JPH0896509A - Recorder - Google Patents

Abstract

PURPOSE: To provide a recording/reproducing device directly recording a band- compressed digital signal on the recording/reproducing device without providing a device performing band-compression on the recording/reproducing device itself. CONSTITUTION: This device is provided with a channel decoder 6 receiving the band-compressed signal modulated so as to be transmitted through a transmission line, demodulating the received signal and outputting the signal in the band-compressed state and the recording/reproducing device 12 recording the output signal of the channel decoder 6 on an information recording medium. Thus, since the need for a means for expanding band range is eliminated, constitution of the recording/reproducing system is facilitated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for recording / reproducing a digitized information signal, and particularly to efficiently digitizing and transmitting the information signal on a recording medium with little deterioration of the information signal. The present invention relates to the structure of an apparatus capable of recording and reproducing.

[0002]

2. Description of the Related Art A conventional recording / reproducing apparatus will be described below with reference to the drawings.

In FIG. 3, reference numeral 50 is a TV camera for converting an image such as a landscape into an electric signal, and 51 is an analog-digital converter (hereinafter referred to as ADC) for converting an output signal (analog signal) of the TV camera 50 into a digital signal. And 52 is a compression device for band-compressing the output signal of the ADC 51. The TV camera 50, the ADC 51, and the compression device 52 form the transmitter A. Next, 53 is a transmission line such as an electric wire, a space, or an optical fiber for transmitting the output signal of the transmitter A to the receiver B described later. .

Next, 54 is a decompression device corresponding to the compression device 52, which decompresses the signal compressed by the compression device 52 to the original signal. Reference numeral 55 denotes a digital-analog converter (hereinafter abbreviated as DAC) that converts an output signal (digital signal) of the decompressing device 54 into an analog signal, and 5
6 is a display for displaying the output signal of the DAC 55 as an image, and 57 is a recording / reproducing apparatus capable of recording the output signal of the DAC 55 (an analog signal which is not compressed).

The operation of the conventional recording / reproducing apparatus as described above will be described below. The video imaged by the TV camera 50 is converted into an electric signal, this signal is converted into a digital signal by the ADC 51, band-compressed by the compression device 52, and output to the transmission line 53 as an output signal of the transmission device A.

The signal transmitted through the transmission path 53 is received by the receiving device B, expanded by the decompressing device 54 in the reverse manner of the compression device 52, expanded to the original signal, and restored to the original image by the DAC 55. .

The restored signal is displayed as an image on the display 56. The restored signal can be recorded by inputting it to the recording / reproducing device 57.

When a signal to be recorded on the information recording medium of the recording / reproducing device 57 (hereinafter abbreviated as a recording signal) is recorded as a band-compressed digital signal, a device for band-compressing the recording signal is separately provided. And the output signal of the band compression device is recorded on the information recording medium of the recording / reproducing device.

[0009]

However, in the conventional recording / reproducing apparatus as described above, since the band compressing apparatus is very expensive, the recording / reproducing apparatus itself is expensive and the structure is complicated. Further, when the band compression and the band expansion of the video signal and the information signal are repeated, the video signal and the information signal are deteriorated. Further, it has been required to reproduce the portion of which recording has already been completed during recording, but it is also difficult to set the relative speed of the recording medium and the recording head and the reproducing head so that recording and reproduction can be performed.

The present invention solves such a problem, and provides a recording / reproducing apparatus for recording a band-compressed digital signal in the recording / reproducing apparatus without providing the recording / reproducing apparatus itself with a device for band compression. The purpose is to do.

[0011]

In order to achieve this object, a recording / reproducing apparatus of the present invention records a compressed digital signal transmitted from a transmitting apparatus via a transmission line in the recording / reproducing apparatus as it is. This is a configuration that can be done.

More specifically, receiving means for receiving a signal that is data-compressed and modulated so that it can be transmitted on a transmission line,
Demodulation means for demodulating the output signal of the reception means and outputting a data-compressed signal, and recording means for recording the output signal of the demodulation means on an information recording medium. Further, the head for reproducing the recorded portion was set at a position where the reproduction data transfer speed was higher than the recording data transfer speed.

[0013]

With the above-described structure, the recording capacity required for the recording / reproducing apparatus can be greatly reduced, and since the digital signal is recorded, the signal can be stored without deterioration of the signal. It is also possible to reproduce the recorded information signal immediately after.

[0014]

【Example】

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, A is a transmission system which is a transmission means for band-compressing the signal and modulating the signal so that it can be transmitted through a transmission path, and B is a reception means for receiving the modulated signal transmitted by the transmission system A. A receiving system, and C is a recording / reproducing system which is a recording unit for recording the output signal of the receiving system B on an information recording medium.

In the transmission system A, 1 is a video signal encoder for inputting a video signal and band-compressing it, and 2 is an information signal encoder for inputting an information signal and band-compressing it. A switch 3 packetizes the video signal band-compressed by the video signal encoder 3 and the information signal band-compressed by the information signal encoder 4. Four
Is a channel encoder that modulates the output signal of the switch 3 into a signal format suitable for the transmission path.

Next, 5 is a transmission line for sending the output signal of the transmission system A to the reception system B.

In the receiving system B, 6 is a channel decoder which is a demodulating means for decoding (demodulating) the modulated signal transmitted through the transmission path 5. Reference numeral 7 is a switch for converting a packetized signal sequence which is an output signal of the channel decoder 6 into a parallel signal, and separates the band-compressed video signal and the band-compressed information signal here. Reference numeral 8 is a video signal decoder that decodes (expands) the band-compressed video signal of the output signal of the switch 7, and 9 is an information signal decoder that decodes (expands) the band-compressed information signal of the switch 7. .

In the recording / reproducing system C, reference numeral 10 is a correction code adding means for adding a code for error correction when reproducing a signal recorded on an information recording medium described later, to the output signal of the demodulating means. Correction signal adding means 1
0a and memory 10b. The error correction signal adding means 10a is a device to which the output signal of the switch 7 is input and which adds an error correction signal to the band-compressed video signal and the band-compressed information signal.
Is for storing the output signal of the channel decoder 6, which is a demodulating means, via the switch 7, and stores an overflow signal due to the difference between the transmission speed of the information signal and the video signal and the transfer speed of transferring the signal to the recording / reproducing apparatus. It is to be stored temporarily.

Reference numeral 11 is an coder for modulating the output signal of the error correction code adding means in order to facilitate the recording of the signal on the information recording medium of the recording / reproducing apparatus 12 which will be described later. Reference numeral 12 is a recording / reproducing apparatus for recording the output signal of the encoder 11 on the information recording medium. In this embodiment, an optical disc is used as the information recording medium, and the signal is recorded on this. A decoder 13 demodulates an output signal (reproduction signal) of the recording / reproducing apparatus 12 and outputs a band-compressed video signal and an information signal. Of the signals decoded (demodulated) by the decoder 13, band-compressed. The video signal is input to the video signal decoder 8, and the band-compressed information signal is input to the information signal decoder 9.

The operation of the recording / reproducing system configured as described above will be described with reference to the drawings.

In the transmission system A, a video signal is band-compressed by a video signal encoder 1 conforming to a standard such as MPEG, and an information signal is band-compressed by an information signal encoder 2. The band-compressed video signal and the band-compressed information signal are packetized by the switch 3.

Here, "packetization" will be described with reference to FIG. In this embodiment, "packetization" means
The band-compressed video signal and the band-compressed information signal are divided at regular time intervals, and a header signal for distinguishing the type of the divided signal on the receiving system B side is added to the head of each division. Then, the divided signals are one-dimensionally arranged. For example, in FIG. 2, 21, 23, 24,
Is a video signal, 25, 27, and 28 are header signals indicating that they are video signals, 22 is an information signal, and 2
Reference numeral 6 is a header signal indicating that it is an information signal.

The packetized band-compressed video signal and band-compressed information signal (hereinafter abbreviated as packet signal) are encoded (modulated) by a channel encoder 4 into a signal format that allows the signal to be transmitted through a transmission line 5. ), And transmits to the receiving system B via the transmission line 5. In this embodiment, the "QAM modulation method" is used for encoding.

In the receiving system B, the modulated packet signal transmitted via the transmission path 5 is decoded (demodulated) into a packet signal by the channel decoder 6, and this packet signal is band-compressed by the switch 7 and band-compressed. It is separated into a compressed information signal. The band-compressed video signal is decoded (expanded) by the video signal decoder 8 to become a video signal. The band-compressed information signal is decoded (expanded) by the information signal decoder 9 to become an information signal.

In the recording / reproducing system C, when a signal is recorded on the information recording medium (for example, an optical disk in this example) of the recording / reproducing apparatus 12, the band-compressed video signal which is the output signal of the switch 7 and the band-compressed information. An error correction code is added by the error correction signal adding means 10a of the error removing means 10, and the signal is encoded (modulated) into a signal format suitable for recording on the information recording medium (optical disk) of the recording / reproducing apparatus 12 by the encoder 11. After that, it is recorded on the information recording medium (optical disk) of the recording / reproducing apparatus 12.

When reproducing the signal recorded on the information recording medium (optical disk) of the recording / reproducing apparatus 12, the output signal of the recording / reproducing apparatus 12 is encoded (demodulated) by the encoder 13.
Then, the error correction signal is confirmed by the error correction signal confirmation means 10c of the error removal means 10, and if there is an error, the error is removed to obtain a band-compressed video signal and a band-compressed information signal. The band-compressed video signal is converted into a video signal by the video signal decoder 8 of the receiving system B,
The band-compressed information signal is converted into an information signal by the information signal decoder of the receiving system B.

The transmission speed of the band-compressed video signal and the band-compressed information signal output from the switch 7 and the transfer speed at which the encoder 11 transfers the signal to the recording / reproducing apparatus 12 (recording speed of the recording / reproducing apparatus). ) And the overflow signal is temporarily stored in the memory 17b. This prevents the information signal and the video signal from overflowing while maintaining the synchronous relationship between them.

Although an optical disc is used as the information recording medium of the recording / reproducing apparatus in this embodiment, other information recording medium such as a magnetic disc may be used.

In this embodiment, the band-compressed video signal and the band-compressed information signal are used as the signals to be recorded in the recording / reproducing apparatus 12, but the video signal is mainly large in capacity as the information amount of the signal. Therefore, only the video signal may be band-compressed and the information signal may be recorded as it is on the information recording medium of the recording / reproducing apparatus 12.

As described above, according to the present embodiment, the recording / reproducing system C does not require the means for band-compressing the video signal and the information signal and the means for expanding the band.

Band compression of the video signal and the information signal is performed only in the transmission system A.
It is possible to prevent deterioration of the video signal and the information signal due to repeated band expansion.

(Embodiment 2) Next, a method for preventing overflow printing of a band-compressed video signal and a band-compressed information signal will be described below.

(1) Transfer rate V1 (byte / second) <maximum recording speed V2 (byte / second)

In the above-mentioned embodiment, the transfer rate V1 (byte / second) at which the channel decoder 6 transfers a signal to the information recording medium of the recording / reproducing apparatus 12 via the switch 7, the error correction code adding means 10a and the encoder 11 is set. When the maximum recording speed at which the recording / reproducing apparatus as a recording means records a signal on the information recording medium is V2 (byte / second), the bandwidth is compressed by setting V2 (byte / second)> V1 (byte / second). It is possible to prevent the video signal and the band-compressed information signal from overflowing.

(2) A method of providing a memory. In the above-described embodiment, the channel decoder 6 includes the switch 7, the error correction code adding means 10a, and the encoder 11.
The transfer speed V1 (bytes / second) at which a signal is transferred to the information recording medium of the recording / reproducing apparatus 12 via the recording / reproducing apparatus 12, and the maximum recording speed at which the recording / reproducing apparatus as a recording means records a signal on the information recording medium is V2 (bytes / second). ), The storable capacity of the memory 10b is M (bytes), and the maximum delay time of the signal due to the memory 10b, the processing time for controlling the memory, the signal processing time at the time of recording / reproducing, etc. is T (second). In the case (V2-V1) / M <T, it is possible to prevent the band-compressed video signal and the band-compressed information signal from overflowing.

(Embodiment 3) FIG. 4 is an embodiment of a recording / reproducing apparatus, and is a block diagram showing an apparatus for reproducing a recorded information signal immediately after or with a time difference during recording. A description will be given below with reference to the drawings.

Reference numeral 60 is an optical disk, and rotation is controlled by a disk motor 61. Reference numeral 62 is a recording optical head, 63 is a reproducing optical head, 64 is an information signal input terminal which is an input signal of a recording / reproducing apparatus, 65 is an error correction code adding apparatus, and 66.
Is a memory, 67 is a recording controller, 68 is a CPU for controlling the entire recording / reproducing apparatus, 69 is a disk motor controller,
A reproduction processor 70 processes the reproduction signal of the reproduction optical head 63, inputs it to the decoder 71, and outputs it to 73 as an information signal. 72 is a memory. The operation of the recording / reproducing apparatus configured as above will be described.

An error correction code is added to the information signal input to 64 by the error correction code addition device 65.
The 67 recording controller modulates the 67 output and modulates the output laser light of the 62 recording optical head to record on the 60 optical disk. The recording transfer rate at this time is set to R1 bit / sec. The recording optical head 62 is scanned from the outer peripheral portion to the inner peripheral portion of the optical disc 61. The reproducing optical head 63 is also scanned from the outer peripheral portion toward the inner peripheral portion in the form of tracking the recorded track. Since the relative speed of the recording or reproducing optical head of the optical disk is larger in the outer peripheral portion than in the inner peripheral portion when the rotation speed of the optical disk is constant, the recording optical head is directed from the outer peripheral to the inner peripheral in this embodiment. When the data reproduction speed of the reproduction optical head is R2, R2 is set to be larger than R1. 73
Since the data rate required to output the information signal of 1 is a constant rate, the difference between the transfer rate of the output signal of 70 and the transfer rate of the information signal output of 73 is adjusted by the memory of 72.

Since recording by the recording optical head is performed in real time, if the transfer rate to the optical disk is changed to be larger than the transfer rate of the information signal input 64 for a long time, the capacity of the memory 66 needs to be infinite. The disk motor 61 is controlled so that the recording optical head realizes a specified relative speed. At this time, the transfer rate R1 bit / sec is set to a value which is substantially equal in both the information signal input 64 and the output of the recording controller 67. On the other hand, the reproduction optical head 63 outputs the information signal output from the transfer speed of reading from the optical disk
The transfer time is set to be larger than the transfer rate of No. 3, and the difference time is in a standby state until the information in the memory 72 is sufficiently discharged and the stored content of the memory is reduced by interrupting the reproduction at the same position by a method such as a track jump. To do. Here, the transfer speed of the reproducing optical head is R2 bits / sec, which is higher than that of R1 by the amount that the reproducing radius is outside.
The information signal output 73 has a value substantially equal to R1 by adjusting with, and as a result, can be made equal to the information signal input 64. The information to be reproduced is a television receiver or an audio stereo device that receives the information, and it is necessary to match the transfer speed to the receiver side. This role is the memory 72 and the track jump of the reproducing optical head. It can be easily realized by adjusting the combination of the standby time.

With this configuration, the recording start is started at the time when the program is sent out, and then the reproducing optical head has an offset from the start of the recording at a time convenient for the operator. It can be chased and played back, and while recording in real time, it can be used for reading the time-shifted program from the beginning and seeing and listening in a perfect form, and further, playing speed of the playback optical head such as track jump It is also possible to incorporate special playback such as high-speed playback, low-speed playback, and to catch up by reducing the offset of the recording optical head and the playback optical head described above.
On the contrary, it can be made larger, and unlike media such as tapes, it has the great effect that there is no need to wait until the end of recording for reproduction.

Although the description has been centered on the combination of the optical disk device and the video, the present invention is not limited to this, and a recording medium of another principle such as a magnetic disk is used to transfer other information such as voice and data. It is obvious that handling is also within the scope of the present invention.

[0043]

As described above, according to the present invention, since the recording / reproducing system C does not need the means for band-compressing the video signal and the information signal and the means for expanding the band, the structure of the recording / reproducing system C becomes easy. .

Band compression of the video signal and the information signal is performed only in the transmission system A.
It is possible to prevent deterioration of the video signal and the information signal due to repeated band expansion.

Further, in the recording / reproducing apparatus, the recording transfer speed of the recording head is set to be large so that the reproduction data transfer speed of the reproducing optical head is set, so that the recorded contents can be reproduced while recording. As a result, for example, it is possible to provide a device capable of retroactively playing back the time while recording a program of a baseball relay program or the like.

[Brief description of drawings]

FIG. 1 is a block diagram of a recording / reproducing apparatus showing an embodiment of the present invention.

FIG. 2 is a conceptual diagram of a packetized signal.

FIG. 3 Diagram of conventional recording / reproducing system

FIG. 4 is a diagram of a recording / reproducing system of the present invention.

[Explanation of symbols]

 1 Video Signal Encoder 2 Information Signal Encoder 3 Switch 4 Channel Encoder 5 Transmission Channel 6 Channel Decoder 7 Switch 8 Video Signal Decoder 9 Information Signal Decoder 10 Error Removing Means 11 Encoder 12 Recording / Reproducing Device 13 Decoder 62 Recording Optical Head 63 Reproducing Optical Head 66 Memory 72 memory

Claims (5)

[Claims] 1. Demodulation means for receiving a signal which has been band-compressed and modulated so that it can be transmitted on a transmission path, demodulates the received signal, and outputs the signal in a band-compressed state.
A recording device comprising: recording means for recording the output signal of the demodulating means on an information recording medium. 2. Demodulation means for receiving a signal which is band-compressed and modulated so that it can be transmitted through a transmission path, demodulates the received signal and outputs the signal in a band-compressed state.
Recording means for recording a signal on an information recording medium, and correction code adding means for adding a code for error correction when reproducing the signal recorded on the information recording medium of the recording means to the output signal of the demodulating means And a recording device configured to record the output signal of the correction code adding unit on the information recording medium of the recording unit. 3. A transfer rate at which the demodulating means transfers a signal to the information recording medium is V1 (byte / second), and a maximum recording speed at which the recording means records a signal on the information recording medium is V2 (byte / second).
The recording apparatus according to claim 1 or 2, wherein V2> V1. 4. A storage means for storing the output signal of the demodulation means, wherein the storage capacity of the storage means is M (bytes), and the maximum delay time of the signal by the storage means is T (seconds).
The recording apparatus according to any one of claims 1 to 3, wherein (V2-V1) / M <T is satisfied. 5. The information recording medium is disk-shaped, the recording device is provided with a recording head and a reproducing head which is displaced independently of the recording head, and the relative speed between the recording head and the information recording medium. 5. The speed is set to be smaller than the relative speed of the reproducing optical head and the information recording medium, and the information immediately after recording is read by the reproducing head. The recording device described.