JP2005278008A - Recording and reproducing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve troublesome and inconvenience for a user that an apparatus which can carry out time-shift regeneration, can not display images after switching channels in a short time. <P>SOLUTION: The apparatus is provided with an instruction input part which inputs an instruction selecting broadcasting stations; a demodulation means which outputs a 1st signal demodulated from a broadcasting signal; a compression means which performs compression processing to the 1st signal; a recording and reproducing means which records compressed digital data by the compression means in a recording medium, and reproduces the data from the recording medium; an expanding means which outputs a 2nd signal applied with expanding processing for reproduced digital data from the recording and reproducing means; a switching means which changes over the 1st signal outputted from the expansion means and a 2nd signal outputted from demodulation means, and outputs them; a modulation means which modulates an output of the switching means, and outputs an analog image signal; and a control part which performs the control of the switching of the switching means when the changing-over operation of broadcasting stations is carried out based on the instruction of the instruction input part, and outputting the 2nd signal to the modulation circuit. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a recording / reproducing apparatus that receives a broadcast signal, records the signal on a recording medium, and reproduces the broadcast signal recorded on the recording medium.

  In recent years, a recording / reproducing apparatus for recording and reproducing a video signal and an audio signal on a recording medium such as a disk by reducing the price of a video chip for performing digital compression / decompression processing on a video signal and increasing the capacity and price of a hard disk drive Has been commercialized one after another.

  In such a recording / reproducing apparatus, taking advantage of being able to simultaneously read and write a large amount of data at a high speed, while recording a video signal and an audio signal, on the other hand, an already recorded video signal and audio signal can be reproduced or recorded. It has a function of “time shift reproduction” for reproducing video signals and audio signals (for example, television programs) with a delay of several seconds to several minutes.

  As a device having such a time-shift playback function, a broadcast signal received by a TV tuner is always encoded, the encoded data is recorded on a hard disk drive, the data recorded on the hard disk drive is read, the data is decoded, and the TV There is a device that outputs a video signal and an audio signal to a John receiver or a monitor.

  The time-shift playback function described above requires processing time of several seconds to encode data, record data to the hard disk drive, read data from the hard disk drive, and decode the data. The broadcast signal output from the apparatus and viewed by the viewer is delayed by the processing time described above.

  When the user gives an instruction to switch channels, he / she wants to view the desired channel immediately. However, the delay of the video switching time described above makes the user feel uncomfortable and also makes the user feel inoperable.

  As a method of eliminating the above-mentioned unpleasant feeling given to the user, at the time of channel switching, information based on the electronic program guide (Electronic Program Guide: EPG) of the channel to be switched is temporarily displayed on the display, and the sound of the channel after switching is displayed. A digital television receiver that demodulates an audio signal first and outputs it from a speaker is disclosed in Patent Document 1.

  Further, Patent Document 2 discloses a receiving apparatus and an image reproduction method for temporarily displaying a video prepared in advance in a storage area of a storage unit in the receiving apparatus when switching channels.

JP 2001-339663 A JP 2002-176599 A

  However, even with the techniques of Patent Document 1 and Patent Document 2 described above, the video of the channel desired by the user cannot be displayed in a short time after the channel is switched, and another information (video) is displayed every time the channel is switched. Since it is displayed, there is a problem that it is troublesome for the user and is not easy to use.

  In particular, when switching the channel and watching the video of the switched channel and then immediately switching to another channel, that is, when continuously switching the channel, every time the channel is switched, Since the video other than the video of the desired channel is once displayed, it is troublesome, and it takes time until the user searches for the desired channel, resulting in poor operability.

  It is an object of the present invention to provide a recording / reproducing apparatus that can output a video of a channel that has been switched in a short time without causing the viewer to feel bothersome or inconvenient when changing the channel.

  In the recording / reproducing apparatus of the present application, a receiving means for receiving a broadcast signal and selecting a receiving broadcast station, an instruction input unit for outputting an instruction signal based on an instruction to select a receiving broadcast station, and the receiving means Demodulating means for outputting a first signal obtained by demodulating the received broadcast signal, a first buffer memory for storing the first signal, a compressing means for digitally compressing the first signal, and a digital compressed by the compressing means Recording / reproducing means for recording data on the recording medium and reproducing from the recording medium, and a second buffer memory for storing the digital data reproduced by the recording / reproducing means, digitally decompress the digital data and output a second signal Expansion means; switching means for switching and outputting the first signal output from the demodulation means and the second signal output from the expansion means; and the switching means A modulation unit that modulates the output and outputs an analog video signal, and a time measuring unit that measures a switching time of the broadcasting station in the instruction input unit are provided, and a switching operation of the broadcasting station is predetermined based on an instruction from the instruction input unit. And a control unit that controls the switching unit to always output the first signal to the modulation unit when it is continuously performed within a predetermined time.

  In the invention of the present application, in the above-described recording / reproducing apparatus, the control unit further includes a memory for storing auxiliary video data, and the broadcasting unit is switched in the receiving unit based on an instruction from the instruction input unit. And a control unit that performs control to superimpose the auxiliary video data read from the memory for a second predetermined time on the second signal and output the second signal to the modulation unit.

  The invention of the present application provides a recording / reproducing apparatus that receives a broadcast signal and receives a broadcast station for selecting a broadcast station, a demodulator that outputs a first signal obtained by demodulating the broadcast signal received by the receiver, A compression unit that includes a first buffer memory that stores one signal, and that digitally compresses the first signal; a recording / reproduction unit that records and reproduces the digital data compressed by the compression unit to and from the recording medium; An instruction input unit that outputs an instruction signal based on an instruction to select a broadcast station to be received by the receiving unit and an instruction to pause and resume reproduction of digital data from the recording / reproducing unit, and the recording / reproducing unit reproduces A second buffer memory for storing the digital data; a decompression means for digitally decompressing the digital data and outputting a second signal; and an output from the demodulation means. A data storage unit for storing the first signal, a switching unit for switching and outputting the first signal output from the data storage unit and the second signal output from the decompression unit, and an output of the switching unit Modulating means for modulating and outputting an analog video signal, and switching means switching when the broadcast station is switched in the receiving means based on an instruction from the instruction input section, and switching the first signal to the modulating means The first signal stored in the data storage unit after a predetermined time has passed without the input of the instruction signal from the instruction input unit with respect to the first signal having a predetermined number of frames. Control that outputs the first signal of one frame redundantly, switches the switching means when the first signal having a predetermined amount of data is stored in the data storage unit, and outputs the second signal to the modulation means Wherein it comprises a control unit that performs.

  According to the present invention, in the recording / reproducing apparatus described above, the control unit is instructed to pause by the instruction input unit before the first signal having a predetermined amount of data is accumulated in the data storage unit. The output of the second signal in the decompression means is temporarily stopped, the data accumulation amount of the first signal in the data storage unit and the presence / absence of an instruction to resume reproduction by the instruction input unit are monitored, and the data storage unit is preliminarily stored. When the first signal having a predetermined amount of data is accumulated, the switching means is switched, and after the instruction input unit is instructed to resume reproduction, output of the second signal from the data storage unit is started and the second signal is modulated. And a control unit that performs control to output to the means.

  According to the present invention, in the recording / reproducing apparatus, it is possible to output a video of a channel that has been switched in a short time without causing the viewer to feel bothersome or inconvenient when changing the channel.

FIG. 1 is a diagram showing a schematic configuration of an embodiment of the recording / reproducing apparatus of the present invention.
In FIG. 1, a recording / reproducing apparatus includes a television tuner 1, an NTSC (National Television Standards Committee) decoder 2, an MPEG (Moving Picture Experts Group) encoder 3, an MPEG decoder 4, a hard disk drive 5, a bus 6, a switching unit 7, and an NTSC encoder. 8, a user interface unit 9, a timer 10, a display unit 11, and a system controller 12.

  In the recording / reproducing apparatus, an antenna 13 is connected to the TV tuner 1. A monitor 14 is connected to the recording / reproducing apparatus, and a signal output from the NTSC encoder 8 is displayed on the monitor 14 as an image. Here, the broadcast signal recorded and reproduced by the recording / reproducing apparatus includes a video signal and an audio signal. In this embodiment, the video signal will be described, and the description regarding the audio signal will be omitted.

  The TV tuner 1 demodulates the signal received by the antenna 13 and outputs the demodulated broadcast signal (video signal) to the NTSC encoder 2. Based on a control signal from the system controller 12, the TV tuner 1 oscillates an internal oscillator set in advance for each channel of the broadcast station, and selects a broadcast station to be received from the radio waves received by the antenna 13.

  The NTSC decoder 2 demodulates the color signal of the broadcast signal received by the TV tuner 1 from the video signal of the NTSC color system, and supplies the digital video data consisting of the luminance signal (Y) and the color difference signals (Cb, Cr) to the MPEG encoder 3. Output.

  The MPEG encoder 3 includes an encoder buffer memory 3a for storing digital video data. The MPEG encoder 3 encodes the digital video data output from the NTSC decoder 2 by digital compression using the MPEG method, and stores the encoded MPEG data in the encoder buffer memory 3a. The digital video data stored in the encoder buffer memory 3a is output to the hard disk drive 5 via the bus 6 when a predetermined amount of data is accumulated.

  The MPEG decoder 4 includes a decoder buffer memory 4 a that stores MPEG data input from the hard disk drive 5 via the bus 6. The MPEG decoder 4 decodes the MPEG data stored in the decoder buffer memory 4 a by performing MPEG digital decompression processing and outputs the decoded digital video data to the switching unit 7.

  Here, the NTSC decoder 2 and the NTSC encoder 8 can be replaced with a PAL (Phase Alternation by Line) system or a SECAM (SEquential Couleur A Memoire) system decoder and encoder according to the target television system.

  The hard disk drive 5 records the MPEG data output from the MPEG encoder 3 under the control of the system controller 12, reads the recorded MPEG data, and outputs it to the MPEG decoder 4.

  The bus 6 transmits data between the MPEG encoder 3 and the hard disk drive 5 and between the hard disk drive 5 and the MPEG decoder 4.

  The switching unit 7 switches between the input signal from the NTSC decoder 2 and the input signal from the MPEG decoder 4 based on the control of the system controller 12 and switches the digital video data output to the NTSC encoder 8.

  The switching unit 7 normally sets the input signal on the MPEG decoder 4 side and outputs the signal from the MPEG decoder 4 to the NTSC encoder 8. In the switching unit 7, when the output signal to the NTSC encoder 8 is set on the MPEG decoder 4 side, the signal output from the NTSC decoder 2 is passed through the MPEG encoder 3, the hard disk drive 5, and the MPEG decoder 4. 7 to the NTSC encoder 8. Hereinafter, this signal path is referred to as a standard signal path.

  In the user interface unit 9 to be described later, when there is an operation of switching a receiving broadcast station (hereinafter referred to as channel switching), the switching unit 7 controls the system controller 12 to input an input signal to the NTSC encoder 8. The signal from the NTSC decoder 2 is output to the NTSC encoder 8. When the switching unit 7 switches the input signal to the NTSC decoder 2 side, the signal output from the NTSC decoder 2 is directly input to the switching unit 7 and output from the switching unit 7 to the NTSC encoder 8. Hereinafter, this signal path is referred to as a path signal path.

  Further, based on the control of the system controller 12, the switching unit 7 superimposes and outputs auxiliary video data (described later) sent from the system controller 12 on digital video data output to the NTSC encoder 8.

  The NTSC encoder 8 performs NTSC color modulation on the digital video data (Y, Cb, Cr) input from the switching unit 7, performs digital-analog conversion, and outputs an analog video signal to the monitor 14.

  The user interface unit 9 includes operation buttons related to recording / playback such as recording start / stop, playback start / stop, and pause, and operation buttons related to selection of a broadcast station to be received. Is input to the system controller 12 as an instruction signal corresponding to the input instruction.

  The timer 10 measures a predetermined time based on the control of the system controller 12. In the present embodiment, the predetermined time is 5 seconds. The timer 10 sets the initial value of the timer count value to 5 seconds, and starts counting down under the control of the system controller 12. The timer 10 counts down and outputs the value (time) being measured to the system controller 12 as time information.

  The display unit 11 displays the operation content of the recording / reproducing apparatus, the selected channel number, and the like under the control of the system controller 12.

  The system controller 12 switches broadcast stations received by the TV tuner 1, encodes and decodes the NTSC decoder 2, MPEG encoder 3, MPEG decoder 4, NTSC encoder 8, records digital video data to the hard disk drive 5, and The entire recording / reproducing apparatus is controlled such as the reading process, the operation state of the recording / reproducing apparatus on the display unit 11 and the display of the process being executed.

  The system controller 12 controls the switching unit 7 based on the input of the instruction signal from the user interface unit 9, and the path of the signal input to the NTSC encoder 8 according to the channel switching operation is changed to a path signal path or a standard signal path. Switch.

  The system controller 12 switches when a channel switching operation is performed, or when a channel switching operation is performed and a channel switching operation is newly performed within a predetermined time after switching to a path signal path. The unit 7 is controlled to switch to the path signal path. The system controller 12 uses the timer 10 to measure a predetermined time.

  For example, when a channel switching instruction signal is first input from the user interface unit 9, or after the switching to the path signal path, the time until the next channel switching instruction signal is input in advance. If the time is within a predetermined time (for example, 3 seconds), the switching unit 7 switches the input signal to the NTSC decoder 2 side under the control of the system controller 12 and outputs the NTSC decoder 2 signal to the NTSC encoder 8.

  When there is no channel switching operation, or when the channel switching operation is performed and switching to the path signal path is not performed, a new channel switching operation is not performed within a predetermined time. 7 is switched to the standard signal path.

  For example, when there is no input of a channel switching instruction signal from the user interface unit 9, or a time from when switching to a path signal path to when the next channel switching instruction signal is input is a predetermined time. When the time elapses, the switching unit 7 switches the input signal to the MPEG decoder 4 side under the control of the system controller 12 and outputs the signal of the MPEG decoder 4 to the NTSC encoder 8.

  The system controller 12 includes a memory 12a that stores auxiliary video data. The auxiliary video data is, for example, text information such as “shifting to time shift playback”, “overlapping playback”, and the like, and when the signal path is switched from the path signal path to the standard signal path, switching is performed under the control of the system controller 12 In the unit 7, it is superimposed on the digital video data input from the MPEG decoder 4 and output to the NTSC encoder 8. In this embodiment, the auxiliary video is text information, but is not limited to this, and video other than text may be used.

A recording operation in the recording / reproducing apparatus of the present embodiment will be described.
When a broadcast station to be received is selected by the user interface unit 9, an instruction signal related to the broadcast station selected from the user interface unit 9 is output to the system controller 12. The system controller 12 outputs a control signal for specifying a broadcast station to be received to the television tuner 1.

  The TV tuner 1 extracts and demodulates a signal corresponding to the broadcast station selected by the viewer from the radio waves received by the antenna 13 based on the control signal from the system controller 12, and outputs the broadcast signal to the NTSC decoder 2. To do.

  The NTSC decoder 2 converts the input broadcast signal into a digital video signal by an internal analog-digital converter. The digital video signal is color demodulated by the color subcarrier and output to the MPEG encoder 3 as digital video data of a luminance signal (Y) and color difference signals (Cb, Cr).

  The MPEG encoder 3 compresses the input digital video data according to the compression algorithm of the MPEG2 system or the MPEG4 system, which is an international standard. The compressed MPEG data is stored in a buffer 3 a inside the MPEG encoder 3. The MPEG data stored in the buffer 3a is periodically read out under the control of the system controller 12 and recorded in the hard disk drive 5 according to a predetermined data format.

The recording / reproducing apparatus performs the recording operation described above and the reproduction described below.
The system controller 12 periodically reads out the MPEG data sequentially written in the hard disk drive 5 by the recording operation, and writes it in the buffer 4 a in the MPEG decoder 4.

  The MPEG decoder 4 decompresses the input MPEG data according to an MPEG2 or MPEG4 decompression algorithm. The expanded digital video data (luminance signal (Y), color difference signals (Cb, Cr)) is input to the NTSC encoder 8 via the switching unit 7.

  The NTSC encoder 8 modulates the color difference signal of the input digital video data and superimposes it on the luminance signal (Y) as a color subcarrier. The generated video signal is converted into an analog video signal by a digital / analog converter inside the NTSC encoder 8 and then output to a monitor 14 connected to a recording / reproducing apparatus.

Usually, a recording / reproducing apparatus for viewing a broadcast signal will be described.
Normally, when a broadcast signal is viewed, the signal output from the TV tuner 1 is recorded in the hard disk drive 5 via the NTSC decoder 2 and the MPEG encoder 3. The data recorded in the hard disk drive 5 is read out immediately after being recorded, and is output to the monitor 14 via the MPEG decoder 4, the switching unit 7, and the NTSC encoder 8.

  Therefore, when the digital video data is output from the switching unit 7 to the NTSC encoder 8 when the signal output from the NTSC decoder 2 is used as a reference, the hard disk drive 5 and the MPEG decoder 4 pass through the MPEG encoder 3. A delay time τ is obtained by adding up the time required for the above processes. For this reason, even if the broadcast station received by the TV tuner 1 is switched by the channel switching instruction, the encoding from the NTSC encoder 8 is performed by the encoding process of the MPEG encoder 3, the recording / reading process of the hard disk drive 5, and the decoding process of the MPEG decoder 4. There is a delay time τ until the output signal is switched.

Next, the operation at the time of channel switching in the recording / reproducing apparatus of the present embodiment will be described.
FIG. 2 is a flowchart showing an operation at the time of channel switching in the recording / reproducing apparatus of the present embodiment.
In FIG. 2, the system controller 12 detects the presence / absence of a channel switching operation by the viewer based on an instruction signal from the user interface unit 9 (step 21).

  When there is no channel switching operation (step 21), the system controller 12 determines whether the timer count value of the timer 10 is 0 seconds and whether the signal path is a path signal path (step 22). Unless the timer count value of the timer 10 is 0 and the signal path is a path signal path (step 22), the process returns to step 21 and the processes of steps 21 and 22 are repeated. This is because when the viewer does not perform the channel switching operation and continuously watches the same broadcast signal, the timer 10 does not measure the time (timer count value = 0 seconds), and the standard signal path Will continue to be selected.

  When there is a channel switching operation (step 21), the system controller 12 switches the reception channel in the TV tuner 1 to the broadcast station selected by the viewer (step 23).

  Then, the system controller 12 controls the switching unit 7, switches the switching unit 7 so that the output of the NTSC decoder 2 is input to the NTSC encoder 8, that is, the signal path becomes the path signal path, and sets the timer count value. Set to 5 seconds (step 24).

  Next, the system controller 12 starts measuring time with the timer 10 (step 25). In this embodiment, the time (timer count value) measured by the timer 10 is 5 seconds, and the timer 10 counts down 5 seconds.

  After starting the time measurement by the timer 10, the system controller 12 returns to step 21 and repeats the processing of step 21 and step 22 until the measured time (timer count value) reaches 0 seconds, and the timer It is monitored whether there is a new channel switching operation before the count value reaches 0 seconds.

  If there is a new channel switching operation before the timer count value reaches 0 seconds (step 21), the system controller 12 performs the processing of step 23 to step 25. In other words, if there is a new channel switching operation within a predetermined time after channel switching, the channel of the receiving broadcast station is switched and the path signal path has already been selected, so the selection is made immediately. The broadcast signal of the selected channel can be output from the monitor.

  As a result, while the channel switching operation is repeated within a predetermined time, the signal path continues to be selected as the signal path. Since the signal passing through the path signal path does not pass through the MPEG encoder 3, the hard disk drive 5, and the MPEG decoder 4, the delay time τ described above does not occur, and the video signal based on the channel switching operation of the viewer is simultaneously performed with the channel switching. Is output.

  After channel switching operation (step 21), reception channel switching of the TV tuner 1 (step 23), path signal path selection (step 24), and time count start by the timer 10 (step 25) are performed. If there is no channel switching operation (step 21) and the time count value becomes 0 second (step 22), the signal path is shifted from step 22 to step 26 because the path signal path is selected. It is determined that after the viewer switches the channel, the channel to be viewed is determined, and continuous viewing of the broadcast signal of the channel is started.

  When the time count value is 0 second and the path signal path is selected (step 22), the system controller 12 controls the switching unit 7 to switch the signal path to the standard signal path (step 26).

  Then, the system controller 12 controls the switching unit 7 to switch to the standard signal path, and then the auxiliary video data stored in the memory 12a is output from the MPEG decoder 4 for a time corresponding to the delay time τ described above. And control to output to the NTSC encoder 8 (step 27). Then, it returns to step 21 and repeats the process from step 21.

  When the time count value is 0 second, the path signal path is selected (step 22), the system controller 12 controls the switching unit 7, and switches the signal path to the NTSC encoder 8 to the standard signal path (step) 26) The video output from the NTSC encoder 8 is a video delayed by the delay time τ with respect to the video of the path signal path. The viewer views the broadcast signal at the same time as the broadcast time (broadcast time) when the channel is switched, and after the predetermined time has elapsed after switching the channel, the video is delayed by a delay time from the broadcast time by switching the signal path. Will be watched again.

  In such a case, the duplicated video is displayed on the monitor during the delay time, but the viewer views the duplicated video without knowing the reason after the channel is switched, which causes a sense of incongruity. For this reason, since the video that has already been viewed by the viewer after the channel is switched until the predetermined time elapses, the auxiliary video signal is superimposed on the video signal and monitored for a time corresponding to the delay time τ. To display.

  By superimposing and displaying the auxiliary video on the video signal, it is possible to know that the shift from the reproduction by the channel switching process to the time shift reproduction is made, and the current operating state of the recording / reproducing apparatus can be known. Therefore, the viewer can view the broadcast signal without causing a sense of incongruity due to the sudden display of overlapping images.

  As described above, the video signal is output to the monitor via the MPEG encoder 3, the hard disk drive 5, and the MPEG decoder 4 for normal viewing, and the MPEG encoder 3, the hard disk drive 5, and the MPEG decoder 4 are switched when switching channels. The signal input from the NTSC decoder 2 is output from the NTSC encoder 8 without passing through the signal path. Accordingly, since the video signal being viewed is switched immediately after the channel switching operation, the viewer does not feel uncomfortable.

  In the embodiment described above, auxiliary video is superimposed on the video signal until a predetermined time elapses after channel switching in order to inform the viewer that transition from channel switching to time-shifted playback has occurred. However, the display is not limited to this. When switching from the path signal path to the standard signal path after a predetermined time elapses after the channel switching, the output speed (reproduction speed) of the digital video data in the path signal path is decreased, and the digital from the data storage unit 15 in the path signal path When the output time of the video data matches the output time of the digital video data from the MPEG decoder 3 in the standard signal path, the path signal path may be switched to the standard signal path. Here, the output time of the digital video data is based on the digital video data output from the NTSC decoder 2 when a predetermined time has elapsed after the channel switching, and is based on the MPEG decoder 4 of the standard signal path or the path signal path. This is a time corresponding to each frame of digital video data output from the data storage unit 15 described later.

Another embodiment of the recording / reproducing apparatus of the present invention will be described.
FIG. 3 is a diagram showing the configuration of another embodiment of the recording / reproducing apparatus of the present invention.
In the recording / reproducing apparatus shown in FIG. 3, the TV tuner 1, NTSC decoder 2, MPEG encoder 3, MPEG decoder 4, hard disk drive 5, bus 6, switching unit 7, NTSC encoder 8, user interface unit 9, timer 10 and display unit 11 is a television tuner 1, NTSC decoder 2, MPEG encoder 3, MPEG decoder 4, hard disk drive 5, bus 6, switching unit 7, NTSC encoder 8, user interface unit 9, timer 10 of the recording / reproducing apparatus shown in FIG. Since it is the same structure as the display part 11, detailed description is abbreviate | omitted.

  The recording / reproducing apparatus shown in FIG. 3 further includes a data storage unit 15 in addition to the recording / reproducing apparatus shown in FIG. 1, and digital video data output to the NTSC encoder 8 after channel switching in the system controller 12 is transmitted from the path signal path. The process for switching to the standard signal path is different.

  In the recording / reproducing apparatus shown in FIG. 3, the data storage unit 15 is constituted by, for example, a FIFO (First In First Out) memory or the like, and the data storage unit 15 is a delay of digital video data output of the standard signal path with respect to the path signal path. It is a memory that can store data exceeding the data amount corresponding to time, stores the digital video data input from the NTSC decoder 2, and outputs the digital video data in the stored order. Storage and reading of digital video data in the data storage unit 15 is controlled by the system controller 12. In this embodiment, the data storage unit 15 is a FIFO memory. However, the present invention is not limited to this, and a storage unit such as a hard disk drive that can store a large amount of data may be used.

  When the system controller 12 performs switching from the path signal path to the standard signal path after channel switching, the output time of the digital video data output from the data storage unit 15 is output from the MPEG decoder 4. Adjustment is performed so as to coincide with the time, and when the output times of the two coincide, the switching unit 7 performs control to switch from the path signal path to the standard signal path.

  Since the standard signal path has a delay time (for example, 5 seconds) with respect to the path signal path, the digital video data at time t1 output from the NTSC decoder 2 in the path signal path is from the MPEG decoder 4 in the standard signal path. Is output at time t1 + delay time. The recording / reproducing apparatus of the present embodiment eliminates the difference in delay time between the path signal path and the standard signal path, and when the switching unit 7 switches the signal path from the path signal path to the standard signal path, On the other hand, the digital video data is output so as not to feel the switching from the path signal path to the standard signal path after the channel switching.

  When switching from the path signal path to the standard signal path, the system controller 12 controls the system controller 12 to delay the output speed (reproduction speed) of the digital video data output from the data storage section 15 and output from the data storage section 15. The process of matching the output time of the digital video data to the output time of the digital video data output from the MPEG decoder 4 and switching the path signal path to the standard signal path when the output times of the two digital video data match. Do. Hereinafter, this process is referred to as a time adjustment process.

  As a method of delaying the output speed of the digital video data output from the data storage unit 15, for example, the digital video data stored in the data storage unit 15 after a predetermined time elapses after channel switching is set to a predetermined frame. Overlapping and outputting one frame for the number.

FIG. 4 is a diagram for explaining a method for outputting digital video data in the data storage unit in the recording / reproducing apparatus of the present embodiment.
FIG. 4A shows digital video data when a broadcast signal received by the TV tuner 1 is directly input from the NTSC decoder 2 to the NTSC encoder 8. FIG. 4B shows digital video data output from the data storage unit 15. FIG. 4C shows digital video data output from the MPEG decoder 4. In the figure, squares indicate frames, and numbers indicate frame numbers.

  In FIG. 4A, digital video data when directly input from the NTSC decoder 2 to the NTSC encoder 8 is video data corresponding to a broadcast signal transmitted from a broadcast station. The digital video data shown in FIG. 4A is input to the data storage unit 15. In contrast to the digital video data in FIG. 4A, a delay time occurs in the digital video data output from the MPEG decoder 4 via the MPEG encoder 3 and the hard disk drive 5 as shown in FIG.

  After a predetermined time elapses after the channel switching, the system controller 12 controls the data storage unit 15 to output the digital video data of the 20th frame twice as shown in FIG. Control is performed so that one frame of digital video data is output redundantly for a predetermined number of frames.

  By repeating this output operation, the output speed of the digital video data output from the data storage section 15 becomes slower than the standard output speed, the output time of the digital video data output from the data storage section 15 is delayed, 4 (b) and (c), in the digital video data of the 40th frame, the output time of the digital video data output from the data storage unit 15 and the output of the digital video data output from the MPEG decoder 4 The time matches. At this time, the system controller 12 controls the switching unit 7 to switch the signal path from the path signal path to the standard signal path side.

  In the time adjustment process, when one frame is output from the data storage unit 15 in an overlapping manner, if the video signal displayed on the monitor is 1/30 frame per second, 6/30 per second (= The same video is displayed at a rate of 1/5) frame, and the video is displayed on the monitor at 0.83 times speed (slow playback). Since the video is displayed at 0.83 times speed, the viewer can watch without feeling uncomfortable without much feeling that the playback speed has changed.

  The system controller 12 stores in the data storage unit 15 a determination as to whether or not the output time of the digital video data output from the data storage unit 15 matches the output time of the digital video data output from the MPEG decoder 4. Based on the amount of data collected.

  In order to display images on the monitor 14 without interruption, the NTSC encoder 8 must always output video data at a constant speed. For this reason, the digital video data output from the MPEG decoder 4 via the switching unit 7 and the digital video data output from the data storage unit 15 via the switching unit 7 have a fixed amount of data. Input to the NTSC encoder 8 at a speed. Since the digital video data output from the MPEG decoder 4 and the digital video data output from the data storage unit 15 have the same output speed, a certain amount of digital video data is output from the MPEG decoder 4. The time and the time taken to output from the data storage unit 15 are the same.

  In the data storage unit 15, when overlapping frames are output every predetermined number of frames by the time adjustment process, the data storage unit 15 outputs the data amount of the digital video data input to the data storage unit 15. Since the amount of digital video data to be reduced is reduced, the digital video data output from the NTSC decoder 2 is sequentially stored in the data storage unit 15.

  Assuming that the delay time of the output time of the digital video data output from the MPEG decoder 4 with respect to the output time of the digital video data output from the data storage unit 15 is 5 seconds, in the time adjustment process, one frame is overlapped with 5 frames. In the case of the output, the output time of the digital video data output from the data storage unit 15 after 30 seconds by the time adjustment process coincides with the output time of the digital video data output from the MPEG decoder 4. A data amount corresponding to a time (30 seconds) in which the output time of the digital video data coincides with the output time of the digital video data output from the MPEG decoder 4 is set as a predetermined data amount in the data storage unit 15.

  When the digital video data is gradually accumulated in the data storage unit 15, the accumulated data amount increases, and when the digital video data accumulated in the data storage unit 15 is accumulated in a predetermined data amount, the system controller 12 It is determined that the output time of the digital video data output from the data storage unit 15 coincides with the output time of the digital video data output from the MPEG decoder 4, and controls the switching unit 7 to control the standard signal from the path signal path. Switch to the route.

The operation of the recording / reproducing apparatus of this embodiment will be described.
FIG. 5 is a flowchart showing the operation at the time of channel switching in the recording / reproducing apparatus of the present embodiment.
In FIG. 5, steps 51 to 55 are the same as steps 21 to 25 shown in FIG.

  There is a channel switching operation (step 51), the reception channel switching in the TV tuner 1 (step 53), the path signal path selection in the switching unit 7 (step 54), and the time count start by the timer 10 (step 55). When the channel count is not operated after the operation is performed (step 51) and the time count value becomes 0 second (step 52), since the path signal route is selected as the signal route, the steps 52 to 56 are performed. Migrate to

  When the time count value is 0 second and the path signal path is selected (step 52), the system controller 12 sends digital video data from the data storage unit 15 at 0.83 times speed based on the time adjustment processing. Output (step 56). Specifically, one frame of video data is output in duplicate with respect to five frames of video data.

  The system controller 12 monitors the amount of data stored in the data storage unit 15 (step 57).

  When a predetermined amount of data is stored in the data storage unit 15 (step 57), the system controller 12 outputs the digital video data output from the data storage unit 15 and the digital video data output from the MPEG decoder 4 And the switching unit 7 is controlled to switch the signal path to the NTSC encoder 2 to the standard signal path (step 58). Then, it returns to step 51 and repeats the process from step 51.

  As described above, when switching from the path signal path to the standard signal path after a predetermined time has elapsed after the channel switching, the digital video data output from the data storage unit 15 is one frame every several frames. The output time of the digital video data output from the data storage unit 15 is slowed down, the output time of the digital video data output from the data storage unit 15 and the digital video data output from the MPEG decoder 4 are When the output time coincides with the output time, the switching unit 7 switches the signal path from the path signal path to the standard signal path.

  As a result, the recording / reproducing apparatus changes the signal path from the path signal path to the standard signal without causing the viewer to feel that the reproduction speed of the video displayed on the monitor has changed after switching the channel. You can switch to a route.

  In the above-described embodiment, in the time adjustment process, the predetermined number of frames is set to 5 frames, and 1 frame is overlapped for 5 frames. However, the predetermined number of frames is 6 frames or more and 30 frames. If it is within.

In the embodiment described above, a case where the viewer performs a pause operation during the time adjustment process will be described.
The recording / reproducing apparatus capable of time-shift reproduction reads the broadcast signal recorded on the hard disk drive while recording the received broadcast signal on the hard disk drive, and outputs it to the monitor. The video data output (reproduction of video data recorded in the hard disk drive 5) can be paused and resumed during the output of the video data in the path. For this reason, in the recording / reproducing apparatus of the above-described embodiment, when the viewer performs a pause / restart operation during the time adjustment process, the data storage unit 15 corresponds to the time from the pause to the resumption of playback. The amount of data to be stored is not stored, and overflow may occur. Then, when playback is resumed, the video may be interrupted.

  For this reason, when a pause / restart operation is performed during the time adjustment process, if there is an instruction to restart playback before a predetermined amount of data is stored in the data storage unit 15, If digital video data is output based on the time adjustment process and there is no instruction to resume playback before the predetermined amount of data is stored in the data storage unit 15, the predetermined amount of data is stored in the data storage unit 15. When the signal is accumulated, the signal path is switched from the path signal path to the standard signal path. As a result, even when a pause / restart operation is performed during the time adjustment process, the viewer does not feel that the playback speed of the video displayed on the monitor has changed. Can be switched from the path signal path to the standard signal path.

FIG. 6 is a flowchart showing an operation when a pause / restart instruction is given at the time of channel switching in the recording / reproducing apparatus of the present embodiment.
In FIG. 6, steps 61 to 65 are the same as steps 51 to 55 shown in FIG.

  In FIG. 6, the system controller 12 outputs the digital video data from the data storage unit 15 at 0.83 times speed based on the time adjustment process when the time count value is 0 second in step 65 and the path signal path (step 65). Step 66).

  The system controller 12 monitors whether or not the digital video data is accumulated in the data storage unit 15 to a predetermined data amount while outputting the digital video data from the data storage unit 15 (step 67). When digital video data is stored in the data storage unit 15 up to a predetermined amount of data (step 67), the switching unit 7 switches from the path signal path to the standard signal path (step 68), and returns to step 61.

  If digital video data has not been stored in the data storage unit 15 up to a predetermined amount of data (step 67), it is determined whether or not a pause instruction has been issued (step 69). If there is no instruction to pause (step 69), the process returns to step 66 to continue outputting video data.

  When there is an instruction to pause until a predetermined amount of data is stored in the data storage unit 15 (step 69), the system controller 12 stops outputting digital video data from the data storage unit 15 (step 69). 70). The digital video data is continuously stored in the data storage unit 15 (step 71).

  The system controller 12 detects whether the data amount stored in the data storage unit 15 has been stored in a predetermined amount while continuing to store the video data in the data storage unit 15 (step 72). . If the predetermined amount of data is not stored in the data storage unit 15 (step 72), the process returns to step 71 and the digital video data is continuously stored in the data storage unit 15.

  When the data amount accumulated in the data storage unit 15 is accumulated in advance (step 72), the system controller 12 temporarily stops the decoding of the MPEG data and the output of the digital video data in the MPEG decoder 4 (step 72). 74) The switching unit 7 is controlled to switch the signal path from the path signal path to the standard signal path (step 75), and it is monitored whether or not there is an instruction to resume reproduction (step 76).

  Then, when there is an instruction to start reproduction (step 76), the system controller 12 starts decoding the MPEG data and outputting the digital video data in the MPEG decoder 4 (step 77), and returns to step 61.

  As described above, when a pause / restart operation is performed during the time adjustment process, a signal path is passed based on a predetermined amount of data in the data storage unit 15 and the presence / absence of a replay restart instruction. Since the signal path is switched to the standard signal path, the data storage unit 15 does not overflow and the video is not interrupted. As a result, as soon as the viewer performs the channel switching operation, the channel is switched. After the channel is switched, the viewer switches from the path signal path to the standard signal path without making the viewer feel uncomfortable. Then, even after a channel change, even when a pause / restart operation is performed during the time adjustment process, the path signal path is changed to the standard signal path without causing the viewer to feel a sense of discomfort. be able to.

The figure which shows schematic structure of one Example in the recording / reproducing apparatus of this invention. The flowchart at the time of the channel switching in the recording / reproducing apparatus of a present Example. The figure which shows the structure of the other Example of the recording / reproducing apparatus of this invention. The figure for demonstrating the output method of the digital video data of the data storage part in the recording / reproducing apparatus of a present Example. The flowchart which shows the operation | movement at the time of the channel switching in the recording / reproducing apparatus of a present Example. The flowchart which shows operation | movement when there exists an instruction | indication of temporary stop and reproduction | regeneration restart at the time of channel switching in the recording / reproducing apparatus of a present Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Television tuner, 2 ... NTSC decoder, 3 ... MPEG encoder, 3a ... Encoder buffer memory, 4 ... MPEG decoder, 4a ... Decoder buffer memory, 5 ... Hard disk drive , 6 ... bus, 7 ... switching unit, 8 ... NTSC encoder, 9 ... user interface unit, 10 ... timer, 11 ... display unit, 12 ... system controller, 12a ... Memory, 13 ... Antenna, 14 ... Monitor, 15 ... Data storage unit.

Claims (4)

  A receiving means for receiving a broadcast signal and selecting a broadcast station to receive, an instruction input unit for outputting an instruction signal based on an instruction to select a broadcast station to receive, and a first demodulated broadcast signal received by the receiving means A demodulating means for outputting a signal; a compressing means for digitally compressing the first signal; and a recording medium for recording and recording the digital data compressed by the compressing means. Recording / reproducing means for reproducing data from the recording medium, second buffer memory for storing the digital data reproduced by the recording / reproducing means, decompressing means for digitally decompressing the digital data and outputting a second signal, and output from the demodulating means Switching means for switching and outputting the first signal and the second signal output from the decompression means, and modulating the output of the switching means and outputting an analog video signal Modulation means and time measuring means for measuring the time for switching the broadcasting station in the instruction input means, and the switching operation of the broadcasting station is continuously performed within a predetermined time based on an instruction from the instruction input unit. And a control unit that controls the switching unit to always output the first signal to the modulation unit.   2. The recording / reproducing apparatus according to claim 1, wherein the control unit further includes a memory for storing auxiliary video data, and when the broadcast station is switched in the receiving unit based on an instruction from the instruction input unit. A recording / reproducing apparatus comprising: a control unit that performs control to superimpose auxiliary video data read from the memory for a second predetermined time on a second signal and output the second signal to the modulation unit.   Receiving means for receiving a broadcast signal and selecting a broadcast station to receive; a demodulating means for outputting a first signal obtained by demodulating the broadcast signal received by the receiving means; and a first buffer memory for storing the first signal. A compressing unit for digitally compressing the first signal; a recording / reproducing unit for recording and reproducing the digital data compressed by the compressing unit; and a broadcast station to be received by the receiving unit. And an instruction input unit that outputs an instruction signal based on instructions to pause and resume reproduction of digital data from the recording / reproducing means, and a second buffer memory that stores the digital data reproduced by the recording / reproducing means A decompression unit that digitally decompresses digital data and outputs a second signal; and a data storage unit that stores the first signal output from the demodulation unit; Switching means for switching and outputting the first signal output from the data storage unit and the second signal output from the decompression means; modulation means for modulating the output of the switching means and outputting an analog video signal; Based on an instruction from the instruction input unit, when the operation of switching the broadcasting station is performed in the receiving unit, the switching unit is switched and control is performed to output a first signal to the modulation unit, and the instruction input unit The first signal stored in the data storage unit is output in duplicate with the first signal of the predetermined number of frames after the predetermined time has passed without the input of the instruction signal from A control unit that performs control to switch the switching unit and output the second signal to the modulation unit when a first signal having a predetermined amount of data is accumulated in the data storage unit. Recording and reproducing apparatus. 4. The recording / reproducing apparatus according to claim 3, wherein when the instruction input unit instructs to pause before the control unit stores the first signal having a predetermined amount of data in the data storage unit, The output of the second signal in the decompression means is temporarily stopped, and the data storage amount of the first signal in the data storage unit and the presence / absence of an instruction to resume reproduction by the instruction input unit are monitored, and predetermined in the data storage unit When the first signal of the data amount is accumulated, the switching means is switched, and after the instruction input unit is instructed to resume reproduction, the second signal is output from the data storage unit and the second signal is sent to the modulation unit. A recording / reproducing apparatus comprising: a control unit that performs output control.

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