Patent Document

CLAIM OF PRIORITY 
     The present application claims priority from Japanese application serial no. JP 2004-266168, filed on Sep. 14, 2004, the content of which is hereby incorporated by reference into this application. 
     BACKGROUND OF THE INVENTION 
     The present invention relates to a recording and reproducing device that can receive digital broadcasting. In recent years, there have been proposed recording and reproducing devices that are combined devices having a digital tuner for receiving digital broadcasting, a hard disk drive (HDD) and a digital versatile disk drive (DVD). An example of the recording and reproducing devices is disclosed in Japanese Patent Laid-open No. 2004-159225. The recording and reproducing device of this patent document includes, as shown in  FIG. 1 , a digital tuner and two MPEG decoders. One of the decoders decodes MPEG-compressed transport streams (abbreviated as “TS” hereinafter) from an HDD (this decoder is referred to as “MPEG_TS decoder” hereinafter). The other decodes MPEG-compressed program streams (abbreviated as “PS” hereinafter) from a DVD (this decoder is referred to as “MPEG_PS decoder” hereinafter). 
     Video and audio signals decoded in the MPEG_TS and MPEG_PS decoders are output from respective output terminals of the device. In this outputting, in order to eliminate time lag of reproduction between the video and audio signals, i.e., in order to achieve lip-sync, a technique disclosed in Japanese Patent Laid-open No. 7-177479, for example, is used to correct the time lag between the video and audio signals, caused at each MPEG decoder. 
     SUMMARY OF THE INVENTION 
     The digital broadcasting encompasses both digital high vision broadcasting (HD broadcasting) and digital standard broadcasting (SD broadcasting). Therefore, a need arises to execute scaling processing for display of the HD broadcasting and conversion of the HD broadcasting into NTSC output for a VTR (VCR) and DVD recorder, i.e., down-conversion of high definition (HD) images into NTSC signals, which are standard definition (SD) images. 
     As such, for example when HD images are converted into SD images for recording, a scaling filter of the recording and reproducing device needs to have a function of up-converting the recorded SD images so that the HD images can be watched. Typically it takes much time to perform the scaling processing, which causes a problem in that video signals are delayed relative to the audio signals and thus lip-sync errors are caused. The above-described patent documents do not refer to such problem at all, and therefore disclose no solution therefor. Thus, in consideration of the above-described problem, the present invention intends to provide users with an easy-to-use recording and reproducing device. 
     An aspect of the invention has the following configuration in order to solve the above-described problem. For example, a recording and reproducing device includes a receiver that receives digital broadcast data, a video/audio signal generator that generates a video signal and an audio signal included in the digital broadcast data received by the receiver, an image processing unit that executes image processing of the video signal input from the video/audio signal generator, and a delay unit that receives the audio signal generated by the video/audio signal generator to adjust time lag between the received audio signal and the video signal processed by the image processing unit. This configuration allows provision of a digital broadcast-enabled recording and reproducing device offering users good usability. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic configuration diagram of a recording and reproducing device illustrating a first embodiment of the present invention. 
         FIG. 2  is a schematic configuration diagram of a recording and reproducing device illustrating a second embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Preferred embodiments of the present invention will be descried below in detail with reference to the drawings. In the drawings, the same parts are given the same numerals. 
     First Embodiment 
       FIG. 1  is a schematic diagram showing a first embodiment of the invention. A TS signal of an HD signal demodulated by a digital tuner  1  for receiving digital terrestrial broadcasting is input to a high-vision level (HL) decoder  10  that decodes the HD signal. The HL decoder  10  includes a demultiplexer  11 , an MPEG_TS decoder  12 , a scaling filter  13 , OSD circuits  14  and  15 , and video encoders  16  and  17  that will be described later. 
     An MPEG_PS CODEC  30  encodes (compresses) video/audio signals into MPEG_PS, and decodes MPEG_PS. The MPEG_PS CODEC  30  includes an A/D converter  33 , an MPEG_PS encoder  32 , an MPEG_PS decoder  31 , and an IDE I/F  34 . The recording and reproducing device also includes a delay circuit  24  and a transmission format converter  23  that converts digital audio signals into a transmission format of a digital interface defined by IEC60958. 
     The operation of this configuration will be described. First, reproduction of digital broadcasting will be described. A TS signal is input to the HL decoder  10 . The demultiplexer  11  selects and separates from the TS signal a TS packet of a desired program (channel). Video and audio signals of the TS signal of the desired program are decoded by the MPEG_TS decoder  12 , respectively. A digital video signal Vd 1  of an HD image output from the MPEG_TS decoder  12  is transmitted to the scaling filter  13 . The scaling filter  13  subjects the digital video signal Vd 1  to down-conversion from an HD image to an SD image or up-conversion from an SD image to an HD image as well as image processing such as enlargement, reduction, or conversion into a desired aspect ratio. 
     An HD signal output from the scaling filter  13  is applied, via the OSD circuit  14  that adds character information to the signal for example, to the video encoder  16  for converting digital video signals into analog video signals. The HD signal is then converted into a 1080i HD video signal in the video encoder  16  so as to be output from a terminal V 1 . 
     Furthermore, an SD signal output from the scaling filter  13  is applied, via the OSD circuit  15  that adds character information to the signal for example, to the video encoder  17  for converting digital video signals into analog video signals. The SD signal is then converted into an NTSC signal that is a 480i SD video signal by the video encoder  17  so as to be output from a terminal V 2 . The signals output from the terminals V 1  and V 2  are input to an image display unit  70 , and either one of the signals is selected and displayed on the image display unit  70 . A device for selecting either one of the signals may be included in the image display unit  70 . 
     The scaling filter  13  is also fed with a digital video signal Vd 3  of an SD image decoded and output by the MPEG_PS decoder  31 . The scaling filter  13  up-converts the digital video signal Vd 3  to an HD signal, and executes predetermined scaling processing. The SD signal output from the scaling filter  13  passes through the OSD circuit  15  and the video encoder  17  sequentially, and is output from the terminal V 2  as a 480i NTSC signal. The HD signal output from the scaling filter  13  passes through the OSD circuit  14  and the video encoder  16  sequentially, and is output from the terminal V 1  as a 1080i HD video signal. The signals output from the terminals V 1  and V 2  are input to the image display unit  70  similar to the operation described previously, and either one of the signals is selected and displayed on the image display unit  70 . 
     In contrast, a digital audio signal Ad 1  decoded and output by the MPEG_TS decoder  12  is input to the delay circuit  24 , followed by being delayed by predetermined time. To the delay circuit  24 , a digital audio signal is also input from the MPEG_PS decoder  31  of the MPEG_PS CODEC  30 . 
     The delay circuit  24  delays and outputs the audio signal Ad 1  from the MPEG_TS decoder  12  by time corresponding to the delay time of the video signal relative to the audio signal at the scaling filter  13 . This delay time is determined in advance in consideration of the processing time it takes for the scaling filter  13  to perform image processing. The determined time information is stored in a storage unit (not shown) for storing data. A CPU (not shown) refers to the time information to allow the audio signal Ad 1  to be outputted with delayed time. 
     The signal output from the delay circuit  24  is converted into an analog signal by a D/A converter  21  and then output from a terminal A 1 . The signal output from the delay circuit  24  is also input to the transmission format converter  23  so as to be converted into a transmission format of a digital interface defined by IEC60958. The resulting transmission format is then output from a terminal AD 1  as an optical digital audio output. Either one of the signals output from the terminals A 1  and AD 1  is selected and output from an audio amplifier  80 . A device for selecting either one of the signals may be included in the audio amplifier  80 . 
     As described above, the present embodiment provides the delay circuit  24  for delaying the audio signal Ad 1  output from the MPEG_TS decoder  12 . More specifically, the delay of the video signal relative to the audio signal, generated due to scaling processing in the scaling filter  13 , is corrected not by the MPEG_PS decoder but by delaying the audio signal Ad 1  in the delay circuit  24 , to thereby achieve lip-sync. 
     This configuration can eliminate lip-sync errors attributed to processing time in the scaling filter  13 , and thus allows users to enjoy videos without feeling uncomfortable. 
     Description will be made on how to record broadcast signals received by the digital tuner  1  to an HDD  34  or a DVD  44 . Here, how to record an SD image to the HDD  34  or the DVD  44  will be described. 
     Referring to  FIG. 1 , Coupled to the IDE I/F  34  are the DVD  43  and the HDD  44  via a DVD controller  41  for controlling reading and writing of the DVD  43  and via an HDD controller  42  for controlling the HDD  44 , respectively. To the A/D converter  33 , one of video/audio signals from an analog tuner  101  and video/audio signals from the terminals V 2  and A 1  is input after being selected by a switch  51 . 
     A broadcast signal received by the digital tuner  1  is input to the HL decoder  10 . The processing in the HL decoder  10  is the same as the above-described processing. A video signal output by the video encoder  17  and an audio signal output from the D/A converter  21  are input via the switch  51  to the MPEG_PS CODEC  30 . The video and audio signals input to the MPEG_PS CODEC  30  are converted from analog signals to digital signals by the A/D converter  33  included in the MPEG_PS CODEC  30 . Passing through the MPEG_PS encoder  32  and the IDE I/F  34  sequentially, the digital signals is recorded to the HDD  44  or the DVD  43  in a PS format. 
     The above-described processing is controlled by the CPU (not shown) based on recording instruction data input via an input part (not shown) of a remote controller or the like of a user. When information is recorded in the HDD  44  or the DVD  43 , the HDD controller  42  or the DVD controller  41  controls the recording in regards to a recording format, recording rate and so forth. Here, the recording to the HDD  44  or the DVD  43  is controlled to be implemented in a PS format. 
     The above-described processing allows a user to record broadcast signals received by the digital tuner  1  to the HDD  34  or the DVD  44 . 
     Description will be made on how to reproduce a program, film or the like recorded to the DVD  43  or the HDD  44 . 
     In this case also, the above-described lip-sync correction unit (the delay circuit  24  of  FIG. 1 ) is utilized. Specifically, program data recorded in the DVD  43  or the like is input via the DVD controller  42  and the IDE I/F  34  to the MPEG_PS decoder  31 . Of the program data input to the MPEG_PS decoder  31 , a video signal is output to the scaling filter  13  while an audio signal is output to the delay circuit  24 . 
     Thus, even when a program or the like recorded in a DVD is reproduced, lip-sync errors due to processing time it takes for the scaling filter  13  to perform processing can be eliminated, permitting a user to enjoy video or audio without feeling uncomfortable. In addition, the delay circuit  24  can commonly be used to achieve lip-sync for all the cases of reproduction of a broadcast program, a program recorded in a storage medium, and so on, which contributes to reduction of the circuit scale. 
     It should be noted that the invention is not limited to the above-described example in which a program recorded to a DVD is reproduced. Any other configuration is available as long as a program or the like recorded in a storage medium that can record digital signals, such as an HDD or CD-ROM, is reproduced. 
     The following description is about the case of dubbing from the HDD  44  to the DVD  43 , for example. In this case, signals do not pass through the scaling filter  13 . If, as is conventional, the MPEG_PS decoder  31  is arranged to correct the delays of video signals, caused by the scaling filter  13 , this delay correction by the MPEG_PS decoder  31  would cause lip-sync errors for dubbing from the HDD  44  to the DVD  43 . 
     In contrast, the present embodiment has a configuration in which the MPEG_PS decoder  31  does not have a function of correcting delays caused by the scaling filter  13 . In other words, for both the system of the HL decoder  10  (reproduction of broadcasting) and the system of the MPEG_PS CODEC  30  (reproduction from a storage medium), lip-sync is achieved by the common delay circuit  24  provided externally of the MPEG_PS decoder  31 . If an instruction of dubbing, for example, of program information or the like recorded in the HDD  44  is issued, the program information or the like is read out from the HDD  44  by the HDD controller  42 . The program information read from the HDD  44  is input via the IDE I/F  34  to the MPEG_PS decoder  31  and decoded thereat. Then, the program information thus decoded is encoded in the MPEG_PS encoder  32 , after which the program information passes through the DVD controller  41 , followed by subjecting to recording to the DVD  43 . 
     Thus, the problem of lip-sync errors does not arise also in the case of dubbing from the HDD  44  to the DVD  43 . As a result, users can view and hear images constructed of video/audio signals subjected to dubbing from the HDD  44  to the DVD  43  without feeling uncomfortable, achieving good usability. 
     Although the above-described example has illustrated the case of dubbing from the HDD  44  to the DVD  43 , the above-described configuration can provide similar advantages also for dubbing from the DVD  43  to the HDD  44 . 
     Furthermore, the invention is not limited to the above-described example in which the data recorded in the HDD  44  is program information including both video and audio. For example, the data recorded in the HDD  44  may be data including only audio or video, such as music by a singer or a silent film. 
     In addition, in the above-described example, the delay circuit  24  offers lip-sync for both the system of the HL decoder  10  (reproduction of broadcasting) and the system of the MPEG_PS CODEC  30  (reproduction from a storage medium). In contrast to this, for example, in the system of the HL decoder  10  (reproduction of broadcasting), lip-sync errors due to the scaling filter  13  may be corrected with the MPEG_TS decoder  12  without transmitting audio signals to the delay circuit  24 . Such a configuration can also eliminate lip-sync errors in dubbing from the HDD  44  to the DVD  43  as well as lip-sync errors by the scaling filter  13  in reproduction with the system of the MPEG_PS CODEC  30  (reproduction from a storage medium), allowing users to view and hear video and audio without feeling uncomfortable. 
     Second Embodiment 
     A second embodiment of the invention will be described.  FIG. 2  is a configuration diagram of a recording and reproducing device illustrating the second embodiment. The second embodiment is different from the first embodiment in that digital video/audio signals are directly recorded as they are without conversion into analog signals. Other features are the same as those in the first embodiment. 
     Specifically, a video signal from the scaling filter  13  and an audio signal from the delay circuit  24  are input directly as digital signals, via the switch  52  to the MPEG_PS CODEC  30 . The switch  52  also receives an output from the analog tuner  101 , converted from an analog signal to a digital signal by the A/D converter  102 . The output from the analog tuner is recorded in the DVD  43  or the HDD  44 . This configuration eliminates the need to provide the A/D converter  33  of  FIG. 1 , contributing to high-speed processing and reduction of the circuit scale. 
     According to the above-described configuration, users can view and hear images constructed of the recorded digital video/audio signals without feeling uncomfortable, achieving good usability. 
     It should be noted that the invention is not limited to the above-described embodiments, but the disclosed principles and novel characteristics encompass a wide technical scope. For example, the above-described configuration block diagrams, flow charts, display screen examples and so forth are Just only examples for specifically illustrating the embodiments, and are not restricted by the disclosed scope.

Technology Category: 5