JP2008310887A - Disk reproducing unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a disk reproducing unit which can quickly output decoded data from a decoder through simple control. <P>SOLUTION: The disk reproducing unit comprises a selector switch 12 which makes selection between an output of a first storing means 5 and data from a signal processing circuit 4 for an input of a second storing means 6, so that data can be quickly inputted to the second storing means 6 to quickly start decoding and the decoded data can be quickly output from the decoder. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a disc reproducing apparatus for reproducing compressed audio data recorded on a CD (Compact Disc) or the like.

  In a conventional disk reproducing apparatus, data read from a disk such as a CD is temporarily stored in a memory or the like, and the decoding process is performed by storing the data in another memory used by the decoder. Was output to the outside.

FIG. 4 shows a configuration of a conventional disk reproducing device 400.
In the conventional disc reproducing apparatus 400 shown in FIG. 4, 1 is a disc recorded after applying modulation such as EFM (Eight to Fifteen Modulation) to compressed data such as audio data, and 2 is recorded on the disc 1. A pickup 3 for reading the data, a demodulating circuit 3 for demodulating the data read by the pickup 2, a signal processing circuit 4 for restoring the data demodulated by the demodulating circuit 3 to the original compressed digital signal, 5 Is a first storage means for storing the digital signal restored by the signal processing circuit 4, and 6 is a second storage means for storing the data stored in the first storage means 5 for use by the decoder.

  Reference numeral 7 denotes a decoder for decoding data such as a compressed audio file (for example, MP3 (MPEG-1 Audio Layer-3)) using the data stored in the second storage means 6, and 8 for decoding by the decoder 7. A D / A conversion circuit for D / A converting the converted data, 9 is an analog output terminal for outputting analog data converted from digital data by the D / A conversion circuit 8, and 10 is a decoder 7 An interface circuit 11 outputs the decoded data as digital data to the outside, and 11 is a digital output terminal for outputting a digital signal from the interface circuit 10 to the outside.

  Next, the operation will be described. Data such as compressed audio data recorded on the disk 1 is taken out by the pickup 2. This data is not compressed data itself but is modulated by EFM or the like at the time of recording.

  The data taken out by the pickup 2 is demodulated by the demodulation circuit 3 by the modulation such as EFM performed at the time of recording, and further restored to the original compressed digital signal by the signal processing circuit 4.

  The compressed digital signal is temporarily stored in the first storage unit 5 and then stored in the second storage unit 6.

  The first storage means 5 has a large capacity but at a low speed, and has a role as a so-called shock proof memory that prevents skipping of the reproduced sound due to an impact physically applied to the disk reproducing apparatus. The storage means 6 has a small capacity but a high speed, and has a role corresponding to a so-called cache memory that promptly supplies data to the decoder 7.

  The compressed data read from the second storage means 6 is expanded by the decoder 7, converted to an analog audio signal by the D / A conversion circuit 8, and output to the outside from the analog output terminal 9.

  The digital audio data expanded by the decoder 7 is converted into digital data in a format that can be handled by another digital device by the interface circuit 10 and output to the outside through the digital output terminal 11.

  Further, as a conventional disk reproducing apparatus that does not include a decoder, that is, a decompression circuit performs decompression of an audio signal encoded with high efficiency, there has been one disclosed in Patent Document 1.

In a conventional disc playback apparatus that does not include this decoder, before playing a song recorded on the disc, the audio data read from the disc is stored in a memory in advance (when the power is turned on, etc.) When there is a signal for playback, the audio data stored in the memory is output, and at the same time, servo system access is started, and when the servo system access preparation is completed, it is output to the audio data read from the disk. Is switched, the time required for servo system access preparation is shortened, and the beginning of a song is accelerated (for example, see Patent Document 1).
JP 7-176174 A

  However, in the conventional disc reproducing apparatus including the decoder (see FIG. 4), when the storage unit 5 and the storage unit 6 do not store data, for example, at the start of decoding, first, the first storage unit 5 is used. Since the data from the first storage means 5 is stored in the second storage means 6 after that, there is a time difference from when the decoding start signal is actually received until the decoding can be started. There was a problem that the start was delayed and the output of the decoded data was delayed.

  In addition, the conventional disk reproducing device described in Patent Document 1 can solve the problem that the reproduction output appears slowly after the reproduction instruction is issued, but the problem is that the control for that is complicated. there were.

  The present invention has been made to solve the above-described conventional problems, and an object of the present invention is to provide a disc reproducing apparatus capable of speeding up the start of decoding and speeding up the output of decoded data by simple control. And

  In order to solve the above-mentioned conventional problems, a disc reproducing apparatus according to claim 1 of the present invention comprises a reading means for reading data from a disc on which data such as a compressed digital audio signal is recorded, and the reading from the disc. First storage means for storing data read by the means, second storage means for storing data read from the first storage means, and data input to the second storage means A first changeover switch for switching between a path through which the data read from the first storage means is input and a path through which the data read by the reading means is input; and the first switch Changeover switch means comprising a switch control circuit for controlling changeover of the changeover switch, and second data for determining the amount of data stored in the second storage means Determination means; decoding means for decoding data stored in the second storage means; and data output means for outputting data decoded by the decoding means, wherein the second storage means When not stored, the data read by the reading means from the disk is stored in the first storage means and the second storage means, respectively up to a predetermined amount, and the second data amount determination means, When it is determined that a predetermined amount of data is stored in the second storage means, the path of the data input to the second storage means is read from the first storage means by the changeover switch means. It is characterized by switching to a route through which the output data is input.

  As a result, since the data is first stored in the second storage means, the time stored in the first storage means can be shortened, the start of decoding can be accelerated, and the output of decoded data can be reduced. You can do it quickly.

  According to a second aspect of the present invention, there is provided a disc reproducing apparatus according to the first aspect, wherein the first data amount judging means for judging the data amount of the data stored in the first storage means. And when the first data amount determination means and the second data amount determination means determine that the first storage means and the second storage means do not store data, The first storage means and the second storage means store the data read by the reading means from the disk to a predetermined amount, respectively, and the second data amount determination means stores the predetermined amount in the second storage means. When the data read out from the first storage means by the change-over switch means, the route of the data input to the second storage means is determined. Switching the path to be force, characterized in that.

  Thereby, since the data is first stored in the second storage means, the time stored in the first storage means can be shortened, the start of decoding can be made earlier, The output can be made faster.

  According to a third aspect of the present invention, there is provided a disc reproducing apparatus according to the first or second aspect, wherein the reading means and the first storage means are turned on or off. The switch control circuit further includes a second changeover switch, and the switch control circuit selects a path through which the data read from the first storage means is input to the second storage means. The first storage unit is turned on, and the first changeover switch selects a path through which the data read by the reading unit is input to the second storage unit. The first and second changeover switches are switched so as to turn off between the reading means and the first storage means.

  Thereby, since the data is first stored in the second storage means, the time stored in the first storage means can be shortened, the start of decoding can be made earlier, The output can be made faster.

  According to the disk reproducing apparatus of the present invention, when the second storage means does not store data as described above, the data read from the disk by the reading means is reduced to a predetermined amount, respectively. When the second data amount determining means determines that a predetermined amount of data is stored in the second storage means, the second storage means is stored in the storage means and the second storage means. Since the data switching path is switched to the path where the data read from the first storage means is input by the changeover switch means, the output of the decoded data can be performed by simple control. There is an effect that can be made faster.

The best mode for carrying out the present invention will be described below with reference to the drawings.
(Embodiment 1)
FIG. 1 shows a block diagram of a disc playback apparatus 100 according to Embodiment 1 of the present invention.
In FIG. 1, 1 is a disk on which compressed audio data or the like is recorded, 2 is a pickup for reading data recorded on the disk 1, 3 is a demodulation circuit for demodulating EFM data or the like read from the pickup 2, 4 is a signal processing circuit for restoring the data demodulated by the demodulation circuit 3 to the original digital signal, 5 is a first storage means for storing the digital signal restored by the signal processing circuit 4, and 12 is the signal processing circuit 4. This is a first changeover switch for switching between the restored digital signal and the data stored in the storage means 5 and selecting one of them.

  Reference numeral 6 denotes second storage means for storing data selected by the first change-over switch 12 for use by the decoder when demodulating, and reference numeral 13 denotes data stored in the second storage means 6. A data amount judgment circuit 14 for judging the data amount is a first switch control circuit 14 for controlling the switching operation of the first changeover switch 12, and the first storage means 5 and the second storage at the start of decoding or the like. When the means 6 does not clearly store data, the first changeover switch 12 selects the digital signal restored by the signal processing circuit 4 on the b side of the two input terminals a and b. Thereafter, when it is determined by the data amount determination circuit 13 that the second storage means 6 has stored data up to a predetermined amount, the changeover switch 12 is output from the a side, that is, from the first storage means 5. Select data Controlling the first changeover switch 12 so as to. The first switch control circuit 14 constitutes a first changeover switch means 20 together with the first changeover switch 12.

  Reference numeral 7 denotes a decoder that decodes compressed audio files, for example, data such as MP3, using data stored in the second storage means 6, and reference numeral 8 denotes D that D / A converts the data decoded by the decoder 7. An analog output terminal for outputting analog data converted from digital data by the D / A conversion circuit 8 to the outside, and an interface for outputting data decoded by the decoder 7 as digital data A circuit 11 is a digital output terminal for outputting a digital signal from the interface circuit 10 to the outside.

Next, the operation of the disc playback apparatus 100 according to the first embodiment will be described below.
First, data from the disk 1 is read by the pickup 2, and the read data is demodulated by the demodulation circuit 3, and then restored to the original data such as a compressed audio file by the signal processing circuit 4.

  In the first stage of reproduction, the first switch control circuit 14 selects the b side of the two input terminals a and b of the first changeover switch 12, and the signal processing circuit 4 selects a compressed audio file or the like. The data restored to the original data is stored in the first storage means 5 and the second storage means 6, and then the second data indicates that the amount of data in the second storage means 6 has reached a predetermined amount. When the amount determination circuit 13 determines, the first switch control circuit 14 selects the a side of the first changeover switch 12 and directly outputs the data input to the second storage means 6 from the signal processing circuit 4. The switching is performed so that the data to be output is changed to the data output from the first storage means 5. This predetermined amount may be set to an amount slightly larger than the data amount necessary for starting decoding, for example. Thereafter, the data output from the signal processing circuit 4 is once stored in the first storage means 5 and then input to the second storage means 6.

  When the amount of data stored in the second storage unit 6 reaches a decodable amount, the decoder 7 starts decoding and outputs the decoded data to the D / A conversion circuit 8 and the interface circuit 10. The D / A conversion circuit 8 receives the decoded data and converts it into analog data, and outputs it from the analog output terminal 9. The interface circuit 10 receives the decoded data, converts it into data in a format that can be received by an external circuit, Output from the digital output terminal 11.

  As described above, according to the disc reproducing apparatus 100 according to the first embodiment, data is read from a disc on which data such as a compressed digital audio signal is recorded, stored once in the first storage means, and then stored in the second storage unit. When the data is stored in the storage means and supplied to the decoder, the amount of data stored in the second storage means is determined, and when there is no data in the second storage means, such as when the power is turned on, the data is read. When data is stored in the first and second storage means at the same time and a predetermined amount of data is stored in the second storage means, the data is once stored in the first storage means as described above. Since the data is stored in the second storage means and supplied to the decoder, the time for storing the data in the first storage means, which is necessary in the conventional disk reproducing apparatus, can be omitted by simple control. Rukoto can, there is an effect that it is possible to quickly output the decoded data.

(Embodiment 2)
FIG. 2 shows a block diagram of a disc playback apparatus 200 according to Embodiment 2 of the present invention.
2, the same reference numerals as those in FIG. 1 denote the same or corresponding parts. As in the first embodiment of FIG. 1, 13 is a second data amount judgment circuit for judging the data amount of data stored in the second storage means 6, and 15 is stored in the first storage means 5. A first data amount judgment circuit 16 for judging the data amount of the current data, and a second switch control circuit 16 for controlling the switching operation of the first changeover switch 12. The output of the second data amount judgment circuit 13 When the first storage means 5 and the second storage means 6 do not store data based on the output of the first data amount determination circuit 15 and 2 of the first changeover switch 12. The digital signal restored by the signal processing circuit 4 on the b side of the two inputs a and b is selected, and then the second data amount determination circuit 13 causes the second storage means 6 to store a predetermined amount of data. When it is determined that the data has been stored up to a side of the switch 12, i.e., selects the data outputted from the first storage means 5. The second switch control circuit 16 constitutes the second changeover switch means 22 together with the first changeover switch 12.

Next, the operation of the disc playback apparatus 200 according to the second embodiment will be described below.
First, data from the disk 1 is read by the pickup 2, and the read data is demodulated by the demodulation circuit 3, and then restored to the original data such as a compressed audio file by the signal processing circuit 4.

  The data stored in the first storage means 5 and the second storage means 6 has been used up due to an abnormal condition such as being in the first stage of reproduction or being unable to input data due to the rotation of the disc being stopped. In the state or the like, the second data amount determination circuit 13 and the first data amount determination circuit 15 determine that no data is stored in each of the first storage unit 5 and the second storage unit 6. When the second switch control circuit 16 selects the b side of the first changeover switch 12, the data restored to the original data such as the compressed audio file by the signal processing circuit 4 is stored in the first storage unit 5. And stored in the second storage means 6. Thereafter, when it is determined by the second data amount determination circuit 13 that the data amount of the second storage means 6 has reached a predetermined amount, the second switch control circuit 16 is connected to the a side of the first changeover switch 12. And the data input to the second storage means 6 is switched from the data output from the signal processing circuit 4 to the data output from the first storage means 5. Thereafter, the data output from the signal processing circuit 4 is once stored in the first storage means 5 and then input to the second storage means 6.

  The decoder 7 starts decoding when the data amount of the second storage means 6 reaches a decodable amount, and outputs the decoded data to the D / A conversion circuit 8 and the interface circuit 10. The D / A conversion circuit 8 receives the decoded data and converts it into analog data, and outputs it from the analog output terminal 9. The interface circuit 10 receives the decoded data, converts it into data in a format that can be received by an external circuit, Output from the digital output terminal 11.

  As described above, according to the disk reproducing apparatus 200 according to the second embodiment, in the disk reproducing apparatus similar to that of the first embodiment, the data amount of the first storage means is also determined, and the first storage means and If it is determined that no data is stored in the second storage means, the first storage means and the second storage means store the data read by the reading means up to a predetermined amount, respectively. When it is determined that a predetermined amount of data is stored in the storage means 6, the data is stored in the second storage means after the data is stored in the first storage means. Not only when the data in the first storage means and the second storage means have been used up due to an abnormal condition such as the disk stopping and no data being input. The data stored in the first storage means and the second storage means can be input at the same time, and the time for storing the data in the first storage means, which is necessary in the conventional disk reproducing apparatus, with simple control. Can be omitted, and an effect of enabling the output of decoded data to be accelerated is obtained.

(Embodiment 3)
FIG. 3 shows a block diagram of a disc playback apparatus 300 according to Embodiment 3 of the present invention.
3, the same reference numerals as those in FIGS. 1 and 2 denote the same or corresponding elements. Reference numeral 17 denotes a second changeover switch for stopping the input from the signal processing circuit 4 to the first storage means 5, and reference numeral 18 denotes the first storage means 5 and the second storage at the start of decoding. When both means 6 do not clearly store data, the digital signal restored by the b side of the first changeover switch 12, that is, the signal processing circuit 4 is selected, and the input of the second changeover switch 17 is selected. When the stop state (off state) is selected and then the second data amount determination circuit 13 determines that a predetermined amount of data has been stored in the second storage means 6, the first changeover switch 12 a third switch control circuit for selecting the data output from the first storage means 5 and selecting the input state (ON state) of the second changeover switch 17; With switch 12 Constitute the third change-over switch means 24.

Next, the operation of the disc playback apparatus 100 according to the third embodiment will be described.
First, data from the disk 1 is read by the pickup 2, and the read data is demodulated by the demodulation circuit 3, and then restored to the original data such as a compressed audio file by the signal processing circuit 4.

  In the first stage, the third switch control circuit 18 selects the b side of the first changeover switch 12 and puts the second changeover switch 17 in the input stop state. The data restored to the original data such as a compressed audio file by the signal processing circuit 4 is stored, while the first storage means 5 is not written. Thereafter, when the second data amount determination circuit 13 determines that the second storage means 6 has reached the predetermined amount, the third switch control circuit 18 selects the a side of the first changeover switch 12. In order to set the second changeover switch 17 to the input state, the continuation of the data directly input to the second storage means 6 starts to be input to the first storage means 5, and the second storage means 6 Is switched to data output from the first storage means 5, and the subsequent data portion input from the signal processing circuit 4 is input to the first storage means 5.

  When the second storage means 6 reaches an amount that can be decoded, the decoder 7 starts decoding and outputs the decoded data to the D / A conversion circuit 8 and the interface circuit 10. The D / A conversion circuit 8 converts the received decoded data into analog and outputs it from the analog output terminal 9, and the interface circuit 10 converts the received decoded data into a format that can be received by an external circuit, Output from the output terminal 11.

  As described above, according to the disk reproducing apparatus 300 according to the third embodiment, when data is not stored in the first storage means and the second storage means in the same disk reproducing apparatus as in the first embodiment. By blocking the input of data to the first storage means, only the second storage means stores the data read by the reading means up to a predetermined amount, respectively, and the second storage means stores a predetermined amount of data. Is stored in the first storage means and then stored in the second storage means and supplied to the decoder as described above. The time required to store data in the first storage means required in the disk reproducing apparatus can be omitted, and the data required in the conventional disk reproducing apparatus can be saved by the simple control. Time to be stored in the storage means can be omitted, there is an effect that it is possible to quickly output the decoded data.

  In the third embodiment, since the first storage means is not initially written to, the power consumption can be reduced and unnecessary radiation can be reduced. .

  In the third embodiment, the determination of the data amount has been described as determining the data amount in the second storage means, as in the first embodiment. Similarly to 2, the data amount in the first and second storage means may be determined, and the same effect can be obtained.

  As described above, the disc playback apparatus according to the present invention can speed up the output of decoded data, and thus is useful as a disc playback apparatus for playing back compressed audio recorded on a CD or the like.

It is a figure which shows the structure of the disc reproducing | regenerating apparatus 100 by Embodiment 1 of this invention. It is a figure which shows the structure of the disc reproducing | regenerating apparatus 200 by Embodiment 2 of this invention. It is a figure which shows the structure of the disc reproducing | regenerating apparatus 300 by Embodiment 3 of this invention. It is a figure which shows the structure of the disc reproducing apparatus 400 of a prior art example.

Explanation of symbols

100, 200, 300, 400 Disc playback device 1 Disc 2 Pickup 3 Demodulation circuit 4 Signal processing circuit 5 First storage means 6 Second storage means 7 Decoder 8 D / A conversion circuit 9 Analog output terminal 10 Interface circuit 11 Digital Output terminal 12 Changeover switch 13 Second data amount judgment circuit 14 Switch control circuit 15 First data amount judgment circuit 16 Switch control circuit 17 Changeover switch 18 Switch control circuit

Claims (3)

Reading means for reading data from a disc on which data such as a compressed digital audio signal is recorded;
First storage means for storing data read from the disk by the reading means;
Second storage means for storing data read from the first storage means;
The data input to the second storage means is switched between a path for inputting data read from the first storage means and a path for inputting data read by the reading means. A changeover switch means comprising a first changeover switch and a switch control circuit for controlling the changeover of the first changeover switch;
Second data amount judging means for judging the amount of data stored in the second storage means;
Decoding means for decoding data stored in the second storage means;
Data output means for outputting the data decoded by the decoding means,
When the second storage means does not store data, each of the data read from the disk by the reading means is stored in the first storage means and the second storage means to a predetermined amount,
When the second data amount determining means determines that a predetermined amount of data is stored in the second storage means, the path of the data input to the second storage means is changed to the changeover switch means. To switch to a path through which data read from the first storage means is input,
A disc player characterized by that. The disc player according to claim 1, wherein
A first data amount judging means for judging a data amount of data stored in the first storage means;
When the first data amount determination means and the second data amount determination means determine that the first storage means and the second storage means do not store data, the first storage means Each of the data read by the reading means from the disk is stored in the second storage means to a predetermined amount;
When the second data amount determining means determines that a predetermined amount of data is stored in the second storage means, the path of the data input to the second storage means is changed to the changeover switch means. To switch to a path through which data read from the first storage means is input,
A disc player characterized by that. The disc player according to claim 1 or claim 2,
A second changeover switch for turning on or off between the reading unit and the first storage unit;
The switch control circuit, when the first changeover switch selects a path through which the data read from the first storage means is input to the second storage means, When the first changeover switch selects a path through which the data read by the reading unit is input to the second storage unit, the first switching switch and the first storage unit are turned on. Switching the first and second changeover switches so as to turn off between the storage means and
A disc player characterized by that.

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