JPH0332156B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a playback device used to play back information recorded on a disk such as a digital audio disk (hereinafter referred to as DAD), and particularly to a playback device used for playing back information recorded on a disk such as a digital audio disk (hereinafter referred to as DAD). A disk reproducing device is capable of selectively reproducing desired pieces of recorded program information with a resolution exceeding that obtained by address information recorded with each program information. This is a proposal.

Digitized audio signals are recorded as program information on a rotating disk-shaped recording medium, forming a spiral recording track.
In a DAD, recorded digital signals have a predetermined format. For example, as shown in FIG. It consists of a part 1 with a frequency of 7.35 kHz), a subcode part 2, and a data part 3 containing program information. The subcode section 2 is divided into, for example, eight channels from P to W, of which the Q channel contains address information accompanying the program information of the data section 3. If the Q channel is expressed continuously by narrowing the frame interval, it will look like Figure 1B.
For example, one frame consisting of 98 frames as shown in
The unit is a block. One block is 98 frames, so 136 μsec x 98 ≒ 13.3 m
It has a period of seconds, and its contents include block period synchronization information B and C (repetition frequency is 75Hz for both).
, a number for each piece of program information, for example, part 6 representing the song number m, a number for each division in one program information, for example, part 7 representing the movement number n, one piece of program information. having portions 8, 9, and 10 containing time address information min, sec, and 1/10S representing minutes, seconds, and 1/10 seconds from its beginning for each of the sections;
These parts 6 to 10 are parts containing address information. Therefore, address information is reproduced every block, ie, every 13.3 msec, and the minimum division of address information is 1/10 second.

A DAD in which a digital signal having the above-mentioned format is recorded to form a spiral recording track is, for example, rotated at a speed such that the velocity in the tangential direction of the recording track relative to the information reading means, that is, the linear velocity is constant. is changed and rotated,
For example, one rotation takes about 0.13 seconds at the inner circumference and about 0.13 seconds at the outer circumference.
It is said to be about 0.29 seconds, which means that the time in the middle part is 0.2 seconds.
It will be about seconds. Therefore, one of the spiral recording tracks
This means that the cycle includes one to three recording parts where the address information 1/10S, which represents the minimum division of address information in units of 1/10 seconds, does not change. FIG. 2 shows this situation, where part 12 of the spiral recording track 11 on the disk contains the song whose song number m is M, that is, the movement whose movement number n is N of the Mth song, that is,
Address information for x minutes y + 0.2 seconds from the beginning of the Nth movement is recorded, and in the following part 13, the same M
Address information for x minutes y + 0.3 seconds from the beginning of the Nth movement of the th song is recorded. Note that the address increases from the inside to the outside of the spiral recording track 11. In this case, the same 1/10 second address information 1/10S is recorded over approximately half the circumference of the spiral recording track 11.

When playing such a DAD, x
To selectively reproduce the program information from the address position of minute y + 0.3 seconds, the following can be done. First, reproduction address information is obtained and decoded from the reproduction signal read by the information reading means, and the reading position of the information reading means is set at any location within the portion 13, for example, point a in FIG. ,M
When the address information for x minutes y + 0.3 seconds from the beginning of the Nth movement of the th song is obtained, the reading position of the information reading means is moved back (moved inward) by one recording track to perform a track jump. , the reading position of the information reading means is moved to point a' on the recording track one track inside. Next, if reading is performed along the recording track from point a' as shown by the dashed line, the address part of x minutes y + 0.3 seconds from the beginning of the Nth movement of the Mth song will be read. Opening part 1
3s, and the address information for x minutes y + 0.3 seconds is obtained again from the beginning of the Nth movement of the Mth song, so at that point, without performing the track jump described above, Obtain playback program information as output. In this way, desired program information can be selectively reproduced.

However, in such a case, since the minimum division of address information recorded on the disk is 1/10 second, program information cannot be found with a resolution of 1/10 second or less. That is, when selectively reproducing recorded program information, it is only possible to specify a desired location in units of 1/10 seconds at the most. This results in the inconvenience that the disk playback device is functionally insufficient when, for example, the disk playback device is used to cue or edit a song in broadcasting operations.

Therefore, the present invention provides synchronization information recorded along with the program information, such as frame period synchronization information or block period synchronization information, in addition to address information when reproducing program information recorded on a disk such as the above-mentioned DAD. The purpose of the present invention is to provide a disc playback device that can selectively play back recorded program information with a resolution that exceeds the resolution obtained by the minimum division of address information by using synchronization information. Examples of the present invention will be described below.

FIG. 3 shows the main parts of an example of a disc playback device according to the present invention. Reference numeral 21 denotes a disk, which is used for reproduction by the disk reproduction apparatus according to the present invention, on which a digital signal having a format as shown in FIG. 1 is recorded to form a spiral recording track. This is a DAD as described above which has the manner of recording address information as shown in the figure.
This disk 21 is attached to a disk rotating section 23 that is rotated by a motor 22, and is rotated at a predetermined constant linear speed. Also, disk 21
An information reading means 24 is disposed to face the spiral recording track forming portion, and its reading position is controlled by a reading means driving section 25.
The reproduced signal read by the information reading means 24 is passed through the amplifier circuit 26 to the waveform conversion circuit 27.
After being converted into a digital signal with an appropriate waveform, it is supplied to a decoder 28. Decoder 28
Reproduction program information A _d is obtained from the program information processing circuit 29 and supplied to the program information processing circuit 29 , and an audio output signal A _a based on the reproduction program information A _d is obtained from the program information processing circuit 29 . is derived via . The muting circuit 30 has a program selection command PS.
It is assumed that mutating is applied.

Furthermore, the decoder 28 outputs playback address information Q.
is obtained, and this is supplied to the address information decoding section 31 to obtain a decoding output Q' of the reproduced address information Q. This decoding output Q' is supplied to the comparator 32,
Similarly, the address designation section 3 is supplied to the comparison section 32.
It is compared with the designated address data _D1 from 3.
The comparator 32 generates a match output H ₁ when the decoded output Q' and the designated address data D ₁ match, and supplies this to the controller 34 . When the control unit 34 receives the coincidence output H ₁ from the comparison unit 32 when the program selection command PS is input and is in the program selection state, the control unit 34 generates a track jump control signal J and activates the reading means driving unit 25 . supply to.
The reading means driving section 25 receives the track jump control signal J and causes the information reading means 24 to perform a track jump of returning the reading position on the disk 21 by one recording track (moving it toward the inner circumference).

Furthermore, the output Y of the decoder 28 is
5, and the synchronization detection unit 35 obtains synchronization information A of the reproduced frame period. This synchronization information A is supplied to the counter 37. The counter 37 is reset at the leading edge of the coincidence output _H1 from the comparator 32 and counts the synchronization information A, and the counting result C _a is constantly supplied to the comparator 39, and is separately supplied to the comparator 39. Address specification section 33
is compared with the specified address data _D2 from D2.
The comparator 39 calculates the count result C _a from the counter 37
When the specified address data D ₂ and the specified address data D 2 match, a match output H ₂ is generated and supplied to the control section 34 . When the control unit 34 receives the coincidence output H ₂ from the comparison unit 39 when the reproduction operation command PY is input, the control unit 34 generates a muting release control signal K and supplies it to the muting circuit 30 . The muting circuit 30 releases the muting when the muting release control signal K is supplied.

Next, a program selection operation in an example of a disc playback device according to the present invention in which each part functions as described above will be described in detail.

First, the address of desired program information recorded on the disk 21 is, for example, M
If it is x minutes y + 0.34 seconds from the beginning of the Nth movement of the Mth song, the address information representing x minutes y + 0.34 seconds from the beginning of the Nth movement of the Mth song is designated address information D, and the address It is input to the designation section 33. Then, a program selection command PS for starting a program selection operation is input to the muting circuit 30, the addressing section 33, and the control section 34, and a program selection operation state is entered. As a result, the muting circuit 30 is brought into a state where mutating is applied, and the address designating section 33 is set to the Nth tune of the Mth song in the designated address information D.
From the beginning of the movement to x minutes y + 0.3 seconds, i.e. 1/10
The address data corresponding to the part up to the second is output as designated address data _D1 , and the address data corresponding to the 0.04 second part of the designated address information D is output as the designated address data _D2 . In this case, the specified address data
D ₂ is assumed to correspond to the counting output of the counter 37. Here, the counter 37 has a frame period,
That is, since the synchronization information A having a cycle of 136 μsec is counted, the counter 37 counts every 136 μsec. Therefore, if the address information corresponds to a time of 136 microseconds or more, it can be converted into information corresponding to the counting output of the counter 37. However, accurate conversion is possible only for times that are integral multiples of 136 μs.
In other cases, the conversion is performed by approximating to the nearest integral multiple of these times.

In this state, the information recorded on the spiral recording track 11 formed on the rotating disk 21 is
A reproduced signal is obtained by being read intermittently or continuously by the information reading means 24, and the reproduced signal is read by the decoder 2.
Although the playback program information A _d is obtained from 8, the audio output signal A _a based on this is muted by the muting circuit 30, so no playback sound is output.

At this time, the reproduced address information Q obtained from the decoder 28 is decoded by the address information decoder 31 to obtain a decoded output Q', but as shown in FIG. a portion 13 of the helical recording track 11 of
That is, x minutes y+ from the beginning of the Nth movement of the Mth piece.
When reaching a location a within the part where 0.3 seconds of address information can be obtained, the decoding output Q' is M
This represents x minutes y + 0.3 seconds from the beginning of the Nth movement of the th song. Therefore, at this time, the decoding output
Q' and designated address data _D1 match, and the comparator 32 generates a match output _H1 . This matching output H ₁
The control unit 34 that received the program selection command PS
Since the track jump control signal J is generated, the information reading means 24 is caused to perform a track jump to return its reading position by one recording track. The reading position moves to point a' in FIG.

Thereafter, the information reading means 24 reads along the recording track as shown by the dashed line in FIG. When input, the program selection state changes to the playback operation state. The reading position of the information reading means 24 is x minutes y+ from the Nth movement of the Mth song.
After passing through part 12 where address information is obtained for 0.2 seconds,
When the beginning part 13s of part 13 is reached, the address information for x minutes y + 0.3 seconds from the beginning of the Nth movement of the Mth song is obtained again, and the comparison unit 32 outputs a coincidence output H ₁
occurs. At this time, the control unit 34 outputs a coincidence output.
Even if it receives _H1 , it does not generate the track jump control signal J because it is not in the program selection state. Therefore, the information reading means 24 continues to read the recording track 11 without performing a track jump.
Reading in part 13 is then performed.

On the other hand, at this time, the counter 37 is reset at the leading edge of the coincidence output _H1 from the comparator 32, and then
Recording track 1 supplied from the synchronization detection section 35
The reproduced synchronization information A in the reproduced signal from the portion 13 of 1 is counted. Then, when the reading position of the information reading means reaches the address location x minutes y + 0.34 seconds from the beginning of the Nth movement of the Mth song in section 13, that is, the target address location T, Since the count result C _a of the counter 37 matches the designated address data D ₂ corresponding to 0.04 seconds, the comparator 39 generates a match output H ₂ . The control section 34 that has received this coincidence output _H2 is in the reproducing operation state where the reproducing operation command PY has been input, so it generates the muting release control signal K, thereby canceling the muting in the muting circuit 30. Playback program information after that time
Reproduced audio is obtained from the audio output signal A _a based on A _d . In this way, the program information from x minutes y + 0.34 seconds from the beginning of the Nth movement of the target Mth song is selectively played back.
Selective playback can be performed with a resolution that exceeds the resolution based on the minimum division of address information recorded in 1, that is, the resolution in units of 1/10 seconds. In this case, since the frame period, that is, the synchronization information A with a period of 136 microseconds is counted by the counter 37, selective reproduction with a maximum resolution of 136 microseconds is possible. That is, in the most detailed case, the designated address can be set in units of 136 μsec.

Note that during the above-mentioned operation, the reading position of the information reading means 24 changes from point a in FIG.
After the track jump to a′ is performed, if you continue to keep the program selected,
Thereafter, when the reading position of the information reading means 24 reaches the beginning 13s of the portion 13 of the recording track 11 and the comparison section 32 generates a coincidence output _H1 , the control section 34 generates a track jump control signal J. , the information reading means 24 is caused to perform a track jump to return its reading position by one recording track, and this operation is repeated thereafter. Therefore, the reading position of the information reading means 24 moves along a loop that jumps back by one recording track at the beginning 13s of the portion 13, as shown by the two-dot chain line in FIG. and enters playback standby mode. Further, the reading position of the information reading means 24 mentioned above is from point a in FIG.
After the track jump to move to a' is performed, the rotation of the disk 21 is detected and the disk 21
If one pulse is generated every time the information reader rotates once, and this pulse causes the information reading means 24 to perform a track jump to return its reading position by one recording track, the reading position of the information reading means 24 can be changed to a point. It is possible to enter a playback standby state in which the data moves along a loop that jumps back by one recording track at a. After entering the playback standby state, if the playback operation command PY is input, the selective playback as described above is performed.

The example described above uses the frame period synchronization information A, but instead of the synchronization detection section 35, counter 37, and comparison section 39 in FIG.
As shown by the dotted line connection path, a synchronization detection section 36 that detects the synchronization information B of the block period, a counter 38 that counts the synchronization information B, and a comparison section 40 may be provided, and the synchronization information B of the block period may be used. can. In this case as well, the counter 38 is
The comparator ₄₀ receives designated address data D ₃ similar to the designated address data D ₂ from the addressing section.
is supplied, the count result C _b of the counter 38 is compared with the specified address data D ₃ , and when they match, a coincidence output H ₃ similar to the coincidence output H ₂ is obtained from the comparing section 40 and is supplied to the control section 34 . be done. When the control section 34 receives the coincidence output _H3 , it performs the same operation as when it receives the coincidence output _H2 .

However, in this case, the counter 38 counts at a block period, that is, every 13.3 msec, so the designated address data D ₃ is an integral multiple of 13.3 msec.
Alternatively, it is necessary to convert the time that is closest to the integral multiple of 13.3 msec into a time that corresponds to the count output of the counter 38. Therefore, in this case, program information can be selectively reproduced with a resolution of 13.3 msec, and the designated address can be set in units of 13.3 msec.

As explained above, according to the disc playback device according to the present invention, by using the synchronization information recorded on the disc along with the program information, the resolution obtained by the minimum division of the address information recorded on the disc is achieved. It is possible to set a specified address with a resolution exceeding 100 kHz, and selectively reproduce recorded program information based on the specified address. Furthermore, when setting the specified address, the output based on the playback program information is muted by the muting means, so that undesired audio is not output, and furthermore, the specified address can be set. When the program information is subsequently reproduced, muting by the muting means for the output based on the reproduction program information is automatically canceled.
Therefore, the disc playback device according to the present invention can be used without any inconvenience as a DAD playback device used in broadcasting services.

Note that the disc reproducing apparatus according to the present invention is not limited to the apparatus for reproducing DAD mentioned in the above-mentioned embodiments, but can be applied to any device in which a signal including DAD is recorded in a format including predetermined synchronization information. The present invention can be configured in various ways as an apparatus for reproducing various types of disks on which spiral recording tracks are formed.

[Brief explanation of the drawing]

FIG. 1 is a diagram used to explain the recording signal format of DAD, FIG. 2 is a diagram used to explain selective reproduction of program information in a DAD reproduction device, and FIG. 3 is a diagram used to explain the selective reproduction of program information in a DAD reproduction device. FIG. 4 is a block connection diagram showing the main parts of the example, and is a diagram used to explain selective reproduction of program information in the example of the disk reproducing apparatus according to the present invention. In the figure, 21 is a disk, 24 is an information reading means, 25 is a reading means driving section, 28 is a decoder,
29 is a program information processing circuit, 30 is a mutating circuit, 31 is an address information decoding section, 32,
39 and 40 are comparison sections, 33 is an address specification section,
34 is a control section, 35 and 36 are synchronization detection sections, 37
and 38 are counters.

Claims (1)

[Claims] 1. A spiral recording track in which synchronization information and address information are recorded together with program information,
Information reading means for reading information from a rotatably driven disk to obtain a playback signal; driving means for moving the information reading means with respect to the disk; obtaining playback program information from the playback signal and converting it to the playback program information. a program information processing means for transmitting the original output; a muting means for mutating the output based on the playback program information; a synchronization information detection means for obtaining playback synchronization information from the playback signal; and the synchronization information detection means a counting means for counting reproduction synchronization information obtained from the reproduction signal; an address information detection means for obtaining reproduction address information from the reproduction signal; and an address for transmitting first specified data regarding the address information and second specified data regarding the synchronization information. a specifying means; and during a program selection operation, muting is applied by the mutating means, and reproduction address information obtained from the address information detecting means is transmitted to the first address from the address specifying means.
When the address is specified by the specified data, the driving means causes the information reading means to perform a track jump to return the reading position on the disk by one recording track, and then the reproduction address information is changed to the first one. When the specified data is specified by the address specifying means, the counting means is operated without causing the information reading means to perform the track jump. 2. A disc playback device comprising: a control unit that sets a state in which muting by the muting means is canceled when the data specified by the specification data of item 2 is reached;