Patent Abstract:
There is disclosed a recording apparatus having first and second recording modes for recording image signals of one frame in tracks, the numbers of which are different in the first and second recording modes. On the first recording mode, a still image is recorded for a first predetermined period. On the second recording mode, a still image is recorded for a second predetermined period. Lengths of these first and second predetermined periods are respectively set according to the first and second recording modes.

Full Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a recording apparatus and, more particularly, an apparatus for recording motion and still images. 
   2. Related Background Art 
   A digital VCR has hitherto been known for recording/reproducing an image signal as a digital signal on a magnetic tape. Recently, HD Digital VCR Council has presented a DV format as a format of a consumer digital VTR. 
   In the DV format, there are defined SD Specifications (SD mode, hereinafter) for recording an image signal of NTSC in ten tracks per one frame, and SD High Compression Specifications (SDL mode, hereinafter) for recording an image signal in five tracks per one frame. On the SDL mode, a quantity of data to be recorded is set to about ½ of that of the SD mode, a tape feeding speed is set to ½ of that of the SD mode, and data of one frame is recorded in five tracks. Accordingly, a recording period can be double as long as that of the SD mode with a tape length equal. 
   As a video camera integral VTR based on such a DV format, there is known one having a photomode for recording still image data of, for example 6 to 7 sec., on a tape for a predetermined period in addition to recording of normal motion image data. 
   As ID used to detect the still image data, photo picture ID (PPID) is defined in the DV format. The PPID must be recorded continuously for 5 sec. 
   In the above-described VTR capable of performing recording/reproducing on the SD mode and the SDL mode, the still image may be recorded on the SD mode and the SDL mode. 
   However, since the SDL mode has a smaller number of tracks per one frame compared with that of the SD mode, when the still image data is searched while the tape is fed at a speed higher than that during normal reproducing, even if the PPID data is detected and the searching operation is finished, a recording position of the target still image data is passed, making it impossible to perform accurate searching. 
   Furthermore, on the photomode, still image data is recorded for a period longer than that of the PPID, normally 6 to 7 sec. Accuracy during searching may vary depending on a recording position of PPID in the period of 6 to 7 sec. No ideas have been presented regarding an optimal recording position of the PPID in the photomode of the SDL mode. 
   SUMMARY OF THE INVENTION 
   An object of the present invention is to solve the above-described problems. 
   Another object of the invention is to accurately detect still image data recorded by a recording mode having a small quantity of information or a small number of tracks per frame. 
   In order to achieve the above-described object, in accordance with an aspect of the prevent invention, there is provided a recording apparatus, comprising: recording mode setting means for setting a first recording mode for recording image data having a first information quantity per unit time, and a second recording mode for recording image data having a second information quantity larger than the first information quantity per unit time; recording means for recording image data on a recording medium; and control means for controlling the recording means to record on the recording medium still image data and detection data for detecting still image according to recording instruction of the still image, wherein the control means controls the recording means to record on the recording medium the still image data of the first recording mode and the detection data for detecting the still image data for a first predetermined period when the first recording mode is set by the recording mode setting means, and to record on the second recording medium the still image of the second recording mode and the detection data for a second predetermined period different in length from the first predetermined period when the second recording mode is set, and wherein a length of the first predetermined period is set according to the first recording mode, and a length of the second predetermined period is set according to the second recording mode. 
   These, other objects and features of the invention will become apparent upon reading of the following detailed description of the preferred embodiments with reference to the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1 , which is comprised of  FIGS. 1A and 1B , is a block diagram showing a configuration of a VTR, to which the present invention is applied. 
       FIG. 2  is a view showing a recording format on an SD mode. 
       FIG. 3  is a view showing an example of a recording format on an SDL mode. 
       FIG. 4  is a view showing a recording format on a DL mode according to an embodiment of the invention. 
       FIG. 5  is a flowchart showing an operation on a photomode according to the embodiment of the invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Hereinafter, description will be made of the preferred embodiment of the present invention. 
     FIGS. 1A and 1B  are functional block diagrams of a camera integrated VTR  100 , to which the invention is applied. The apparatuses of  FIGS. 1A and 1B  records/reproduces image data, audio data and the like in the above-described DV format. 
   In  FIGS. 1A and 1B , a reference numeral  101  denotes a microphone for collecting audios;  102  an audio input processing unit for performing predetermined signal processing for an audio signal captured from the microphone  101 ;  103  an A/D converter for converting an analog audio signal into a digital audio signal;  104  an audio signal encoding unit for encoding an audio signal outputted from the A/D converter  103 ;  105  an image pickup unit for picking up an image of an object;  106  an A/D converter for converting an analog video signal into a digital video signal;  107  a video input processing unit for performing predetermined signal processing for a video signal subjected to A/D conversion according to an SD mode or an SDL mode;  108  a video signal encoding unit for encoding a video signal; and  109  a camera system control unit composed of a microcomputer or the like to control the image pickup unit  105  and the video input processing unit  107  according to instruction of a system control unit  123 . 
   A reference numeral  111  denotes a recording signal processing unit including a data switching unit  11   a  for switching and outputting an encoded digital audio signal, an encoded digital video signal, and subcode data;  112  a mechanical unit including a magnetic head for recording a signal outputted from the recording signal processing unit  111  on a magnetic tape T, and reproducing a digital signal recorded on the magnetic tape T; and  113  a reproduced signal processing unit including a data switching unit  113   a  for switching and outputting the digital audio signal, the digital video signal and the subcode data reproduced from the mechanical unit  112 . The recording signal processing unit  111 , the mechanical unit  112 , and the reproduced signal processing unit  113  constitute a recording/reproducing circuit  110 . 
   A reference numeral  114  a video signal decoding unit for decoding a digital video signal switched and separated by the data switching unit  113   a ;  115  a D/A converter for converting the decoded digital video signal into an analog video signal;  116  a video output processing unit for performing predetermined signal processing for the analog video signal;  118  an on screen display (OSD) control unit for superimposing various bits of information including a date, time, a menu and the like according to instruction from the system control unit  123 ; and  117  a liquid crystal monitor for multiplexing and displaying a video signal outputted from the video output processing unit  116  or the video input processing unit  107 , and information obtained from the OSD control unit  118 . 
   A reference numeral  119  denotes an audio signal decoding unit for decoding an audio signal outputted from the data switching unit  113   a ;  120  a D/A converter from converting the decoded audio signal into an analog audio signal;  121  an audio output processing unit for performing predetermined signal processing for the analog audio signal from the D/A converter; and  122  a speaker. 
   A reference numeral  123  denotes a system control unit;  124  a subcode encoding unit for generating subcode data containing a current date and time generated by a clock unit, or various ID data such as PPID according to instruction from the system control unit  123 ;  126  a subcode data detection unit for outputting subcode data from a subcode encoding unit  126  to the data switching unit  111   a , and detecting and outputting subcode data from the data switching unit  113   a  to the subcode decoding unit; and  127  a subcode data decoding unit for detecting and outputting subcode data (photographing date, time data, or various ID data such as PPID) from the subcode data detection unit  126  to the system control unit  123 . The subcode encoding unit  125 , the subcode detection unit  126 , and the subcode decoding unit  127  constitute a subcode data processing circuit  124 . 
   A reference numeral  128  denotes a clock unit;  129  a remote control signal receiving unit for receiving a remote control signal from a remote commander R or sending a remote control code to the system control unit  123 ;  130  a camera system switch including various switches (zooming, focusing and the like) for operating a camera system;  131  a recording system switch including various switches (up-down, and left-right keys, a menu key, a reproducing key, a fast-forward key, winding and stopping keys, a recording trigger key, a photokey, a photosearch key, and the like) for a recording system and the entire VTR; and  132  a mode switch for selecting a power supply mode (camera, VTR, OFF) of the main body. 
   The system control unit  123  includes a microcomputer or the like, which is in charge of overall control various functions of the camera integral VTR  100 , including a timer function. The system control unit  123  mainly performs mode control, operation mode transition control of each operation block, display control of various information, storage, holding and the like of various photographing modes. Further, following switching of a normal compression recording mode/a high compression recording mode, the system control unit  123  performs system data setting in recording, recording/reproduced signal processing, control of the mechanical unit  112 , and the like. 
   Next, description is made of a recording operation of the camera integral VTR  100  constructed in the above-described manner. 
   In the digital VTR of the embodiment, a recording mode can be set between the SD mode and the SDL mode, and a user can set a recording mode by the menu selection function of the recording system switch SW  131 . 
   An audio signal captured from the microphone  101  is subjected to predetermined signal processing by the audio input processing unit  102 , and then converted into a digital signal by the A/D converter  103 , and outputted to the audio signal encoding unit  104 . Based on recording mode information from the system control unit  123 , the audio signal encoding unit  104  encodes the audio signal according to a currently set recording mode, i.e., the SD mode or the SDL mode, and outputs the encoded audio signal to the data switching unit  111   a  of the recording signal processing unit  111 . 
   A video signal captured from the image pickup unit  105  is outputted to the A/D converter  106  and the video output processing unit  116 . The A/D converter  106  converts the video signal from the image pickup unit  105  into a digital signal, and outputs it to the video input processing unit  107 . The video output processing unit  116  selects on the recording mode, the video signal from the image pickup unit  105  based on a control signal from the system control unit  123 , supplies it to the liquid crystal monitor  117  to display a video image picked up by the image pickup unit  105 . 
   The video input processing unit  107  performs predetermined signal processing for the digital video signal from the A/D converter  106 , according to the SD mode or the SDL mode, and then outputs it to the video signal encoding unit  108 . Based on the recording mode information from the system control unit  123 , the video signal encoding unit  108  encodes the video signal according to a currently set recording mode, i.e., the SD mode or the SDL mode, and outputs the encoded video signal to the data switching unit  111   a  of the recording signal processing unit  111 . In the embodiment, processing by the video input processing unit  107  and the video signal encoding unit  108  is carried out such that on the SD mode, a quantity of information per one frame can be ½ of that of the SD mode. 
   The system control unit  123  controls the subcode encoding unit  125  based on current date and time data from the clock unit  128 , generates subcode data containing date and time information, and other information, and outputs the subcode data through the subcode detection unit  126  to the data switching unit  111   a  of the recording signal processing unit  110 . 
   The data switching unit  111   a  switches and outputs respective data according to a tape recording format defined by the DV format such that a digital audio signal, a digital video signal, subcode data and ITI data can be recorded in predetermined areas of respective recording tracks on a tape T, and then supplies the data to the magnetic head of the mechanical unit  112 . 
   The mechanical unit  112  includes a capstan for feeding the tape T. The system control unit  123  controls a feeding operation of the capstan so as to switch a feeding speed of the tape T according to a set recording mode. 
   For example, when the SD mode is set, the tape T is fed at a speed V corresponding to the SD mode. When the SDL mode is set, the tape T is fed at a speed V/D corresponding to the SDL mode. Data indicating a recording mode is generated by the subcode encoding unit  125 , included into VAUX data by the subcode detection unit  126 , and recorded through the data switching unit  111   a  in a predetermined position of each track on the tape T. 
   As described above, in the camera integral VTR  100 , the digital audio signal, the digital video signal, and the data indicating the photographing date thereof are simultaneously and continuously recorded digitally in different areas on the magnetic tape T. 
   Next, description is made of a reproducing operation of the camera integral VTR  100 . 
   The digital audio signal, the digital video signal, the subcode data and the ITI data are outputted to the data switching unit  113   a , and then switched and outputted in times series by the data switching unit  113   a.    
   The digital video signal from the data switching unit  113   a  is outputted to the video signal decoding unit  114 . Based on the recording mode information from the system control unit  123 , the video signal decoding unit  114  decodes the video signal according to the recording mode of the reproduced video signal, and outputs it to the D/A converter  115 . The D/A converter  115  converts the decoded video signal into an analog signal, and outputs it to the video output processing unit  116 . Based on the control signal from the system control unit  123 , the video signal processing unit  116  selects on a reproducing mode, the video signal from the D/A converter  115  and supplies the video signal to the liquid crystal monitor  117  to be displayed. 
   The digital audio signal from the data switching unit  113   a  is outputted to the audio signal decoding unit  119 . Based on the recording signal information from the system control unit  123 , the audio signal decoding unit  119  decodes the audio signal according to the recording mode of the reproduced audio signal, and outputs it to the D/A converter  120 . The D/A converter  120  converts the decoded audio signal into an analog audio signal, the audio output processing unit  121  performs predetermined signal processing on the converted analog audio signal to output it from the speaker  122 . 
   The subcode data from the data switching unit  113   a  is detected through the subcode detection unit  126  by the subcode decoding unit  127 , and entered to the system control unit  123 . Then, the system control unit  123  performs time difference correction for the photographing date data based on correction information regarding a time difference, entered beforehand by the user, converts it into character display data, and outputs it to the OSD control unit  118 . The OSD control unit  118  converts this character display data into superimposition data, and outputs it with the video signal from the video output processing unit  116  to the liquid crystal monitor  117 . The liquid crystal display unit  117  displays the reproduced video and the information of photographing date/time subjected to time difference correction in a superimposing manner. 
   The subcode detection unit  126  detects information indicating the recording mode of the currently reproduced video and audio data from the VAUX data included in the reproduced data, and outputs it to the system control unit  123 . Based on this recording mode information, the system control unit  123  can detect the recording mode of the reproduced video and audio data. 
   Next, description is made of a recording operation of still image data on the photomode. 
   The user operates the photokey of the recording system switch SW  131  in recording pause or during motion image data recording. The system control unit  123  stores in an internal memory a image signal of one frame entered in the video input processing unit  107  at a point of time of the photokey operation. Then, the image data of one frame is repeatedly read during a period defined by the SD mode or the SDL mode as described later, and outputted to the video signal encoding unit  108 . The image data is then encoded as described above, and recorded as still image. Then, the subcode processing unit  124  and the recording/reproducing circuit  110  are controlled such that the PPID data can be recorded at a predetermined timing. 
   Next, description is made of an operation of recording images, in an order of a motion image A, a still image A and a motion image B, in a number of helical tracks on the magnetic tape, and searching the still image A held between motion image recording areas. 
   As described above, there is PPID as data for detecting still image data recorded on the photomode. This is information data for still image searching, defined by the DV format, and it is decided that recording is carried out continuously for 5 sec. In addition, on the SD mode, data of one frame is recorded in ten tracks and, on the SDL mode, data of one frame is recorded in five tracks. 
   That is, in comparison based on the same number frames, when recording is carried out on the SDL mode, a recording length on the magnetic tape is set to half of that during SD mode recoding. 
     FIG. 2  shows an example of recording motion and still images on the SD mode, where a still image A is recording in an area after a recording area  201  of a motion image A for about 6.5 sec. In this case, substantially simultaneously with still image recording, the PPID is recorded for 5 sec with being superimposed. Then, a motion image B is recorded in a recoding area  203 . 
   When the recorded still image A is searched from the recording area  201  of the emotion image A, the tape T is first fed forward at a speed faster by 9.5 times, the speed is reduced to a normal speed when the PPID is detected, a slowing operation is carried out, then the process is stopped in a position  205  to perform still image reproducing. Then, conversely, when the recorded still image A is searched from the recording area  203  of the motion image B, first, the tape is reversely fed at a speed after by 9.5 times, the speed is reduced to reverse normal speed when the PPIID is detected, a reverse slowing operation is carried out, the process is then stopped in a position  206  to perform still image reproducing. As apparent from the drawing, in either case, still image reproducing operation is finished within a range of the recording area  202  of the still image A. 
     FIG. 3  shows an example of recording motion and still images on the SDL mode, where a still image A is recorded for about 6.5 sec., subsequently to a motion image A. In this case, substantially simultaneously with still image recording, the PPID is recorded for 5 sec with being superimposed. Then, a motion image B is recorded. 
   When the recorded still image A is searched from a recording area  301  of the emotion image A, the tape T is first fed forward at a speed faster by 9.5 times, the speed is reduced to a normal speed when the PPID is detected, a slowing operation is carried out, then the process is then stopped in a position  305  to perform still image reproducing. Then, conversely, when the recorded still image A is searched from a recording area  303  of the motion image B, first, the tape is reversely fed at a speed after by 9.5 times, the speed is reduced to reverse normal speed when the PPIID is detected, a reverse slowing operation is carried out, the process is then stopped in a position  306  to perform still image reproducing. 
   As can be understood from  FIG. 3 , when the searching is carried out in the forward direction, the still image reproducing is carried out in the position  305  near a boundary of the recording area  302  of the still image A and the recording area  303  of the motion image B. When the searching is carried out in the reverse direction, the recording area  302  of the still image A is passed, and the still image reproducing operation is finished completely in the recording area  301  of the motion image A. Thus, the still image searching operation fails. 
   Thus, when the still image is searched, control is performed in such a manner that the PPID is detected while the tape is fed at a high speed, and the tape feeding is stopped when the PPID detected. In the case of the still image recorded on the SDL mode, even if the still image is recorded for 6.5 sec., as in the case of the SD mode, since a length of its recording area is only half of that of the SD mode, the recording area of the still image may be passed. To avoid this, a tape feeding speed in searching must be slowed down. However, if the feeding speed is slow, searching time is made longer, worsening usability. 
     FIG. 4  shows an example of recording motion and still images on the SDL mode including the features of the invention, where after a motion image A, a still image A is recording for about 8.5 sec. In this case, PPID is recorded with being superimposed in a center position of a recording area  402  of the still image A. Subsequently, a motion image B is recorded in a recording area  403 . 
   Here, when the recorded still image A is searched from the recording area  401  of the emotion image A, the tape T is first fed forward at a speed faster by 9.5 times, the speed is reduced to a normal speed when the PPID is detected, a slowing operation is carried out, then the process is stopped in a position  405  to perform still image reproducing. Then, conversely, when the recorded still image A is searched from the recording area  403  of the motion image B, first, the tape is reversely fed at a speed after by 9.5 times, the speed is reduced to reverse normal speed when the PPIID is detected, a reverse slowing operation is carried out, the process is then stopped in a position  406  to perform still image reproducing. 
   As apparent from  FIG. 4 , in either case, the tape feeding is stopped within a range of the recording area  402  of the still image A. 
   Therefore, according to the embodiment, when the still image is recorded on the SDL mode, by setting a still image recording period to about 8.5 sec., and the recording position of the PPID in the center position of the still image recording area, it is possible to search the still image at a high tape feeding speed equal to that in searching of the still image data recorded on the SD mode. 
   Next, description is made of a control operation of the system control unit  123  when the invention is applied to still image recording on the SDL mode, by referring to a flowchart of  FIG. 5 . 
   In  FIG. 5 , photokey detection for instructing starting of still image recording is carried out in S 501  and, after the photokey is depressed, the process is branched to S 502 . In S 502 , a currently set recording format is detected. If an SDL mode is selected, the process proceeds to S 503 . If an SD mode is selected, the process proceeds to S 510 . Selection of a recording mode is set beforehand by a menu operation or the like. 
   In S 503 , feeding of the tape T at a speed set according to the SDKL mode is started, recording of still image data encoded according to the SDL mode is started as described above, the internal counter of 1.75 sec., is started, and the process waits for an end of the counter in S 504 . After a passage of 1.75 sec., from the start of recording, recording of the PPID is started in S 505 , the internal counter of 5 sec., is started, and the process waits for an end of the counter in S 506 . 
   Then, after a passage of 5 sec., the recording of the PPID is finished in S 506 , the internal counter of 1.75 sec., is started again, and the process waits for an end of the counter in S 508 . After a passage of 1.75 sec., the still image recording-on a high compression recording format is finished in S 509 . 
   In S 510 , feeding of the tape T at a speed set according to the SD mode is started, recording of still image data encoded according to the SD mode is started as described above, and recording of the PPID is started in S 511 . Then, the counter of 5 sec., is started, and the process waits for an end of the counter in S 512 . After the end of the counter, the recording of the PPID is finished in S 513 , the counter of 1.5 sec., is started, and the process waits for an end of the counter in S 514 . After the end of the counter, the still image recording on the SD mode is finished in S 515 . 
   Next, description is made of an operation of searching the still image data recording in the above-described manner. 
   When the photo search key of the recording system switch SW  131  is operated, the system control unit  123  controls a capstan driving unit of a recorder unit  22  such that the tape T can be fed forward or backward at a predetermined high speed faster than a normal speed, for example at a speed faster by 9.5 times than that in recording. 
   Then, when the PPID reproduced by the recording/reproducing circuit  110 , and detected through the subcode detection unit  126  and the subcode decoding unit  127  is entered, the system control unit  123  outputs a control signal to the recording/reproducing circuit  110  as described above, the feeding speed of the tape T is reduced to a normal or reverse normal speed, and then the process proceeds to still image reproducing. 
   Therefore, according to the embodiment, by setting the recording period on the still image recording mode of the SDKL mode longer than that of the SD mode, and the recording position of the ID data for still image detection substantially in the center of the still image recording area, it is possible to surely detect the still image data recorded on the SD mode and the still image data recorded on the SDL mode while feeding the tape at the same feeding speed in searching. 
   The embodiment has been described by way of example, where the invention is applied to the VTR having the SDLK mode for recording the image data of one frame in the five tracks, and the SD mode for recording the same in the ten tracks. The invention is not limited to this, and it can be similarly applied to, for example a case where still image data is recorded on a mode for recording in an n number of tracks per one frame, and on a mode for recording in an m (m&gt;n) number of tracks. 
   Furthermore, the recording periods on the photomode were respectively set to 6.5 sec., and 8.5 sec., on the SD and SDL modes. Other periods may be set as long as they are longer than 5 sec., of the recording period of the PPID, and the recording period on the SDL mode is longer. 
   Many widely different embodiments of the present invention may be constructed without departing from the spirit and scope of the present invention. It should be understood that the present invention is not limited to the specific embodiments described in the specification, except as defined in the appended claims.

Technology Classification (CPC): 7