CN102194484A - Method for discriminating track distance of compact disc - Google Patents

Abstract

The invention discloses a method for discriminating a track distance of a compact disc, which is applicable to a compact disc driver. The method comprises the following steps of: moving an optical pickup head to a preset position to keep the optical pickup head a preset distance away from the axis of a spindle motor; reading a data sector address on the compact disc; and discriminating the size of the track distance of the compact disc according to the size of a numerical value of the data sector address.

Description

Distinguish the method for CD-RW discsCD-RW gauge

Technical field

The present invention relates to a kind of method of distinguishing the CD-RW discsCD-RW gauge, and be particularly related to a kind of method that the rail action can be distinguished the CD-RW discsCD-RW gauge of only need once seeking.

Background technology

CD-RW discsCD-RW can be stored the lot of data data, has become medium the most widely at present, and has become necessity outfit of computer and family expenses AV device (for example sound equipment, Video Recorder) in order to the CD-ROM device of read-write CD-RW discsCD-RW.

The surface of CD-RW discsCD-RW has data-track and stores data, and data-track is shape in the shape of a spiral, from inside to outside around.Have a plurality of data segments on the data-track, each data segments has unique recognizable data segments address, and the data segments address is to be provided with in the mode of encoding with progression from inside to outside.Some traditional CD-RW discsCD-RW dwindles standard gauge to increase the memory capacity of CD-RW discsCD-RW, has optical head in the CD-ROM device and comes data on the reading of data track, please refer to Fig. 1.Fig. 1 is the synoptic diagram according to the CD-ROM device servo-drive system of prior art.Spindle motor 120 is used for rotating CD-RW discsCD-RW 110, and optical head (optical pickup head) 140 then is the data segments that is used for reading on the track.When CD-ROM device grow distance seek rail the time, can utilize sled motor 130 rotating screw bolts 150 optical head 140 to be moved to the position E of target track by current position D.

Rail numbers therebetween such as the distance between position D and the E multiply by gauge.CD-ROM device can calculate required mobile distance earlier, utilizes sled motor 130 to come flying optical head 140 then.Yet CD-RW discsCD-RW has different types, and its gauge is also incomplete same.When the displacement of calculating optical head 140,, make optical head 140 can't arrive target location E fast if use wrong gauge to cause to surpass or the not enough distance that reads.For example use the gauge of the standard CD video disc of 1.6um gauge carry out the 1.4um gauge the CD-R video disc seek the rail computing time, because the gauge of standard CD video disc is bigger, therefore can produce the long problem of displacement, therefore detecting gauge has significant effects for long apart from seeking rail.

Summary of the invention

The invention provides a kind of method of distinguishing the CD-RW discsCD-RW data orbital distance, be applicable to CD-ROM device, this method only need read the gauge size that the one point data sector address can be judged CD-RW discsCD-RW, therefore can shorten the time that CD-ROM device is detectd the siding track distance.

The present invention provides a kind of method of distinguishing the CD-RW discsCD-RW data orbital distance in addition, utilizes with reference to disk data to compare with the target video disc, can directly try to achieve the gauge size of target video disc.

The present invention proposes a kind of method of distinguishing the CD-RW discsCD-RW data orbital distance, be applicable to CD-ROM device, this CD-ROM device has spindle motor and optical head, and spindle motor is in order to rotate this CD-RW discsCD-RW, and this optical head is in order to read this CD-RW discsCD-RW.This method comprises the following steps: that at first flying optical head to predeterminated position makes the axle center of optical head and spindle motor at a distance of predeterminable range; Read the data segments address on the CD-RW discsCD-RW; Then, distinguish the gauge size of CD-RW discsCD-RW according to the numerical values recited of the data segments address of being read.

In one embodiment of the invention, said method comprises that also a comparing data sector address and a threshold value (threshold value) belong to big gauge video disc or little gauge video disc to distinguish CD-RW discsCD-RW.

In one embodiment of the invention, wherein also comprise in the step that reads this data segments address on this CD-RW discsCD-RW: detecting is striden rail speed and is striden the rail direction; And, read the data segments address on the CD-RW discsCD-RW striding rail speed less than desired value and stride the rail direction when meeting preset direction.Wherein, stride the moving direction of the track of rail direction indication CD-RW discsCD-RW with respect to read head.

In one embodiment of the invention, wherein stride rail speed and also comprise according to seeking signal or radio-frequency ripple signal detection with the step of striding the rail direction and stride rail speed and stride the rail direction according to seeking signal and radio-frequency ripple signal detection in detecting.Wherein, it should be noted that striding rail speed only needs can try to achieve according to seeking signal or radio-frequency ripple signal, striding the rail direction then needs to get via comparing seeking signal and radio-frequency ripple signal two signals.

In one embodiment of the invention, wherein above-mentioned preset direction represents that the track of CD-RW discsCD-RW moves from inside to outside with respect to read head or ecto-entad moves.

The present invention proposes a kind of method of distinguishing the CD-RW discsCD-RW data orbital distance in addition, be applicable to CD-ROM device, this CD-ROM device has spindle motor and optical head, this spindle motor is in order to rotate CD-RW discsCD-RW, this optical head is in order to read this CD-RW discsCD-RW, this method comprises the following steps: at first, the stored reference disk data, above-mentioned with reference to disk data comprise with reference to the gauge of video disc with corresponding to default address of reading distance; Then, the eccentric rail number of detecting target video disc; Flying optical head to predeterminated position to read the data segments address of target video disc; And according to data segments address, eccentric rail number and the gauge that calculates CD-RW discsCD-RW with reference to disk data.

In one embodiment of the invention, wherein comprise that in the step of the eccentric rail number that utilizes detecting target video disc the detecting optical head is default striding the rail number and reading the number of turns and stride the rail number and calculate eccentric rail number according to default of reading in the number of turns to be read.Based on above-mentioned, the present invention directly utilizes the data segments address to distinguish the gauge size of video disc, and utilizes and to stride rail speed and to stride the rail direction and select to lock rail (tracking on) position to avoid mechanism's off-axis or video disc Influence from Eccentric detecting result's correctness.The present invention does not need to read the data content of CD-RW discsCD-RW, and the address that only need read the CD-RW discsCD-RW data segments can detect the gauge size of video disc, does not avoid disk data good and cause instability.

For above-mentioned feature and advantage of the present invention can be become apparent, embodiment cited below particularly, and cooperate appended graphic being described in detail below.

Description of drawings

Fig. 1 is the synoptic diagram according to the CD-ROM device servo-drive system of prior art.

Fig. 2 is the video disc track synoptic diagram according to first embodiment of the invention.

Fig. 3 is the gauge method of discrimination process flow diagram according to the CD-RW discsCD-RW of present embodiment.

Fig. 4 is the eccentric view according to second embodiment of the invention.

Fig. 5 is the data segments address change curve according to second embodiment of the invention.

Fig. 6 is the seeking signal synoptic diagram according to second embodiment of the invention.

Fig. 7 is according to the seeking signal of second embodiment of the invention and radio-frequency ripple signal schematic representation.

Fig. 8 is the method flow diagram of distinguishing the CD-RW discsCD-RW data orbital distance according to second embodiment of the invention.

Fig. 9 is the experimental result according to second embodiment of the invention.

Figure 10 is according to the two kinds of different gauges of video disc T and video disc S of third embodiment of the invention and the test synoptic diagram of different offsets.

Figure 11 is the method flow diagram of distinguishing the CD-RW discsCD-RW data orbital distance according to second embodiment of the invention.

[main element symbol description]

11,140: optical head

12,120: spindle motor

110: CD-RW discsCD-RW

130: the sled motor

150: screw rod

420: spindle motor

440: optical head

451: track

612: signaling point

614: signaling point

620: dotted line

630: luminous point

D, E: video disc position

O: CD-RW discsCD-RW home position

P: track reference position

Q: the track of CD-RW discsCD-RW

N: rail number

D: gauge

L: the length of data segments

r ₀: the distance between position O and the P

X: read distance

K: offset

Ns, Nt: rail number

Dt, Ds: gauge

R ₀: the internal diameter parameter of video disc

S11～S13: step

S310～S380: step

S810～S895: step

Embodiment

First embodiment

Please refer to Fig. 2, Fig. 2 is the video disc track synoptic diagram according to first embodiment of the invention.O is the CD-RW discsCD-RW home position, and P is the track reference position, and Q is a track of CD-RW discsCD-RW, n be original orbit to the rail number between the track Q, d is a gauge.Distance between position O and the P is r ₀, the distance between position P and the Q can be represented by n * d.The track of CD-RW discsCD-RW is a spiral trajectory, and (data sector) is formed by connecting by a plurality of data segments.The track on Fig. 2 left side is launched into straight line can be as shown in the figure on Fig. 2 the right, and data-track is just as the data tape of being made up of rectangular data segments one by one, and the length of each data segments is l.

Each data segments has a data sector address (data sector address), and the data segments address is to be encoded in the mode of progression by CD-RW discsCD-RW inner race track to outer race track.Therefore, more littler, bigger near the data segments address of track Q near the data segments address of CD-RW discsCD-RW center of circle O.Because of gauge d is very little than the track spiral radius, so track can be similar to concentric circles one by one.Can know that by above explanation Fig. 2 left side annular area (dash area) and the right rectangular area equate, that is following equation:

Or

$\mathrm{ID}\&times;d=\frac{\mathrm{\&pi;}\&times;[{(n\&times;d+r_0)}^2-{{\mathrm{<figure-callout\; id="0"\; label="r"\; filenames="HSA00000044371000041.png"\; state="\{\{state\}\}">r</figure-callout>}}_0}^2]}{l}$

Wherein ID is certain data segments address on the video disc, if flying optical head 140 is to predeterminated position, then a n * d+r with respect to spindle motor 120 axle center ₀And r ₀Be definite value.According to the CD-RW discsCD-RW specification, general data section length l also is a definite value, and therefore by above-mentioned formula as can be seen: data segments address (ID) is inversely proportional to gauge (d), and wherein gauge (d) the little data segments address (ID) that then reads of healing is big more.Present embodiment promptly utilizes this principle, utilizes the size of data segments address (ID) to judge the gauge size of CD-RW discsCD-RW.Next, please be simultaneously with reference to Fig. 1～Fig. 3, Fig. 3 is the gauge method of discrimination process flow diagram according to the CD-RW discsCD-RW of present embodiment.

At first, optical head 140 is moved to predeterminated position, make optical head 140 and spindle motor 120 axle center, just read CD-RW discsCD-RW (step S310) with the fixed position at a distance of a predeterminable range.Carry out the focusing flow process (FCS ON) (step S320) of optical head 140 then, after focusing was finished, running spindle motor 120 was to rotate CD-RW discsCD-RW (step S330).At this moment, optical head 140 just can be locked rail (TRK ON) (step S340) and the action (step S350) of reading the data segments address of CD-RW discsCD-RW.Then, data segments address and the threshold value that is read compared, judge that whether it is greater than threshold value (step S360).If greater than threshold value, represent that then this CD-RW discsCD-RW is a little gauge CD-RW discsCD-RW (step S370); If less than threshold value, represent that then this CD-RW discsCD-RW is a big gauge CD-RW discsCD-RW (step S380).

From the above, the relation that present embodiment utilizes gauge size and data segments address to be inversely proportional to distinguishes that with the fixing distance data segments address that read of reading CD-RW discsCD-RW is to belong to big gauge CD-RW discsCD-RW or little gauge CD-RW discsCD-RW.Because the gauge of CD-RW discsCD-RW is that secundum legem is stipulated mostly, as long as therefore know that it is big gauge CD-RW discsCD-RW or little gauge CD-RW discsCD-RW, just can know its possible gauge value by inference, for example the gauge of CD is 1.6um, can classify as big gauge, if the gauge of DVCD (a kind of non-standard specification of CD) is 1.33um, can classify as little gauge.Utilization can obtain identical or close gauge to seek the rail action with the mode of gauge classification when seeking rail, quicken the speed of seeking rail thus.

Second embodiment

Under ideal state, the geometric center of CD-RW discsCD-RW and rotation center should be positioned on the same point, and when spindle motor rotation CD-RW discsCD-RW, the orbital region of CD-RW discsCD-RW can be center of circle rotation with the center of circle of CD-RW discsCD-RW.Yet, when the manufacture process of CD-RW discsCD-RW produces deviation, just can make the swing-around trajectory center of CD-RW discsCD-RW and geometric center is non-is positioned on the same point, this is called off-centre (eccentricity).When passing the video disc center axis parallel with the CD-ROM device screw rod axis parallel with the CD-ROM device screw rod with passing the object lens center when non-coincidence, we are referred to as axle (de-center) partially.Have eccentric CD-RW discsCD-RW or the inclined to one side mechanism of axle is arranged when rotated, its track has the mobile component that radially makes progress with respect to optical head.Therefore, the optical head on the fixed position can detect seeking signal, and track can move in or out with respect to optical head.In the present embodiment, promptly be at CD-RW discsCD-RW or have the explanation of the inclined to one side mechanism of axle how to distinguish the method for its CD-RW discsCD-RW gauge with eccentricity issues.

Please refer to Fig. 4, Fig. 4 is the eccentric view according to second embodiment of the invention.CD-ROM device has spindle motor 420 and optical head 440.Because CD-RW discsCD-RW has eccentric phenomena, even if therefore optical head 440 is not driven, the track 451 on the CD-RW discsCD-RW 450 still has moving radially with respect to optical head 440.As shown in Figure 4, the stationkeeping of optical head 440, because the axle center of spindle motor 420 and the center of circle of CD-RW discsCD-RW 450 are not to be positioned on the same point, therefore when spindle motor 420 rotated CD-RW discsCD-RW 450, the eccentric displacement that is caused can make track 451 move with respect to optical head 440.Concern that via the position of track 451 and optical head 440 track 451 as can be seen is subjected to the displacement situation of Influence from Eccentric, as state 1～3.

When state 1～3 expression CD-RW discsCD-RW 450 is rotated, three kinds of relative positions between track 451 and the optical head 440.With state 1, because eccentric axle center of causing the close spindle motor 420 of orbital region of optical head 440 these sides, so the orbital position that optical head 440 is read is much larger than track 451 residing positions.So the data segments address that optical head 440 is read can be greater than the data segments address at track 451 places.In state 1, the rail direction of striding that optical head 440 is detected is from inside to outside, and is represented as arrow, and just track 451 can move from inside to outside with respect to optical head 440.In other words, the data segments address that optical head 440 is detected can be more and more little, and simultaneously it is striden rail speed and also can accelerate gradually.

In state 2, optical head 440 can read track 451, and it strides the rail direction may be inside or outside.When optical head read track 451, the axle center of spindle motor 420 was close with the orbital region of both sides distance.At this moment, optical head 440 is detected, and to stride rail fastest, and then along with the data segments address that is read is more and more little, it strides rail speed can be slack-off gradually.In the time of state 3 expression displacement maximums, track 451 can move to the right side of optical head 440, and it strides rail direction ecto-entad (as shown by arrows), and promptly track can move with respect to optical head 440 ecto-entads.At this moment, track 451 is positioned at the right of optical head 440, the center of circle of the most close CD-RW discsCD-RW 450 of track that optical head 440 is read, and the address of its data segments is less.State 3 and state 1 all are to be positioned at when striding the turnover of rail direction, and it is lower that it strides rail speed, is fit to lock rail with the reading of data sector address.

Because eccentric cause, so when spindle motor 420 rotation CD-RW discsCD-RW 450, the track that optical head 440 read can change along with the relative position of CD-RW discsCD-RW 450 and become.The variation of data streams read sector address can present sinusoidal curve (Sinusoid/Sine wave), as shown in Figure 5.Fig. 5 is the data segments address change curve according to second embodiment of the invention.Fig. 5 represents the optical head 440 and the axle center of spindle motor 420 are read CD (74 minutes, 1.6um standard gauge) and two kinds of CD-RW discsCD-RW of DVCD (90 minutes, 1.33um gauge) respectively at a distance of the 30mm place data segments address, wherein movement and video disc composite eccentric amount 480um.Ordinate among Fig. 5 is represented the video disc address of reading in the 30mm place, and horizontal ordinate is represented the number of turns that video disc rotates.

Can be found out obviously that by Fig. 5 read CD or DVCD with offset on the fixed position, the change curve of the data segments address that it reads can present sinusoidal curve, each position of its curve can be corresponding to the state among above-mentioned Fig. 4 1～3.With the CD curve is example, and in the data segments address maximum that state 1 is read, stride the rail direction this moment is from inside to outside.Then, belong to state 2 at the center section of curve, stride the rail direction this moment inwardly and to stride rail speed very fast, the data segments address that is read descends gradually.Then, then be to belong to state 3 when striding the rail direction when outwards beginning to be converted to inside state, the data segments address that read this moment is lower, and it is slower to stride rail speed.In the present embodiment, promptly be to utilize state 1 or state 3 etc. to stride the slow state of rail to lock rail to make things convenient for the reading of data sector address, present embodiment is not limited to this certainly, as long as optical head 440 can accurately be locked rail.

Because eccentric distance usually can be much larger than gauge, even the therefore stationkeeping of optical head 140, the data segments address that is detected also has very significantly and changes.Under this situation, if will differentiate the gauge size of CD-RW discsCD-RW by the data segments address, except the position that needs fixed optics 140, also need to be fixed on detecting under a kind of state (as state 1～3) and could accurately distinguish big gauge CD-RW discsCD-RW or little gauge CD-RW discsCD-RW.For instance, if CD-ROM device all is that state is locked rail 1 time, the data segments address that is detected all be track 451 to the more situation of intrinsic displacement, therefore can directly judge that by its data segments address it is big gauge CD-RW discsCD-RW or little gauge CD-RW discsCD-RW.In like manner, CD-ROM device also can or be locked rail for 3 times with the detecting gauge at state 2, locks rail under the identical state and just can eliminate eccentric error and directly judge the gauge size with the data segments address so long as be in.Can find out obviously that by Fig. 5 when detecting, the data segments address of CD and DVCD differs greatly under equal state (state 1～3), but if compare the DVCD of state 1 and the CD of state 3, then both differences are little.Therefore, must under identical condition, compare and to offset eccentric influence the detecting result.

CD-ROM device can (Radio Frequency RippleSignal, RFRP) detecting be striden rail speed and is striden the rail direction, please refer to Fig. 6 and Fig. 7 via seeking signal and radio-frequency ripple signal.Fig. 6 is the seeking signal synoptic diagram according to second embodiment of the invention, and Fig. 7 is according to the seeking signal of second embodiment of the invention and radio-frequency ripple signal schematic representation.In Fig. 6, the light-beam position that luminous point 630 expression optical heads 440 are throwed on laser disc, luminous point 630 can move on CD-RW discsCD-RW along with the rotation of CD-RW discsCD-RW 450, and its luminous point is passed through track shown in dotted line 620.Optical head 440 can produce seeking signal through the video disc track time, the one-period of seeking signal represents that luminous point 630 strides across a video disc track, and wherein signaling point 612 expressions are away from the video disc track, and signaling point 614 represents that then luminous point 630 is on the video disc track.

Video disc record signal (RF) signal when optical head 440 process tracks is maximum, and the radio-frequency ripple signal is that video disc record signal envelope subtracts each other the result, whether in orbit can reflect optical head 440.When luminous point 630 is when being positioned on the track, the phase place of seeking signal and RFRP has the differences of 90 degree.Just can judge according to seeking signal or the arbitrary signal frequency of RFRP and to stride rail speed, just can judge the direction that relatively moves and utilize the leading of seeking signal and RFRP phase place or fall behind.When seeking signal took the lead the radio-frequency ripple signal, the expression track moved from inside to outside with respect to optical head 440; When seeking signal fell behind the radio-frequency ripple signal, the expression track moved with respect to optical head 440 ecto-entads.Present embodiment utilizes seeking signal or RFRP to stride the reference signal of rail speed as detecting video disc, and the higher expression of its signal frequency is striden rail speed sooner.The frequency of above-mentioned reference signal is if represent just that below desired value the relative optical head speed of video disc track is low, and the action that lock rail this moment is as the state among Fig. 41 or 3.

In the present embodiment, be that example is locked the method for detecting that rail illustrates gauge with state 3, please refer to Fig. 8.Fig. 8 is the method flow diagram of distinguishing the CD-RW discsCD-RW data orbital distance according to second embodiment of the invention.At first, make optical head 440 move to predeterminated position, allow optical head 440 and spindle motor 420 axle center, just read CD-RW discsCD-RW (step S810) with the fixed position at a distance of predeterminable range.Carry out the focusing flow process (FOCUS ON) (step S820) of optical head 440 then, after focusing was finished, running spindle motor 420 was to rotate CD-RW discsCD-RW (step S830).Then, judge whether be lower than desired value (step S840) with judgement stride rail direction whether meet preset direction, promptly track moves (step S850) with respect to the optical head ecto-entad if striding rail speed.To be lower than desired value and track be just to lock rail (step S860) and reading of data sector address steps such as (step S870) when moving with respect to the optical head ecto-entad striding rail speed.Then, data segments address and threshold value that is read compared, judge that whether it is greater than threshold value (step S880).If greater than threshold value, represent that then this CD-RW discsCD-RW is a little gauge CD-RW discsCD-RW (step S890); If less than threshold value, represent that then this CD-RW discsCD-RW is a big gauge CD-RW discsCD-RW (step S8950).

It should be noted that in above-mentioned steps S850, also can detect track and whether move from inside to outside, as state 1 with respect to optical head 440.As long as the state of the CD-RW discsCD-RW of detecting has identical test condition with employed threshold value, present embodiment is not limited.In addition, the order of step S840 and step S850 also can exchange or integrate, and present embodiment is not limited.Comprehensively above-mentioned, present embodiment promptly is to utilize to stride the rail speed video disc position corresponding with the rail direction selection that collapses with the reading of data sector address, offsets the eccentric video disc displacement difference that is caused thus.

Fig. 9 is the experimental result according to second embodiment of the invention, and the CD-RW discsCD-RW type of experiment comprises DVCD, CD, ECC140, ECC210, ECC280 and ECC DVCD.Wherein, ECC280 represents general gauge normal light video disc, and has the offset of 280um; ECC210 represents general gauge normal light video disc, and has the offset of 210um; ECC140 represents general gauge normal light video disc, and has the offset of 140um; CD represents general gauge normal light video disc; DVCD represents the CD-RW discsCD-RW that gauge is closeer; ECC DVCD represents the CD-RW discsCD-RW that gauge is closeer, and CD-RW discsCD-RW has off-centre to a certain degree.

Experimental technique is for to move on to predeterminated position with optical head 440, when under the desired value that the video disc track is setting with respect to the rail speed of striding of optical head 440 and the video disc track interiorly lock track when mobile with respect to optical head is past, read the data segments address of the CD-RW discsCD-RW when locking afterwards.Experimental result has been converted into this address data segments (Sector) number and has been unit, and for example 1 minute and 05 second: 62 data field hop count equivalences were 1*60*75+5*75+62=4937, and transverse axis is represented experiment number, and the longitudinal axis is represented the data field hop count.The data field hop count that the data segments address of being read under predeterminable range by above-mentioned several types video disc is conversed, it is big more to work as the close more then institute of video disc gauge sense data sector number as can be seen, if the big more then data field of video disc eccentric degree hop count is more little, the method if with data field hop count 3000 as threshold, if data segments numeric ratio threshold value then is greatly the video disc that gauge is dredged, otherwise, be the closeer video disc of gauge.

Comprehensively above-mentioned, present embodiment is considered the influence of video disc off-centre to the data segments address that read, is qualifications to stride the rail direction with striding rail speed, is chosen in reading of data sector address under the identical condition, and then compares with threshold value.Because the detecting condition limits, therefore can reduce eccentric to the data segments address that read influence and obtain the value of detecting more accurately, can distinguish the gauge classification of laser disc section fast, for example big gauge CD-RW discsCD-RW or little gauge CD-RW discsCD-RW.

The 3rd embodiment

Because the video disc address of being read can be subjected to gauge size and two kinds of factor affecting of video disc eccentric degree, as shown in figure 10.Figure 10 is according to the two kinds of different gauges of video disc T and video disc S of third embodiment of the invention and the test synoptic diagram of different offsets.Video disc S is the standard video disc, does not have offset, and video disc T is for having the video disc of offset K striding the rail direction.Utilize the identical distance X that reads to read video disc T and video disc S, in video disc S, the distance of shaft centers of its relative spindle motor 12 in lock rail position is from being expressed as R ₀+ Ns * Ds; In video disc T, the distance of shaft centers of its relative spindle motor 12 in lock rail position is from being expressed as R ₀+ K+Nt * Dt, wherein R ₀Distance between axle center to the inboard of orbital region of the spindle motor 12 of expression standard video disc S, Ns represents the rail number that read on the video disc S, and Ds represents the gauge of video disc S, and Nt is illustrated in the rail number that is read on the video disc T, and Dt represents the gauge of video disc T.

Because both read apart from identical, so K+Nt * Dt=Ns * Ds.Video disc S is with reference to video disc, can earlier it be write down to compare video disc T with reference to disk data, then can cancellation K parameter by calculating offset K.

Please be mentioned under the situation of not considering off-centre by aforementioned formula simultaneously with reference to Fig. 2

In addition if represent r at predeterminated position lock rail ₀+ n * d is a fixed value, will obtain ID ∝ n * (nd+2r after the arrangement of two formulas ₀), nd+2r again ₀Be fixed value, so ID and rail count n and be directly proportional, just can learn Nt.

The Nt and the address of reading are to be directly proportional under the influence of therefore eliminating off-centre, and therefore, parameter N t, K, Ns, Ds are all the known gauge Dt that just can calculate video disc T.

The account form of above-mentioned offset K then is described as follows: because the video disc with offset K when rotated, the fixed position detected stride the rail number can be along with the rotating cycle of its video disc, therefore as long as the record rotating cycle with strode the just pairing eccentric rail number of computable number offset K of rail number in that the fixed position detected.The ins and outs of calculating the eccentric rail number of offset K can not repeat them here with reference to the disclosed method of TaiWan, China patent I304582.

In other words, present embodiment can utilize one group of known reference disk data to try to achieve the gauge of unknown video disc, and said method can reduce a kind of method of distinguishing the CD-RW discsCD-RW data orbital distance, is applicable to CD-ROM device, please refer to Figure 11.Figure 11 is the method flow diagram of distinguishing the CD-RW discsCD-RW data orbital distance according to second embodiment of the invention.At first, stored reference gauge data, this with reference to the gauge data comprise with reference to the gauge of video disc S with read the address of distance (promptly with reference to the data segments address on the video disc S corresponding to default, also can calculate the number of overstepping the limit by the data segments address) (step S11), then flying optical head 11 to predeterminated position to read the data segments address (step S12) of target video disc T.Then, according to data segments address, eccentric rail number and gauge with reference to gauge data compute CD-RW discsCD-RW T.

In the present embodiment, the selection of lock rail position can be with reference to the embodiment of above-mentioned second embodiment, according to stride rail speed with stride the rail direction detect track with respect to the correspondence position of video disc to lock rail.After via exposure of the present invention, present technique field those of ordinary skill should be known its embodiment easily by inference, does not add tired stating at this.

In sum, the present invention directly utilizes the data segments address to distinguish the gauge type of CD-RW discsCD-RW, can judge the gauge size by reading the video disc one point data.Simultaneously according to striding rail speed and striding the influence when reducing mechanism's off-axis or video disc off-centre to the detecting gauge of position that the rail direction selects to lock rail, the correctness of gauge size is differentiated in the amount of variability influence that can avoid CD-ROM device mechanism or video disc to make.

Though the present invention discloses as above with embodiment; right its is not in order to limit the present invention; any person of an ordinary skill in the technical field when doing a little change and retouching, is as the criterion so protection scope of the present invention ought be looked the claim person of defining without departing from the spirit and scope of the present invention.

Claims (10)

1. a method of distinguishing the CD-RW discsCD-RW gauge is applicable to CD-ROM device, and this CD-ROM device has spindle motor and optical head, and this spindle motor is in order to rotate CD-RW discsCD-RW, and this optical head is in order to read this CD-RW discsCD-RW, and this method comprises:

Moving this optical head to predeterminated position makes the axle center of this optical head and this spindle motor at a distance of predeterminable range;

Read the data segments address on the CD-RW discsCD-RW; And

Distinguish the gauge size of this CD-RW discsCD-RW according to the numerical values recited of this data segments address, wherein relatively this data segments address and a threshold value belong to big gauge video disc or little gauge video disc to distinguish this CD-RW discsCD-RW.

2. the method for distinguishing the CD-RW discsCD-RW gauge according to claim 1 wherein also comprises in the step that reads this data segments address on this CD-RW discsCD-RW:

Detecting is striden rail speed and is striden the rail direction; And

Stride rail speed at this and stride the rail direction when meeting preset direction, read this data segments address on this CD-RW discsCD-RW less than desired value and this;

Wherein, this strides the moving direction of the track of this CD-RW discsCD-RW of rail direction indication with respect to this read head.

3. the method for distinguishing the CD-RW discsCD-RW gauge according to claim 2, wherein this strides rail speed and this step of striding the rail direction also comprises in detecting:

This strides rail speed according to seeking signal or radio-frequency ripple signal detection, and this strides the rail direction according to this seeking signal and this radio-frequency ripple signal detection.

4. the method for distinguishing the CD-RW discsCD-RW gauge according to claim 2, wherein this preset direction represents that the track of this CD-RW discsCD-RW moves from inside to outside with respect to this read head.

5. the method for distinguishing the CD-RW discsCD-RW gauge according to claim 2, wherein this preset direction represents that the track of this CD-RW discsCD-RW moves with respect to this read head ecto-entad.

6. a method of distinguishing the CD-RW discsCD-RW gauge is applicable to CD-ROM device, and this CD-ROM device has spindle motor and optical head, and this spindle motor is in order to rotate CD-RW discsCD-RW, and this optical head is in order to read this CD-RW discsCD-RW, and this method comprises:

The stored reference disk data, this comprises with reference to the gauge of video disc and corresponding to default address of reading distance with reference to disk data;

The eccentric rail number of detecting target video disc;

Move this optical head to this predeterminated position to read the data segments address of this target video disc; And

According to this data segments address, this off-centre rail number and the gauge that calculates this CD-RW discsCD-RW with reference to disk data.

7. the method for distinguishing the CD-RW discsCD-RW gauge according to claim 6, wherein the step at this off-centre rail number of detecting this target video disc comprises:

Detect this optical head default read in the number of turns to be read stride the rail number; And

Stride the rail number and calculate this off-centre rail number according to this default number of turns and this of reading.

8. the method for distinguishing the CD-RW discsCD-RW gauge according to claim 6 wherein also comprises in the step that reads this data segments address on this CD-RW discsCD-RW:

Detecting is striden rail speed and is striden the rail direction; And

Stride rail speed at this and stride the rail direction when meeting preset direction, read this data segments address on this target video disc less than desired value and this;

Wherein, this strides the moving direction of the track of this CD-RW discsCD-RW of rail direction indication with respect to this read head.

9. the method for distinguishing the CD-RW discsCD-RW gauge according to claim 8, wherein this strides rail speed and this step of striding the rail direction also comprises in detecting:

This strides rail speed according to seeking signal or radio-frequency ripple signal detection, and this strides the rail direction according to this seeking signal and this radio-frequency ripple signal detection.

10. the method for distinguishing the CD-RW discsCD-RW gauge according to claim 8, wherein this preset direction represents that the track of this CD-RW discsCD-RW moves from inside to outside with respect to this read head or moves with respect to this read head ecto-entad.

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