The device stabilize the rotation speed of the optical disk


G11B19/24 - Arrangements for providing constant relative speed between record carrier and head

 

(57) Abstract:

The device is used when recording and reproducing information on optical drives and allows to increase the degree of stabilization of the rotation speed of the optical disc during the recording and reproduction of information, and to record on the optical disc that does not have pre-made tracks with service information. The device stabilize the rotation speed of the optical disk contains a speed sensor of the optical disc mounted on the motor shaft sector disk equal to the size of readable and/or writable optical disks, optical labels in the form of a sector with radius equal to the radius of the sector of the disk, and the unit of comparison error signal of the current value of the velocity from its reference value, connected in series with a power correction speed associated with the engine. The speed sensor optical drive contains a laser focusing system and radial displacement of the beam that reads the information from the sector of the disk associated with the sensors radial displacement of the beam, the reading or recording information on an optical disc, connected in series receiver with longitudinal Petrini, the output of which is connected to the Comparer. The correction block rate coupled with a system of radial displacement of the beam. 4 C.p. f-crystals, 4 Il.

The invention relates to the field of recording and reproducing information on optical disks.

Changing the repetition rate data recorded on the optical disk signalosome lead in terms of working with channel codes, taking into account inter-symbol interference, change the level of intersymbol interference and distortion of the playback signal.

Deviations from the nominal value of the linear velocity of the track when recording and reproduction are summed and have a destabilizing effect on the system data synchronization playback.

Changing the repetition rate data recorded on the optical disk signalosome appear because of the variability of the linear velocity of a track of data that changes as a consequence of the reduction of the radius of the track data in the process of reading information, and due to random fluctuations in the speed of the motor shaft, the eccentricity of the track, the deformation of the disk and the relative angle between the surface of the playback of the optical disk and the surface of LTI track data is typically a few hundredths of a percent.

Known systems of recording and reproducing information on optical disks containing the control system and stabilization of the rotation speed of the optical disk (for example, US patent N 4674076, CL 11 In 7/095, 1987). The system includes a speed sensor, an optical disc, working on put on the tracks of the optical disk service marks, block electronic signal processing, the output of which is connected with the rotation drive of the drive.

This system enables high-quality recording information on an optical disk, having previously completed it marks.

Know the use of the control dial during playback or recording information on an optical disk that does not have pre-made tracks with service information (US patent N 5590102, CL G 11 7/095, 1996). Signals error correction terms and focus reading or writing beam produced by block by comparing the current data and data obtained by reading the reference scale. However, this does not provide a correction block rotation speed of the optical disk, in addition, the accuracy requirements for the performance of control scales are hard.

The most which should be used for recording, and when reproducing information containing the speed sensor, including laser, receiver and special sector-by-sector disk with optical labels, made in the form of sectors with radii equal to the radius of the sector disc mounted on the motor shaft, the block comparison of the current value of the velocity from its reference value, and the correction block (application EPO N 0344994 A2, G 11 29/247, 06.12.89). The specified device eliminates the instability of the speed of rotation of the motor shaft.

The disadvantage of this sensor is the inability to control the deviation of the linear velocity of the track of the optical disk caused by its eccentricity, but also caused by deformation of the disk and the angle of inclination of the surface of the optical disk; it also requires high precision manufacturing sector of the disk.

The objective of the invention is to increase the degree of stabilization of the rotation speed of the optical disc during the recording and reproduction of information by controlling the deviation of the linear velocity of the track of the optical disk because of the variability of the linear speed of the data track, random fluctuations in the speed of the motor shaft, the eccentricity of the track, the deformation of the disk and on playscheme. In addition, the device allows you to record on the optical disc that does not have pre-made tracks with service information. An object of the invention is also reduced requirements for precision manufacturing sector of the disk.

The problem is solved in that the device for the stabilization of the rotation speed of the optical drive that contains the speed sensor of the optical disc mounted on the motor shaft sector disk with optical labels, and unit comparing the error signal of the current value of the velocity from its reference value, connected in series with a power correction speed associated with the engine, a sector of the disk is made equal to the size of readable and/or writable optical disks, optical labels in the form of sectors with radii equal to the radius of the sector of the disk, the speed sensor optical drive contains a laser focusing system and radial displacement of the beam, read information from the sector of the disk associated with the sensor radial displacement of the beam, the reading or recording information on an optical disc, and connected in series receiver with a longitudinal photoelectric installed prettylinks averaging of measurement results the output of which is connected with a power comparison of the error signal and the correction block rate coupled with a system of radial displacement of the beam, the reading or recording information on an optical disc, the size of the receiving area of the receiver with longitudinal photoelectric effect and the size of the shielding mask consistent with the size of the optical labels on pie disk and the distance between them so that during the rotation of the optical disc receiver with longitudinal photoelectric effect produced pulses of different polarity.

In particular the unit of statistical averaging of the results of measurements made in the form of an operational amplifier whose output is connected to three selectors negative pulses and three selectors of positive pulses, the outputs of the selectors negative pulses through the pulse shaper start connected respectively with the first three inputs of the switching triggers, the outputs of the selectors of positive pulses through the pulse shaper breakdown connected respectively with the second inputs trigger outputs trigger is connected with the first inputs of three schemes match, the second inputs of which are connected with the master oscillator, and outputs schemes match sondigo averaging the results of measurements further comprises connected with the meter shaper reset pulse, connected to the output of the first trigger.

In one particular case of optical labels on pie comes in the form of plots, reflecting the radiation and shaped sectors, with a laser and a receiver with a shielding mask is installed on one side of the sector of the disk.

In another particular case, the optical labels on pie comes in the form of plots transmissive and having the form of sectors, with a laser and a receiver with a shielding mask installed on different sides of the sector of the disk.

In Fig. 1 shows a block diagram of a device for the stabilization of the rotation speed of the optical disk of Fig. 2 - the location of the receiver with longitudinal photoelectric effect with respect to the optical labels sector of the disk; Fig. 3 schematically depicts a sector of the disk; Fig. 4 is a timing chart of a signal taken from the collector of the receiver with longitudinal photoelectric effect.

The device stabilize the rotation speed of the optical disk mounted on the shaft 1 of the engine 2, contains the sector from the optical disk 3 marks 4, 5 receiver with longitudinal photoelectric shielding mask 6, is installed directly in front of the photosensitive surface of the receiver, photojournale disk or passed through them, the laser light 7, and block electronic signal processing.

Receiver with longitudinal photoelectric effect (inversion photodiode) produces longitudinal EMF, the magnitude and polarity of which depends on the displacement of the beam relative to the center of the receiver (see Yakushenko Y., fundamentals of optical-electronic instrument. - M.: Soviet radio, 139-141 C.). Inversion characteristic of the receiver with longitudinal photoelectric effect is shown in Fig. 4.

For the speed sensor, you must ensure that the size of the photosensitive areas of the receiver 5 with longitudinal photoelectric effect, the dimensions of the shielding mask 6, the size of the optical labels 4 and the distance between them, as well as the width of the beam of laser radiation 7. These parameters must be selected so that during the rotation of the sector disc receiver with longitudinal photoelectric effect produced pulses of different polarity (Fig. 4) corresponding to the intersection of each optical label beam of laser radiation, i.e., to the photosensitive area of the receiver with longitudinal photoelectric effect simultaneously did not get the signals from the two optical labels sector of the disk. Typically, the distance between the labels exceeds the distance between the slits is of amnike longitudinal photoelectric effect; typically, when the rotation speed of 25 Rev/s (disk radius of about 50 mm) labels applied with a spatial frequency of about 200 l/mm Temporal frequency signal receiver with longitudinal photoelectric effect is about 1.5 MHz. These requirements satisfy modern receivers with longitudinal photoelectric effect, the time constant which is measured in microseconds.

The width of the beam of laser radiation can be achieved by focusing the beam; can be used a cylindrical lens or optical system split beam of laser radiation at two. In the latter cases considerably more complicated unit 8 focus readout beam; however, because the accuracy of the velocity measurements in the presence of the shielding mask and the statistical averaging of the measurement results do not depend on the size of the beam, it is preferable for the appropriate selection of the size of the focused beam of laser radiation.

During the rotation of the sector of the optical disk labels 4 cross slot in the shielding mask 6, and the collector receiver with longitudinal photoelectric effect appear corresponding to the points of intersection of the current pulses of different polarity (Fig. 4), which come to the inverting input of pettapiece and uniform illumination of the current pulses will be identical regardless of the form of the optical labels, and, therefore, the time interval between pulses for any arbitrarily given phase will be strictly constant and equal to t = L/v, where L is the distance between slits shielding mask, v is the linear speed of movement of the optical labels.

Because of the identical form of cracks and surface imperfections of the photosensitivity of the photodetector signal pulses can be spread in a certain area; to improve the accuracy of speed measurement it is necessary to reduce the measurement error of time delay pulses by statistical averaging of measurement results produced for the different phases of the signals. In particular, the averaging is performed by the accumulation of statistical sums the results of the three dimensions of t1, t2, t3in block 10 of the statistical averaging of the measurement results. For this purpose, the output signal of the operational amplifier 9 is fed to three selector 11, 12, 13 negative pulses and three selector 14, 15, 16 positive pulses. To ensure the identity of the phases of the signals at the output of the amplitude selectors their thresholds limits selected, respectively, are pairwise equal. The output signal of the amplitude selectors after the formation of their respective formerly schema matching 26, 27, 28 at the time intervals t1, t2, t3. On the second inputs of the circuits match 26, 27, 28 pulses from oscillator 29 reference frequency f0shifted in phase by a time interval t0= 1/3 f0. The counter 30 pulses, connected to the outputs of the circuits match 26, 27, 28 through the circuit OR 31 registers the number of pulses proportional to the value t = t1+ t2+ t3= L/v + t1+ t2+ t3than is provided by the averaging.

The device may further comprise a pulse shaper reset, the input connected to the output of the trigger 23, and the output of the counter 30 pulses, which allows for resetting the counter to zero at the beginning of the next measure and, thereby, increase the time zone determined by the repetition frequency tags.

The signal proportional to the linear velocity of the optical labels sector of the disk, is served in the block 32 comparison, which produces a signal proportional to the error in the magnitude of velocity.

Since the velocity of motion read (recordable) disk area is directly proportional to the speed and inversely proportional to the radius of the track is read (write) for ware in order to ensure the speed of rotation of the disk.

The block 33 of the speed correction produces a control signal in accordance with a signal proportional to the measured error in the velocity and in accordance with the radius of the track is read (write). This correction is provided by the communication unit 33 to the sensor radial displacement of the beam, the reading or recording information on an optical disc. In order to take into account the eccentricity of the deformation of the disk and the relative angle between the surface of the playback of the optical disk and the objective lens surface readout or recording system, block 34, the radial displacement of the beam that reads the information from the sector of the disk, is connected with the sensor radial displacement of the beam, the reading or recording information on an optical disc that provides simultaneous radial displacement of these rays, thereby accounting radius and the error radius of the track of the optical disk.

When using the proposed device correction rate, the maximum error rate is not more than 0.01%. The requirements for precision manufacturing sector of the disk are not hard due to the presence of shielding mask and the results of measurements.

1. The mouth of serum, the receiver is installed on the motor shaft sector disk with optical labels, made in the form of sectors with radii equal to the radius of the sector of the disk, and the power comparison signal of the current value of the velocity from its reference value, connected in series with a power correction speed associated with the engine, characterized in that sector of the disk is made equal to the size of readable and/or recordable optical disk, the laser contains system focus and radial displacement of the beam that reads the information from the sector of the disk associated with the sensors radial displacement of the beam, the reading or recording information on an optical disc, front receiver, made with longitudinal photoelectric effect, set the shielding mask for separating the bus receiver attached different bias voltages, the speed sensor optical disk contains connected in series with the receiver unit static averaging of the measurement results, the output of which is connected to the block comparison and correction block rate coupled with a system of radial displacement of the beam, the reading or recording information on an optical disc, the size of the receiving area of the receiver with PR the ke and the distance between them thus, so that when the rotation of the optical disc receiver with longitudinal photoelectric effect produced pulses of different polarity.

2. The device under item 1, characterized in that the static block averaging measurements made in the form of an operational amplifier whose output is connected to three selectors negative pulses and three selectors of positive pulses, the outputs of the selectors negative pulses through pulse shapers run connected respectively with the first three inputs of the switching triggers, the outputs of the selectors of positive pulses through the pulse shaper breakdown connected respectively with the second inputs trigger outputs trigger is connected with the first inputs of three schemes match, the second inputs of which are connected with the master oscillator, and outputs schemes match connected with the circuit OR the output of which is connected with the pulse counter.

3. The device under item 1, characterized in that the static block averaging of measurements further comprises connected with the counter pulse shaper reset connected to the output of the first trigger.

4. Device according to any one of paragraphs.1 to 3, characterized in that the optical Meir and receiver with shielding mask is installed on one side of the sector of the disk.

5. Device according to any one of paragraphs.1 to 3, characterized in that the optical labels on pie comes in the form of plots transmissive and having the form of sectors, with a laser and a receiver with a shielding mask installed on different sides of the sector disc.

 

Same patents:

FIELD: optical data carriers.

SUBSTANCE: from optical disk, on which standard samples of similar length are recorded in a way to deviate from middle of track in opposite directions, signals are reproduced, which are detected from standard samples. On basis of determined values of detected signals value of balance value is determined, on basis of which servo error is detected. As standard samples, "vfo" template signals recorded on disk can be used. Values of balanced values, received for adjoining sectors, can be brought to average. Balance value for detection of incline error can be determined on basis of subtraction signal RF_pp, which is signal of subtraction V2-V1, where V1, V2 - signals from radial couples of photo-detector.

EFFECT: more stable servo control, maintained optimal state for recording and reproduction.

11 cl, 15 dwg

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