JPS6396772A - Information signal reproducing device - Google Patents

Abstract

PURPOSE:To shorten a search time, by supplying the rotational speed of a spindle motor corresponding to a searching opposite as a targeted value at time of searching, and controlling the rotation of motor. CONSTITUTION:To a register 1, the address data SDATA of a disk 11 of the searching opposite is supplied and fetched at time of issuing a search instruction, and the address data of the disk 11 corresponding to an optical system 14, that is, a pickup position, is supplied and fetched in order at time of reproduction. The address data fetched in the register 1 is supplied to a conversion table 2. In the conversion table 2, the address data is converted to a rotational speed data which represents the rotational speed of the spindle motor 12 corresponding to the shown address of the disk 11. In this way, since the rotational speed of the spindle motor is controlled, and it is performed separately from the slide control of the optical system in parallel independently, the control of the rotational speed can be performed rapidly, thereby, it is possible to shorten the search time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an information signal reproducing device suitable for application to, for example, a video disc player that reproduces a disc whose recording format is a constant linear velocity method (CLV method). .

[Summary of the invention]

The present invention provides an information signal reproducing device that controls the motor wire speed for rotating a disk-shaped recording medium to be constant, and provides a target value for the rotational speed of a spindle motor according to a search destination during a search. The search time is shortened by controlling the rotation of the spindle motor.

[Conventional technology]

FIG. 2 is a block diagram of the main parts of a video disc player that plays back discs whose recording format is constant linear velocity (CLV).

In the figure, C1υ is a disk, (121 is a spindle motor that rotates this disk av, and (13 is a frequency generator that generates a frequency signal SFG corresponding to the rotation speed of this spindle motor C121.

Maft and a4 are optical systems including, for example, a semiconductor laser pickup. The FM signal picked up by this optical system α is supplied to the FM demodulation circuit α6 via the RF amplifier (L51), and the video signal SV is output from this FM demodulation circuit (IF3). After being supplied to the collector and subjected to time axis correction, it is supplied to the A side terminal of the changeover switch α.

For example, a video signal SvB for a blue screen is supplied to the B side terminal of the changeover switch a&. This changeover switch αg is supplied with a switching control signal Sc from a system controller (hereinafter referred to as "system controller"), although not shown, and is connected to side A during playback, and connected to side B during search, for example.

The video signal from this switch ugJ is supplied to, for example, a monitor receiver (tl).As a result, a screen based on the video signal Sv is displayed on the monitor receiver σ9 during playback, and a blue screen based on the video signal SvB during search is displayed on the monitor receiver σ9. be done.

Further, the video signal Sv from the FM demodulation circuit αe is supplied to the synchronization separation circuit CD, and the horizontal synchronization signal HD from this synchronization separation circuit (2D is supplied to the phase comparator (22) and is in phase with the reference horizontal synchronization signal HDRF. be compared.

The phase error signal SDI output from the phase comparator (2z) is supplied to the A-side terminal of the changeover switch (23).

In addition, the frequency signal SFG from the frequency generator (13) is supplied to the frequency/voltage conversion circuit (hereinafter referred to as 1'-F/V conversion circuit) c24, and from this F/V conversion circuit C24), the frequency signal SFG from the frequency generator (13) is supplied to the spindle motor α20 rotations. A signal EM with a level corresponding to the number is obtained, and this signal EM is supplied to the I inverting input terminal of the operational amplifier (29).
, therefore, it is a potentiometer for detecting the position of the pickup, and the position signal E from this potentiometer (to) is
p is supplied to the non-inverting input terminal of the operational amplifier (29).

A difference signal SE2 between the position signal Ep and the signal EM is obtained from the operational amplifier (29), and is supplied to the B side of the changeover switch (c).

Also, the difference signal SE2 from the amplifier (c) is supplied to the window generator @.
A signal SSW is obtained which has a high level "'1" and a low level 10" at other times. This signal SSW is supplied to the changeover switch (To) as a switching control signal, and the changeover switch (To) When the high level is ``'l'' and the low level is 10'', the output signal of the changeover switch (c) is switched to the A side and the B side, respectively. (to) will be supplied.

In the above configuration, during a search, the optical system, and therefore the pickup, are sequentially moved to the search destination under the control of a slide servo circuit (not shown).

Therefore, the position signal Bp from the potentiometer (c) also changes sequentially, so the difference signal SE2 outputted from the operational amplifier is large, and the output signal SSW of the window generator is at a low level. The switch is B
can be switched to the side. Therefore, the difference signal SE2 from the motor servo circuit (2) and rarely the operational amplifier (c) is supplied as a control signal.
The rotational speed of the spindle motor σ2 is controlled so that it becomes equal to σ2. That is, the rotational speed of the spindle motor (121) is controlled to be a rotational speed corresponding to the position of the optical system a4.

Then, when the optical system I is moved to the search destination, the rotation speed of the spindle motor (lz) becomes extremely close to the rotation speed corresponding to the position of the optical system I. Then, the signal EM becomes extremely close to the position signal Ep, and the difference signal SE2 is small, the output signal Ssw of the window generator is at a high level "'l", and the changeover switch is switched to the A side.Therefore, the motor sage circuit receives a phase error signal from the phase comparator @. SE1 is supplied as a control signal.This causes F
The rotation speed of the spindle motor a21 is controlled so that the jitter of the video signal S2 from the M demodulation circuit aO falls within a predetermined range.

[Problems to be Solved by the Invention] As described above, according to the example in FIG. 2, during the search, the difference signal SE2 from the operational amplifier (c) is supplied to the motor circuit (to), and Rotation speed is optical system I
It is controlled so that the rotation speed corresponds to the moving position of . However, according to the example in FIG. 2, the position of the optical system I is detected by the potentiometer I20, and the control is performed based on the position signal Ep, which is the detection signal, so it is inevitable to slide the optical system α. Since rotation control of the spindle motor t1z is performed after this, there is a drawback that the search time is long.

In view of this point, the present invention aims to shorten the search time.

[Means for solving problems]

The present invention is based on an information signal reproducing apparatus that controls a motor that rotates a disc-shaped recording medium so that the linear velocity is constant. The present invention controls the rotation of the motor by giving a rotational speed corresponding to the search destination on the recording medium as a target value during a search. For example, when searching, the search data S DATA is converted to the conversion table (2).
is converted into rotational speed data. Then, a difference signal Szi is obtained between the signal ES corresponding to this rotational speed data and the signal EM obtained by the F/V conversion circuit (3) to which the frequency signal SFG from the frequency generator a3 is supplied. The rotation of the spindle motor (12) is controlled by the difference signal SE'r.

[Effect]

In the above configuration, the rotation of the motor is controlled by giving a rotational speed corresponding to the search destination on the recording medium as a target value, and the movement position of the optical system is detected as in the conventional case, and the position signal is used to control the rotation of the motor. It is not controlled based on That is, the rotation control of the motor is performed separately and in parallel with the slide control of the optical system.

〔Example〕

Hereinafter, a simple embodiment of the present invention will be described with reference to FIG. In FIG. 1, parts corresponding to those in FIG. 2 are designated by the same reference numerals, and detailed explanation thereof will be omitted.

In the figure, (1) is a register, and when a search command is issued, the search destination disk αB is stored in this register (1).
address data 5DATA (for example, 0 minutes 0 seconds) is supplied and incremented, and during playback, address data of the optical system I, and hence of the disk (11) corresponding to the pickup position, is sequentially supplied and taken in. This register (1)
The address data taken in is supplied to a conversion table (2) constituted by, for example, a ROM. In this conversion table (2), the address data is converted into rotational speed data indicating the rotational speed of the spindle motor (1z) corresponding to the address of the disk (111) indicated by the address data.

The rotation speed data from this conversion table (2) is D/
The signal ES from the D/A converter (3) is then supplied to the non-inverting input terminal of the amplifier (25).

A difference signal SE/2 between the signal Es and the signal EM from the F/V conversion circuit Nz4) is obtained from the operational amplifier (25), and is supplied to the B side of the changeover switch (231).

Further, the difference signal SE6 from the operational amplifier C5) is supplied to the window generator (2). This wind generator (5)
From then on, the difference signal SE! A signal SS- is obtained which is a high level 1111'' when the value becomes small and falls within a predetermined range, and which is a low level "0" at other times.

This signal SSW is supplied to the changeover switch +231 as a changeover control signal, and when the changeover switch (23) has a high level "1" and a low level "0", the changeover switch (23)
It is switched and connected to the side and B side.

The rest of the structure is the same as the example shown in FIG.

In this example, when a search command is issued, address data 5 DATA of the disk to be searched for is supplied to register (1) K and taken in, converted to rotational speed data in conversion table (2), and then sent to the D/A converter ( 3), a signal ES corresponding to this rotational speed data is obtained. In this case, the spindle motor α2 initially uses the address data S DAT
The rotational speed corresponding to the address of the disk αV indicated by A is not reached, the difference signal SE2' is large, and the wind generator (A)
The output signal S anchor is at a low level "0", and the changeover switch (to) is switched to the B side. Therefore, the difference signal SE2 from the operational amplifier (c) is supplied to the motor servo circuit (to) as a control signal. As a result, the rotational speed of the spindle motor σ2 is controlled so that the signal EM becomes equal to the signal E3. That is, the rotational speed of the spindle motor 0z is controlled to be the rotational speed corresponding to the address of the disk U indicated by the address data SDATA.

When the rotational speed of the spindle motor (1z) approaches the rotational speed corresponding to the address of the disk (ill) indicated by the address data 5DATA, the signal EM approaches the signal ES extremely and the difference signal SE becomes small. The output signal Ss- becomes high level "1" and the selector switch (to) is switched to the A side.Therefore, the motor sensor circuit (to) receives the phase error signal S from the phase comparator.
EI is provided as a control signal. This allows FMS
The soter of the video signal Sv from the adjustment circuit (le) is controlled so that it falls within a predetermined range.

This control is similar to the example in FIG.

In this example, when searching, the rotation of the spindle motor α2 is determined based on the signal E3 corresponding to the rotation speed of the spindle motor (121) corresponding to the disk address indicated by the length data 5DATA, that is, the search destination. The speed is controlled and performed independently and in parallel with the slide control of the optical system (14).Therefore, according to this example:
The rotational speed of the spindle motor (121) is controlled quickly, and the search time can be significantly shortened.

Although the above-mentioned embodiment applies the present invention to a video disc player, the present invention can be similarly applied to other information signal reproducing apparatuses that reproduce discs having a CLV recording format.

〔Effect of the invention〕

As is clear from the embodiments described above, according to the present invention, the rotational speed of the spindle motor according to the search destination is given as a target value during a search, the rotational speed of the spindle motor is controlled, and the rotational speed of the optical system is controlled. Since the slide control is performed separately and in parallel, the rotational speed of the spindle motor can be quickly controlled, and the search time can be shortened.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG. 2 is a block diagram of a conventional example. (1) is a register, (2) is a conversion table, (3) is a D
/A converter, σB is a disk, 2 is a spindle motor, (13 is a frequency generator, α4 is an optical system, aω is an FM demodulation circuit, αη is a time pace collector, (181 and (to) are a changeover switch, ( 2υ is synchronous separation circuit, (company)
is a phase comparator, c! 4) is a frequency/voltage conversion circuit, (c) is an op-amp, @ is a wind generator, and (to) is a motor circuit.

Claims (1)

[Claims] In an information signal reproducing device that controls a motor that rotates a disc-shaped recording medium so that the linear velocity is constant, the rotational speed of the motor according to a search destination on the recording medium during a search is provided. An information signal reproducing device characterized in that the rotation of the motor is controlled by giving a target value of .