JPS63129575A - Information track retrieval device - Google Patents

Abstract

PURPOSE:To precisely count the number of crossed tracks by permitting a filter corresponding to the moving speed of a conveyance base to shape the waveform of a track crossing signal and outputting binary values corresponding to the moving speed with the same binarization level given. CONSTITUTION:A comparator processes track crossing detection signals which pass through two sets of LPFs in an interruption band corresponding to the moving speed of the conveyance base. The signals are made into two pieces of binary data (d) and (e), and inputted to a switch circuit 77. The two pieces of data (d) and (e) are impressed to the clock terminal (c) of a type D FF 82, to which a speed detection pulse that becomes L or H according to the moving speed of the conveyance base, through a NAND gate 81. The output Q and the inverse of Q of the FF 82 control NAND gates 79 and 80, and two pieces of binarization data (d) and (e) and at H. Binarization data corresponding to the moving speed of the conveyance base is outputted from a NAND gate 83. Even if the conveyance base changes to a high speed from a low speed and vice versa, an error-free track crossing pulse is attainable, which is counted by a counter. Consequently the crossed tracks are precisely counted and a track is retrieved speedily and stably.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a recording/reproducing method in which information is recorded or reproduced by a signal converting means on a disc-shaped record carrier having a track on which information is recorded or a track for recording information. The present invention relates to an information track retrieval device for a device.

2. Prior Art Conventional optical recording and reproducing devices include, for example, the Japanese Patent Application Laid-open No. 5
It is shown in the publication No. 7-69111.

FIG. 6 is an explanatory diagram of a conventional optical recording/reproducing apparatus.

A light beam 2 generated by a light source 1 such as a semiconductor laser is passed through a coupling lens 3. The light passes through a beam splitter 4, is reflected by a reflecting mirror 5, and is focused onto a disk-shaped record carrier 7 by a converging lens 6. The record carrier 7 is attached to the rotating shaft of a motor 8 and rotates at a predetermined number of rotations.

The record carrier 7 has concentric or spiral grooves (hereinafter referred to as tracks) on a base material, and is composed of a recording material layer and a protective layer provided thereon. Address signals are provided sequentially from the inner circumference to the outer circumference. The light beam 2 reflected from the record carrier 7 passes through the converging lens 6 again, is reflected by the reflecting mirror 5 and the beam splitter 4, and is irradiated onto the photodetector 9 having a two-split structure. . The converging lens 6 is attached to a tracking element 10, which is configured to be able to move the converging lens 6 in the radial direction of the record carrier 7, ie in a direction substantially perpendicular to the direction of the tracks on the record carrier 7. ing. Light source 1, coupling lens 3. Beam splinter 4, reflector 6. Photodetector9. The moving parts of the tracking element 10 and the speed detector 11 are attached to a transfer table 12 and are configured to move together in the radial direction of the record carrier 7 by a linear motor 13. The speed detector 11 is composed of a moving part made of a rod-shaped magnet fixed to the transfer table 12 and a fixed part made of a coil, and outputs a signal according to the moving speed of the transfer table 12.

Tracking control for controlling the light beam 2 focused on the record carrier 7 so that it is always positioned on the track will be described. Each signal of the photodetector 9 is transmitted to a differential amplifier 14.
The differential amplifier 14 outputs a difference signal between the respective signals of the photodetector 9. The direction of the dividing line of the photodetector 9 is the track direction of the track pattern included in the reflected light on the photodetector 9, and the signal from the differential amplifier 14 determines the positional relationship between the light beam 2 on the record carrier 7 and the track. The signal representing the tracking control signal, that is, the tracking control signal, is well known and will not be described in detail. The signal of the differential amplifier 14 is transferred to the switch 15. The signal is transmitted to the trunking element 10 via a phase compensation circuit 16 for compensating the phase of the tracking control system and a drive circuit 17 for driving the tracking element 1o.

The tracking element 10 is therefore controlled to move the converging lens 6 in response to the signal from the differential amplifier 14 so that the light beam 2 on the record carrier 7 is positioned on the track.

The range in which the tracking element 1o can move is approximately 60μm, and if the transfer table 12 moves significantly, the tracking control will be lost 1. To prevent this, the tracking element 10 should be moved around its natural state, i.e. The movement of the transfer table 12 is controlled by driving the linear motor 13 so that the signal from the drive circuit 17 is on average at zero level. To explain this transfer control, the differential amplifier 1
4 signal is sent to switch 16. The linear motor 13 is connected to the linear motor 13 via a phase compensation circuit 1g for compensating the phase of the transfer control system, and a drive control circuit 19 for driving and controlling the +7 linear motor 13.
The linear motor 13 is transmitted to the transfer stage 12 so that the tracking element 10 moves around its natural state.
move. The switch 16 is for disabling trunking control and transfer control.

The signal from the speed detector 11 is input to a drive control circuit 19, and by feeding and tracking the speed signal, drive control of the linear motor is made more stable.

Recording and reproduction of signals will be explained. When recording a signal on a track on the record carrier 7, the intensity of the light beam 2 generated from the light source 1 is modulated in accordance with the signal to be recorded while the tracker, knocking control, and transport control are operated. The recording material at the location irradiated with the intense light beam 2 changes its state or shape, and a signal is recorded on the track on the record carrier 7. When reproducing a signal recorded on a track on the record carrier 7, the light beam 2 generated from the light source 1 is made to have a weak constant intensity while the tracking control and transport control are in operation, and the light beam 2 generated from the light source 1 is made to have a weak and constant intensity, and the light beam 2 that is reflected from the track is The light is received by the photodetector 9, and a composite signal of the respective signals of the photodetector 9 is obtained. (not shown) Note that in the optical recording/reproducing device, the light beam 2 irradiated onto the record carrier 7 is
Focusing is controlled so that the beam diameter of the beam is always constant, but since this is not directly related to the present invention, a detailed explanation will be omitted.

The basic configuration of the optical recording/reproducing device has been described above, and one important function of this device is to search for a desired trunk at high speed and stably, and this search will be explained below.

The search system is composed of an information processing control device 2o including a microcomputer. Address A of the desired track in the address input device 21. When inputted, the information processing control device 2o reads the address A of the track where the light beam 2 is currently located, and calculates (person, - person). I
Al-Ao1≧N(1mu, -muo1 is (mu+-A(+)
, and N is a positive integer. ), then the information processing control device 20 is lA, -A. The value of 1 and the direction signal are sent to the drive control circuit 19. The value of 1A+-Ao1 is pre-sensed to the counting circuit included in the drive control circuit 19, and at the same time, the switch/soter 16 is opened to perform tracking control and transfer. Disable the control. Drive control circuit 1
9 drives a linear motor 13 to move the transfer table 12 in the direction where a desired track exists. Differential amplifier 14
The signal is input to the track crossing detection circuit 22, and the signal of the track crossing detection circuit 22 is input to the drive control circuit 1.
9 is entered. When the transfer table 12 moves in the radial direction of the record carrier 7, the output of the differential amplifier 14
The signal that the upper light beam 2 crosses the track is output,
The track crossing detection circuit 22 shapes the waveform of the signal from the differential amplifier 14 and transmits this signal to the drive control circuit 19.

A counting circuit included in the drive control circuit 19 counts the signal from the track crossing detection circuit 22, detects that the light beam 2 on the record carrier 7 has come onto the track with one opening of IA+-Ao, and then outputs the signal to the drive control circuit 19. 19 sends a coincidence signal to the information processing control device 20. The information processing control device 2o is a linear motor 1
3 is transmitted to the drive control circuit 19 and the switch 16 is short-circuited to operate the tracking control and transport control, and read the address A2 of the track where the light beam 2 is located on the record carrier 7. (Hereinafter, this search will be referred to as a coarse search.)

If Ao=A2, the search ends, but 1mu2 ”01
If ≧N, the above-described rough search is performed again.

If lA2 '01<', the information processing control device 2o opens the switch 16, sends a signal to the drive circuit 17, drives the tracking element 1o, and short-circuits the switch 15 again. After performing interlaced scanning (hereinafter referred to as "jumping") and repeating this jumping 1 times, the address A3 of the track where the light beam 2 is located is read (hereinafter this search will be referred to as "fine search"). ).If MU0=MU, the search ends, but if MU0\MU!1(AO\
A3 is A. This means that and M3 are not equal. ), the coarse search and fine search described above are repeated to search for the desired track.

By the way, in order to record digital information on a track on the record carrier 7, since the length of the information is undefined, it is advantageous to record the track by dividing it into a plurality of information areas (hereinafter referred to as sectors). . In order to distinguish these multiple sectors from each other and to clarify the number of the current sector during recording and playback (sector number), a sector separator area is provided at the beginning of each sector, and at one location per disk rotation. The above address signal recording areas (hereinafter referred to as address areas) are provided in advance. An example of the record carrier is shown in FIG.

The record carrier 7 in FIG. 7 has a sector area 81 for recording information.
~S32. Each sector area is composed of sector separator areas SP1 to 5P52 and address areas TA, TA, TA2 indicating track addresses.

FIG. 8a shows the sector area S of the track 22 in FIG.
, sector separator area SP, address area Tm1
FIG. 8 is a cross-sectional view of the disk along the track of FIG. The depth of the track is δ, the width of the groove is W, δ is A8 degrees of the wavelength λ of the laser beam in order to easily obtain a tracking signal, and W is approximately 0.6 Btn for high density. Address areas TA, (same for TA2), sector separator areas sp, (same for sp2 to sp, □) are provided with information in advance on the disk depending on the presence or absence of grooves, and are created simultaneously at the time of groove cutting.

Therefore, it is necessary to perform the above-mentioned search in a short time, and in order to perform a high-speed search, it is necessary to drive the linear motor 13 and move the transfer table 12 at high speed in the direction of the desired track. However, when the record carrier 7 having the above-mentioned tilt structure is used, when the potential beam 2 on the record carrier 7 crosses the track at high speed, the converged light beam 2 moves from A to O as shown in No. 9Na. The output signal of the differential amplifier 14 in FIG. 6, that is, the tracking signal, has a one-cycle figure-8 signal waveform (FIG. 9b). However, in the address area or sector separator area, if the reflected light is affected by diffraction due to the address information or sector separator information (unevenness) created on the track as shown in section 81, the tracking signal will be disturbed (section 9). Diagram b
).

The track crossing detection circuit 22 in FIG.
4, the tracking signal is waveform-shaped and the drive control circuit 19
to communicate. The counting circuit included in the drive control circuit 19 is
The signals of the track crossing detection circuit 22 are counted.

Problems to be Solved by the Invention However, with the above configuration, when the light beam 2 passes through the entire address area or sector separator area, it is not possible to accurately count the tracks traversed by the light beam due to the effect of the uneven pits. Therefore, a coarse search must be performed even for narrow openings, making it difficult to perform a high-speed search.

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide an information track search device that eliminates the above-mentioned conventional drawbacks and can search for a desired track at high speed and stably.

Means for Solving the Problems The present invention provides a signal conversion means for reproducing or recording a signal on a track on a record carrier, and a track deviation detection means for detecting that the scanning position of the signal conversion means has deviated from the track. , a first moving means for moving the scanning position of the signal converting means in a direction substantially perpendicular to the track direction on the record carrier based on the signal of the track deviation detecting means; a second moving means that moves including the first moving means in a direction substantially perpendicular to a trunk direction on the record carrier; and a scanning position of the signal converting means is always on the trunk on the record carrier. a control means for driving and controlling the first and second moving means in such a manner;
a first binarizing means for binarizing the signal of the track deviation detecting means when the scanning position of the signal converting means is moved by the second moving means via a first filter; a second binarizing means for binarizing the signal of the track deviation detecting means when the scanning position of the signal converting means is moved by the moving means via a second filter;
Alternatively, there is provided a counting device for counting the output signal of the second binarizing device.

Effect of the present invention With the above-described configuration, when the output signal of the first binarizing means and the output signal of the second binarizing means become the same level, the first or second binarizing means By switching the output signal and inputting it to the counting means, it is possible to accurately detect that the signal converting means has crossed a track, and a desired track can be accessed at high speed.

190 for fruitfulness The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a block diagram of an information track retrieval device according to an embodiment of the present invention. In explaining FIG. 1, parts that overlap with those in FIG. 6 will be briefly explained.

61 is a light source, 52 is a light beam, 63 is a force/sampling lens, 64 is a beam splitter, 65 is a reflecting mirror, 56 is a converging lens, 67 is a record carrier, 58 is a motor, 69 is a 2
This is a photodetector with a split structure.

Each signal from the photodetector 59 is input to a differential amplifier 64. The signal from the differential amplifier 64 is input to a track crossing detection circuit 72 and a switch 66.
The output of note 65 is input to phase compensation circuits 66 and 68. The signal from the phase compensation circuit 66 is input to the drive circuit 67, and the signal from the drive circuit 67 is input to the tracking element 6o. A signal from the phase compensation circuit 68 is input to a drive control circuit 69 for driving and controlling the linear motor 63, and a signal from the drive control circuit 69 is input to the linear motor 63, respectively. A signal from the speed detector 61 that outputs a signal corresponding to the moving speed of the transfer table 62 is input to a drive control circuit 69 and a track crossing detection circuit 72, respectively. The photodetector 73 detects the address area (TA, ,
TA2) and sector separator area (sp, ~SP
6□) is detected, and the signals from the trunk crossing detection circuit 72 and the truck crossing detection circuit 72 are input to the drive control circuit 69, respectively. The address input device 71 is only for inputting information necessary for a search, and the signal from the address input device 71 is input to the information processing control device 0. The information processing control device 70 is for controlling the switch 65, the drive circuit 67, and the drive control circuit 69 according to the comfort.

FIG. 2 shows a specific example of the trunk crossing detection circuit 72 of FIG. 1, in which the signal output from the differential amplifier circuit 64 of FIG. 1 is input to the low-pass filters 74 and 76. Power of low pass filter 74 1. off frequency j°. 1
and the power of the low-pass filter 76・7) Off frequency j°
. The relationship between 2 is j. , <J. Set it to 2. The signal from the low pass filter 74 is sent to the switch circuit 82 via a comparator 75 which converts it into a binary signal, and the signal from the low pass filter 78 is sent via a comparator 77 which converts it to a binary signal. It is transmitted to the switch circuit.

b is the signal output from the speed detector 61 in Fig. 1 and has a ratio of 1.
It is input to the wringer 78. The comparator 78 compares the level of the input signal with a reference value, and if the human power level is lower than the reference value, it inputs ethics LOW' to the switch circuit 77, and if it is higher than the reference value, it inputs ethics HIGH'.

FIG. 3 shows a specific example of the switch circuit 77. Comparator 75
The signal d output from the comparator 76 is input to one side of the AND circuit 79.81, and the signal e output from the comparator 76 is input to the AND circuit 8Q.
and the other of the AND circuit 81, and the output of the AND circuit 81 is input to the clock terminal of the flip-flop 82.

The signal f output from the comparator 78 in FIG. are entered into each.

The output of the AND circuit 79 is input to one side of the AND circuit 83, the output of the AND circuit 80 is input to the other side of the AND circuit 83, and the signal C output from the ANI) circuit 83 is transmitted to the drive control circuit 69 in FIG. Ru.

Next, search will be explained. When the address Ao of a desired track is input to the address input device 71, the information processing control device 7o reads the address of the track where the light beam 52 is currently located and calculates (A, -Ao). lAi
-An I≧N (lAi-Aat represents the absolute value of (A, -Ao), and N is a positive integer), then the patrol processing control device 70 determines the value and direction of IA, -Aol. A signal is sent to the drive control circuit 69, and the value of lAi'of is set in the counting circuit included in the drive control circuit 69, and at the same time, the switch 65 is opened, and the tracking allocation 11 and transfer control are disabled. let Drive control circuit 6
9 drives the linear motor 63 to move the transfer table 62 in the direction where the desired track exists.

The signal from the differential amplifier 64 is input to a track crossing detection circuit 72, and the signal from the track crossing detection circuit 72 is input to a drive control circuit 69.

When the transport stage 62 moves in the radial direction of the record carrier 5, the output of the differential amplifier 64 has a light beam 62 on the record carrier 5.
The signal that crosses the track is outputted, high-frequency component noise is removed by a low-pass filter 3, binarized by a comparator 75, and transmitted to a switch 77. When the moving speed of the transfer table 62 is slow (that is, just before the start of acceleration or stop), the signal of the speed detector 61 is low, so the output of the comparator 78 is in the LOW state, and therefore the flip-flop 8
The output of the (terminal 2) is in the HIGH state. Therefore, the AN
The switch circuit 77 transmits the signal d input from the comparator 76 to the drive control circuit 69 by the D circuits 79, 80, 83, and the counting circuit included in the drive control circuit 69 transmits the signal d input via the switch circuit 77. Count. When the light beam 52 crosses the sector separator area or address area on the record carrier 57 as shown in FIG. 9, the output signal waveform of the differential amplifier 64 becomes as shown in FIG.

Next, when approaching the target truck, the moving speed of the transfer platform 62 slows down, so that the signal from the speed detector 61 becomes smaller and the output from the comparator 78 becomes LOW. Then, in the switch circuit 77, the D input terminal of the flip-flop 82 becomes LOW, and both the input signals d and e become HI.
When the signal becomes GH, the output of the AND circuit 81 becomes a LOW state, the Q output of the flip-flop 82 becomes a HIGH state, and the Q output becomes a LOW state.

Therefore, the signal C output from the switch circuit 77 is output after switching from the input signal e to the input signal d, and is transmitted to the drive control circuit 69, and the counting circuit included in the drive control circuit 69 is inputted via the switch circuit. Count the signals that occur.

FIG. 4 shows waveforms at various parts of the switch circuit. FIG. 4A shows the waveform of the signal input from the comparator 78, FIG. 4B shows the waveform of the signal input from the comparator 75, and FIG.
6 is the waveform of the signal inputted from the switch circuit 77, and FIG.

Therefore, even if the moving speed of the transfer table 62 changes from low speed to high speed or from high speed to low speed, the signal input via the low pass filter 73 and the comparator 75 and the low pass filter 7
4. No error occurs when switching the signal input via the comparator 76, and it is possible to accurately detect that the track has been crossed.

Therefore, the counting circuit included in the drive control circuit 69 accurately counts the signal from the track crossing detection circuit 72 and detects the signal on the record carrier 5.
When it is detected that the light beam 52 on 7 has arrived on the first track of 1AIAO, the linkage allocation circuit 69 sends a coincidence signal to the information processing control device 70. The alarm processing control device 70 transmits a signal for stopping the linear motor 63 to the drive control circuit 69, and also short-circuits the switch 65 to stop the linear motor 63.
The soaking control and the transfer control are operated to read the track address A2 on the record carrier 57 where the light beam 52 is located. If it is Ao-A2, the search ends, but lA2
- If Ao1≧N, the above-mentioned rough search is performed again. If lA2'21<N, the information processing control device 70 returns Q1. While opening the terror 6, the drive circuit 6
7 to drive the tracking element 6o and short-circuit the switch 15 again to perform one jump, and after repeating this jumping 1A2'01 times, the address A of the trough where the light beam 2 is located is , read. If it is Ao-A, the search ends, but if it is AoXA3, the above-mentioned coarse search and fine search are repeated to search for the desired track.

Next, when the moving speed of the transfer table 62 becomes slow, the speed detector 6
The signal of 1 becomes large and the output of the comparator 78 becomes HIGH. Then, in the switch circuit 77, the D input terminal of the flip-flop 82 becomes HIGH, and when the input signals d and e both become HIGH, the output of the AND circuit 81 becomes LOW, and the Q output of the flip-flop 82 becomes HIGH. It is in the HLOW state, and the Q output is in the HIGH state.

Therefore, the signal C output from the switch circuit 77 is output after switching from the input signal d to the input signal e, and is transmitted to the drive control circuit 69, and the counting circuit included in the drive control circuit 69 is inputted via the switch circuit. Count the signals that occur.

FIG. 6 shows waveforms at various parts of the switch circuit. 6A is the waveform of the signal input from the comparator 78, FIG. 5A is the waveform of the signal input from the comparator 75, FIG. FIG. 5E shows the waveform of the output signal of the switch circuit 77.

Effects of the Invention In the present invention, a track crossing signal during a rough search is waveform-shaped by each filter according to the speed of the transfer table, this signal is binarized by each comparator, and the output level of the binarized comparator is When they are the same, by switching the output signal of the comparator and counting, the crossing tracks can be accurately counted, and the performance and reliability of the device can be significantly improved with a simple configuration.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an information track retrieval device according to an embodiment of the present invention, FIG. 2 is a block diagram showing details of a track crossing detection circuit in the embodiment, and FIG. 3 is a switch diagram in the embodiment. A specific circuit diagram of the circuit, Figure 4,
Fig. 6 is a waveform diagram showing the waveforms at each point in Fig. 3, Fig. 6 is a block diagram showing an example of a conventional information track search device, and Fig. 7 is a plane diagram schematically showing each area on the disk. Figure 8a is a plan view showing the address area and separator area;
The figure is a cross-sectional view of the same, and Figure 9 is the optical subwoofer at the time of search. FIG. 3 is an explanatory diagram showing the relationship between points and tracks and tracking waveforms. 72...Track crossing detection circuit, 73.74
・・・・・・Low pass filter, 75.76.78・
...Comparator, 77...Switch circuit, 7
9, 80. 81.83...AND circuit, 82...Flip-flop. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 4 Monument ＼) Figure 5 亦) Figure 6 Figure 7 A2 Figure 8 Figure 9 tb) Lolio Eyeway

Claims (1)

[Claims] a signal converting means for reproducing or recording a signal on a track on a record carrier; a track deviation detecting means for detecting that the scanning position of the signal converting means has deviated from the track; a first moving means for moving the scanning position of the signal conversion means in a direction substantially perpendicular to the track direction on the record carrier; and a first moving means for moving the scanning position of the signal conversion means in a direction substantially perpendicular to the track direction on the record carrier a second moving means including the first moving means in the direction;
and said first and second moving means so that the scanning position of said signal converting means is always on a track on said record carrier.
a control means for driving and controlling the moving means, and a signal from the track deviation detecting means when the scanning position of the signal converting means is moved by the second moving means is binarized through a first filter. a first binarizing means; and a second binarizing means which binarizes the signal of the track deviation detecting means when the scanning position of the signal converting means is moved by the second moving means via a second filter. digitizing means, and counting means for counting the output signal of the first or second binarizing means, the output signal of the first binarizing means and the output of the second binarizing means. 1. An information track retrieval device characterized in that when the signal levels become the same, the output signal of the first or second binarization means is switched and inputted to the counting means.