JPH039554B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a recording/reproducing apparatus having an automatic tracking control means for automatically scanning a signal converting means for recording or reproducing a signal along a track on a record carrier. The present invention relates to jumping scanning means for moving the means to a desired track.

Conventionally, devices for recording or reproducing signals as concentric or spiral signal tracks on a rotationally driven disc-shaped recording medium include optical recording/reproducing devices, magnetic recording/reproducing devices, magneto-optical recording/reproducing devices, capacitors, etc. However, when searching for a desired track and recording a signal or reproducing a recorded signal, jumping scanning is essential.

Conventionally, jumping scanning in the above-mentioned apparatus was performed by disabling the tracking control means, applying a constant signal to the driving means of the signal conversion means to move the signal conversion means, and then operating the tracking control means again. Due to changes in the track pitch or eccentricity of the track, the tracking control may sometimes be operated while the scanning position of the converting means is at the edge of the track, resulting in instability.

Further, when jumping scanning a plurality of tracks at once, the scanning position of the converting means may not be located on the desired track, resulting in extremely unstable results.

SUMMARY OF THE INVENTION An object of the present invention is to provide a jumping scanning device capable of eliminating the above-mentioned conventional drawbacks and performing stable and accurate jumping scanning.

The present invention disables the tracking control means, causes the scanning position of the converting means to scan in the track width direction on the recording medium, and detects when the scanning position of the converting means is on a desired track by a signal from the tracking signal detecting means. The purpose is to detect this and operate the tracking control means again to perform jumping scanning.

The present invention will be described in detail below with reference to the drawings.
Note that the same numbers are used to describe the drawings.

FIG. 1 shows an embodiment in which the present invention is applied to an optical recording/reproducing device.

A disk-shaped recording medium 1 (hereinafter referred to as a recording disk) is attached to a rotating shaft of a motor 2 and rotates at a predetermined number of rotations. A light beam 4 generated from a light source 3 such as a semiconductor laser is incident on a converging lens 8 via a coupling lens 5, a semi-transparent mirror 6, and a reflecting mirror 7, and is converged onto the recording disk 1 by the converging lens 8. . The emitted light 9 reflected from the recording disk 1 passes through the converging lens 8 again, and then passes through the reflecting mirror 7 and the semi-transparent mirror 6.
The light is reflected by the light beam and irradiated onto the photodetector 10 having a two-part structure.

The converging lens 8 is incorporated into a control element 11, and the control element 11 has a structure that allows the converging lens 8 to be moved in the radial direction of the recording disk 1.

light source 3, coupling lens 5, semi-transparent mirror 6,
The reflecting mirror 7, the control element 11, and the photodetector 10 are each attached to a transfer table 12, and are configured to be able to move together in the radial direction of the recording disk 1.

To detect the deviation between the light beam 4 focused on the recording disk and the track, that is, the tracking signal, as will be described in detail later, each output of the photodetector 10 is input to the differential amplifier 13 to obtain a difference signal. I'm walking around. Tracking control is performed by applying the output of the differential amplifier 13 to the control element 11 via a switch 14, a phase compensation circuit 15 for compensating the phase of the tracking control system, and a drive circuit 16 for driving the control element 11. The light beam 4 focused on the disc 1 is controlled so as to always be located on the track.

Further, the output of the switch 14 is connected to a phase compensation circuit 17,
It is applied to a transfer motor 19 via a drive circuit 18, and the transfer motor 19 moves and controls the transfer table 12 in the radial direction of the recording disk 1 so that the control element 11 moves around its natural state. A switch 14 (hereinafter this control will be referred to as transfer control) is for disabling tracking control and transfer control, and a compensation circuit 17 is for compensating the phase of the transfer control system.

A simple structure of the recording disk 1 is shown in FIG. The recording disk 1 has a base material 3 having concentric grooves 31 with concave and convex grooves.
2. It is composed of a recording material film 33 and a protective layer 34, and the light beam 4 is irradiated from the side of the base material 32,
Tracking control is applied to position it on the groove.

A case in which a concentric track is subjected to tracking control and another track is caused to perform jumping scanning will be described with reference to FIG. 1.

When a jumping scanning direction signal indicating whether jumping scanning is to be performed to the inner track of the track where the light beam 4 is currently located or jumping scanning is to be performed to the outer track and the number of jumping scanning lines are input to the setting circuit 20, the setting circuit 20
presets the number of jumping scans in the counting circuit 21, and transmits the jumping scan direction signal to the track crossing detection circuit 22 and the jumping scan signal generation circuit 23. The counting circuit 21 transmits the jumping scanning signal to a switch 24, a control operation control circuit 25, and a jumping scanning signal generation circuit 2.
3. The switch 24 is short-circuited to transmit the signal of the track crossing detection circuit 22 to the counting circuit 21, and the control operation control circuit 25 is connected to the switch 1.
4 is opened to disable tracking control and transfer control, and the jumping scanning signal generation circuit 23
transmits a signal according to the jumping scanning direction to the drive circuit 16 to drive the control element 11. The control element 11 moves the converging lens 8 to
The upwardly focused light beam 4 is scanned approximately in the track width direction. When the optical beam 4 focused on the recording disk 1 is scanned, a signal corresponding to the scanning of the optical beam is generated in the differential amplifier 13, and the track crossing detection circuit 22 generates a signal from the differential amplifier 13 and the jumping scanning signal. Generates a track crossing signal in response to the direction signal. The counting circuit 21 counts the signals from the track crossing detection circuit 22 to detect that the light beam 4 has come onto the desired track, and sends a jumping scanning stop signal to the switch 24, the jumping scanning signal generation circuit 23, and the control operation control circuit. 25. The switch 24 is opened,
The jumping scanning signal generation circuit 23 transmits a brake signal for stopping the movement of the converging lens 8 to the drive circuit 16. When the brake signal ends,
The jumping scanning signal generation circuit 23 transmits a termination signal to the control operation control circuit 25, which short-circuits the switch 14 and operates the tracking control and transfer control again, so that the light beam 4 is placed on the desired track. let it be located.

Detection of tracking signals will be explained with reference to FIG. Figure A shows the state in which the light beam 4 is moved in the direction of the arrow 41. The light beam 4a shows the state in which the light beam 4 is located directly above the track 31, and the light beams 4b and 4c show the state in which the light beam 4 is located directly above the track 31. This shows a state in which the light beam 4 is slightly shifted from directly above 31. Figures B and C show the respective outputs 42a and 42b of the photodetector 10 and the output 4 of the differential amplifier 13 when the light beam 4 is moved as shown in Figure A.
3 is expressed with the center position of the track as x=0, with the center position of the light beam 4 on the x-axis and the output on the y-axis. In Figure B, the outputs 42a and 42b are approximately line symmetrical with respect to x=0, and therefore the tracking signal 43 is approximately point symmetrical with respect to x=0 and y=0.

Therefore, by driving the control element 11 so that the tracking signal becomes zero, the light beam 4 can be always positioned on the track. There is also a position between the tracks where the tracking signal becomes zero, but since the control systems have different polarities, no control is applied between the tracks.

The track crossing detection circuit 22 will be explained with reference to FIG. The track crossing detection circuit 22 includes a waveform shaping circuit 51, an OR circuit 52, a NAND circuit 53, and
It is composed of an AND circuit 54. A tracking signal is input to the input A, and the input A is connected to the input of the waveform shaping circuit 51. Input B
A jumping scanning direction signal is input to , and input B is connected to the inputs of an OR circuit 52 and a NAND circuit 53. The output of the waveform shaping circuit 51 is input to the OR circuit 52 and the NAND circuit 53, and the output of the OR circuit 52 and the NAND circuit 53 is
It is input to the AND circuit 54. AND circuit 54
The output C is the output of the track crossing detection circuit 22, and is connected to the switch 24 in FIG.

The operation of the track crossing detection circuit 22 during jumping scanning will be explained with reference to the timing chart of FIG. Figure A is the tracking signal, Figure B is the output of the waveform shaping circuit 51, Figure C is the jumping scanning direction signal, Figure D is the output of the NAND circuit 53,
Diagram E shows the output of the OR circuit 52, and diagram F shows the output of the AND circuit 54.
represents the output waveform of Regions G and H represent different jumping scanning directions.
In figure A, T ₀ to T ₅ and T ₀ ′ to _{T 4} ′ represent the center of the track, and T ₀ and T ₀ ′ represent the center of the track where the light beam was located just before starting the jumping scan. There is. The arrows in Figures B, D, E, and F contain information about the movement of the light beam across tracks to adjacent tracks. The signal from the track crossing detection circuit 22, that is, the rising edge of the waveform shown in Fig. F has information that the track has moved to the adjacent track, and the counting circuit 21 shown in Fig. 1 counts the rising edge of the signal from the track crossing detection circuit 22. It is detected that the light beam 4 has arrived on the desired track.

The jumping scan shown in FIG. 1 will be explained together with the timing chart shown in FIG. 6. Figure 6 shows the case where six jumping scans are performed, where Figure A is a load signal for presetting the number of jumping scans in the counting circuit 21, Figure B is a jumping scanning direction signal, Figure C is a tracking signal, and Figure D is a jumping scan direction signal. The figure shows the output of the track crossing detection circuit 22, and the figure E shows the output of the counting circuit 21.
The output of the F diagram is the jumping scanning signal generation circuit 2.
3 to the drive circuit 16, Figure G shows the signal applied from the jumping signal generation circuit 23 to the control operation control circuit 25, and Figure H shows the signal applied from the control operation control circuit 25 to the switch 14 to disable tracking control and transfer control. This is a signal for During jumping scanning, the signals applied to the control element 11 are pulse signals,
It is a composite signal of a step signal and a ramp signal.

The track crossing detection circuit 22 shown in FIG. 1 can also be configured as shown in FIG. The track crossing detection circuit 22 includes comparators 61 and 62, OR
It is composed of a circuit 63, a NAND circuit 64, and an AND circuit 65, and a tracking signal is applied to input A, which is connected to comparators 61 and 62. A jumping scanning direction signal is applied to input B, and input B is connected to an OR circuit 63 and a NAND circuit 64.
The comparison levels of comparators 61 and 62 are positive and negative levels, and their respective outputs are
It is input to an OR circuit 63 and a NAND circuit 64. The outputs of the OR circuit 63 and NAND circuit 64 are
It is input to the AND circuit 65, and the AND circuit 65
The output C of is connected to switch 24 in FIG.
The waveforms during the jumping scan shown in FIG. 7 are shown in the timing chart of FIG. Figure A shows the tracking signal, Figure B shows the output of the comparator 6, Figure C shows the output of the comparator 62, Figure D shows the jumping scanning direction signal, and Figure E shows the output waveform of the AND circuit 65. Regions F and E represent different jumping scan directions. T ₀ to T ₄ and
T ₀ ′ to T ₄ ′ represent the center of the track, and T ₀
and T ₀ ' represent the center of the track where the light beam 4 was located just before starting the jumping scan. The arrows shown in Figures B, C and E contain information about the movement of the light beam to the adjacent track.
The rising edge of the signal from the track crossing detection circuit 22, that is, the waveform shown in Figure E, has information that the light beam has moved to the adjacent track, and the falling edge has information that the light beam 4 has approached the center of the track. ing. Therefore, by counting the rise or fall of the signal from the track crossing detection circuit 22 using the counting circuit 21, it is possible to detect that the light beam 4 has arrived at a desired track.

The track crossing detection circuit 22 of FIG. 1 can be constructed as shown in FIG. The track crossing detection circuit 22 is composed of an inversion circuit 71, switches 72 and 73, a waveform shaping circuit 74, and an inverter 75. A tracking signal is input to input A, and input A is connected to an inverting circuit 71 and a switch 72. The inversion circuit 71 inverts the tracking signal and inputs it to the switch 73.
The outputs of switches 72 and 73 are connected and input to a waveform shaping circuit 74. A jumping scanning direction signal is input to input B, and input B is input to switch 73 and inverter 75. The inverter 75 inverts the jumping scanning direction signal and transmits it to the switch 72. When the jumping scanning direction signal is HIGH, the switch 72 is open, the switch 73 is short-circuited, and the signal from the inverting circuit 71 is input to the waveform shaping circuit 74 via the switch 73. Jumping scan direction signal
In the case of LOW, the switch 72 is short-circuited and the switch 73 is opened, and the tracking signal is input to the waveform shaping circuit 74 via the switch 72.
The waveform shaping circuit 74 shapes the waveform of the input signal and connects it to the switch 24 in FIG. 1 so as to transmit a track crossing signal.

Further, the track crossing detection circuit 22 can be constructed as shown in FIG. The track crossing detection circuit 22 includes waveform shaping circuits 81 and 82, OR
It is composed of circuits 83 and 84, an AND circuit 85, and an inverter 86. Photodetector 10 in FIG.
The respective outputs are input to waveform shaping circuits 81 and 82, respectively, and the outputs of waveform shaping circuits 81 and 82 are inputted to OR circuits 83 and 84, respectively. A jumping scanning direction signal is input to input B, and input B is connected to an OR circuit 83.
and is input to the inverter 86. Inverter 86 inverts the jumping scan direction signal.
It is input to the OR circuit 84. The outputs of OR circuits 83 and 84 are input to an AND circuit 85,
The output C of the AND circuit 85 is connected to the switch 24 in FIG.
The track crossing signal is transmitted to the track crossing signal.

FIG. 11 shows a timing chart during the jumping scan in FIG. 10. Figure A shows the tracking signal, Figures B and C show the respective outputs of the photodetector 10 that are input to the waveform shaping circuits 81 and 82, and D and E.
The figure shows the output of the waveform shaping circuits 81 and 82, the figure F shows the jumping scanning direction signal, and the figure G shows the AND circuit 85.
This is the output waveform of Regions H and I represent different jumping scanning directions. Figure A
T ₀ to _{T 4} and T ₀ ′ to _{T 4} ′ represent the center of the track, and T ₀ and T ₀ ′ represent the center of the track where the light beam 4 was located immediately before starting the jumping scan. There is. The output C of the AND circuit 85, that is, the rising edge of the G diagram has information that the light beam 4 has moved to the adjacent track, and the falling edge has information that the light beam 4 has moved to the adjacent track.
has information that is located near the center of the track. Therefore, if the output of the AND circuit 85 is input to the switch 24 and the counting circuit 21 is configured to count the rise or fall of the signal from the AND circuit 85 during jumping scanning, the light beam 4 can arrive at the desired track. It is possible to detect that something has happened.

Although one embodiment of the present invention has been described in detail above, it goes without saying that the present invention is not limited to this embodiment.
It can also be applied to jumping scanning performed by driving 9.

This book can also be used to perform special playback of slow-motion images, still images, back-motion images, quick-motion images, etc. in so-called optical video disk devices that play back images spirally recorded on the recording disk 1. Able to adapt inventions.

By applying the present invention, it is possible to easily detect when the light beam has arrived on a desired track during jumping scanning, and the position of the light beam on the track when the tracking control is activated is always the same. Since it is almost constant, extremely stable and accurate jumping scanning can be performed.

Further, extremely stable jumping scanning can be performed even when there is track pitch unevenness or eccentricity.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention;
2 is a side sectional view of the recording disk used in the embodiment of FIG. 1, FIG. 3 is an explanatory diagram of the tracking signal detection operation, and FIG. 4 is an example of the track crossing detection circuit 22 of FIG. 1. 5 is a timing diagram of the track crossing detection circuit of FIG. 4 during jumping scan, FIG. 6 is a timing diagram of the jumping scan of FIG. 1, and FIG.
9 and 10 show the track crossing detection circuit 2.
8 is a block diagram showing another embodiment of 2.
The timing diagram of the track crossing detection circuit 22 shown in the figure during jumping scanning, FIG.
FIG. 3 is a timing diagram of the track crossing detection circuit 22 shown in the figure during jumping scanning; FIG. DESCRIPTION OF SYMBOLS 1... Recording medium, 3... Light source, 8... Converging lens, 10... Photodetector, 11... Control element, 13
... Differential amplifier, 14 ... Switch, 15 ... Phase compensation device, 16 ... Drive circuit, 17 ... Phase compensation circuit, 19 ... Transfer motor, 20 ... Setting circuit, 21 ... Counting circuit, 22 ... Track crossing detection circuit, 23 ... Jumping scanning signal generation circuit, 24 ... Switch, 25 ... Control operation control circuit.

Claims (1)

[Claims] 1. Conversion means for reproducing a signal from a record carrier having a track for recording a signal or a track of a recorded signal, and a scanning position of the conversion means on the record carrier. a moving means that moves relatively in the width direction of the track; a tracking signal detecting means that detects a positional deviation between the track on the record carrier and the scanning position; and a moving means that moves the moving means in response to a signal from the tracking signal detecting means. tracking control means for driving and controlling the scanning position so that it is always located on the track; opening/closing means for disabling the tracking control means; direction specifying means for specifying the direction of jumping scanning; track position detecting means for detecting that the scanning position is on or near a desired track based on a signal from the direction specifying means and a signal from the tracking signal detecting means; generating a signal for disabling the tracking control means, moving the scanning position in the direction specified by the direction specifying means, and generating a signal for stopping the movement of the scanning position in response to a signal from the tracking position detecting means; 1. A jumping scanning device comprising: means for generating a jumping scanning signal. 2. The tracking position detection means is configured by waveform shaping means for shaping the signal of the tracking signal detection means, and switching means for switching the polarity of the signal from the waveform shaping means in accordance with the signal from the direction specifying means. A jumping scanning device according to claim 1. 3. an inverting means for inverting the signal of the tracking signal detecting means; a switching means for switching and outputting the signal of the tracking signal detecting means and the signal of the inverting means according to the signal of the direction specifying means; 2. A jumping scanning device according to claim 1, further comprising a waveform shaping means for shaping a waveform and a track position detecting means. 4. Conversion means for reproducing signals from a record carrier having a track for recording a signal or a track of a recorded signal, and a scanning position of the conversion means on the record carrier relative to the width direction of the track. a tracking signal detection means for detecting a positional deviation between a track on the record carrier and the scanning position; tracking control means for controlling the track so that it is always positioned on the track; opening/closing means for disabling the tracking control means; designation means for designating the direction of jumping scan and the number of jumps; track crossing detection means for detecting that the scanning position has crossed a track from the signal of the tracking signal detection means in accordance with a direction signal designated by the means; and counting the signals of the track crossing detection means; a counting means for generating a coincidence signal by determining that the scanning position is on or near a desired track when the number of jumps specified by the specifying means coincides with the number of jumping lines specified by the specifying means; Generating a signal for disabling the tracking control means by the opening/closing means and moving the scanning position in a direction specified by the specifying means, and generating a signal for moving the scanning position in accordance with the signal from the counting means. 1. A jumping scanning device comprising a jumping scanning signal generating means that stops. 5. The track crossing detection means is constituted by waveform shaping means for shaping the signal of the tracking signal detection means, and switching means for switching the polarity of the signal of the waveform shaping means in accordance with the direction signal designated by the designation means. A jumping scanning device according to claim 4. 6. Inverting means for inverting the signal of the tracking signal detecting means, switching means for switching and outputting the signal of the tracking signal detecting means and the signal of the inverting means according to the direction signal specified by the specifying means, and the switching means. 5. The jumping scanning device according to claim 4, further comprising a waveform shaping means for shaping the waveform of the signal and a track crossing detection means.