SU1509993A1 - Optical memory - Google Patents

Abstract

The invention relates to optical storage devices of computer technology and improves the reliability of recording and reading information. The optical storage device containing disk information carrier 1, lens 3 on movable carriage 2, photodetector 4, laser interferometer 5, pulse shaping unit 6, current address counter 7, comparison circuit 8 and servomotor 10, additionally introduced an address converter switch 12, adders 13 and 14, the address register of the reference track 15, the reversible counter 16, the subtractor 17, the comparison circuits 18 and 19, the register of the track 20, the timer 21, the band-pass filter 23, the driver 24, the control unit 27 and the pulse switch 25 connected by In this way, it is possible to improve the accuracy of determining the position of the reference track on the information carrier. 1 il.

Description

The invention relates to automation and computing technology and is intended for use in optical data recording drives, in which a laser interferometer is used as a position sensor of a positioner with an optical head.

The purpose of the invention is to increase the reliability of recording and reproducing the HH-JQ formation.

The drawing shows a block diagram of a storage device.

The optical storage device contains a disk 1, a carriage 2, a lens 3, a photodetector 4, a laser interferometer 5, an add and subtract pulse shaping unit 6, a current address counter 7, a first comparison circuit 8, a reproduction amplifier 9, a servo 20 water 10 , the specified address register 11, the address converter switch 12, the first adder 13, the second adder 14, the reference track address register 15, the reversible counter 16, the subtractor 17.25 second comparison circuit 18 with the first constant, the third comparison circuit 19 with the second constant, register 20 dear timer 21, circuit 22, poloWhen entering into register 11 a given address from the control unit of a new logical address track Aj, the address of the nearest reference track A is determined using the switch 12 of the address transformer, the first adder 13 and the second adder 14 by the formula

(A, / 2) (A, / 2), where 2

number of information

tracks in the zone;

2 - the number of tracks in the guard zone;

5 E (A / 2) -part of the part from dividing the AZ by 2, corresponding to the number of the zone in which the information path is located.

The signals on lines A and D record the address of the reference track Ajn into the reference address address register 15 and into the reversible counter 16. Using the subtractor 17, the difference between the value of the reference track address and the current address of the position of the carriage 2 contained in the counter 7 is calculated current address, then using the third comparison circuit 19

filter fil.tr 23, shaper 24, com-zo verifies the need for correction

pulse mutator 25, control block 27.

divider 26,

current address. If the absolute value of the difference Aop-A is greater than the second constant, equal to the zone size, this indicates that the indicated track is in another zone, and a signal is set on line h, indicating the need for correction. If the device has not been accessed for a long time, i.e. the correction did not occur, the signal to carry out the correction along the line t gives the timer 21 to take into account thermal expansions. Different situations are possible.

40

45

The device works as follows.

On the optical disc there are deposited at equal intervals the reference tracks, which are a record of a sequence of pulses of frequency f, which is in the skip band of the playback channel. The information tracks are located between the reference tracks to form an information recording area, and there is a security zone near the reference tracks, forming a reference track area in which no information is recorded. The size of the information zone is chosen so that its temperature changes do not exceed the permissible positioning error. The value 50 on the guard zone is chosen greater than the magnitude of the temperature variation of the dimensions of the optical disk in a given operating temperature range. The correction of the current address is made either 55 when moving to another information zone, or after a certain period of time to take into account temperature changes in the size of the disk.

When registering in the register 11 of the specified address from the control unit of the new logical address of the track Aj, the address of the nearest reference track A is determined using the switch 12 of the address converter, the first adder 13 and the second adder 14 according to the formula

(A, / 2) (A, / 2), where 2

number of information

tracks in the zone;

2 - the number of tracks in the guard zone;

The E (A / 2) -part is the part from dividing the AZ into 2, corresponding to the number of the zone in which the information path is located.

Signals on lines A and D record the address of the reference track Ajn into the register 15 of the address of the reference track and into the reversible counter 16. Using the subtractor 17, the difference between the value of the address of the reference track and the current address of the position of the carriage 2 contained in the current 7 counter is calculated addresses, then using the third comparison circuit 19

0

five

5 0 5

current address. If the absolute value of the difference Aop-A is greater than the second constant, equal to the zone size, this indicates that the indicated track is in another zone, and a signal is set on line h, indicating the need for correction. If the device has not been accessed for a long time, i.e. the correction did not occur, then the signal to carry out the correction along the line t gives the timer 21 to take into account thermal expansions. Different situations are possible.

1. In the absence of signals on lines h and t, the correction is not needed, the signals on which the conversion of a given address is made using the formula

 Ae, Az + 2 g (Az / 2), where AZ „is the converted address of the specified track.

In this case, the value A is entered in the converted address register 20. At the output of the comparison circuit 8, a mismatch signal appears that controls the servo motor 10, which moves the carriage 2. During movement

.1509993,

jo

the carriage at the output of the laser interface corresponds to the position of the carriage

In meter 5, signals appear that are relative to the reference track. By sending through the block 6 of forming the front of this signal to it, the shaping pulses of addition and subtraction and the slit 24 generates a pulse, which are fed into the counter 7 of the current address, the contents are entered

The state of the counter changes from the corresponding reversible counter 16 to counter 7

with carriage movement. The incoming address is also issued.

output on a given track readings signal on the line of the end of the correction

the counter corresponds to the value of the code. and the timer 21 is reset, After giving the converted register 20, an action similar to that of the error signal to the output of step 1 is performed,

comparison circuits are removed. In the device- 3, the appearance of a signal on the line t

The control facility (CU) transmits a signal, which means that after the last correction, that the carriage left the nation, it was determined by the timer 21

specified track, time and re-correction required

2, If there is a signal on the line h on the reference track. The follower is corrected readings counting the functioning of the device

current address. On line x, Sanalog paragraph 2, After finishing

or B and L are set. The signals are corrected; the carriage is set to

which is used to transform the same track on which it found the specified track address according to the formula before correction,

A d

 Ep on -

Claims (1)

The sign of the second term depends on the formula of the invention on the relative position of the carriage and the need for the optical information track, which determines the information disk containing the signal on the line (for correcting through the focusing one must cross the reference track). on the movable. The value of the ARC is recorded in the register 20 of the carriage, with a photodetector, the output of the co-transformed address, in the register it is connected to the amplifier of the repro- duction of the address of the reference track and reversing light. th interferometer ny counter 16 rassogla-On signal is optically coupled to the carriage and popping from the comparison circuit 8 through karetkapodklyuchenny forming unit is moved toward the support dorols-pulse addition and subtraction to ki. When the carriage enters the guard-counting input of the counter of the current baseband destination zone, at the output of the 35pgca circuit, the output of which is connected to one 18 comparison with the first constant from the inputs of the comparison circuit, the other is a signal that allows pass-through to the output of the address register returning the signal from the output of the amplifier 9 hands, and its output - with a servo drive, reproducing through the AND circuit 22 mechanically connected with the carriage, to the band-pass filter 23. When Peres-differing, in that the reference track at the output increase reliability of an image filter, a signal appears, the width and readout of 1 information, decisive passing of signals from the output are connected in series with the pulse shaping unit 6, the complex-register of the specified address, the switch, and the subtractor through the address converter switch 25, the first sum of pulses to one-digit counter 26tor, second adder, address register and then to reversible counter 16. support track, extractor, second Since before the arrival the pulse-comparison circuit, the AND circuit, the stripe ow to the addition or subtraction inputs In this case, the filter, driver, timer, and block in the counter contain the code of the corresponding control, the third input of which is a sub-center of the reference track, and a signal to the driver's output, and a third comparison circuit and a sequence of dividing by 2, when the reference track is intersected by a switch from one edge to each other, the divider and reversal counting — the code value in the count changes 55ch, with a third comparison circuit half the width of the reference track. ie Discount at the time of termination of the signals of the output of the subtractor, and the output to the even-output of the bandpass filter, the code in the counting-up input of the control unit, the second input of the control unit is connected to the output of the second comparison circuit, the fifth to the control output, and its first output is connected to the address register of information track j second to the control input of the reversible counter, third and fourth respectively to the minus and plus inputs of the second adder, fifth to the control input of the address converter switchboard, sixth to the reference register address and the second input of the address register of the reference track, the first input of which is connected to the input of the address register of the information road ki, and the output with the information input of the reversible counter, in addition, the pulse switch with the control input is connected to a bandpass filter, and with the information input to the counting input of the current address counter, the control input of which is connected to the driver, the information input with a reversible counter and its output is connected to the second input of the subtractor, the second output of the register of the specified address is connected to the second input of the first adder, and the third output of the switch, the address converter is connected to the second input of the second totalizer ora