JPS60125974A - Retrieval device of information track - Google Patents

Abstract

PURPOSE:To retrieve a desired track in high speed stably by giving a moving start signal to a moving stand and also making a control means inoperative by means of a signal giving a delay to the moving start signal and counting a track crossing signal after the moving stand starts actually the movement by means of a counter means. CONSTITUTION:When a signal delayed by a delay circuit 85 of a counter circuit 74 is inputted to an information processing controller 78, the controller 78 outputs a signal to a switch 63 so as to make the tracking control and the moving control inoperative. Then the moving stand 71 crosses a light beam 2 while being moved by a linear motor 69, a signal as the result of the light beam 2 crossing a track on a recording medium 7 is outputted at an output of a differential amplifier 60, the counter circuit 74 counts the clock, a signal generating circuit 75 generates a signal in response to the counter output so as to control the moving speed of the moving stand 71. The counter circuit 74 counts the track number crossed by the light beam 2 on the recording medium 57, coarse and minute retrieval is attained and a desired track is retrieved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a recording/reproducing device for recording or reproducing information using a signal conversion 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.

Conventional Structure and Problems There is an optical recording/reproducing apparatus as one of the suitable recording/reproducing apparatuses to which the present invention is applied.

A conventional optical recording/reproducing device will be explained with reference to FIG.

FIG. 1 is an explanatory diagram of an optical recording/reproducing device.

A light beam 2 generated from 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 6, and is focused onto a disc-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 multiple recording material layers and protective layers provided on the grooves. The address signals are provided sequentially from the inner circumference to the outer circumference. The reflected light of the light beam 2 reflected from the recording medium 7 passes through the converging lens 6 again, is reflected by the reflecting mirror 5 and the beam splinter 4, and is irradiated onto the photodetector 9 having a two-split structure. The zero convergence lens 6 is attached to the tracking element 10, and
The tracking element 10 is configured such that the converging lens 6 can be moved in the radial direction of the record carrier element, 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 42 reflecting mirror 51 photodetector 9. The moving parts of the tracking element 1o 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 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 is determined by the position of the light beam 2 on the recording medium 7 and the track. The signal representing the relationship, 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 16 . The signal is transmitted to the tracking element 10 via a phase compensation circuit 16 for compensating the phase of the tracking control system and a drive circuit 10 for driving the tracking element 1o.

Therefore, the tracking element 10 is controlled to move the converging lens θ in accordance with 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 10 can move is approximately 500 μm, and if the transfer table 12 moves significantly, tracking control will be lost. In order to prevent this, the linear motor 13 is driven so that the tracking element 10 moves around its natural state, that is, the signal of the drive circuit 17 becomes zero level on average, and the movement of the transfer table 12 is controlled. To explain this transfer control, the differential amplifier 14
The signal of 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 is connected to the tracking element 1.
The transfer table 12 is moved so that 0 moves around the natural state. Switch 16 disables tracking control and transfer control.
y'$ A :1 - The signal from the speed detector 11 is input to the drive control circuit 19, and the drive control of the linear motor is made more stable by feeding the speed signal.

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 recording signal while the tracking control and the transport control are operated. The recording material at the location irradiated with the intense light beam 2 changes 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, with tracking control and transport control in operation, the light beam 2 generated from the light source 1 is made to have a weak constant intensity, and the reflection from the trunk The light is received by the photodetector 9, and a composite signal of the respective signals of the photodetector 9 is obtained.

Note that in the optical recording/reproducing device, the beam diameter of the light beam 2 irradiated onto the record carrier 7 is sb ry −
,6ry? 71- A ty -y fortune-/ , 7
xasusn>>, -y- However, since it is not directly related to the present invention, detailed description thereof will be avoided.

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 track at high speed and stably, and this search will be explained below.

The search system is composed of an information processing control device 20 including a microcomputer. When the address of a desired track is entered in the address input device 21, the information processing control device 2o reads the address A1 of the track where the light beam 2 is currently located and calculates (A1-Ao).

IAl-A01≧N (IAl-Aol is (A1-A.)
, and N is a positive integer. ), the information processing control device 2Q sends the value of lA1-Aol and the direction signal to the drive control circuit 19, presets the value of IAl-AolO in the counting circuit included in the drive control circuit 19, and simultaneously turns on the switch 15. It is opened and the tracking control and transfer control are disabled. 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 from the differential amplifier 14 is input to a track crossing detection circuit 22, and the signal from the track crossing detection circuit 22 is input to a drive control circuit 19.

When the transfer table 12 moves in the radial direction of the record carrier element, 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 This signal is waveform-shaped and transmitted 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 is on the 0th track of the first IAl-Ao, and
sends a coincidence signal to the information processing control device 20. The information processing control device 20 transmits a signal for stopping the linear motor 13 to the drive control circuit 19 and shorts the switch 16 to operate tracking control and transport control, so that the light beam 2 on the record carrier γ is positioned. Address A of the truck
2 (hereinafter this search will be referred to as a coarse search). If 80-A2, the search ends, but if IA2-A01≧N, the above-mentioned rough search is performed again. Also l A2
- If Aol<N, the information processing control device 20 opens the switch 15, sends a signal to the drive circuit 1, drives the p-tracking element 10, and shorts the switch 15 again, thereby making one track. After performing interlaced scanning (hereinafter referred to as "jumping") and repeating this jumping to lA2- once, the address A3 of the track where the light beam 2 is located is read (hereinafter this search will be referred to as "fine searching"). ). If it is Ao-A3, the search ends, but if it is Ao-A3, it is Ao-A3 (AONA3 is 80 and A
3 represents unequal. ), the coarse search and fine search described above are repeated to search for the desired trunk. By the way, since the record carrier 7 is eccentrically attached to the rotating shaft of the motor 8, the tracking control and The light beam 2 on the record carrier 7 performs transport control,
It is always positioned on a predetermined track. When performing a rough search, the tracking control and transport control are disabled, and the drive circuit 19 drives the linear motor to move in the direction where the desired track is located, but the linear motor generally uses coils and magnets. Because it is configured, it has a time constant. Therefore, even if the drive circuit 19 applies voltage to the linear motor, the transfer table 12 does not start moving immediately but starts moving with a time constant. Therefore, during the time from when the tracking control and transport control are disabled until the linear motor starts moving, the light beam on the record carrier 7 is not positioned on a predetermined track due to the eccentricity of the rotation axes of the record carrier 7 and the motor 8. Cross the track. Then the drive circuit 19
Since the counting circuit included in the 3D 3D counts these tracks, it is not possible to perform a rough search accurately, and the rough search has to be performed many times, making it difficult to perform a high-speed search.

OBJECTS OF THE INVENTION It is an object of the present invention to provide an apparatus which eliminates the above-mentioned conventional drawbacks and is capable of searching for a desired trunk at high speed and stably.

Structure of the Invention The present invention provides a record carrier having a trunk of a recorded signal or a track for recording the signal, a converting means for reproducing or recording a signal from a track on the record carrier, and a scanning position of the converting means. a first moving means for moving the scanning position of the converting 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 converting means in a direction substantially perpendicular to the track direction on the record carrier. a second moving means for moving including the converting means; a control means for driving and controlling the first moving means so that the scanning position of the converting means is always on a track on the record carrier; comprising a counting means for counting the output signal of the converting means that has traversed the track on the carrier, and a delay means for delaying a movement start signal of the second moving means, when moving the second moving means,
A means for supplying a movement start signal to the second moving means and disabling the control means by a signal obtained by delaying the movement start signal, and counting a track crossing signal after the second moving means actually starts moving. It is configured to count according to the following.

DESCRIPTION OF EMBODIMENTS The present invention will now be described in detail with reference to the drawings. FIG. 2 shows an embodiment of the present invention. In explaining FIG. 2, the explanation will be simplified for the parts that are the same as those in FIG.
is a tracking element, 67 is a record carrier, 58 is a motor,
69 is a photodetector with a two-part structure. Each signal from the photodetector 69 is input to a differential amplifier 6Q and a combining circuit 61 for obtaining a combined signal of the respective signals from the photodetector 69. The signal of the differential amplifier 60 is input to a waveform processing circuit 62 and a switch 63, and the output of the switch 63 is input to 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 66.

The signal of the phase compensation circuit 65 is sent to the combining circuit 68 and the combining circuit 6
The signal 8 is the drive circuit 7 for driving the linear motor 69.
The signals from the drive circuit 70 are inputted to the linear motor 69 at the respective positions o. A signal from a speed detector 72, which outputs a signal corresponding to the moving speed of the transfer table 71, is input to a combining circuit 68 and a counting circuit 74, respectively. The counting output of the counting circuit 74 is transmitted to a signal generating circuit 75, and the signal of the signal generating circuit 75 is transmitted to the combining circuit 68 via a switch 76. The combining circuit 68 is for combining the output signals of the speed detector 722, the phase compensation circuit 65, and the switch 76.

FIG. 3 is a specific example of the waveform processing circuit 62 shown in FIG. The filters 79 and 80 are input to comparators 81 and 82, respectively, and the outputs of the comparators 81 and 82 are connected to the counting circuit 74.

FIG. 4 shows a specific example of the counting circuit 74 shown in FIG. 2, and the serial data and clock search commands necessary for searching the information processing control device 78 shown in FIG. 2 are sent to d and e, respectively.

It is input to f. The data and clock input to d and e of the information processing control device 78 are respectively input to a serial/parallel conversion circuit 83.The serial/parallel conversion circuit 83 receives serial data input from the information processing control device 78. signal) to a parallel signal, and its output signal is sent to the up/down counter 84.
is input.

The search command f is input to an up/down counter 84 and a delay circuit 86, and the output of the delay circuit 86 is input to a timing processing circuit 86. Inputs S and C are signals input from the waveform processing circuit 62 in FIG. The output signal of the speed detector 72 shown in FIG. The signal from the comparison circuit 87 is input to the timing processing circuit 86. FIG. 6 shows a specific example of the comparator circuit 87 shown in FIG.
The (-) side terminal of the 0 comparator 8, which is input to the side terminal, is connected to a voltage obtained by dividing the voltage tDD, -vss by resistors R2 and R3°u6. Comparison Masuda.

The outputs of 89 are added together and input to a timing processing circuit 86. Here, as the speed of the transfer table 71 increases, the absolute value of the output signal of the speed detector 72 shown in FIG.
8.89, the output of the comparator circuit 87 becomes HiGH state. Further, as the speed of the transfer table 71 becomes slower, the absolute value becomes smaller and the output of the comparator circuit 87 becomes LOW. Further, the polarity is assumed to change depending on the direction in which the transfer table 71 moves.

FIG. 6 shows a specific example of the timing processing circuit 86 shown in FIG. 4, where b and cic are input with the output signals of the second waveform processing circuit 62, and are connected to the gate circuit 90° switch 92. . The output of the gate circuit 90 is input to the flip-flop 19 as a clock. Also, the output signal of the comparator circuit 87 in FIG. 4 is input to the flip-flop 91 as data. The flip-flop 91 takes in data in the rising waveform of the clock input, and outputs the resulting output from the Q terminal to the switch 92 as a command signal. The switch 92 switches the input signals A and C based on the flip-flop command signal and outputs them to the gate circuits 93 and 94. Figure 4 up/
The signal from the down counter 84 is input to the gate circuit 93.
．． It is connected to an inverter 95. The signal of the inverter 96 is input to the gate circuit 94, and the gate circuit 93°9
4 signals o and p are up/down counters 84, respectively.
has been entered. Figure 4 Up-down counter 84
The signal is generated by the signal generating circuit element 6. Each is input to the information processing control device 78.

FIG. 7 is a waveform diagram showing the timing of each part when searching (search will be explained later); Similarly, search command f1 (c) is input to the serial/parallel conversion circuit 83.
2 output signal, (f) is the output waveform obtained by comparing the output signal of the speed detector 72 with the comparison circuit 87, and (b) is the search command f.
The signal delayed by the delay circuit 86, (e) is the signal delayed by the differential amplifier 6
0 is the output signal, (f) is the output signal of the comparison circuit 87, and (g) is the control signal input to the switch 63 from the information processing control device 7B.

To explain the search using FIGS. 2 to 7, when the address A0 of a desired track is input to the address input device A7, the information processing control device 78 detects the light beam on the record carrier 67 based on the signal from the combining circuit 61. Read address A of the track where is located, and if lA1-A01≧N, lA
1-Aol Converts the O value to serial data, and outputs the serial data of the counting circuit 4 as serial data d and clock e.
The signal is input to the parallel conversion circuit 83 [Fig. 7 (a)]. The serial/parallel conversion circuit 83 converts the serial input signal into a parallel signal and converts it into an up/down counter.
84. The information processing control device 78 outputs the search command f [FIG. 7 (b)] to the up/down counter 84 of the counting circuit 74 and the delay circuit 85, and also outputs a switching signal to the switch 76. Short circuit. The up/down counter 84 sends a direction signal to the timing processing circuit 86 to indicate whether the direction signal is to move the Unehan Gongryo 1 from the outer periphery to the inner periphery, or from the inner periphery to the outer periphery. It is a signal to move in the direction, and the former is the LO
W, and the latter as Hi GH. ) (here, HiGH is output). It also outputs the counter value to the signal generation circuit 76 as an output signal. Signal generation circuit 7
6 generates an output corresponding to the counter value of the counting circuit, and outputs it to the drive circuit 70 via the switch 76 and the synthesis circuit 68, and the drive circuit To drives the near motor, thereby starting the transfer table 71.

The Q output of the flip-flop 91 is HiGH, the switch 92 selects the input, and outputs to the gate circuits 93 and 94.

The signal delayed by the delay circuit 86 (shown in FIG. 7) is sent to the timing processing circuit 86. When input to the information processing control device 78, the information processing control device 78 operates the tracking control and the transport control to control the light beam 2 on the record carrier 7.
was always located on the predetermined track, but switch 6
3 to disable tracking control and transfer control. Then, since the transfer table 71 moves by the linear motor 69, the light beam 2 is transferred to the record carrier 7 as shown in FIG.
The signal crossing the upper track is output, the low-pass filter 79 of the waveform processing circuit 62 removes high-frequency component noise, and the comparator 81 binarizes the track crossing signal.
It is input to gate circuits 93 and 94 via switch 92. Since the output of the inverter 96 is LOW, the output signal of the gate circuit 94 is LOW, and the gate circuit 94 gates the signal input from the switch 92 and does not output it. In addition, the gate circuit 93
Since the input signal n is in the Hi GH state, the switch 92
The input signal is input to the up/down counter 84 as an up clock. The up/down counter 84 counts this input clock and outputs the counter output to the signal generation circuit 76.
generates a signal according to the counter output to control the moving speed of the transferred milt 1.

As the speed of the transfer table 71 increases, the output of the speed detector increases and the output j of the comparison circuit 87 in FIG. 4 becomes HiGH [FIG. 7(v)]. In FIG. 6, when the input signal j becomes HiGH, when the input signals S and C become HiGH, the output signal of the gate circuit 90 becomes HiGH, and the flip-flop 91 becomes HiGH. The flip-flop 91 latches the input signal at the rising edge of the input signal of the gate circuit 9Q and outputs HiGH to the switch 92, and the switch 92 switches the input signal from b to C and outputs it to the gate circuits 93 and 94. Low-pass filter 80 in the figure. The track crossing signal is binarized by the comparator 82, and the switch 92 of FIG. 4 through the gate circuit 93/
This will be input to the down counter 84. Set the cutoff frequency of the low-pass filter 79.80 to "CI T
Assuming that iO2 is the relationship fcl<fc2. Here, even if the phases of the output signals S and c of the two low-pass filters 79 and 8o are different, the flip-flop 91 is activated by the gate circuit 9o only when the signals S and C become HiGH.
The signal of the comparison circuit 87 is latched. Therefore, when the switch 92 is actuated and signaled by the output command of the latched result, C is switched, so there is no possibility of malfunction.

The counting circuit 74 counts the number of tracks crossed by the light beam on the record carrier 67, and when the number of tracks traversed by the light beam on the record carrier 67 reaches near 0, the signal generating circuit shown in FIG. 76, outputs a signal to the drive circuit 7o via the synthesis circuit 68; When the speed of the transfer table 71 decreases, the output signal of the speed detector decreases, and the output of the comparison circuit 87 in FIG. 4 becomes LOW. Signals S and C in Fig. 6 are H.
When iGH, the output of the gate circuit 9o becomes HiGH, the flip-flop 91 launches the input signal of the comparison circuit 87 at the rising edge of the input signal of the gate circuit 90, and outputs LOW to the switch 92. Then, the switch 92 switches the input signal from C to b and outputs it. Low-pass filter 79 in FIG. The trunk crossing signal is binarized by the comparator 81, and the switch 92 in FIG. It is input to the up/down counter 84 in FIG. 4 via the gate circuit 93.

The counting circuit 74 counts the number of tracks crossed by the light beam on the record carrier 67, detects that the light beam has arrived on the trunk of the main port, and processes the coincidence signal m. to the 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 78 sends a signal to the switch 63 to short-circuit the switch 63 to perform tracking control and Activate the transport control and select the address A of the track where the light beam on the record carrier 57 is located.
Read 2. If A2-Ao, end the search and l
If A2-Aol≧N, perform the rough search described above,
If ``2''Ol<N, the above-described dense search is performed to search for the desired track.

Effects of the Invention By applying the present invention, at the start of a coarse search, the counting circuit accurately counts the tracks traversed by the light beam on the record carrier 67', regardless of eccentricity, thereby making it possible to perform an accurate search. Equipment performance.

Reliability can be significantly improved.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of a conventional optical recording/reproducing device, FIG. 2 is an overall block diagram illustrating an embodiment of an information track retrieval device of the present invention, and FIG. 3 is a waveform processing shown in FIG. A concrete block diagram of the circuit, Figure 4 is a concrete block diagram of the counting circuit in Figure 2, Figure 5 is a concrete electric circuit diagram of the comparison circuit in Figure 4, and Figure 6 is a concrete block diagram of the counting circuit in Figure 4. FIG. 7 is a detailed block diagram of the timing processing circuit shown in FIG. 7, and is an operation waveform diagram for explaining the present invention. 51... Light source, 55... Converging lens,
66...Tracking element, 57...
Record carrier, 59...Photodetector, 60...
・Differential amplifier, 62... Waveform processing circuit, 74.
... Counting circuit, 75 ... Signal generation circuit, 6
3.76...Switch, 79.80...
・Low pass filter, 81.82... Comparator, 83... Serial/parallel conversion circuit, 84
...Up/down counter-185...
...delay circuit, 86...timing processing circuit,
87... Comparison circuit, 90.93.94...
...Gate circuit, 91...Flip-flop,
92...Switch, 96...Inverter. Name of agent: Patent attorney Toshio Nakao (1st person)
Figure 2

Claims (1)

[Scope of Claims] A record carrier having a track for a recorded signal or a track for recording the signal, a converting means for reproducing or recording a signal from a track on the record carrier, and a scanning position of the converting means. a first moving means for moving a scanning position of the converting means in a direction substantially perpendicular to a track direction on the record carrier; and a first moving means for moving the scanning position of the converting means in a direction substantially perpendicular to a trunk direction on the record carrier. 2nd to move including means
a moving means, a counting means for counting the output signal of the converting means in which the scanning position of the converting means is described, and a delay means for delaying a movement start signal of the second moving means;
When moving the second moving means, a moving start signal is given to the second moving means, and a signal obtained by delaying the moving start signal makes the control means inoperable, and the second moving means actually starts moving. An information track retrieval device characterized in that the counting means counts trunk crossing signals after a trunk crossing signal is started.