JPH09120634A - Optical disc drive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize high speed access by calculating a correction coefficient from the difference between a target address and an arriving address and correcting the linear velocity, innermost circumferential radius and track pitch thereby determining the number of seek tracks to the target address accurately. SOLUTION: A linear velocity calculating means 10 calculates a linear velocity at the time of recording/playing inherent to a memory medium, i.e., an optical disc 1, based on the address information from an address detector 6. An innermost circumferential radius calculating means 11 calculates the innermost circumferential radius of optical disc at that time and a track pitch calculating means 12 calculates the track pitch of optical disc. Since the number of seek tracks can be calculated accurately based on the linear velocity, the innermost circumferential radius and track pitch, the number of times for seek retry is decreased and the access time to be target address can be shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk device, and a CLV type disk device (for example,
CD (compact disk), CD-ROM, optical disk device)
It is concerned with calculation of the number of tracks at the time of seek in the access control of

[0002]

2. Description of the Related Art In the track access of a conventional optical disk device, the number of seek tracks from a current address to a target address in a disk (medium) as a storage medium is calculated, and the track jump is performed by the tracking means by the calculated number of seek tracks. It is common to do

A case where the number of seek tracks in the case of a conventional disk device, for example, a CD, is obtained will be described with reference to FIG. As shown in FIG. 10 (a), a case will be described where seek is performed from point A (current address) to point B (target address) on the optical disc (media) 1. A track 1T is formed on the medium 1 as shown in the sectional view of FIG. 10B, and when a light spot crosses the track 1T, a track crossing signal as shown in FIG. 10C is obtained. . This track crossing signal is binarized to obtain a binarized signal pulse as shown in FIG. By counting this pulse, the number of tracks actually traversed can be counted.

Tracks on an optical disk (medium) are spirally recorded, and the unit of recording / reproduction is a sector.
In the case of the CLV system, normally, sector numbers from the innermost circumference (numbers in ascending order) are assigned as sector addresses and recorded in advance. Therefore, it is necessary to convert the sector number into a track number in order to calculate the seek track number.

In the case of a CD, the sector number is recorded by time. An equation for converting the sector number (time) in this case into a track number is given by (Equation 1).

[0006]

(Equation 1)

Here, t is the track number to be obtained, s is the sector number, V is the linear velocity during recording and reproduction, R is the radius of the innermost circumference, and P is the track pitch. Further, the seek track number Δt when seeking from the sector s ₁ to the sector s ₂ (where s ₂ > s ₁ ) is (Equation 2).

[0008]

(Equation 2)

In the case of a CD, the linear velocity V is 1.2 to 1.4 m / sec.
However, the linear velocity is not recorded on the media. If the linear velocity is not accurate, the values themselves of (Equation 1) and (Equation 2) will be inaccurate. Therefore, some means for obtaining the linear velocity of the medium have been proposed. For example, in Japanese Patent Publication No. 5-50074, the pickup is forcibly moved from the program start position of the disc to the inner circumference side of one track and the reproduction frame synchronization signal is counted until the program start position is detected again. The linear velocity of the media is calculated by.

[0010]

However, in the case of the CD, the tolerance is allowed not only for the linear velocity of the medium but also for the radius of the innermost circumference of the medium and the track pitch. That is, the radius of the innermost circumference is 24.9 ± 0.2 mm and the track pitch is 1.6 ± 0.1 μm. Therefore, the number of seek tracks calculated by obtaining only the linear velocity is still about 2
Since there is an error of%, the error causes an increase in the number of track jumps, resulting in a problem that the access time to the target address is prolonged.

The present invention solves the above-mentioned problems, and calculates a correction coefficient from the difference between the target address and the arrival address, and corrects the linear velocity, the innermost radius, and the track pitch. Accurate linear velocity and innermost radius,
An object of the present invention is to provide an optical disk device capable of high speed access by obtaining a track pitch and accurately calculating the number of seek tracks to a target address.

[0012]

In order to achieve the above object, the present invention provides a spindle motor for rotating a storage medium, a spindle motor controller for controlling the rotation of the spindle motor, and the storage medium. An optical head for reproducing the above signal or recording the signal on the storage medium; and an optical head drive device for driving the optical head,
A track crossing signal detector for detecting a track crossing signal from the reproduction signal of the optical head, a track crossing signal counter for counting the track crossing signals detected by the track crossing signal detector, and a sector from the reproduction signal of the optical head Address detector for detecting the address information of the storage medium, a linear velocity calculating means for calculating the linear velocity of the storage medium from the address information detected by the address detector, and the memory based on the address information detected by the address detector. Innermost radius calculation means for calculating the innermost radius of the medium, track pitch calculation means for calculating the track pitch of the storage medium from the address information detected by the address detector, track crossing signal counter, line Speed calculation means,
And a controller for controlling the operations of the spindle motor controller and the optical head drive device based on the outputs from the innermost radius calculating means and the track pitch calculating means.

The second means is the same as the first means, and the linear velocity measuring means measures the linear velocity of the storage medium from the rotation information and radius information of the storage medium attached to the rotary shaft of the spindle motor. It is characterized by

A third means is characterized in that, in the structure of the first means, the innermost radius measuring means measures the innermost radius of the storage medium from the position of the optical head.

A fourth means is characterized in that, in the structure of the first means, the track pitch measuring means measures the track pitch of the storage medium from the position of the optical head.

[0016]

According to the first means of the present invention, it is possible to accurately detect the linear velocity, the innermost radius and the track pitch at the time of storage / reproduction peculiar to the storage medium from the address information from the address detector.

According to the second means, as in the first means, the innermost radius and the track pitch at the time of recording / reproduction peculiar to the storage medium, and the storage medium attached to the rotary shaft of the spindle motor are used. The linear velocity can be accurately detected from the rotation information and the radius information of each.

According to the third means, as in the first means, the linear velocity and track pitch at the time of recording / reproduction peculiar to the storage medium, and the innermost radius from the position of the optical head are accurately measured. Can be detected.

According to the fourth means, the linear velocity at the time of recording / reproducing peculiar to the storage medium, the innermost radius, and the track pitch from the position of the optical head can be accurately measured as in the first means. Can be detected.

As described above, the number of seek tracks can be accurately calculated from the linear velocity, the innermost radius and the track pitch accurately detected by each means, and the number of seek retries can be reduced to reach the target address. It is possible to shorten the access time until the start.

[0021]

1 is a block diagram showing the configuration of an optical disk device according to a first embodiment of the present invention. In FIG. 1, 1 is an optical disk as a storage medium, 2 is a spindle motor that rotates the optical disk 1, 3 is a spindle motor controller that controls the rotation of the spindle motor 2, and 4 is a signal on the optical disk 1. Alternatively, an optical head 5 for recording a signal on the optical disk 1 is an optical head driving device for driving the optical head 4, 6 is an address detector for detecting address information of a sector from a reproduction signal of the optical head 4, and 7 is the above A track crossing signal detector for detecting a track crossing signal from the reproduction signal of the optical head 4, 8 is a track crossing signal counter for counting the track crossing signals detected by the track crossing signal detector 7, and 9 is the track crossing signal. Counter 8, linear velocity calculation means 10, which will be described later, innermost radius calculation means 11 and track pitch calculation A controller for controlling the operations of the spindle motor controller 3 and the optical head driving device 5 based on the output from the means 12, and 10 calculates the linear velocity of the optical disk 4 from the address information detected by the address detector 6. A linear velocity calculating means, 11 is an innermost radius calculating means for calculating the innermost radius of the optical disk 4 from the address information detected by the address detector 6, and 12 is address information detected by the address detector 6. To track pitch calculating means for calculating the track pitch of the optical disk 4.

In the optical disk device of this embodiment, the target address is determined based on the address information from the address detector 6.
Based on the difference between the (sector number) and the reached address (sector number) after seek, the linear velocity calculation means 10 determines the linear velocity, the innermost radius calculation means 11 determines the innermost radius, and the track pitch calculation means 12 The track pitch is calculated respectively by. The flow of the seek algorithm in this case is shown in FIG.

The seek algorithm of this embodiment will be described below with reference to FIG. First, appropriate values are set as initial values for the linear velocity V, the innermost radius R, and the track pitch P.
(V = V ₀ , R = R ₀ , P = P ₀ ) is set (a). Next, the address of the sector where the optical head 4 is currently located is read, and the sector number (s ₁ ) is converted into the track number (t ₁ ) using (Equation ₁ ) ((s ₁ ) → ( t ₁ )) (b). Next, the target sector number (s ₂ ) is converted into the track number (t ₂ ) using (Equation 1) ((s ₂ ) → (t ₂ )) (c). At this time, the linear velocity, the innermost radius, and the track pitch also use the values given as the initial values. From the current track number (t ₁ ) and the target track number (t ₂ ), the seek track number (Δt) (Δt = | t ₂
-T ₁ |) and seek direction are set (d). Next, the number of seek tracks (Δt) is determined (e). If the number of seek tracks (Δt) is 0, the target track has been reached, and the seek is ended (f). If the seek track number (Δ
If t) is not 0, seek is executed (g). After performing the seek, in order to confirm the position of the optical head 4 after the seek, the current address is read and the sector number (s ₃ )
Then, the error address calculation (Δs = s ₂ −s ₃ ) is performed (h).

Linear velocity given as an initial value, innermost radius,
Since the track pitch is not an appropriate value, the sector number of the target address and the sector number of the reached address after seeking are different, causing an error. The linear velocity, the innermost radius, and the track pitch are changed based on the evaluation function so as to reduce the error address. For example, the following function is used as the evaluation function.

When the sector number after the seek is larger than the sector number of the target address before the seek, the linear velocity calculation means 10 decreases the linear velocity by ΔV, and the innermost radius calculation means 11 decreases the innermost radius by ΔR. Then, the track pitch calculation means 12 increases the track pitch by ΔP for correction (i). Alternatively, when the sector number after seek is smaller than the sector number of the target address before seek, the linear velocity calculation means 10 increases the linear velocity by ΔV, and the innermost radius calculation means 11 increases the innermost radius by ΔR. Decrease,
The track pitch is calculated as ΔP by the track pitch calculation means 12.
Correct by reducing only (i). When increasing or decreasing, the changes ΔV, ΔR and ΔP are proportional to the error address as in (Equation 3), (Equation 4) and (Equation 5).

[0026]

[Formula 3] ΔV = K _V · Δs

[0027]

[Formula 4] ΔR = K _R · Δs

[0028]

[Formula 5] ΔP = K _P · Δs The correction coefficients K _V , K _R , and K _P are set in advance. For example, set as follows. When (Equation 1) is transformed, (Equation 6) is obtained. Accurate linear velocity of optical disk (media) 1,
The innermost radius and the track pitch are Ve and R, respectively.
If e and Pe, the correct sector number S of the track number t
_e is given by (Equation 7). On the other hand, the errors of the linear velocity, the innermost radius and the track pitch are respectively ΔV, ΔR and ΔP.
Then, the relational expressions of (Equation 8), (Equation 9), and (Equation 10) are obtained. Here, since the direction in which the sector number increases is positive,
The linear velocity polarities are reversed.

[0029]

(Equation 6)

[0030]

(Equation 7)

[0031]

(8) V = V _e −ΔV

[0032]

## EQU9 ## R = R _e + ΔR

[0033]

[Equation 10] P = P _e + ΔP

[0034]

[Equation 11]

(Equation 6), (Equation 7), (Equation 8), (Equation 9), (Equation 10)
(11) is derived from. (Equation 11) is a relational expression indicating the influence of errors in linear velocity, innermost radius and track pitch on sector number errors. Obtain the sector number error (Δs _V ) when ΔV is maximum, the sector number error (Δs _R ) when ΔR is maximum, and the sector number error (Δs _P ) when ΔP is maximum. Aside (number 12),
As in (Equation 13) and (Equation 14), the error of the sector number is distributed in that ratio.

[0036]

(Equation 12)

[0037]

(Equation 13)

[0038]

[Equation 14]

The correction coefficient K _V obtained as described above,
The linear velocity, innermost radius, and track pitch are corrected by K _R and K _P. Using the corrected linear velocity, innermost radius, and track pitch, the target track number and the current track number are calculated again using (Equation 1), and the seek track number is set (j). A seek retry (dense seek) is executed based on the number of seek tracks. This correction operation may be performed each time a seek is performed, or may be performed only during a rough seek in which the optical head 4 is largely moved. It may also be executed when the optical disk (media) is replaced.

When this seek operation is repeated, the linear velocity, the innermost radius, and the track pitch are as shown in FIGS. 3 (a), 3 (b) and 3 (c). speed
It approaches (a), the innermost radius (b), and the track pitch (c). If the difference between the linear velocity before and after the correction, the innermost radius, and the track pitch is less than a certain threshold value, consider that the difference has converged and add an algorithm to stop the subsequent correction operation. You can also

As described above, according to this embodiment, the linear velocity, the innermost radius, and the track pitch each time the seek is repeated, the linear velocity and the innermost radius at the time of recording / reproducing peculiar to the optical disk (medium) 1. , Approaching the track pitch. Eventually, the calculated error track becomes 0, and the target track can be reached by one seek, and the access time can be shortened.

FIG. 4 is a block diagram showing the structure of an optical disk device according to the second embodiment of the present invention. In FIG. 2, blocks having the same functions as those in the first embodiment (FIG. 1) are designated by the same reference numerals, and the description thereof will be omitted. Here, 13 is a linear velocity measuring means for detecting the linear velocity from the rotation information and radius information of the optical disk attached to the rotary shaft of the spindle motor 2 instead of the linear velocity calculating means 10 of FIG.

FIG. 5 is a block diagram showing the structure of the linear velocity measuring means 13 shown in FIG. As shown in FIG. 5, the rotation speed information 131a of the optical disk 1 obtained by the rotation speed measurement device 131, which is composed of the rotation speed measurement device 131 and the linear velocity calculation means 132 and is attached to the rotation shaft of the spindle motor 2, and the optical head. The linear velocity information 132a is obtained by the linear velocity calculation means 132 from the radius information 4a where 4 is located.

That is, since the linear velocity Ve of the optical disk (medium) 1 is obtained by the linear velocity measuring means 13, according to the above (Equation 7), the unknowns are the true innermost radius Re and the true track. Since there are two pitches Pe, they can be obtained by simultaneous equations from the error addresses obtained as a result of at least two seek operations. In this way, the innermost circumference radius Re can be obtained by the innermost circumference radius calculating means 11 and the track pitch Pe can be obtained by the track pitch calculating means 12.

As described above, according to this embodiment, it is possible to obtain the linear velocity at the time of recording / reproducing, the innermost radius and the track pitch, which are peculiar to the optical disk (medium), by performing the seek operation at least twice. Since the exact number of seek tracks up to the target track can be calculated, the target track can be reached by one seek, and the access time can be shortened.

FIG. 6 is a block diagram showing the structure of an optical disk device according to the third embodiment of the present invention. In FIG. 6, blocks having the same functions as those in the first embodiment (FIG. 1) are designated by the same reference numerals and the description thereof will be omitted. Here, reference numeral 14 is an innermost radius measuring means for measuring the innermost radius of the optical disk (medium) 1 from the position of the optical head 4 instead of the innermost radius calculating means 11 of FIG.

FIG. 7 is a block diagram showing the structure of the innermost radius measuring means 14 shown in FIG. As shown in FIG. 7, a position voltage converter 141 for converting the position of the optical head 4 into a voltage and a radius calculation device 142 for obtaining the radius of the optical disk 1 from the output of the position voltage converter 141 are provided. It moves to the innermost circumference of the optical disc 1, and the position voltage converter 14 at that time
The radius calculation unit 142 converts the output of 1 into a position to obtain the innermost radius Re.

That is, since the innermost circumference radius Re of the optical disk (media) 1 is obtained by the innermost circumference radius measuring means 14, according to the above (Equation 7), the unknown number is the true linear velocity Ve.
And the true track pitch Pe becomes two, so at least 2
As a result of the seek operation of the number of times, the error addresses obtained are obtained by simultaneous equations. In this way,
The linear velocity calculation means 10 can determine the linear velocity Ve, and the track pitch calculation means 12 can determine the track pitch Pe.

As described above, according to this embodiment, it is possible to obtain the linear velocity at the time of recording / reproducing, the innermost radius and the track pitch, which are peculiar to the optical disk (medium), by performing the seek operation at least twice. Since the exact number of seek tracks up to the target track can be calculated, the target track can be reached by one seek, and the access time can be shortened.

FIG. 8 is a block diagram showing the structure of an optical disk device according to the fourth embodiment of the present invention. In FIG. 8, blocks having the same functions as those in the first embodiment (FIG. 1) are designated by the same reference numerals, and the description thereof will be omitted. Here, 15 is a track pitch measuring means for measuring the track pitch of the optical disk (medium) 1 from the position of the optical head 4 instead of the track pitch calculating means 12 of FIG.

FIG. 9 shows the track pitch measuring means shown in FIG.
FIG. 16 is a block diagram showing a configuration of 15. As shown in FIG. 9, it comprises a linear encoder 151 for detecting the position of the optical head 4 and a track pitch calculator 152 for calculating the track pitch from the output of the linear encoder 151.

That is, since the track pitch Pe of the optical disk (medium) 1 is obtained by the track pitch measuring means 15, according to the above-mentioned (Equation 7), the unknowns are the true linear velocity Ve and the true innermost circumference. Since there are two radiuses Re, at least 2
As a result of the seek operation of the number of times, the error addresses obtained are obtained by simultaneous equations. In this way,
The linear velocity calculation means 10 can determine the linear velocity Ve, and the innermost circumference radius calculation means 11 can determine the innermost circumference radius Re.

As described above, according to this embodiment, it is possible to obtain the linear velocity, the innermost radius, and the track pitch at the time of recording / reproducing, which are peculiar to the optical disk (medium), by performing the seek operation at least twice. Since the exact number of seek tracks up to the target track can be calculated, the target track can be reached by one seek, and the access time can be shortened.

[0054]

As described above, the optical disk device of the present invention can accurately detect the linear velocity, the innermost radius, and the track pitch during recording and reproduction, which are peculiar to the optical disk (medium). . As a result, the number of seek retries can be reduced, so that the access time to reach the target track can be shortened.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an optical disc device according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing the seek algorithm of FIG.

FIG. 3 is a diagram showing convergence of linear velocity, innermost radius, and track pitch of FIG.

FIG. 4 is a block diagram showing a configuration of an optical disc device according to a second embodiment of the present invention.

5 is a block diagram showing a configuration of a linear velocity measuring means shown in FIG.

FIG. 6 is a block diagram showing a configuration of an optical disc device according to a third embodiment of the present invention.

FIG. 7 is a block diagram showing the configuration of the innermost radius measuring means of FIG.

FIG. 8 is a block diagram showing a configuration of an optical disc device according to a fourth embodiment of the present invention.

9 is a block diagram showing the configuration of the track pitch measuring means in FIG.

FIG. 10 is a diagram showing seek on a medium.

[Explanation of symbols]

1 ... Optical disc (media), 2 ... Spindle motor,
3 ... Spindle motor controller, 4 ... Optical head, 5 ... Optical head drive device, 6 ... Address detector,
Reference numeral 7 ... Track crossing signal detector, 8 ... Track crossing signal counter, 9 ... Controller, 10 ... Linear velocity calculating means, 11 ... Inner circumference radius calculating means, 12 ... Track pitch calculating means, 13 ... Linear velocity measuring means, 14 ... innermost circumference radius measuring means, 15 ... track pitch measuring means, 131 ... rotation speed measuring device, 132 ... linear velocity calculating means, 141 ... position voltage converter, 142 ... radius calculating device, 151 ... linear encoder, 152 ... track Pitch calculator.

Claims (4)

[Claims] 1. A spindle motor for rotating a storage medium, a spindle motor controller for controlling the rotation of the spindle motor, an optical head for reproducing a signal on the storage medium or recording a signal on the storage medium, An optical head driving device for driving an optical head, a track crossing signal detector for detecting a track crossing signal from a reproduction signal of the optical head, and a track crossing signal for counting the track crossing signals detected by the track crossing signal detector. A counter; an address detector for detecting sector address information from the reproduction signal of the optical head; a linear velocity calculating means for calculating the linear velocity of the storage medium from the address information detected by the address detector; The innermost circumference for calculating the innermost radius of the storage medium from the address information detected by the detector Radius calculating means, track pitch calculating means for calculating the track pitch of the storage medium from the address information detected by the address detector, track crossing signal counter, linear velocity calculating means, innermost radius calculating means and track. An optical disk device comprising: a controller for controlling the operations of the spindle motor controller and the optical head drive device based on the output from the pitch calculation means. 2. A spindle motor for rotating a storage medium, a spindle motor controller for controlling rotation of the spindle motor, an optical head for reproducing a signal on the storage medium or recording a signal on the storage medium, An optical head driving device for driving an optical head, a track crossing signal detector for detecting a track crossing signal from a reproduction signal of the optical head, and a track crossing signal for counting the track crossing signals detected by the track crossing signal detector. A counter, an address detector for detecting sector address information from the reproduction signal of the optical head, and an innermost radius calculation means for calculating the innermost radius of the storage medium from the address information detected by the address detector. And the track pitch of the storage medium is calculated from the address information detected by the address detector. Track pitch calculation means to be output,
Linear velocity measuring means for measuring the linear velocity of the storage medium from the rotational speed information and radius information of the storage medium attached to the rotary shaft of the spindle motor, the track crossing signal counter, the innermost circumference radius calculating means, and the track pitch calculation. And a controller for controlling the operations of the spindle motor controller and the optical head drive device based on the outputs from the means and the linear velocity measuring means. 3. A spindle motor for rotating a storage medium, a spindle motor controller for controlling the rotation of the spindle motor, an optical head for reproducing a signal on the storage medium or recording a signal on the storage medium, An optical head driving device for driving an optical head, a track crossing signal detector for detecting a track crossing signal from a reproduction signal of the optical head, and a track crossing signal for counting the track crossing signals detected by the track crossing signal detector. A counter; an address detector for detecting sector address information from the reproduction signal of the optical head; a linear velocity calculating means for calculating the linear velocity of the storage medium from the address information detected by the address detector; The track pitch of the storage medium is calculated from the address information detected by the detector. Rack pitch calculation means, innermost circumference radius measurement means for measuring the innermost circumference radius of the storage medium from the position of the optical head, the track crossing signal counter,
An optical disk device comprising: a linear velocity calculating means, a track pitch calculating means, and a controller for controlling the operations of the spindle motor controller and the optical head driving device based on outputs from the innermost circumference radius measuring means. 4. A spindle motor for rotating a storage medium, a spindle motor controller for controlling rotation of the spindle motor, an optical head for reproducing a signal on the storage medium or recording a signal on the storage medium, An optical head driving device for driving an optical head, a track crossing signal detector for detecting a track crossing signal from a reproduction signal of the optical head, and a track crossing signal for counting the track crossing signals detected by the track crossing signal detector. A counter; an address detector for detecting sector address information from the reproduction signal of the optical head; a linear velocity calculating means for calculating the linear velocity of the storage medium from the address information detected by the address detector; The innermost circumference for calculating the innermost radius of the storage medium from the address information detected by the detector Radius calculating means, track pitch measuring means for measuring the track pitch of the storage medium from the position of the optical head, the track crossing signal counter,
An optical disk apparatus comprising: a linear velocity calculating means, an innermost radius calculating means, and a controller for controlling the operations of the spindle motor controller and the optical head driving device based on outputs from the track pitch measuring means.