to second memory  15  ( FIG. 2 ). 
   A detailed illustration of the recording process is given in  FIG. 3 , using the example of recording pieces of music from a continuously received broadcast program. In the case of the embodiment on which  FIG. 3  is based, the radio receiver is one for receiving broadcast signals transmitted according to a digital standard, such as “XM” or “SIRIUS.” Along with the actual radio program (music, spoken comments), additional information is transmitted, including for example, in the case of a piece of music  23  that is just being transmitted, the name of the artist or interpreter, the title of piece  23 , and beginning and end markers for piece  23  that is just being transmitted. 
   The currently received audio signals are written into first memory  13 , that is, the above-described buffer memory, in such a way that the oldest audio signals present in the memory are always overwritten by audio or music signals just received. 
   At an observation moment captured in  FIG. 3 , there are in memory  13  still audio signals of an older piece of music  22 , as well as its end marker  222 , which was also recorded. Subsequently, additional audio data  23   a  of music piece  23  just received, as well as its beginning marker  231 , are stored in memory  13 . Audio data  23   a  represent audio signals  101  of currently receivable music piece  23 , already broadcast at the moment of observation and received by radio broadcast receiver  1 . 
   Now if a record command is initiated at the moment depicted in  FIG. 3 , for example by operation of a corresponding control element on control  16  by the user, the content of first memory  13 , beginning with beginning marker  231  of currently receivable music piece  23 , i.e. the already received and buffered audio signal segment  23   a  of piece  23 , is copied to a free memory location in second memory  15 . The first free memory location in memory  15  follows music pieces  24 ,  25  and  26 , which are already stored there in the same manner. The record command also causes segment  23   b  of currently received music piece  23 , which is still to be received, to be written directly into second memory  15  from continuously received radio program signal  101  (=audio signal). Here second segment  23   b  of music piece  23  is written immediately following first audio signal segment  23   a  of music piece  23 , which was first buffered in first memory  13  and then copied to the second memory. The recording of second audio signal segment  23   b  from the ongoing program is terminated upon recognition of end marker  232 , which is received along with the audio signal. A subsequently received additional signal  27 , identified by the beginning marker  271 , is then written again to first memory  13  in the described manner. 
   If the receivable broadcast signal transmits no end marker for audio signal units, but instead only a beginning marker, a total length of the piece of music and/or a display of progress, the end of the writing to second memory  15  may be determined from the current program on the basis of the beginning marker and the total length of the piece, or alternatively or additionally on the basis of the total running time of the piece and of the progress display, by comparison with an internal clock within the device. 
   If no data directly or indirectly indicating the end of the piece of music are transmitted or received, this may be determined by recognition of a signal pause, for example through zero level detection, and the recording process may be terminated upon recognition of the signal pause. 
   Even if the user initiates a record command at control unit  16  only after playback of an audio signal received via radio has begun, in particular for example a piece of music, the described recording process nevertheless causes the entire audio signal unit  103 , in particular the entire music piece  23 , to be recorded in second memory  15 , including its beginning, which preceded the triggering command in time. 
   However, that requires the record command to be given at control unit  16  by the user within the recording period after the beginning of the audio signal received by radio specified by the capacity of first memory  13 . A recording capacity of first memory  13  of about 30 seconds appears to be adequate. 
   According to a refinement of the present invention, a means of blocking the recording may be provided for cases where the record command is not given within the period after the beginning of the audio signal specified by the recording capacity of first memory  13 . Consequently, audio signal units whose beginning is no longer available due to the limited capacity of first memory  13  are not recordable in second memory  15 . 
   As described, the beginning of an audio signal unit, in particular a piece of music, may be recognized for example by zero level detection, i.e. by testing the received audio signals for segments in which the level of the signal drops below a specified value for a prescribed length of time. Suitable values for the specified value of the audio signal level may preferably be determined empirically and as a function of background noise or a measure of reception disturbances. That ensures reliable recognition of pauses, even with poor or noisy received audio signals. The specified time period after which a zero level is recognized as a pause in the audio signal may also be determined empirically, for example as a function of the dynamics of the received audio signal. 
   The described zero level detection for recognizing the beginning may also be used for limiting the signal copied from first memory  13  into second memory  15  at the record command. That makes it possible to prevent portions of the signal that occur earlier than the beginning of the audio signal unit (music piece), which have not yet been overwritten in first memory  13 , from being copied into second memory  15  as signal components supposedly belonging to the beginning of the current audio signal unit. 
   It is possible for example in the case of a receiver for digital radio broadcast signals to also transmit beginning and/or end markers for audio signal units by radio. These may then be utilized advantageously instead of the described zero level detection to recognize the beginning of an audio signal unit  103  which has been recorded or is to be recorded. For example, in the “XM” satellite broadcast system operated in the U.S., as mentioned, alongside a music signal, the names of the artist and the piece of music are also transmitted periodically, as well as the length and progress, in time units, of the piece of music currently being transmitted, and furthermore the length and starting time of the piece that will follow next. The satellite broadcast system “SIRIUS,” which is also operated in the U.S., is similar. The time data included in the transmission can be used in conjunction with a clock provided in receiver  1 , to recognize the beginning of a piece of music or an audio signal unit. 
   By using an appropriate selection command via control unit  16 , instead of a current radio transmission or a CD or DVD signal the audio signal stored in second memory  15  may be played back via source selector switch  11  and playback unit  12 . To this end, control unit  16  generates a corresponding selection control command  164  to control second memory  15  to emit the stored audio signal, and a corresponding source selection command  165  to switch source selector switch  11  over to the output of second memory  15 . 
   Second memory  15  may be advantageously implemented for example as a card read/write device for memory chip cards, in particular for example for an MMC (multi media card) with embedded storage medium (MMC). 
   Particularly advantageous is an implementation of second memory  15  in which the actual storage media are exchangeable, as in the case of the MMC. An alternative implementation of second memory  15  could be for example a read/write device for the essentially-known MiniDisc™ (MD), where the MiniDisc may be utilized as a replaceable storage medium. Alternatively, second memory  15  could be implemented for example in the form of a removable hard drive, or a miniature hard drive such as the Microdrive™. 
   Even though the described exemplary embodiment is directed substantially at a car radio for receiving FM-modulated radio broadcast signals transmitted in the VHF band, having integrated CD or DVD playback device, this is not intended to limit the object of the present invention in any way. Rather, the present invention is certainly applicable in principle to all radio receivers, whether for example to radio receivers for digital broadcasts such as DAB (digital audio broadcasting), satellite radio or the like. In the case of coded audio signals, in particular those transmitted in compressed form, for example according to MPEG-2, MPEG-3 or some other standard, these signals may also be written advantageously in compressed form to first and second memories  13 ,  15 . This permits improved memory utilization, and consequently greater memory capacity, in the case of first memory  13  in particular a longer response time for the user to enter the record command after playback of the audio signal being received has begun. In this case, the decoding is advantageously integrated into playback unit  12 , to which the audio signals that are present in coded form are supplied for the purpose of playback. 
   An additional exemplary embodiment of the present invention will be explained next on the basis of  FIGS. 4 and 5 . 
   This embodiment is also based on the radio or broadcast receiver as described above in particular in reference to  FIG. 1 , but also the additional  FIGS. 2 and 3 . A significant difference between this embodiment and the radio receiver named above is in the recording capacity of first memory  13 , which is preferably designed in the present case so that a number of pieces of music of average length (for example  3 . 5  minutes), for example five pieces, may be stored in first memory  13 . First memory  13  may also be implemented here as a separate memory component, such as flash memory, but it is also possible to reserve a memory segment in second memory  15  to implement first memory  13  and buffer the most recently received audio signals. As with the exemplary embodiment described earlier, the current content of first memory  13 , in which the audio signals received most recently via radio are stored, is also overwritten by currently receivable audio signals when its capacity limit is exceeded, so that at any given moment of observation audio signals  21 ,  22 ,  23   a  received immediately before that moment are always present in first memory  13  ( FIG. 5 ). According to  FIG. 5 , together with buffered audio signals  21 ,  22 ,  23   a , corresponding beginning and end markings  211 ,  231  and  212 , if already received, are also stored. 
     FIG. 4  shows the front cover of a car radio  1  according to the present invention which, in the installed state in a motor vehicle, is accessible to the user; at the same time its control unit  16  is shown. The latter includes a display unit  170  on which a variety of information is or may be displayed, such as the name  181  of a radio program currently being received, the name  183  of a piece of music  23  current being received, and the name  182  of the artist or interpreter of the piece of music currently being received. The front cover of car radio  1  also includes control elements, such as a rotatable incrementer  191  for adjusting a selectable parameter, for example the playback volume, or for selecting one of a plurality of radio programs receivable at the reception location, and a four-way rocker switch  192  for maneuvering in a two-dimensional selection menu depictable on display  170  or for selecting a parameter to be set by the incrementer  191 . 
   The front cover also includes station buttons  193 ,  194 ,  195 ,  196  and  197 , on which radio program data are normally stored in conventional car radios for optional selection of a particular radio program. These station buttons  193  through  197  are used in connection with the present invention to select a piece of music  21 ,  22 ,  23  temporarily stored in first memory  13  and to enter a record command to record or transfer the particular piece  21 ,  22  or  23  from first memory  13  into second memory  15 . Here the design also provides for each of the individual station buttons  193  through  197  to be assigned to a piece of music  21 ,  22 ,  23  etc. that is temporarily stored in first memory  13 . The design provides for a maximum number of pieces of music to be stored at all times in first memory  13  corresponding to the number of station buttons  193  through  197  available on front cover  16  of car radio  1 , so that each temporarily stored piece is clearly assignable to a station button. 
   In the case of  FIGS. 4 and 5 , at the moment of observation captured there, two music pieces  21  and  22  with their beginning and end markers  211  and  212  are already completely recorded in first memory  13 . These are assigned to the first two station buttons  193  and  194 . Also present in the first memory is a first segment  23   a  of a third piece of music  23 , together with its beginning marker  231 . Third music piece  23  is assigned to third station button  195 . 
   According to a particularly advantageous implementation of this exemplary embodiment of the present invention, station buttons  193 ,  194 ,  195 ,  196  and  197  may be illuminated individually by individually assigned light sources  173 , 174 ,  175 ,  176  and  177 . The current illumination status of each station button  193  to  197  indicates the assigned memory content of first memory  13 . In the case of  FIGS. 4 and 5 , two pieces of music  21  and  22  are present in their entirety in first memory  13 . 
   Station buttons  193  and  194  assigned to these two pieces are illuminated by their assigned light sources  173  and  174 , for example red. Also present in first memory  13  is a first segment  23   a  of a third piece  23 , which is currently being written into first memory  13 . Station button  195 , assigned to third piece  23 , is illuminated by assigned light source  175 , for example flashing red. The different, in this case flashing, illumination of third station button  195  indicates that third music piece  23  is just being written into the first memory. Additional station buttons  196  and  197  are not illuminated, since no assigned music pieces are present in first memory  13 . 
   Through activation of one of the illuminated station buttons, in the case of  FIGS. 4 and 5   193  or  194 , and the selection and record command which that triggers, assigned music piece  21  or  22  is copied from first memory  13  to the next free memory location in second memory  15 . In the situation shown in  FIG. 5 , there are already music pieces  24 ,  25  and  26  stored in second memory  15 . Upon actuation of second station button  196 , the second music piece  22  present in first memory  13  is copied to the free memory address in the second memory that follows music piece  26 . 
   However, if third flashing station button  195  is actuated, the recording process described earlier in connection with  FIGS. 1 to 3  follows; that is, the first part  23   a  of first music piece  23 , which is already present in the first memory, is copied to the second memory, while the second segment  23   b  of third music piece  23  from currently received broadcast program  101 , which has not yet been recorded, is written directly into second memory  15  at the address immediately following first segment  23   a.    
   The end of the recording of third music piece  23  may be triggered advantageously, as already indicated, by received end marker  232 . Additional music pieces  27  (with beginning marker  271 ) contained in the broadcast signal are then also written to first memory  13  in the described manner. 
   The above exemplary embodiments were described primarily on the basis of audio signals or music pieces. This is not intended to be understood as a restriction to audio signals, however, but rather any other type of information may also be recorded in the same manner, for example, video information or information from data services, such as traffic messages transmitted in coded form for example.