JPH0432476B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a disc record playback device suitable for, for example, a CD (optical compact disc) type DAD (digital audio disc), and particularly relates to a disc record playback device that can quickly reproduce desired data. Regarding a search system for selecting (cueing).

[Technical background of the invention and its problems]

Recently, in the field of audio equipment, digital recording and playback methods that utilize PCM (pulse code modulation) technology are being adopted in order to achieve high-speed playback as much as possible. In other words, this is what is called digital audio, and the audio characteristics do not depend on the characteristics of the recording medium and are much superior to those using conventional analog recording and playback methods. This is because it is established in principle.

In this case, a system that uses a disk as a recording medium is called a DAD system.
Optical, electrostatic, and mechanical methods have been proposed as recording and reproducing methods, but no matter which method is adopted, the reproducing device that embodies it is still the conventional one. There is a need for devices that can satisfy a variety of advanced control functions and performance that are not commonly seen before.

In other words, taking the CD system as an example, this is a transparent resin disk with a diameter of 12 [cm] and a thickness of 1.2 [mm] with pits (irregularities with different reflectances) corresponding to digital (PCM) data. The disk, which is coated with a thin metal film that forms the This type of pickup uses linear tracking to play from the inner side to the outer side, but the track pitch of the disc is
The program area (radius 25 to 58 mm) contains a huge amount of information that is 1.6 μm and can provide approximately 1 hour of stereo playback even on one side.
This can be easily seen from the fact that the index data etc. are recorded in the lead-in area (radius 23 to 25 mm).

However, in conventionally known disk record playback devices of this type, it is particularly important to select (cue) desired data (songs) from among a plurality of data (songs) recorded in the program area. This is considered to be an issue that needs to be solved urgently because a so-called search function that can be performed accurately and quickly has not yet been realized.

[Purpose of the invention]

This invention was made based on the above-mentioned circumstances, and is an extremely effective method for achieving a quick and accurate search function with a simple configuration, especially in a disc record playback device that plays back discs containing digitized data. The purpose is to provide a good disc record playback device.

[Summary of the invention]

That is, the present invention provides a disc record reproducing apparatus which reads out digital data and temporal information via an optical pickup from a disc on which digital data obtained by converting an information signal into PCM is recorded together with temporal information. , a setting means for setting temporal information of a target position to which the pick-up should be moved; and a setting means for setting temporal information of a target position to which the pick-up is to be moved, and corresponding to each temporal information based on the temporal information set in the setting means and the temporal information read from the pickup calculation means for calculating radius information of each of said disks, and distance data between said pick-up's current position and said target position by subtracting each radius information calculated by said calculation means, and said pick-up at said target position. a subtracting means for generating a drive signal for moving the disk in the radial direction of the disk; a moving amount detecting means for generating moving amount detection data corresponding to a distance moved by the pick-up based on an output of the pick-up that changes in response to crossing; and a moving amount output from the moving amount detecting means. The device is characterized by comprising a stop means for stopping the movement of the pick-up in a state where the detection data corresponds to the distance data calculated by the subtraction means, and the pick-up is moved quickly and accurately to the target position. It was designed so that

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. First, an overview of a CD-based DAD playback device to which the present invention is applied will be explained.

That is, FIG. 1 shows a front external view.
In the figure, reference numeral 111 denotes a Kangaru-pocket type disk loading section provided on the front surface of the cabinet 110 so as to be openable and closable. And this disk loading section 11
An EJECT key 112 for opening/closing the disk loading section and a POWER key 113 for connecting/disconnecting the power supply are provided on the left side of the disk drive unit 1 .

In addition, on the upper right side of the disk loading section 111,
A display section 114 for making various displays, a reverse (REV) key 115 for so-called reverse word operation, a first forward (FF) key 116 for first forward operation, and a play (PLAY) key for play operation. 117 is provided. Also in the middle row are the NEXT PLAY key 118, the REPEAT key 119, and the PAUSE key.
A key 120 and a STOP key 121 are provided. Similarly, in the lower row, 0, 1,
Numerical keys 122 to 131 of 2, . . . , 9, a memory read (M READ) key 132, a memory (MEMORY) key 133, and a clear (CLEAR) key 134 are provided.

The above-mentioned display section 114 includes an EJECT display 114a and a SEARCH display.
Display 114b, error (ERROR) display 11
4c, repeat (REPEAT) indicator 114d,
MANUAL indicator 114e, AUTO indicator 114f, MEMORY indicator 114g, and 8-channel memory indicator (MEMORY)
INDICATOR) 114h and song number (MUSIC
NO.) display 114i and a time (TIME) display 114j are provided.

Furthermore, during the play (PLAY) key 117 and the pause (PAUSE) key 120, there is also a play (PLAY) indicator 114k and a pause (PAUSE) key, respectively.
A display 114l is provided.

Here, Figure 2 shows the CD method shown in Figure 1.
This shows the electrical circuit system of the DAD playback device.
That is, 140 in FIG. 2 is a disk, which is attached to the disk loading section 111 and connected to the disk motor 141 so that its rotational force is transmitted when the disk loading section 111 is closed. A pickup 142 is also provided to face the signal recording surface of the disk 140. This pick up 1
42 is supported so as to be movable in the radial direction of the disk 140, and is moved by the driving force of the pick-up feed motor 143. The above-mentioned pick-up 142 is actually provided on the side where the disk motor 141 is attached (that is, the lower side of the disk 140 in FIG. 2), but it is drawn above the disk 140 in FIG. 2 for convenience. I'll decide.

The pick-up 142 is equipped with a laser emitting section, a beam splitter, a converging lens, a photoelectric conversion element, etc. (not shown), and first, the laser beam emitted from the laser emitting section passes through the beam splitter and is sent to the converging lens. The light is converged and focused (spot) on the surface of the disk 140. Then, the laser beam is directed to the disk 140.
The light changes depending on the presence or absence of the upper pit, is reflected, travels backwards through the converging lens, and is guided by the beam splitter to the photoelectric conversion element. For this reason, the photoelectric conversion element outputs an electrical signal (hereinafter referred to as an RF signal) corresponding to the presence or absence of the pit and its time length, from which the digitized data recorded on the disk 140 is read.

By the way, the program area (radius 25 to 58 [mm]) of the disk 140 includes a plurality of audio data (hereinafter described as songs), data indicating the song number (TNO) of each song, and data indicating the number (TNO) of each song. Data indicating each divided area (hereinafter referred to as index data), elapsed time from start to end of each song (hereinafter referred to as relative address)
Address data such as data indicating the continuous elapsed time from the start of the performance of the first song to the end of the performance of the last song (hereinafter referred to as absolute address) are recorded. That is, the RF signal includes audio data and address data, and in this case, both data are read out in parallel.

In addition, the lead-in area (radius 23 to 25 mm) of the disk 140 contains the track numbers (TNO) of the plurality of songs recorded in the program area, the relative address of each song, and the time point at which the performance of each song starts ( Data (Table of Contents (TOC) data) indicating the absolute address, etc. of the head) is recorded.

Here, the above DAD playback device normally moves the pickup 142 to the inner peripheral portion of the disk 140.
Specifically, it is positioned at a portion of the lead-in area of the disc 140 that corresponds to the playback start position. In addition, the DAD playback device is
The fact that the disk 140 is installed in the disk loading section 111, that the disk loading section 111 is closed, and that the power key 11
3 is operated, the disk motor 141 is rotated, the contents of the lead-in area are automatically read by the pick-up 142, stored in the lead-in data memory to be described later, and the pick-up 142 is read. It is controlled so that it is positioned at a portion of the program area of the disk 140 corresponding to the playback start position and placed in a standby state.
If, for example, the PLAY key 117 is operated in this standby state, the contents of the program area are read out.

Here, the RF signal output from the pickup 142 is transmitted to a focus control circuit 144, a tracking control circuit 145, and a process circuit 146.
are supplied respectively. Of these, the focus control circuit 144 generates a focus error signal from the RF signal, and picks it up 142.
By feedback to disk 14
The converging lens in the pickup 142 is controlled in the direction of the surface of the disk 140 so that the light beam is accurately focused on the zero plane, thereby performing so-called focus servo. Further, the tracking control circuit 145 generates a tracking error signal from the RF signal. This tracking error signal has negative and positive polarity levels because the spot of the light beam on the surface of the disk 140 deviates from the center of the track toward the inner and outer peripheries of the disk 140, and the magnitude of the deviation The absolute value level changes depending on the
0 when the spot is located at the center of the track
This is the level. The tracking control circuit 145 sends the tracking error signal to a switch circuit 147 and an adder circuit 1, which will be described later.
48 to the pickup 142, the converging lens in the pickup 142 is controlled in the radial direction of the disk 140 so that the spot of the light beam on the surface of the disk 140 is precisely located at the center of the track. ,
This is a so-called tracking servo.

Further, the tracking error signal outputted from the tracking control circuit 145 is transmitted to the feed motor control circuit 1 after passing through the switch circuit 147.
49 and a switching circuit 150, which will be described later, to the pickup feed motor 143, and for example, the pickup 14 is supplied as the playback operation progresses.
2 are sequentially moved from the inner circumference to the outer circumference of the disk 140.

Further, the process circuit 146 includes the RF
After time axis conversion, error correction, etc. are performed on the signal, if the RF signal is the content of the lead-in area, the TOC data is stored in the lead-in data memory 151 described above. Furthermore, if the RF signal is the content of the program area, the audio data and address data are separated and the audio data is sent to the DA conversion circuit 1.
52 and outputs the address data to the current address memory 153. Then, the audio data is returned to the original analog data by the DA conversion circuit 152, and is used to drive, for example, a speaker (not shown) through the output terminal 154. Further, the address data is currently stored in the address memory 153 one after another.

Here, a case will be described in which a search function for selecting a desired song from among a plurality of songs recorded on the disk 140 is performed. In other words, 15 in Figure 2
5 is a keyboard section, each key 11 in FIG.
5 to 134. Each key 115 to 134 of this keyboard section 155
By operating according to a predetermined procedure, the song number (TNO) of the song to be selected and the relative address within that song can be set. For example, if you want to select the beginning of the song number "5",
All you need to do is set the song number to "5".
For example, if you want to select the position where 3 minutes have passed since the song started playing (assuming that the total playing time of the song with song number "5" is longer than 3 minutes), select the song number "5".
and set the relative address of the song to "3".
You can set it as "minute".

The song number and relative address set on the keyboard section 155 as described above are stored in the destination address memory register 156. The target address memory register 156 outputs the song number to the lead-in data memory 151 and the relative address to one input terminal of the adder circuit 157. Then, first, the lead-in data memory 151 reads out the absolute address of the beginning of the song corresponding to the song number output from the target address memory register 156, and outputs it to the other input terminal of the adder circuit 157.

At this time, the target address memory register 1
56, one input terminal of the adder circuit 157 is "0", so the absolute address output from the lead-in data memory 151 is added to "0". In the end, the absolute address output from the lead-in data memory 151 is output as is to the output terminal of the adder circuit 157, and this is the output terminal of the adder circuit 157.
This is the absolute address of the destination position to which the target position should be moved. Further, when a relative address is set in the destination address memory register 156, this relative address and the absolute address output from the lead-in data memory 151 are added in an adder circuit 157, and this addition output is sent to the pick-up 142. This is the absolute address of the destination position to be moved.

On the other hand, since address data of the current position of the pickup 142 is stored in the current address memory 153, an absolute address is read from the address data and supplied to the first position calculation circuit 158. In addition, the addition circuit 157
The absolute address output from is supplied to the second position calculation circuit 159. The first and second position calculation circuits 158 and 159 calculate the radius (distance information) on the disk 140 corresponding to the absolute address based on the absolute address which is temporal information. For example, the distance (mm) in the radius of the disk 140 is calculated for the 10 minute portion of the absolute address. That is, the output of the first position calculation circuit 158 is the radius data of the current position of the pickup 142, and the output of the second position calculation circuit 159 is the radius data of the current position of the pickup 142.
This is the radius data of the target position to be moved.

The first and second position calculation circuits 15
A subtraction circuit 160 subtracts one radius data from the other, and outputs the absolute value of the difference component. Therefore, the output of the subtraction circuit 160 becomes distance data indicating the distance between the current position of the pickup 142 and the target position. The distance data output from the subtraction circuit 160 is set as initial data in a movement amount calculation counter 161, and is also supplied to a kick pulse generation circuit 162, which will be described later.

Further, each absolute address output from the current address memory 153 and the addition circuit 157 is input to a subtraction circuit 163 and a pattern matching detection circuit 1 to be described later.
64 and 64, respectively. This subtraction circuit 16
3 subtracts one of the input absolute addresses from the other and outputs the difference component, that is, the time difference component between the current position and the destination position of the pickup 142 to the numerical comparator 165. The numerical comparator 165 then compares the time difference component outputted from the subtraction circuit 163 with a reference value (this reference value is related to the width of the kick pulse that can be generated by the kick pulse generation circuit 162). Here, when the time difference component is larger than the reference value, that is, when the distance between the current position and the target position of the pickup 142 is long, the numerical comparator 165 outputs the first output terminal _O1 at a high level ( When the time difference component is smaller than the reference value, that is, when the distance between the current position and the destination position of the pickup 142 is short, the second output terminal _O2 is set to the H level.

Then, the subtraction circuit 163 determines whether the subtraction result is positive or negative (this is determined by the pick-up 1
The target position is disk 14 with respect to the current position of disk 42.
(corresponds to whether it is on the outer or inner side of 0)
A polarity signal is supplied to a level shaping circuit 166 and a polarity inverting circuit 167 in accordance with the polarity.

Here, the track number (TNO), relative address, etc. are set by the keyboard section 155,
When the last operation corresponding to the search function of the keyboard section 155 is completed, this DAD playback device starts a search operation. At the same time as this search operation starts, the search switch 168 is turned on. This search switch 168
One end is grounded via a DC power supply 169 with the polarity shown, and the other end is connected to a set input terminal S of a set reset flip-flop circuit (hereinafter referred to as an S-RFF circuit) 170. Therefore, when the search switch 168 is turned on, the set input terminal S of the S-RFF circuit 170 becomes H level, so that its output terminal Q is set to H level.

Assume now that the target position is on the outer peripheral side of the disk 140 with respect to the current position of the pickup 142, and that the distance between the current position and the target position is sufficiently large. Then, the first output terminal _O1 of the numerical comparator 165 becomes H level,
Since the output terminal Q of the S-RFF circuit 170 is also at H level, the output terminal of the AND circuit 171 to which both output terminals O ₁ and Q are connected to the input terminal becomes H level. The output of this AND circuit 171 is
It is supplied to one input terminal of another AND circuit 172. The output terminal of a monostable multivibrator 173 is connected to the other input terminal of this AND circuit 172. Here, the monostable multivibrator 173 normally outputs an H level signal,
When a flow signal, which will be described later, is generated from the movement amount calculation counter 161, this flow signal is used as a trigger to output a low level (hereinafter referred to as L level) signal for a predetermined period of time.

Therefore, the output terminal of the AND circuit 172 becomes H level, and the switching circuit 150 is thereby switched to supply the output of the level shaping circuit 166 to the pickup feed motor 143. That is, this switching circuit 150 is switched to supply the output of the level shaping circuit 166 to the pickup feed motor 143 when the output terminal of the AND circuit 172 is at the H level, and to supply the output of the level shaping circuit 166 to the pickup feed motor 143 when the output terminal of the AND circuit 172 is at the L level. The output of the motor control circuit 149 can be switched to be supplied to the pickup feed motor 143. Therefore, under normal playback conditions, the search switch 168
is in the off state, the output terminal Q of the S-RFF circuit 170 is at the L level, so the output terminals of the AND circuits 171 and 172 are both at the L level, and the pick-up feed motor 143 is controlled by the feed motor. It is controlled by the output from the circuit 149, and stable reproduction is performed.

Here, in the search operation as described above, since the output terminal of the AND circuit 172 is at H level, the pickup feed motor 143 is controlled by the output of the level shaping circuit 166. The level shaping circuit 166 outputs a drive signal having a constant level with positive or negative polarity based on the polarity signal output from the subtraction circuit 163. And in this case, pick up 142
Since the target position is on the outer circumferential side of the disk 140 with respect to the current position, the subtraction result of the subtraction circuit 163 is positive. Therefore, the subtraction circuit 163 outputs a polarity signal corresponding to the "positive" subtraction result, and the level shaping circuit 166 outputs a drive signal with a positive polarity level to the pickup feed motor 143.
A pick-up 142 is moved toward the outer circumference of the disk 140. In addition, the subtraction circuit 163
If the subtraction result is negative, the subtraction circuit 163
outputs a polarity signal corresponding to the subtraction result "negative",
As a result, the level shaping circuit 166 outputs a drive signal of a negative polarity level, so that the pickup 142 is moved in the inner circumferential direction of the disk 140.

Meanwhile, the search switch 168 is turned on and S
- When the output terminal Q of the RFF circuit 170 becomes H level, the output of the monostable multivibrator 173 is at H level, so the output terminal of the AND circuit 174 whose both output terminals are connected to the input terminal becomes H level. . Then, the switch circuit 147 is controlled to be in the OFF state. That is, in this switch circuit 147, the output terminal of the AND circuit 174 is set to H.
It is controlled so that it is in the OFF state when it is at the L level, and it is in the ON state when it is at the L level. Therefore, under normal playback conditions, the search switch 16
8 is in the off state, the output terminal of the AND circuit 174 is set to the L level, so the switch circuit 147 is in the on state, and tracking servo is applied by the tracking control circuit 145, and stable reproduction is performed. It is something.

However, as mentioned above, the level shaping circuit 1
In the search state in which the pickup 142 is moved by the drive signal output from the pickup 66, the switch circuit 147 is turned off so that no tracking servo is applied, and the pickup 142 is moved without being affected by the tracking servo. It is designed to move smoothly.

Here, when the pick-up 142 is moved toward the outer circumference of the disk 140 as described above,
A pickup position detection circuit 175 detects how far the pickup 142 has moved from its original position (current position in the above description). This pickup position detection circuit 175 outputs a position detection signal that generates one pulse each time the pickup 142 is moved in the radial direction of the disk 140 and crosses one track, as will be described in detail later. It is something to do.

Therefore, the movement amount calculation counter 161 is
Starting from the previously set initial data, the pulses of the position detection signal output from the pickup position detection circuit 175 are sequentially counted in the reverse direction. Then, when the count result becomes all "0", the movement amount calculation counter 161 generates the flow signal and the monostable multivibrator 1
73. Therefore, the output terminal of the monostable multivibrator 173 becomes L level, and thereby the output terminals of AND circuits 172 and 174 both become L level. Therefore, the switching circuit 150 is switched to supply the output of the feed motor control circuit 149 to the pick-up feed motor 143,
The movement of the pick-up 142 toward the outer circumference of the disk 140 is stopped, and the switch circuit 1
47 is turned on and tracking servo is applied. Then, the disc 140 is played back at the position where the pickup 142 stops.

Here, the position where the pickup 142 stops is approximately the same as the target position described above. That is, the initial data set in the movement amount calculation counter 161 is distance data indicating the distance between the current position of the pickup 142 before the search operation and the target position, as described above. on the other hand,
The position detection signal output from the pickup position detection circuit 175 is a signal in which one pulse is generated every time the pickup 142 crosses one track on the disk 140, and the track pitch is 1.6 [μm] as described above. Therefore, in short, it shows the distance that the pick-up 142 has moved from its current position. Therefore, the fact that the pulses of the position detection signal are sequentially counted in the reverse direction starting from the initial data set in the movement amount calculation counter 161 and the count results are all "0" is no exception. This is because the pickup 142 has moved by the distance between the current position and the destination position.

Therefore, theoretically, the position at which the pick-up 142 stops coincides with the target position, but in reality, due to eccentricity of the disk 140, variations in track pitch, etc., the position is approximately equal to the target position. It is something that

Then, the pickup 142 reproduces the disc 140 at the stopped position as described above. At this time, the RF signal output from the pickup 142 is again separated into audio data and address data by the process circuit 146, and the address data is transferred to the current address memory 153.
is memorized. Then, the absolute address of the new address data stored in the current address memory 153 and the absolute address of the target position outputted from the adder circuit 157 are processed through the first and second position calculation circuits 158 and 159, respectively. The new distance data is subtracted by the subtraction circuit 160, and this new distance data is set in the movement amount calculation counter 161 as initial data. Here, the monostable multivibrator 173 is set to hold the L level for a sufficient period of time to perform playback at the position where the pickup 142 is stopped and to store the address data in the current address memory 153. . Then, when the output terminal of the monostable multivibrator 173 is returned to the H level again, the search operation as described above is started again.

When the movement of the pickup 142 is stopped again in such a second search operation, the pickup 142 performs a reproduction operation at the stopped position, and the series of search operations as described above are repeated.

Here, the repetition of such a search operation is
The absolute address of the current position of the pick-up 142 outputted from the current address memory 153 and the absolute address of the target position outputted from the addition circuit 157 are extremely equal, and the time difference component outputted from the subtraction circuit 163 is transferred to the numerical comparator 165.
It will be stopped when the value becomes smaller than the reference value. That is, when the time difference component output from the subtraction circuit 163 becomes smaller than the reference value, the numerical comparator 165 sets the first output terminal _O1 to L level and sets the second output terminal _O2 to H level. . This is because the output terminals of the AND circuits 171 and 172 both become L level, and the switching circuit 150 is switched so that the output of the feed motor control circuit 149 is supplied to the pickup feed motor 143.

Furthermore, when the time difference component output from the subtraction circuit 163 becomes smaller than the reference value of the numerical comparator 165, it means that on the disk 140, the difference between the current position of the pickup 142 and the target position is the number of tracks. This is when the distance becomes a few tracks, and the distance becomes less than a few μm.

Then, when the second output terminal _O1 of the numerical comparator 165 is set to H level, the S-
Since the output terminal Q of the RFF circuit 170 is also at H level, the output terminal of the AND circuit 176 whose input terminals are connected to both output terminals O ₂ and Q becomes H level. Here, the second output terminal of the numerical comparator 165
_O2 is set to H level when the pick-up 142 stops moving during the above-mentioned search operation and the address data at that position is read out, so the monostable multivibrator The output terminal of 173 is set to L level. Therefore, this monostable multivibrator 17
When the output terminal of No. 3 is returned to the H level, the output terminal of the AND circuit 177 whose input terminal is connected to this output terminal and the output terminal of the AND circuit 176 is set to the H level. Therefore, the kick pulse generating circuit 162 is driven.

This kick pulse generation circuit 162 outputs a so-called kick pulse for accurately moving the pickup 142 by several tracks, as will be described in detail later. A kick pulse is generated to move the pickup 142 by a distance corresponding to the distance data (several tracks). Then, the polarity inversion circuit 167 determines the positive polarity and negative polarity of the kick pulse based on the polarity signal output from the subtraction circuit 163, and supplies the determined polarity to the addition circuit 148. At this time, both the output terminal Q of the S-RFF circuit 170 and the output terminal of the monostable multivibrator 173 are high.
Since the output terminal of the AND circuit 174 is at the H level and the switch circuit 147 is in the OFF state, tracking servo is not performed.

After passing through the adder circuit 148, the kick pulse is sent to the pick-up feed motor 143 via the feed motor control circuit 149 and the switching circuit 150.
is supplied to At this time, the pickup 142 is moved several tracks to reach the target position. In addition, when the above-mentioned pick pulse is of positive polarity or negative polarity, the above-mentioned pick-up 14
2 is moved by several tracks in the outer and inner circumferential directions of the disk 140. When the pickup 142 reaches the target position and reproduces that position, the absolute addresses output from the current address memory 153 and the adder circuit 157 become completely equal. For this reason,
The pattern match detection circuit 164 detects that both absolute addresses completely match, and selects the S-
An H level signal is output to the reset terminal R of the RFF circuit 170. Then, the S-RFF circuit 170
is reset and its output terminal Q is inverted to L level, at which point the entire search operation is completed. Then, the output terminal Q of the S-RFF circuit 170
becomes L level, the AND circuit 1
The output of 74 also becomes H level, and the switch circuit 14
7 is turned on and tracking servo is applied, so that playback can be performed stably from the selected target position.

Next, details of the pickup position detection circuit 175 will be explained. That is, this pickup position detection circuit 175 utilizes the tracking error signal output from the tracking control circuit 145. That is, as shown in FIG. 3, an input terminal 178 to which the tracking error signal is supplied is connected to the movement amount calculation counter 161 via an O level comparator 179 and an output terminal 180. .

That is, as mentioned above, the tracking error signal has negative polarity and positive polarity because the spot of the light beam on the surface of the disk 140 is shifted from the center of the track toward the inner and outer circumferences of the disk 140. It has a level, and the absolute value level changes depending on the size of the deviation.
O when the spot is located at the center of the track
This is the signal that becomes the level. Therefore, when the spot is moved in the radial direction of the disk 140 and crosses a plurality of tracks, the tracking error signal changes as shown in FIG. 4a. In Fig. 4a, the period when the tracking error signal is on the upper right side of the figure indicates the area where tracking servo is possible, and the period where the tracking error signal is on the upper left side of the figure indicates the area where tracking servo is not possible. It is. Therefore, the O level cross point during the period when the tracking error signal is upward to the right in the figure indicates that the spot is located at the center of the track, and the O level during the period when the tracking error signal is upward to the left in the figure indicates that the spot is located at the center of the track. The cross point indicates that the spot is centered between the track and other tracks adjacent to it. Therefore, one period of this tracking error signal corresponds to the spot crossing one track.

Therefore, when the above tracking error signal is compared with the O level by the O level comparator 179, and when the level of the tracking error signal is larger or smaller than the O level, H level and L level signals are generated. A pulse waveform as shown in Figure b is obtained. And this pulse waveform is
One cycle corresponds to the spot crossing one track, so the spot moves to disk 14.
One pulse is generated every time one track on 0 is crossed, and serves as the position detection signal.

Next, the kick pulse will be explained. That is, as shown in FIG. 5, when this kick pulse is requested to start generating at time _T1 , a signal of positive polarity and a constant level is output, and this signal is output at time _T2.
is inverted to a constant level signal of negative polarity at the time
At _T3 , the student returns to the original O level. and,
At time T ₁ , pick-up 142 is on disk 14.
Pickup 1 begins to be moved in the direction of the outer circumference of Pickup 0, and its moving speed reaches its maximum at time T _2. After that, it is sequentially decelerated by the negative polarity level signal, and pick up 1 picks up at Time T ₃ .
42 is stopped. For this reason,
The hard pulse generation circuit 162 is connected to the subtraction circuit 16.
Time T ₁ based on the distance data output from 0
By appropriately setting the width from T3 to _T3 , the pickup 142 can be moved by a predetermined number of tracks.

Here, by applying a brake on the movement of the pick-up 142 in the outer circumferential direction using a negative polarity level signal, the pick-up 142 may overrun the target position due to penetration, or may damped vibrations before and after the target position to reach the target position. This prevents the inconvenience of not being able to stop the machine easily.
The pickup 142 can be quickly moved to the target position and can be completely stopped on the track at the target position.

Further, when the pickup 142 is moved in the inner circumferential direction of the disk 140, it is sufficient to use a negative polarity level signal from time T ₁ to _{T 2} and a positive polarity level signal from time T ₂ to _{T 3} . . The polarity reversing circuit 167 determines whether to output a kick pulse that moves the pickup 142 toward the outer circumference of the disk 140 or toward the inner circumference based on the polarity signal output from the subtraction circuit 163. This is set by .

Note that the time T ₂ at which the positive polarity level is reversed from the negative polarity level and from the negative polarity level to the positive polarity level is:
Even if it is not necessarily at the center between times _T1 and _T3 , it may be controlled by the kick pulse generating circuit 162 as necessary, for example, depending on the number of tracks to which the pickup 142 is to be moved. can.

Therefore, according to the search means shown in FIG. 2, first, the radius of the disk 140 at the current position of the pick-up 142 is calculated from the absolute address of the current position, and the radius of the disk 140 at that position is calculated from the absolute address of the target position. 140 is calculated, and the difference between the two (distance data) is determined to determine the distance to which the pickup 142 should be moved. Then, the pick-up 142 is moved and the spot becomes one track.
The number of pulses of the position detection signal, which is generated every time a pulse is traversed, is counted, and the movement of the pick-up 142 is stopped when the moving distance of the pick-up 142 becomes equal to the above-mentioned distance data. pick up rate 142
can be moved to the target position, and the performance of the search function can be improved.

In this regard, conventional search means are performed as follows. First, when the track number (TNO) of the target position and the relative address within that song are specified, it is determined whether the target position is on the inner or outer side of the disk with respect to the current position of the pick-up, and the pick-up is determined. move in the direction. At this time, focus servo and tracking servo are applied so that the address data is always read out even while the pickup is moving. Then, the pickup is moved until the song number in the read address data matches the song number at the target position. Next, the moving speed of the pick-up is slowed down and the pick-up is moved until the "minute" digit of the relative address in the read address data matches the "minute" digit of the relative address at the target position. Furthermore, the moving speed of the pick-up is further slowed down so that the pick-up is moved until the "seconds" digit of the relative address in the read address data matches the "seconds" digit of the relative address at the destination position. Then, the pick-up is moved to the target position.

For this reason, the moving speed of the pickup must be fast enough to read the address data even at its fastest speed, which poses a problem in that a quick search operation cannot be performed.

However, according to the search means shown in FIG. 2, the pick-up 142 is moved by that distance based on the distance data between the radius of the current position of the pick-up 142 and the radius of the destination position. There is no need to read middle address data, the moving speed of the pickup 142 can be increased, and a quick search operation can be performed.

Furthermore, the configuration is simple, and it goes without saying that most of the circuits can perform their functions through program processing, especially if a microcomputer is used.

Then, as described above, based on the distance data between the radius of the current position of the pick-up 142 and the radius of the destination position, the pick-up 142 is moved by that distance.
The feature of this invention is that 2 is moved.

Furthermore, during the search operation, the level shaping circuit 1
When the pickup 142 is being moved by the drive signal output from the pickup 66 and the kick pulse output from the kick pulse generation circuit 162, the switch circuit 147 is turned off so that no tracking servo is applied. The converging lens therein is moved in the radial direction of the disk 140 without being subjected to any tracking servo, allowing smooth movement and accurate movement to the target position.

In addition, the position detection signal of the pickup 142 is
Since the tracking error signal is generated using changes in the tracking error signal that occur when the spot actually crosses a track, it is possible to generate exactly one pulse each time the spot crosses one track. It is possible to perform reliable operations. Furthermore, since the position detection signal is the tracking error signal converted into a pulse waveform via the O-level comparator 179, it can be realized with an extremely simple configuration.

In the above search operation, first, if the distance between the current position of the pickup 142 and the target position is long, the pickup 142 is moved greatly by the drive signal output from the level shaping circuit 166, and the current position of the pickup 142 is moved. Since the pick-up 142 is moved to the target position by a kick pulse when the distance between the target position and the target position is within a predetermined range, a quick and accurate search operation can be performed. .

It should be noted that the present invention is not limited to the above-mentioned embodiments, and can be implemented with various modifications without departing from the gist thereof.

〔Effect of the invention〕

Therefore, as detailed above, according to the present invention, it is possible to perform a quick and accurate search function with a simple configuration, especially in a disk record playback device that plays back a disk on which digitized data is recorded. Therefore, it is possible to provide an extremely good disc record playback device.

[Brief explanation of drawings]

Figure 1 shows a CD-based DAD to which this invention is applied.
FIG. 2 is a front external view showing an outline of the playback device; FIG. 2 is a block diagram showing an embodiment of the disc record playback device according to the present invention; FIG. 3 is a block configuration diagram showing the electric circuit system of the DAD playback device; A block configuration diagram showing the pickup position detection circuit of the circuit system, Figures 4a and 4b are waveform diagrams for explaining the operation of the pickup position detection circuit, respectively, and Figure 5 is a diagram for explaining the kick pulse of the electric circuit system. FIG. 110... Cabinet, 111... Disk loading section, 112... Eject key, 113... Power key, 114... Display section, 115... Reverse key, 1
16...First reward key, 117...Play key, 118...Next play key, 119...
Repeat key, 120...Pause key, 121...Stop key, 122 to 131...Numeric key, 13
2...Memory read key, 133...Memory key, 1
34...Clear key, 140...Disk, 141...
Disc motor, 142...Pickup, 143
...Pickup feed motor, 144...Focus control circuit, 145...Tracking control circuit, 14
6... Process circuit, 147... Switch circuit, 14
8...Addition circuit, 149...Feed motor control circuit, 1
50...Switching circuit, 151...Lead-in data memory, 152...DA conversion circuit, 153...Current address memory, 154...Output terminal, 155...Keyboard section, 156...Target address memory register, 1
57... Addition circuit, 158... First position calculation circuit,
159...Second position calculation circuit, 160...Subtraction circuit, 161...Movement amount calculation counter, 162...Kick pulse generation circuit, 163...Subtraction circuit, 164...
Pattern match detection circuit, 165... Numerical comparator, 166... Level shaping circuit, 167... Polarity inversion circuit, 168... Search switch, 169... DC power supply, 170... S-RFF circuit, 171, 172...
AND circuit, 173... Monostable multivibrator, 174... AND circuit, 175... Pickup position detection circuit, 176, 177... AND circuit, 1
78...Input terminal, 179...O level comparator, 180...Output terminal.

Claims (1)

[Claims] 1. In a disc record playback device that reads digital data and temporal information from a disc on which digital data obtained by converting an information signal into PCM and temporal information is recorded through an optical pickup, the pickup is a setting means for setting the temporal information of the target position to be moved; and a setting means for setting the temporal information of the target position to be moved, and the disk corresponding to each temporal information based on the temporal information set in the setting means and the temporal information read from the pickup. calculation means for calculating radius information of each;
a subtraction means for subtracting each radius information calculated by the calculation means to generate distance data between the current position of the pickup and the target position and a drive signal for moving the pickup in the direction of the target position; With the pickup being moved in the radial direction of the disk by the drive signal generated by the subtracting means, the output of the pickup changes in response to the pickup traversing the track of the disk. , a movement amount detection means for generating movement amount detection data corresponding to the distance moved by the pick-up, and movement amount detection data outputted from the movement amount detection means corresponding to the distance data calculated by the subtraction means. 1. A disc record reproducing apparatus, comprising: a stop means for stopping the movement of said pickup when the pickup is in the state of the pickup.