Abstract:
An audio and video recording and reproduction apparatus of the present invention is an audio and video recording and reproduction apparatus, comprising: an input switching device for switching an input between a first input signal including a first audio and video signal which is input from a first input, a second input signal including a second audio and video signal which is input from a second input, and a third input signal including a third audio and video signal which is input from a third input, and for outputting one of the first signal, the second signal, and the third signal; and a recording device for recording the second input signal and the third input signal on the information recording medium as one recording unit when the input switching device switches the input from the second input signal to the third input signal.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to an audio and video recording and reproduction apparatus, and in particular to an audio and video recording and reproduction apparatus for converting an audio and video signal to digital data, for separating the digital data into a data file and management information regarding the data file in every recording unit, and recording the data file and the management information on an information recording medium. 
   2. Description of the Related Art 
   As used herein, a “recording unit” refers to a unit of audio and video information used in managing audio and video information during reproduction of recorded audio and video information. 
   An audio and video recording and reproduction apparatus for converting an audio and video signal to digital data, for separating the digital data into a data file and management information regarding the data file in every recording unit, and recording the data file and the management information on an information recording medium has been used. 
   When this audio and video recording and reproduction apparatus switches an input from a first input to a second input in a recording pause mode, an audio and video signal corresponding to the first input before the switching and an audio and video signal corresponding to the second input after the switching are recorded on an information recording medium as different recording units. 
   However, when a plurality of line inputs are switched with each other (for example, a camera input and a title input) for editing a program, the conventional audio and video recording and reproduction apparatus causes audio and video signals before and after the switching to be recorded as different recording units. This manner of recording causes inconvenience in managing the edited program. 
   SUMMARY OF THE INVENTION 
   According to one aspect of this invention, there is provided an audio and video recording and reproduction apparatus, comprising: an input switching device for switching an input between a first input signal including a first audio and video signal which is input from a first input, a second input signal including a second audio and video signal which is input from a second input, and a third input signal including a third audio and video signal which is input from a third input, and for outputting one of the first input signal, the second input signal, and the third input signal; and a recording device for recording the second input signal and the third input signal on the information recording medium as one recording unit when the input switching device switches the input from the second input signal to the third input signal. 
   In one embodiment of the invention, the first input includes a tuner input; the second input includes a line input; and the line input includes a first line input to which the second input signal is input and a second line input to which the third input signal is input. 
   In one embodiment of the invention, the recording device performs: a first recording operation for recording one of the first input signal, the second input signal, and the third input signal; a recording pause operation for allowing the input switching device to switch the input between the first input signal, the second input signal and the third input signal; and a second recording operation performed after the input switching device switches the input between the first input signal, the second input signal and the third input signal. 
   In one embodiment of the invention, the recording device records the third input signal and the second input signal, which are output from the input switching device, as one recording unit when the input switching device switches the input from the third input signal to the second input signal. 
   In one embodiment of the invention, the recording device records the first input signal and the second input signal, which are output from the input switching device, as different recording units when the input switching device switches the input from the first input signal to the second input signal. 
   In one embodiment of the invention, the recording device records the first input signal and the third input signal, which are output from the input switching device, as different recording units when the input switching device switches the input from the first input signal to the third input signal. 
   In one embodiment of the invention, the recording device records the second input signal and the first input signal, which are output from the input switching device, as different recording units when the input switching device switches the input from the second input signal to the first input signal. 
   In one embodiment of the invention, the recording device records the third input signal and the first input signal, which are output from the input switching device, as different recording units when the input switching device switches the input from the third input signal to the first input signal. 
   In one embodiment of the invention, the first input signal includes a fourth input signal and a fifth input signal selected from a multiplexed information signal which is received by a tuner over a radio wave or a wired transmission path; and the recording device records the fourth input signal and the fifth input signal, which are output from the input switching device, as different recording units when the input switching device switches the input from the fourth input signal to the fifth input signal. 
   In one embodiment of the invention, the recording device converts the first audio and video signal, the second audio and video signal and the third audio and video signal to digital data, separates the digital data into a data file and management information regarding the data file in every recording unit, and records the data file and the management information on the information recording medium. 
   In one embodiment of the invention, the audio and video recording and reproduction apparatus further comprises a reproduction device for reproducing the data file by reading the data file from the information recording medium based on the management information recorded on the information recording medium. 
   Thus, the invention described herein makes possible the advantages of providing an audio and video recording and reproduction apparatus which is capable of automatically producing satisfactory program management information. 
   These and other advantages of the present invention will become apparent to those skilled in the art upon reading and understanding the following detailed description with reference to the accompanying figures. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a block diagram of an audio and video recording and reproduction apparatus according to one example of the present invention. 
       FIG. 2  is a timing diagram illustrating an operation of the audio and video recording and reproduction apparatus shown in  FIG. 1 . 
       FIG. 3  is a diagram illustrating a logical arrangement of the data recorded on an information recording medium by the audio and video recording and reproduction apparatus shown in  FIG. 1 . 
       FIG. 4  is a timing diagram illustrating another operation of the audio and video recording and reproduction apparatus shown in  FIG. 1 . 
       FIG. 5  is a diagram illustrating a logical arrangement of the data recorded on the information recording medium by the audio and video recording and reproduction apparatus shown in  FIG. 1 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  is a block diagram of an audio and video recording and reproduction apparatus  100  according to one example of the present invention. The audio and video recording and reproduction apparatus  100  includes an input switching device  101 , a recording device  102 , a reproduction device  103 , a system control device  104 , and line input terminals  105 ,  106 , and  107 . The recording device  102  includes a recording circuit  108 , an audio and video file production circuit  109 , and a file management information production circuit  110 . The reproduction device  103  includes a reproduction circuit  113 , an audio and video file reading circuit  111 , and a file management information reading circuit  112 . For simplicity, an analog-to-digital converting circuit included in the audio and video file production circuit  109  and an digital-to-analog converting circuit included in the audio and video file reading circuit  111  are omitted in  FIG. 1 . 
   The audio and video recording and reproduction apparatus  100  operates as follows. 
   A tuner  151  receives a multiplexed information signal over a radio wave or a wired transmission path. The tuner  151  selects a station from a plurality of stations based on a station selection command received from the system control device  104 . The input switching device  101  selects either an audio and video signal from the station selected by the tuner  151  or audio and video signals which are input from the line input terminals  105 ,  106 , and  107  based on an input switching command received from the system control device  104 , and outputs the selected audio and video signal to the audio and video file production circuit  109 . 
   The audio and video file production circuit  109  performs analog-to-digital conversion of the audio and video signal selected by the input switching device  101  to output a digital audio and video signal. The file management information production circuit  110  produces file management information for managing the digital audio and video signal as a file. The recording circuit  108  records the digital audio and video signal and the file management information produced by the file management production circuit  110  on an information recording medium  152 . 
   The reproduction circuit  113  reads the audio and video signal and the file management information recorded on the information recording medium  152 . The audio and video file reading circuit  111  performs digital-to-analog conversion of the audio and video signal read by the reproduction circuit  113  to output an analog audio-digital signal. The file management information reading circuit  112  controls the operation of the audio and video file reading circuit  111  based on the file management information read by the reproduction circuit  113 . 
     FIG. 2  is a timing diagram illustrating an operation of the audio and video recording and reproduction apparatus  100  ( FIG. 1 ). In this operation, the input switching device  101  switches the input between the line input terminals  105 ,  106 , and  107 , and the line inputs before and after the switching (i.e., the pause period) are recorded on the information recording medium  152  as one recording unit. 
   At time t 0 , the input switching device  101  selects the line input terminal  105 . The recording device  102  records an audio and video signal which is input from the line input terminal  105  on the information recording medium  152  as a recording unit referred to as program  1 . At time t 1 , the recording device  102  pauses the recording. Then, the input switching device  101  selects the line input terminal  106 . 
   At time t 2 , the recording device  102  records an audio and video signal which is input from the line input terminal  106  on the information recording medium  152  also as a recording unit referred to as program  1 . At time t 3 , the recording device  102  pauses the recording. Then, the input switching device  101  selects the line input terminal  107 . 
   At time t 4 , the recording device  102  records an audio and video signal which is input from the line input terminal  107  on the information recording medium  152  also as a recording unit referred to as program  1 . At time t 5 , the recording device  102  pauses the recording. Then, the input switching device  101  selects the line input terminal  105 . 
   At time t 6 , the recording device  102  records an audio and video signal which is input from the line input terminal  105  on the information recording medium  152  also as a recording unit referred to as program  1 . At time t 7 , the recording device  102  stops the recording. 
   The audio and video signal which is input from the line input terminal  105 , the audio and video signal which is input from the line input terminal  106 , and the audio and video signal which is input from the line input terminal  107  are recorded as the same recording unit. Thus, recording counter values are added from the start of the recording (time t 0 ) to the stop of the recording (time t 7 ) except for the pausing periods (from time t 1  to time t 2 , from time t 3  to time t 4 , and from time t 5  to time t 6 ). 
     FIG. 3  is a diagram illustrating a logical arrangement of the data recorded on the information recording medium  152  by the audio and video recording and reproduction apparatus  100 . As described with reference to  FIG. 2 , the audio and video signals before and after the switching are recorded on the information recording medium  152  as one recording unit. 
   The recorded data includes file management information  301  and audio and video information  306 . The file management information  301  includes address information  302  and size information  303 . The address information  302  includes start address information  304  and end address information  305 . 
   As described with reference to  FIG. 2 , the audio and video signals before and after the switching are recorded on the information recording medium  152  as one recording unit when the input switching device  101  switches the input between the line input terminals  105 ,  106 , and  107 . Thus, the file management information  301  has a single unit of file management data  307 . Also, the audio and video information  306  has a single unit of audio and video data  308 . The audio and video data  308  includes an audio and video signal  309  which is input from the line input terminal  105  and recorded from time t 0  to time t 1 , an audio and video signal  310  which is input from the line input terminal  106  and recorded from time t 2  to time t 3 , an audio and video signal  311  which is input from the line input terminal  107  and recorded from time t 4  to time t 5 , and an audio and video signal  312  which is input from the line input terminal  105  and recorded from time t 6  to time t 7 . 
   When the input switching device  101  switches the input from one of the line input terminals  105  to  107  to another one of the line terminals  105  to  107 , the recording device  102  records the audio and video signals before and after the switching on the information recording medium  152  as one recording unit. 
     FIG. 4  is a timing diagram illustrating another operation of the audio and video recording and reproduction apparatus  100 . In this operation, the input switching device  101  switches the input between channels selected by the tuner  151 , and between one of the line input terminals  105  to  107  and the channel selected by the tuner  151 , and the line inputs before and after the switching (i.e., the pause period) are recorded on the information recording medium  152  as different recording units. 
   At time t 8 , the input switching device  101  selects channel A selected by the tuner  151 . The recording device  102  records an audio and video signal corresponding to channel A on the information recording medium  152  as one recording unit referred to as program  1 . At time t 9 , the recording device  102  pauses the recording. Then, the input switching device  101  selects channel B selected by the tuner  151 . 
   At time t 10 , the recording device  102  records an audio and video signal corresponding to channel B on the information recording medium  152  as a recording unit referred to as program  2 , which is different from program  1 . At time t 11 , the recording device  102  pauses the recording. Then, the input switching device  101  selects the line input terminal  106 . 
   At time t 12 , the recording device  102  records an audio and video signal which is input from the line input terminal  106  on the information recording medium  152  as a recording unit referred to as program  3 , which is different from programs  1  and  2 . At time t 13 , the recording device  102  pauses the recording. Then, the input switching device  101  selects channel C selected by the tuner  151 . 
   At time t 14 , the recording device  102  records an audio and video signal corresponding to channel C on the information recording medium  152  as a recording unit referred to as program  4 , which is different from programs  1  to  3 . At time t 15 , the recording device  102  pauses the recording. At time t 16 , the recording device  102  records an audio and video signal corresponding to channel C on the information recording medium  152  also as the recording unit referred to as program  4 . The audio and video signals are recorded as the same recording unit at time t 14  and time t 15  because the input switching device  101  does not switch the input between time t 14  and time t 15 . At time t 10 , time t 12 , and time t 14 , the recording counter value is reset because the recording of the audio and video signal as a different recording unit is started. 
     FIG. 5  is a diagram illustrating another logical arrangement of the data recorded on the information recording medium  152  by the audio and video recording and reproduction apparatus  100 . As described with reference to  FIG. 4 , the audio and video signals before and after the switching are recorded on the information recording medium  152  as different recording units. 
   The recorded data includes file management information  501  and audio and video information  506 . The file management information  501  includes address information  502  and size information  503 . The address information  502  includes start address information  504  and end address information  505 . 
   As described with reference to  FIG. 4 , the audio and video signals before and after the switching are recorded on the information recording medium  152  as different recording units. Thus, the file management information  501  includes a plurality of units of file management data  507 ,  508 , . . . . The audio and video information  506  includes a plurality of units of audio and video data  509 ,  510 , . . . respectively corresponding to the file management data  507 ,  508 , . . . . 
   When the input switching device  101  switches the input between the channels selected by tuner  151 , and between one of the line input terminals  105  to  107  and the channel selected by the tuner  151 , the recording device  102  records the audio and video signals before and after the switching as different recording units. 
   As described above, according to the present invention, a program can be recorded as follows. When a channel is switched to another channel during a pause of recording, the programs before and after the switching are recorded as different recording units. When a line input is switched to another line input during a pause of recording, the audio and video recording and reproduction apparatus is determined to be in an editing mode, and the signals before and after the switching are recorded as the same unit. Therefore, satisfactory program management information can be produced automatically. 
   Various other modifications will be apparent to and can be readily made by those skilled in the art without departing from the scope and spirit of this invention. Accordingly, it is not intended that the scope of the claims appended hereto be limited to the description as set forth herein, but rather that the claims be broadly construed.