JP2004241104A - Digital video recorder, its driving method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital video recorder capable of recording the program contents without missing even in case of a recording fault while recording a broadcast program on an optical disk. <P>SOLUTION: The digital video recorder is capable of recording data on a selected one of a first recording medium (optical disk 1) and a second recording medium (fixed memory device 5). The video recorder is equipped with a abnormal state detecting means 10 for detecting an abnormal event in case of a fault while the data are recorded on the optical disk 1. When the means 10 detects the abnormal event while the data are recorded on the optical disk 1, the video recorder stops recording the data on the optical disk 1 and starts recording the data, which should have been recorded on the optical disk 1, in the fixed memory device 5. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to a digital video recorder capable of recording a broadcasted TV program (data such as moving image / audio) on a recording medium in real time.

  Note that the term “digital video recorder” in this specification is not limited to a stationary digital video recorder used for recording broadcast data, but also includes portable electronic devices such as camcorders and small portable terminals. .

  Digital video recorders for recording digital data on recording media such as optical disks and / or hard disks are rapidly becoming widespread. Among them, a hybrid digital video recorder provided with both an optical disk drive and a hard disk drive (HDD) has attracted attention. In a hybrid digital video recorder, data that a user wants to store can be first recorded on, for example, a hard disk, and then the data on the hard disk can be transferred to the optical disk. Since the hard disk of such a digital video recorder is fixed to the HDD in the digital video recorder, it cannot be easily removed, but the optical disk is removable. Therefore, by loading one of a plurality of optical discs arbitrarily selected into the digital video recorder, the data recorded on the hard disc can be transferred to the optical disc at any time and stored outside the digital video recorder. With such a hybrid digital video recorder, various data (data such as moving images, still images, and audio) can be recorded on a hard disk and / or an optical disk.

  Many of the optical disk drives built in such digital video recorders or digital video cameras have a defect processing function for protecting recorded data. For example, in the digital video recorders disclosed in Patent Documents 1 and 2, a replacement area is provided in advance on an optical disc, and when a defect is found on the optical disc, data is recorded in a peripheral area at a position where the defect exists. Is not performed, but data in the replacement area is recorded instead. A typical example of a defect on an optical disc is dust or scratches on the disc surface.

  By performing such a defect process, loss of recorded information due to a defect or the like is suppressed, and highly reliable information can be recorded and stored.

When recording broadcast data on an optical disk using a hybrid digital video recorder, the data is temporarily recorded on a hard disk built into the digital video recorder before the data is directly recorded on the optical disk. It is. The broadcast data recorded on the hard disk is thereafter read and written on the optical disk. In such a recording method, a hard disk is used as a cache memory for recording on an optical disk. Patent Literature 3 and Patent Literature 4 disclose conventional techniques using a recording medium fixed to a recorder as a cache memory.
JP 2000-100798 A JP-A-2000-112672 JP-A-2002-033997 JP 2002-150683 A

  The above-described replacement process functions effectively when it is predicted in advance that a defect exists on the optical disk, or when the optical disk is waiting to release a busy state of writing on the optical disk. However, it does not function sufficiently against sudden write errors.

  A typical example of a sudden write error is tracking loss. Factors of tracking loss include (1) defects on the optical disk surface, (2) external shocks, and (3) quality of the optical disk itself (for example, large eccentricity and warpage).

  Recently, demand for optical discs such as DVD-Rs that can be recorded only once is rapidly increasing because of their low cost. In the case of such an inexpensive write-once optical disc, a writing error tends to occur at a high frequency.

  If a write error occurs while recording data such as broadcast data, the amount of data loss can greatly exceed the capacity of the spare area previously secured on the optical disc, unlike mere defect processing. Many. Further, even if the capacity of the replacement area is sufficient, there is a problem that there is not enough time to access the area.

  When the optical disk is simply used as a backup, for example, when the optical disk is used for the purpose of archivally saving information in the hard disk, such a problem does not occur much. Even if the number of accesses to the replacement area increases, the time until the completion of the backup simply increases. Also, even if a write error occurs such that the replacement area becomes insufficient, the original data remains on the hard disk, so that after the optical disk is replaced, the backup may be performed again.

  The problem of abnormal writing occurs when broadcast data such as a TV program is stored in real time, or when moving image / audio data from a video camera during shooting is recorded on an optical disk. These signals are non-interactive, and it is not allowed to limit the operation of the data source (master) depending on the situation of the data storage (recording) side (slave). In such a case, once a writing error occurs during the recording operation, real-time data such as broadcast data is continuously transmitted even while the writing is being processed. For this reason, if the replacement process is delayed, it causes information loss as it is.

  It should be noted that if the broadcast program is not directly stored on the optical disk but is cached on a hard disk or DRAM and then stored on the optical disk, most of these problems will be avoided. However, in this case, even when it is desired to store a broadcast program or the like only on the optical disk from the beginning, it is necessary to always record the program on both the optical disk and the hard disk. For this purpose, it is necessary to always operate two types of drives, which is not preferable from the viewpoint of power saving. Power saving is a particularly important issue for video cameras such as camcorders that operate on a power supply such as a battery.

  On the other hand, if a DRAM is used as a cache memory instead of a hard disk, the capacity of each DRAM is smaller than its price, so that it is not practical to use it as a cache for large-capacity data such as a broadcast program.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object the purpose of providing a program content and a broadcast program even when recording abnormalities occur during recording of video / audio data being captured on an optical disc. It is an object of the present invention to provide a digital video recorder capable of recording without losing the imaged content.

  A digital video recorder according to the present invention is a digital video recorder capable of recording data on a recording medium selected from a first recording medium and a second recording medium, wherein the data is recorded on the first recording medium. An abnormal state detecting means for detecting the abnormality when an abnormality occurs during the recording, and the abnormal state detecting means detects the abnormality during the recording of the data on the first recording medium. At this time, recording of the data on the first recording medium is stopped, and data to be recorded on the first recording medium is recorded on the second storage medium.

  In a preferred embodiment, after the abnormal state detecting means detects the abnormality, it further detects that the abnormality has been resolved, and resumes recording data on the first recording medium.

  In a preferred embodiment, after the data to be recorded on the first recording medium is distributed and recorded on the first and second recording media, the data recorded on the second recording medium is transferred to the second recording medium. The data is read from the medium and recorded in a free area of the first recording medium.

  In a preferred embodiment, after the data to be recorded on the first recording medium is distributed and recorded on the first and second recording media, the data is read from the first and second recording media, and the other data is read. Record on a recording medium.

  In a preferred embodiment, based on management information recorded on the second recording medium and address information obtained from a reproduction signal, data read from the first recording medium and data read from the second recording medium are read out. Means for switching at appropriate times are provided.

  In a preferred embodiment, the first recording medium is an optical disk, and the second recording medium is a hard disk or a semiconductor memory.

  In a preferred embodiment, the first recording medium and the other recording medium are optical disks, and the second recording medium is a hard disk or a semiconductor memory.

  In a preferred embodiment, the abnormal state detecting means detects the abnormality based on a tracking error signal obtained during a tracking operation of the optical disc.

  In a preferred embodiment, the abnormal state detecting means detects the abnormality based on a reproduction signal from the optical disc.

  In a preferred embodiment, the first recording medium is exchangeable, and the second recording medium is fixed.

  In a preferred embodiment, the data recorded on the first storage medium is broadcast data.

  In a preferred embodiment, a tuner for receiving the broadcast data is provided.

  In a preferred embodiment, an image sensor is provided, and the data recorded on the first storage medium is data output from the image sensor.

  In a preferred embodiment, data recorded on the first recording medium is delayed by a predetermined time and recorded on the second recording medium.

  In a preferred embodiment, a dummy data generation circuit is provided for recording dummy data on the first recording medium during a period when the data is recorded on the second recording medium.

  In a preferred embodiment, identification information uniquely associated with at least a part of the data recorded on the first recording medium is added to the data recorded on the second recording medium.

  In a preferred embodiment, a logical address of data recorded on the second recording medium has continuity with a logical address of data recorded on the first recording medium.

  A method of driving a digital video recorder according to the present invention is a method of driving a digital video recorder capable of recording data on a recording medium selected from a first recording medium and a second recording medium, wherein Detecting the abnormality during the recording of the data on the medium; and stopping the recording of the data on the first recording medium when detecting the abnormality, and recording the data on the first recording medium. Recording data on the second storage medium.

  The program of the present invention is a program incorporated in a microprocessor of a digital video recorder capable of recording data on a recording medium selected from the first recording medium and the second recording medium. Detecting an abnormality while the data is being recorded on the first recording medium; and stopping the recording of the data on the first recording medium when the abnormality is detected. Recording the data to be recorded on the recording medium on the second storage medium.

  According to the present invention, even if a recording abnormality occurs while recording a broadcast program or video / audio data being captured on a recording medium such as an optical disk, the program content and the captured content are recorded without being lost. be able to.

  Hereinafter, embodiments of the present invention will be described.

(Embodiment 1)
First, a first embodiment of a digital video recorder according to the present invention will be described with reference to the drawings.

  The digital video recorder of the present embodiment is a digital video recorder that can record digital data on the optical disc 1 and the fixed storage device 5. The optical disc 1 is exchangeable and can be removed from the digital video recorder and replaced with another optical disc 1. On the other hand, the fixed storage device 5 is fixed to the digital video recorder.

  In FIG. 1, the components used for the recording operation on the optical disk 1 are described in a plurality of blocks, but the components used for the recording operation on the fixed storage device 5 are “fixed storage device 5”. Are simply described as one block labeled with “.” Therefore, this block indicates not only a “recording medium” but also a driving unit including a mechanism or a circuit that requires writing / reading. Since the configuration and operation of the fixed storage device 5 are known configurations and operations, detailed description thereof will be omitted.

  The digital video recorder according to the present embodiment includes an optical head 9 that irradiates a laser beam to the optical disk 1 loaded in an optical disk drive (optical disk drive) of the digital video recorder. The configuration itself of the optical disk driving unit including the optical head 9 is the same as a known configuration.

  The optical head 9 includes a semiconductor laser that functions as a light source that outputs laser light, an objective lens that focuses the laser light on the optical disk to form a beam spot on the optical disk, an actuator that drives the objective lens, and an optical disk. A light receiving unit that receives the laser light reflected by the light receiving unit 1 and converts it into an electric signal is provided as a component.

  In the example shown in FIG. 1, the reproduction signal RF and the tracking error signal TE output from the optical head 9 are sent to the abnormal state detection circuit 10 and the tracking control circuit 13, respectively. The tracking control circuit 13 controls the operation of the optical head 9 so that the image point of the laser beam is accurately positioned on a desired track. The abnormal state detection circuit 10 can detect that an abnormality has occurred during data recording on the optical disc 1.

  A signal processing circuit that receives the electric signal output from the optical head 9 and processes the electric signal can be functionally realized by an LSI such as a DSP. When such an LSI is used, the abnormality detection circuit 10 and the tracking control circuit 13 are realized not as individual analog circuits but as functional blocks of software for digital signal processing.

  The digital video recorder of the present embodiment includes an encoder 31 that receives broadcast data received by the TV tuner 2 and encodes the broadcast data into, for example, an MPEG2 stream. Data (data stream) encoded by the encoder 31 is selectively stored in the optical disc 1 or the fixed storage device 5.

  In the present embodiment, the analog broadcast wave is received by the TV tuner. However, the TV tuner that can be used in the present invention is not limited to this, and the TV tuner that receives the digital broadcast wave may be used. If the TV tuner 2 can receive digital broadcast and output encoded data (data stream) such as an MPEG2 stream, the encoder 31 shown in FIG. 1 may be omitted. The TV tuner 2 may exist outside the digital video recorder or may be built in the digital video recorder.

  When a broadcast program is directly recorded on the optical disc 1 by the digital video recorder, the above data stream is sent to the modulator 8 through the selectors 4 and 7. The modulator 8 converts the received data stream into a recording signal (for example, a (1,7) PWM signal) suitable for a recording medium.

  The operations of the selectors 4 and 7 are controlled by the microprocessor 11. The program executed by the microprocessor 11 is stored in the program memory 12. Data output from the modulator 8 is written to the optical disk 1 via the optical head 9.

  When an abnormality is detected while data is being recorded on the optical disk 1, the microprocessor 11 operates to stop transferring data to the optical disk 1 and transfer data to the fixed storage device 5.

  Hereinafter, an example of an abnormality detection method during data recording will be described with reference to FIGS.

  FIG. 2A shows a waveform of the tracking error signal TE output from the optical head 9. The tracking error signal TE is a signal indicating a positional shift generated between the center of the information track on the optical disc and the beam spot of the laser light. When such a displacement does not occur, the tracking error signal TE becomes substantially equal to the potential VREF.

  The tracking control circuit 13 performs beam spot positioning control based on the tracking error signal TE. More specifically, the actuator in the optical head 9 is driven such that the level of the tracking error signal TE is always equal to the potential VREF. As a result, the beam spot on the optical disc can follow the center of a desired information track while the optical disc 1 is rotating at high speed.

  When data is written to the optical disk or data is read from the optical disk, if "out of tracking" occurs for some reason, tracking control is disabled. When the tracking error occurs, the level of the tracking signal TE exceeds the upper limit value VTH + shown in FIG. 2A or falls below the lower limit value VTH−. The abnormal state detection circuit 10 compares the level of the tracking error signal TE with the upper limit value VTH + and the lower limit value VTH−, and the level of the tracking error signal TE is out of the range defined by the upper limit value VTH + and the lower limit value VTH−. At this time, an abnormality detection signal VA shown in FIG. The abnormality detection signal VA is at the “Low” level when no tracking error has occurred, and from the “Low” level when the level of the tracking error signal TE is out of the range defined by the upper limit value VTH + and the lower limit value VTH−. The state is transited to “High”.

  The microprocessor 11 generates a transfer switching signal CA shown in FIG. 2C in response to the abnormality detection signal VA. The start of the transfer switching signal CA (the timing of the rise from “Low” to “High”) is determined by the rise of the abnormality detection signal VA, but the end is determined by the microprocessor 11. The transmission of the transfer switching signal CA may be stopped, for example, when it is confirmed that the abnormality detection signal VA no longer occurs within a certain unit time, or may be set in advance from the rise of the abnormality detection signal VA. It may be arranged to stop uniformly after a lapse of the set time (for example, 10 seconds). Alternatively, if the free space of the fixed storage device 5 is sufficient, the transmission switching signal CA may be continuously transmitted until the broadcast program ends.

  Next, another example of a method for detecting an abnormality during data recording will be described with reference to FIGS.

  FIG. 3A shows a waveform of a reproduction signal (RF) obtained from light reflected from the optical disc 1. When the focus position cannot be controlled due to disturbance in the focus direction or the like, the upper envelope of the reproduction signal (RF) becomes small as shown in FIG. An abnormality in writing to the optical disc 1 can be detected from a drop in the upper envelope of the reproduction signal (RF). When the upper envelope of the reproduction signal (RF) becomes lower than a preset level, the abnormal state detection circuit 10 sends the abnormality detection signal VA shown in FIG. In response to the abnormality detection signal VA, a transfer switching signal CA shown in FIG. Specifically, when the level of the transfer switching signal CA transitions from “Low” to “High”, the selector 4 switches the transmission path. That is, the path for transferring information from the encoder 31 to the optical disk 1 is closed, and the path to the fixed storage device 5 is opened instead.

  In the present embodiment, a buffer memory 32 for delaying data output from the encoder 31 shown in FIG. 1 for a predetermined time is provided. Therefore, when the level of the transfer switching signal CA is “High”, the data output from the buffer memory 32 is sent to the fixed storage device 5 through the selector 4.

  When the abnormal state detection circuit 10 operates, it is highly likely that data writing has already failed. In other words, if the buffer memory 32 is not present, if the output of the encoder 31 is started to be written to the fixed storage device 5 in response to the transfer switching signal CA, the information to be recorded is partially lost. There is. Therefore, in the present embodiment, the same data as the above-described lost data temporarily stored in the buffer memory 32 is transferred to the fixed storage device 5 to prevent loss of information.

  In the digital video recorder of the present embodiment, each of the above processes is executed by the program of the microprocessor 11 stored in the program memory 12. As a result of these processes, the data received by the TV tuner 2 is sent to the recording medium selected from the optical disc 1 and the fixed storage device 5 according to the transfer switching signal CA, and recorded.

  FIG. 4 is a schematic diagram showing the relationship between the waveforms of the abnormality detection signal VA and the transfer switching signal CA and the switching of the storage medium.

  When recording of a broadcast program on the optical disk 1 starts, data corresponding to the logical address # 1 starts to be recorded on the optical disk 1. It is assumed that after data to which the logical addresses # 1 to #N are assigned is recorded on the optical disc 1, a write error is detected while data of the logical address # N + 1 is being recorded. In this case, data after the logical address # N + 1 is recorded in the fixed storage device 5.

  To the data (data after logical address # N + 1) sent to the fixed storage device 5, identification information uniquely associated with at least a part of the information stored in the optical disc 1 is added. According to this identification information, it is specified at which position on the optical disk 1 the data recorded in the fixed storage device 5 should have been originally recorded. When such identification information is added, a plurality of abnormalities are detected, and even when data is saved and recorded in the fixed storage device 5 each time, the data can be appropriately reproduced from the fixed storage device 5. Will be able to

  The identification information can include, for example, logical addresses (# N + 1 to # N + 1) that are continuous with the logical addresses (# 1 to #N) attached to the information recorded on the optical disc 1. When the fixed storage device 5 is also used for other purposes (for example, normal program recording), the data must be data (backup data file) written to the fixed storage device 5 at the time of abnormal writing to the optical disk. It is preferable to be able to identify For this reason, it is preferable to add a header including management information for displaying the type of the file. The address and the header are added by the encoder 31.

  In this embodiment, when the level of the transfer switching signal CA is High, that is, when recording is abnormal, dummy data is recorded on the optical disc 1 as shown in FIG. The dummy data is, for example, random number data, and is output from the dummy data generation circuit 6 shown in FIG. Dummy data output from the dummy data generation circuit 6 is supplied to the optical disk 1 by the selector 7 in FIG. 1 and recorded there.

  A main object of the present invention is to prevent loss of recorded data in the middle of a broadcast program due to a scratch on an optical disc or a skipped track caused by vibration disturbance as described above. For this reason, there are many cases where the optical disc itself has no problem, or even if there is a problem, the problem is slight. In such a case, if no data is recorded on the optical disk 1 while data is being recorded on the fixed storage device 5, an unrecorded track is formed, and a so-called worm-eating state occurs.

  In the case of an optical disc having a recording layer formed from a phase change material, the difference in reflectance between a recorded track and an unrecorded track is small, but in the case of a write-once disc having a recording layer formed from a dye-based material, And the reflectance difference is large. Also, in a so-called two-layer type optical disc that transmits and records data to and from one layer while transmitting the other layer, if an unrecorded area exists in a worm-like state, servo unstable operation is likely to occur. This may cause laser power fluctuation when recording on the layer. In order to solve such a problem, in the present embodiment, even when the level of the transfer switching signal CA is High, the data can be recorded on the optical disk (the abnormality detection signal VA is in the Low state). If so, the dummy data is recorded on the optical disk (see FIG. 4).

  As described above, according to the present embodiment, even if a track jump occurs due to a scratch on the optical disk, disturbance vibration, or the like, which seriously hinders the recording of the broadcast program on the optical disk 1, the fixed storage device 5 can be used. Can be used to record the entire program content without data loss.

  In the present embodiment, when an abnormality occurs during recording on the optical disc 1, the recording medium to be subjected to data recording is switched from the optical disc (first recording medium) to the fixed storage device (second recording medium), whereby the “second recording medium” is obtained. Although the data is saved and recorded on the “recording medium”, the second recording medium in the present invention is not limited to a fixed type, and may be a replaceable type. For example, a card-type hard disk device or a semiconductor memory (memory card) inserted into a PCMCIA throttle may be used.

(Embodiment 2)
Next, a second embodiment of the digital video recorder according to the present invention will be described with reference to FIG.

  The digital video recorder according to the present embodiment differs from the digital video recorder according to the first embodiment in that an encoder 33 is provided between the TV tuner 2 and the buffer memory 32, and a semiconductor memory is provided as the fixed storage device 5. It is in the point.

  Since the cost per bit of a semiconductor memory is higher than that of a hard disk, it is not preferable to mount a semiconductor memory having a capacity as large as the capacity of a hard disk because the price of a digital video recorder increases. When a semiconductor memory having a relatively small recording capacity, for example, a 64 MB SRAM is used as the fixed storage device 5, a standard (SD) image of MPEG2 can be recorded on the fixed storage device 5 for only about 1 minute and 30 seconds. In such a case, an abnormality occurs during data recording on the optical disk, and if recovery from the abnormality continues for 1 minute and 30 seconds or more, the data to be recorded on the fixed storage device 5 exceeds the capacity of the fixed storage device 5. This causes information loss.

  In order to solve the above problem, in the present embodiment, as shown in FIG. 5, data to be written to the fixed storage device 5 is encoded by the encoder 33 to reduce the amount of information. Therefore, a semiconductor memory having a relatively small capacity can be used as the fixed storage device 5.

  More specifically, when the information received by the TV tuner is video / audio data, the encoder 33 generates an image / audio stream having a relatively low transfer rate. Although the quality of the image and sound is sacrificed to some extent by the operation of the encoder 33, a moving image for a longer time. The audio data can be recorded in the fixed storage device 5, and the above-described loss of information can be easily avoided. Reducing the transfer rate can be achieved, for example, by reducing the number of pixels or the number of moving images per second.

(Embodiment 3)
Next, a third embodiment of the digital video recorder according to the present invention will be described with reference to FIG.

  The digital video recorder of the present embodiment includes a demodulator 108 and a decoder 131 necessary for reproducing data recorded on the optical disc 1. In the demodulator 108, the light receiving unit in the optical head 9 that has received the laser light reflected by the optical disk 1 generates a reproduction signal RF according to the intensity of the laser light, and generates a beam spot position of the laser light on the optical disk 1. Is also generated.

  Although not shown in FIG. 6, the digital video recorder of the present embodiment also includes an encoder 31 and a modulator 8, like the digital video recorders of the first and second embodiments.

  The digital video recorder of the present embodiment accesses the fixed storage device 5 at the start of the reproducing operation, and reads the header of the file recorded in the fixed storage device 5. The digital video recorder can know that a writing error has occurred on the optical disc 1 based on the contents of the header of the file.

  The digital video recorder according to the present embodiment can identify the information loss position on the optical disc 1 from the logical address (# N + 1) at the head of the file stored in the fixed storage device 5. Therefore, when reading the information recorded on the optical disk 1, after the logical address # N + 1, the storage device 5 accesses the fixed storage device 5 and reproduces the data recorded on the fixed storage device 5.

  Hereinafter, the operation of reproducing the data distributedly recorded on the optical disc 1 and the fixed storage device 5 by the digital video recorder of the present embodiment will be described in more detail.

  The microprocessor 11 in the digital video recorder of the present embodiment constantly monitors the address information obtained by the demodulator 108. The microprocessor 11 having received the above header information from the fixed storage device 5 temporarily stops reproducing data from the optical disc 1 when the address obtained by the demodulator 108 becomes #N. The data reproduction can be stopped by, for example, transmitting a tracking hold command signal (THD) from the microprocessor 11 to the tracking control circuit 13 to prohibit the tracking of the data area after the address #N.

  While stopping the data reproduction from the optical disk 1, the microprocessor 11 switches the selector 104 by issuing the switching signal CA. Thereby, the path of the signal (DOD) reproduced / demodulated from the optical disk 1 is cut off, and the signal (DHD) from the fixed storage device 5 is supplied to the decoder 131.

  The signal DHD includes file information starting from the address # N + 1. Therefore, the decoder 131 can sequentially obtain information having continuous addresses regardless of the information supply source, and as a result, can seamlessly reproduce video information.

  It is preferable that a volume label or the like of the optical disk 1 in which a writing error has occurred is written in the header of the file stored in the fixed storage device 5. The optical disk on which the writing error has occurred can be specified from the holy label. Therefore, even when an optical disk arbitrarily selected by the user from a plurality of optical disks is loaded into the digital video recorder and data is reproduced, the data recorded in the fixed storage device 5 can be appropriately read as necessary. Will be possible.

  A case in which data is read from the fixed storage device 5 and then data from the optical disk 1 is reproduced again will be described. In this case, the microprocessor 11 sends a track jump command TJMP to the tracking control circuit 13 to move the head tracking position to an area immediately after the area where the dummy data shown in FIG.

  The re-synthesized information may be recorded again on the optical disc 1 or the fixed storage device 5 as a completely restored file. The optical disk on which the complete restoration file is recorded is not limited to the optical disk in which the recording error has occurred, but may be another optical disk. As shown by the dashed line in FIG. 6, if the seamless repair data output from the selector 104 is temporarily recorded in the buffer memory 132 and then recorded in the fixed storage device 5, Will leave the file in perfect form. If the optical disc 1 has a free space, the output of the buffer memory 132 may be written to the optical disc 1 through a modulator (not shown in FIG. 6) (the modulator 8 in FIG. 1).

(Embodiment 4)
Next, a fourth embodiment of a digital video recorder according to the present invention will be described with reference to FIG. In this specification, the term “digital video recorder” widely covers a device capable of recording moving image and audio digital data, and includes a video camera.

  The configuration of the present embodiment is different from the configuration of the digital video recorder shown in FIG. 5 in that the video signal source is a video camera imaging unit 120 and an acceleration used for detecting an abnormality in writing to the optical disc 1. That is, the sensor 100 is provided.

  The video camera imaging unit 120 may have a known configuration, and includes, for example, a camera optical system and a CCD imaging device inside. During shooting, the signal supplied from the video camera imaging unit 120 is non-interactive, as in TV broadcast. Therefore, it has the property that interruption due to circumstances on the storage (slave) side is not recognized.

  According to the present embodiment, it is possible to detect an abnormality that has occurred while recording image data on the optical disc 1. When an abnormality is detected, the data is saved in the fixed storage device 5 so that the video shooting data can be recorded without losing information.

  In the case of a video camera that is often carried, it is considered that the main cause of the tracking loss of the optical head is vibration and impact acting on the camera itself. For this reason, in this embodiment, an abnormality at the time of writing is detected using the acceleration sensor 100.

  The acceleration sensor 100 may be a general sensor that operates by a method of measuring the movement of the fine pendulum or a method of detecting an electromotive force generated when the piezo element vibrates. Alternatively, a configuration may be employed in which a change in a focus error signal or a tracking error signal detected by the optical head 9 is detected to detect an abnormal acceleration.

  When the microprocessor 11 determines that the abnormality detection signal VA based on the acceleration detected by the acceleration sensor 100 has exceeded a predetermined threshold, the microprocessor 11 outputs a signal using the video camera imaging unit 120 as an information source. Is switched from the optical disk 1 side to the fixed storage device 5 side. Thereby, since the data saving process is performed, the image data can be recorded on the recording medium without loss even under the vibration and the shock.

  INDUSTRIAL APPLICABILITY The present invention is applied to a digital video recorder including a digital video recorder for recording a broadcast program on an optical disk or the like, and a camcorder for recording moving images or audio on an optical disk or the like.

FIG. 1 is a block diagram showing a first embodiment of a digital video recorder according to the present invention. (A) is a waveform diagram of the tracking error signal TE, (b) is a waveform diagram of the abnormality detection signal VA output by the abnormal state detection circuit in the digital video recorder of the present invention, and (c) is a waveform diagram of the abnormality detection signal VA. FIG. 9 is a waveform diagram of a transfer switching signal CA output in response. (A) is a waveform diagram of the reproduction signal RF, (b) is a waveform diagram of the abnormality detection signal VA output by the abnormal state detection circuit in the digital video recorder of the present invention, and (c) is a response to the abnormality detection signal VA. FIG. 9 is a waveform diagram of a transfer switching signal CA output as a result. FIG. 4 is a diagram showing recording of dummy data. FIG. 4 is a block diagram showing a second embodiment of the digital video recorder according to the present invention. FIG. 7 is a block diagram showing a third embodiment of the digital video recorder according to the present invention. FIG. 11 is a block diagram showing a fourth embodiment of the digital video recorder according to the present invention.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Optical disk 2 TV tuner 4, 7 selector 5 Fixed storage device 6 Dummy data generation circuit 8 Modulator 9 Optical head 10 Abnormal state detection circuit 11 Microprocessor 12 Program memory 13 Tracking control circuit 31 Encoder 32 Buffer memory 108 Demodulator 120 Video camera Imaging unit 131 Decoder 132 Buffer memory

Claims (19)

A digital video recorder capable of recording data on a recording medium selected from a first recording medium and a second recording medium,
An abnormal state detecting means for detecting the abnormality when an abnormality occurs while data is being recorded on the first recording medium;
With
While the data is being recorded on the first recording medium, when the abnormal state detecting means detects the abnormality, the recording of the data on the first recording medium is stopped, and the recording is performed on the first recording medium. A digital video recorder for recording data to be recorded on the second storage medium.   2. The digital video recorder according to claim 1, wherein after the abnormal state detecting means detects the abnormality, it further detects that the abnormality has been resolved, and resumes recording data on the first recording medium. 3.   After the data to be recorded on the first recording medium is distributed and recorded on the first and second recording media, the data recorded on the second recording medium is read from the second recording medium, 3. The digital video recorder according to claim 1, wherein recording is performed in a free area of the first recording medium.   After the data to be recorded on the first recording medium is distributed and recorded on the first and second recording media, the data is read from the first and second recording media and recorded on another recording medium. The digital video recorder according to claim 1.   Means for appropriately switching between data read from the first recording medium and data read from the second recording medium based on management information recorded on the second recording medium and address information obtained from a reproduction signal. The digital video recorder according to claim 3, wherein The first recording medium is an optical disc;
6. The digital video recorder according to claim 1, wherein said second recording medium is a hard disk or a semiconductor memory. The first recording medium and the other recording medium are optical disks;
The digital video recorder according to claim 4, wherein the second recording medium is a hard disk or a semiconductor memory.   8. The digital video recorder according to claim 6, wherein the abnormal state detection unit detects the abnormality based on a tracking error signal obtained during a tracking operation of the optical disc. 9.   8. The digital video recorder according to claim 6, wherein the abnormal state detection unit detects the abnormality based on a reproduction signal from the optical disc. 9. The first recording medium is exchangeable,
The digital video recorder according to claim 1, wherein the second recording medium is a fixed type.   The digital video recorder according to claim 1, wherein the data recorded on the first storage medium is broadcast data.   The digital video recorder according to claim 11, further comprising a tuner that receives the broadcast data. It has an image sensor,
The digital video recorder according to claim 1, wherein the data recorded on the first storage medium is data output from the image sensor.   2. The digital video recorder according to claim 1, wherein data to be recorded on the first recording medium is delayed for a predetermined time and recorded on the second recording medium.   2. The digital video recorder according to claim 1, further comprising a dummy data generation circuit that records dummy data on the first recording medium while the data is recorded on the second recording medium. 3.   2. The digital video recorder according to claim 1, wherein identification information uniquely associated with at least a part of the data recorded on the first recording medium is added to the data recorded on the second recording medium.   The digital video recorder according to claim 16, wherein a logical address of data recorded on the second recording medium has continuity with a logical address of data recorded on the first recording medium. A method of driving a digital video recorder capable of recording data on a recording medium selected from a first recording medium and a second recording medium,
Detecting an abnormality during the recording of the data on the first recording medium;
Stopping the recording of the data on the first recording medium when the abnormality is detected, and recording data to be recorded on the first recording medium on the second storage medium;
A method that includes A program incorporated in a microprocessor of a digital video recorder capable of recording data on a recording medium selected from a first recording medium and a second recording medium,
For the microprocessor,
Detecting an abnormality during the recording of the data on the first recording medium;
Stopping the recording of the data on the first recording medium when the abnormality is detected, and recording data to be recorded on the first recording medium on the second storage medium;
A program that executes

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