JPH01253880A - Retrieving device for information track - Google Patents

Abstract

PURPOSE:To realize stable and high speed retrieval by changing time during which tracking control and transfer control are made not to operate according to retrieving distance, and obtaining a signal to detect correctly that a light beam traversed a track. CONSTITUTION:When the signal delayed by prescribed time by a delay circuit 81 is inputted to a gate circuit 82 and an information processing control device 78, the device 78, which makes the tracking control and the transfer control operate so that the light beam on a record carrier 57 is always positioned on the prescribed track till that time, outputs the signal to a switch 63 so as to make the tracking control and the transfer control not operate. Afterward, the carriage 71 of the beam is started to move by a linear motor 69, and the signal that the beam traversed the track on the record carrier 57 is outputted to the output of a differential amplifier 60, and the noise of a high band part is removed by a waveform processing circuit 62, and the output is binarized, and is counted by an up-down counter 80. Then, by changing the time during which the tracking control and the transfer control are made not to operate according to the retrieving distance, the high speed retrieval is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an apparatus for recording or reproducing information on a disk-shaped record carrier having tracks by means of a signal conversion means. This invention relates to a truck search device.

BACKGROUND OF THE INVENTION An example of an invention related to this type of device is Japanese Patent Application Laid-open No. 1986-
There is one shown in Publication No. 10026.

This will be explained below using FIG. 6. A light beam 2 generated from a light source 1 such as a semiconductor laser is passed through a coupling lens 3. It passes through a beam splitter 4, is reflected by a reflecting mirror 5, and is formed into a disc-shaped record carrier 7 by a converging lens 6.
It is converged on top. The record carrier 7 is attached to the rotating shaft of a motor 8 and rotates at a predetermined number of rotations. Record carrier 7
is a concentric or spiral groove on the base material (
(hereinafter referred to as a track), and address signals are sequentially provided from the inner circumference to the outer circumference. The reflected light of the light beam 2 reflected from the recording carrier 7 passes through the converging lens e again, is reflected by the reflecting mirror 5, the beam splitter, and the vine 4, and is reflected by the light beam 2.
The light is irradiated onto a photodetector 9 having a split structure. The converging lens 6 is attached to a tracking element 10, which allows the converging lens 6 to be moved 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.

Light source 1. Coupling lens 3. Beam splitter-4
9 Reflector 6. Photodetector9. The moving parts of the tracking element 1o and the speed detector 11 are attached to a transfer stage 12, and are moved 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 moving 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. This is a signal representing the tracking control signal.

The signal of the differential amplifier 14 is transferred to the switch 15. The signal is transmitted to the tracking element 10 through a phase compensation circuit 16 for compensating the phase of the tracking control system and a drive port 1 for driving the tracking element 1o.

Therefore, the tracking element 1o is controlled to move the converging lens 6 in accordance with the signal from the differential amplifier 14 so that the light beam 2 on the record carrier 7 is always positioned on the track.

The range in which the tracking element 10 can move is approximately 500 μm, and if the transfer table 12 moves significantly, the tracking control will be lost. In order to prevent this, the linear motor 13 is driven so that the tracking element 1o moves around its natural state, that is, the signal from the drive circuit 17 becomes zero level on average, and the movement of the transfer table 12 is controlled. It's in control.

To explain this transfer control, the signal of the differential amplifier 14 is transferred to the switch 16. Phase compensation circuit 18 for compensating the phase of the transfer control system. The signal is transmitted to the linear motor 13 via a drive control circuit 19 for driving and controlling the linear motor 13, and the linear motor 13 moves the transfer table 12 so that the tracking element 1o moves around its natural state. . The switch 15 is for disabling tracking control and transport control.

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

The basic configuration of the optical recording/reproducing apparatus has been described above, but one important function of this apparatus is to search for a desired track at high speed and stably.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 A1 of the tofusoku where the light beam 2 is currently located, and calculates (A1-Ao).

IAl-Aol≧N (IAl-Aol is (A1-Ao
), and N is a positive integer. ), then the information processing control device 20 sends the value of IAl-Aol and the direction signal to the drive control circuit 19 -'
The included counting circuits IA1-AolO values are preset and at the same time the switch 15 is opened and the tracking and transport controls are deactivated.

The drive control circuit 19 drives the linear motor 13 to move the transfer platform 12 in the direction where a desired track exists.

The signal of the differential amplifier and divider 14 is sent to the track crossing detection circuit 2.
The signal from the track crossing detection circuit 22 is input to the drive control circuit 19. When the transfer stage 12 moves in the radial direction of the record carrier 7, a signal indicating that the light beam 2 on the record carrier 7 crosses the track is outputted from the differential amplifier 14, and the track crossing detection circuit 22 outputs a differential signal. The signal from the amplifier 14 is waveform-shaped and transmitted to the drive control circuit 19.

A counting circuit included in the drive control circuit 19 counts the signals from the track and track crossing detection circuit 22, detects that the light beam 2 on the record carrier 7 is on the 0th track of the first IAl-Ao, and then outputs the signal from the drive control circuit 19. 19 sends a coincidence signal to the information processing control device 20. The information processing control device 20 is a linear motor 13
A signal to stop the light beam 2 is transmitted to the drive control circuit 19, and the switch 15 is short-circuited to operate the tracking control and transport control, and the address A2 of the track on the record carrier 7 where the light beam 2 is located is read. Hereinafter, this search will be referred to as a coarse search.

If Ao=A2, the search ends, but IA2−Aol
If ≧N, the above-described rough search is performed again. Also,
If IA2-Aol<N, the information processing control device 20 opens the switch 15, sends a signal to the drive circuit 1, drives the tracking element 1°, and shorts the switch 15 again to skip one track. scanning(
After repeating this jumping IA2-Aol times, the address A3 of the track where the light beam 2 is located is read.

Hereinafter, this search will be referred to as a dense search. If Ao=A3, the search ends, but if A0~A3, the above-mentioned coarse search and fine search are repeated to find the desired track.

Problems to be Solved by the Invention However, in the above configuration, since the record carrier 7 is eccentrically attached to the rotating shaft of the motor 8, tracking control and transport control are performed to control the movement of the record carrier 7. The light beam 2 is always positioned on a predetermined track. Therefore, when performing a rough search, the tracking control and transport control are disabled, and the drive control circuit 19 drives the linear motor 13 to move in the direction where the desired track exists.
Since it is generally composed of a coil and a magnet, it has a time constant.

Therefore, even if the drive control circuit 19 applies a voltage to the linear motor .degree. C., the transfer table 12 does not start moving immediately, but starts moving with a time constant.

Further, in general, the mixed pressure applied to the linear motor 13 by the drive control circuit 19 is proportional to the distance to be searched.

Therefore, when searching for a long distance, a large voltage is applied to the linear motor 13 and the transfer table 12 starts moving in a relatively short time, but when searching for a short distance, the voltage applied to the linear motor 13 is small and the transfer table 12 starts moving. 12 units will not start working immediately.

Therefore, during the time from when the tracking control and the transport control are disabled until the near motor 13 starts moving, the light beam on the record carrier Y is on a predetermined track due to the eccentricity of the rotation axes of the record carrier 7 and the motor 8. cross the track without being positioned. Then, the counting circuit included in the drive control circuit 19 counts these tracks, making it impossible to perform a rough search accurately and having to perform a rough search many times, making it difficult to perform a π-speed search. Ta.

The present invention overcomes the above problems and provides a device that can always search for a desired track at high speed and stably at any search distance.

Means for Solving the Problems The present invention comprises a converting means for reproducing or recording a track direction signal on a record carrier, and a first converting means for moving the scanning position of the converting means in a direction substantially perpendicular to the track direction. a second moving means that moves the scanning position of the converting means including the first moving means in a direction substantially perpendicular to the track direction; Drive the transportation means of 1 and i! +(Ia), a counting means for counting the output signal of the converting means when the track on the AER recording carrier is crossed, and a variable delay means for delaying the movement start signal of the second moving means. It is equipped with the following.

Effect of the Invention With the above-described configuration, the present invention provides a movement start signal to the second moving means when searching for a desired track, and also provides a variable delay means depending on the distance to which the second moving means is to be moved. , the movement start signal is delayed by the set delay amount by the variable delay means, the υ control means is made inoperable by the output signal of the variable delay means, and the second movement means starts moving. The counting means counts the track-crossing signals from the above-mentioned counting means.

Embodiment Hereinafter, an information track retrieval device according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is an overall block diagram of the device.

In FIG. 1, 51 is a light source, 52 is a coupling lens, 53 is a hub beam splitter, 54 (4 reflecting mirrors, 6
6 is a converging lens, 56 is a tracking element, 67 is a record carrier, 68 is a motor, and 59 is a photodetector having a two-part structure.

The respective signals of the photodetector 69 are input to a combining circuit 61 for obtaining a combined signal of the respective signals of the differential amplifier 60 and the photodetector 59. The signal of the differential amplifier 60 is input to the waveform processing circuit e2 and the switch 63, and the output of the switch 63 is input to the phase compensation circuits 64 and 65. The signal from the phase compensation circuit 64 is input to the drive circuit 67, and the signal from the drive circuit 67 is input to the tracking element 56. The signal from the phase compensation circuit 66 is sent to a combining circuit 68, the signal from the combining circuit 68 is sent to a drive circuit 70 for driving a linear motor 69, the signal from the drive circuit 7o is sent to a linear motor 69,
Each is input.

A signal from a speed detector 72 that outputs a signal corresponding to the moving speed of the transfer table 71 is input to a synthesis circuit 68.

The counting output of the counting circuit 72 is sent to a signal generating circuit 75, and the signal of the signal generating circuit 75 is sent to a combining circuit 68 via a switch 76.
are transmitted to each. The synthesis circuit 68 is a speed detector 72
This is for combining the output signals of the 9-phase compensation circuit 66 and the switch 7e.

FIG. 2 shows a specific example of the counting circuit 74 shown in FIG.
Clock b1 search command C is manually input. The input data a and clock b are input to a serial/L//parallel conversion circuit 79, respectively.

The serial/L//halalel conversion circuit 83 is for converting a signal input as serial data into a ζ parallel signal, and its output signal is sent to an up/down counter 80. Each signal is input to a delay circuit 81. Search command C
are respectively input to the amplifier/rerun counter 80 degree delay circuit 81, and the delay circuit 81 receives data inputted from the parallel conversion circuit 79.
This is to delay the signal of the search command C, and when the data input from the serial data parallel conversion circuit 79 is large (the search distance is far), the delay amount is decreased, and when the input data is small (the search distance is close) ), this is a circuit that increases the amount of delay. The output signal q of the delay circuit 81 is input to the gate circuit 82 and the information processing control device 78 in FIG.

The input d is the output signal of the waveform processing circuit 62 shown in FIG. 1 and is input to the gate circuit 82.

FIG. 3 shows a specific example of the gate circuit 82 of FIG. 2, where d is the output signal of the waveform processing circuit 62 of FIG. 1, which is input to the gate circuits 84 and 85, respectively. q is the second
The output signal of the delay circuit 81 in the figure is 84.85
are input respectively. h is an output signal of the up/down counter 80 in FIG. 2, which is the MSB signal of the counter, and is input to an AND gate 84 and an inverter 83, respectively. The output of inverter 83 is AND gate 8
6 and the outputs i, j of AND gates 84 and 86
are respectively input to the up/down counter 8o in FIG.

FIG. 4 is a waveform diagram showing the timing of each part when searching (search will be explained later); b) Information processing control device 78
The search command is input to the shift/down counter 80 and the delay circuit 81, and Ql (c) is the output signal of the speed detector 72 when the transfer table 71 is driven by the linear motor 69).
(e) is the output signal of the differential amplifier 6°, and (f) is the control signal input to the information processing control device 78 and the switch 63.

Next, the operation of searching for a short distance will be explained using FIGS. 1 to 4. 3. Input the address A of the desired track into the address input device 7.

, the information processing control device 78 reads the signal of the combining circuit 61 and the address A1 of the track on the record carrier 57 where the light beam is located, converts the A1-AoO value into serial data, and converts the A1-AoO value into serial data. ．． It is input as clock b to the serial/parallel converter circuit 83 of the counting circuit 74 [FIG. 4A].

The serial/parallel conversion circuit 79 converts the serial input signal into a parallel signal and inputs it to the up/down counter 80 and the delay circuit 82.

Further, the information processing device 78 outputs the search command C [Fig. Short circuit. The up/down counter 8o sends a direction signal h to the gate circuit 82 (the direction signal is a signal indicating whether to move the transfer table 71 from the outer circumference to the inner circumference of the record carrier 57 or from the inner circumference to the outer circumference). (The former is assumed to be LOW and the latter is assumed to be a high logic level.) (here, a high level is output). It also outputs the counter value to the signal generation circuit 6 as an output signal f.

The signal generation circuit 75 generates an output corresponding to the counter value of the counting circuit 74 and outputs it to the drive circuit To via the switch output 62 synthesis circuit 68, and the drive circuit 70 drives the linear motor 69 to generate the transfer table 71. begins to move [Figure 4 C].

The signal delayed by T1 time by the delay circuit 81 [FIG. 4 2] is sent to the gate circuit 82. When the input is input to the information processing control device 78, the information processing control device 78 operates tracking control and transport control so that the light beam 2 on the record carrier 7 is always positioned on a predetermined track. 63
outputs a signal to disable tracking control and transport control. Thereafter, the light beam 2 begins to be moved by the linear motor 69 on the transfer stage 71, and a signal indicating that the light beam 2 crosses the track on the record carrier 7 is output as the output of the differential amplifier 6o, as shown in FIG. 4E. , the waveform processing circuit 62 removes high-frequency component noise and binarizes the signal. This binarized signal can be input to AND gates 84 and 85. Since the output of the inverter 83 is at a low level, the output signal of the AND gate 85 is at a low level, and the gate does not open to the signal input from the waveform processing circuit 62. Furthermore, since the input signal to the AND gate 84 is at a high level, the signal inputted from the waveform processing circuit 62 is input to the up/down counter 80 as an up clock. The up/down counter 80 counts this input clock and outputs the counter output to the signal generation circuit 76, which generates a signal according to the counter output and transfers the clock to the transfer table 7.
Control the moving speed of 1.

The counting circuit 74 calculates the number of tracks traversed by the light beam on the record carrier 67. When IAl-Ao1 reaches near the current month, the signal generation circuit 76 outputs a signal to the drive circuit 70 via the switch 76 and the synthesis circuit e8 so that the speed of the transfer table 71 is slowed down.

The counting circuit 74 counts the number of tracks crossed by the light beam on the record carrier 67, and when it detects that the light beam has arrived on the 0th track of IA, -A01, it sends a coincidence signal e to the information processing control device 78. . The information processing control device 78 sends a signal to the switch 76 to open the switch 76 and stop the linear motor 69, and the information processing control device 7
8 sends a signal to the switch 63 to short-circuit the switch 63 to operate the tracking control and transport control, and select the address A2 of the track where the light beam on the record carrier 57 is located.
Read. If A2=A0, the search ends and IA2
- If A01≧N, perform the above-mentioned coarse search and IA
2-If Aol<N, the above-described dense search is performed and the search operation for the desired track is completed.

Next, the operation of searching a long distance will be explained.

FIG. 5 is a waveform diagram showing the timing of each part when searching a long distance, and the same numbers as in FIG. 4 indicate waveforms of the same parts. Since the search operation is almost the same as the short distance search described above, it will be explained in a simplified manner.

When the desired track 80' is input to the address input device 77, the information processing control bag @78 reads the current address A1' and sends the large value of A1'-80' to the up/down through the serial/parallel conversion circuit. The signal is input to the down counter 8o and the delay circuit 82.

The information processing control device 78 outputs the search command cc) to the up/down counter 80 and the delay circuit 81, and short-circuits the switch 76. The counter value of the up/down counter 80 is transmitted to the drive circuit 7o via the signal generation circuit 76, switch 76 and synthesis circuit 68. Since a large signal is input to the drive circuit 70, a large current flows through the linear motor 69. The transfer table then immediately begins to move (Figure 5).

The signal delayed by 12 hours (T1>T2) by the delay circuit 81 [FIG. 5 2] is sent to the gate circuit 82. When input to the information processing control device 78, the information processing control device 8 outputs a signal to the switch 63 to disable tracking control and transfer control. After that, the output of the differential amplifier 60 is binarized and counted by an up/down counter 8o.
'-Ao7 By detecting the first track and performing the same operation as described above, it is possible to search for a desired long-distance track.

As described above, during a search, the current applied to the linear motor differs depending on the search distance (a small current for a short-distance search, a large current for a long-distance search), so the acceleration of the linear motor changes depending on the search distance. It varies depending on the situation. For this reason,
By varying the time during which the trunking control and transfer control are inactive depending on the search distance, a signal can be obtained to accurately detect when the light beam has crossed the trunk, and by counting this signal, Accurate rough searches can be performed, and as a result, stable and high-speed searches can be performed.

Effects of the Invention As described above, according to the present invention, after the movement of the second moving means is started, the tracking control means is rendered inactive according to the distance to which the second moving means is to be moved. By changing the time, a desired trunk can always be searched quickly and stably at any search distance.

[Brief explanation of the drawing]

FIG. 1 is an overall block diagram of an information track retrieval device according to an embodiment of the present invention, FIG. 2 is a specific block diagram of its counting circuit, and FIG. 3 is its gate circuit 61...light source,
55... Collection lens, 56... Mountain/tracking element, 67... Record carrier, 6o... Phase differential amplifier, 74... Counting circuit, 78... ...
Information processing control circuit, 79... serial/parallel conversion circuit, 80... up/down counter-181... delay circuit, 82... gate circuit, 83... Inverter, 84.85...
...and gate. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 7β Figure 2 - I L--------J Figure 3z Figure 4 Figure 5

Claims (1)

[Claims] converting means for reproducing signals from or recording signals on tracks on a record carrier; first moving means for moving a scanning position of said converting means in a direction substantially perpendicular to said track direction; and scanning of said converting means. a second moving means for moving the position including the first moving means in a direction substantially perpendicular to the track direction; and a second moving means for moving the first moving means so that the scanning position of the converting means is always on the track. a control means for driving and controlling the means; a counting means for counting an output signal of the converting means when the scanning position crosses a track on the record carrier; and delaying a movement start signal of the second moving means. and a variable delay means for providing a movement start signal to the second moving means when searching for a desired track, and adjusting the variable delay according to the distance to which the third moving means is to be moved. a delay amount of the means is set, the movement start signal is delayed by the set delay amount by the variable delay means, the output signal of the variable delay means makes the control means inactive, and the second movement means moves. An information track retrieval device characterized in that the counting means counts the track crossing signals after the start of the information track retrieval device.