CN100367367C - Method for judging the type of digital versatile disc - Google Patents

Abstract

The present invention relates to a method for determining the type of a digital versatile disc, which is used to distinguish between two types of digital versatile discs, DVD- and DVD+. The main steps are: firstly setting relevant parameters, then reading a pan-wobble signal from a digital versatile disc, then reading the maximum duration value and the minimum duration value of the pan-wobble signal or the wobble signal, and obtaining the peak-to-peak voltage value. Finally, if the peak-to-peak voltage value is greater than a preset critical value, the type of the digital versatile disc is determined to be DVD-, otherwise the type of the digital versatile disc is determined to be DVD+.

Description

Method for judging the type of digital versatile disc

technical field

The present invention relates to a method for judging the type of a digital versatile disc, and in particular to a method for distinguishing DVD- and DVD+ discs.

Background technique

Digital Versatile Disc (referred to as DVD), which has become very popular nowadays, except DVD-ROM which can only be used to read data (the following "ROM" stands for read-only memory, that is, read only memory) In addition, there are also types of data that can be burned. The DVDs that can be used for burning data are divided into two types: DVD- and DVD+ due to different specifications. At present, most of the DVD players are compatible with different specifications, so it is an important technology to determine the type of optical disc inserted by the user.

The current method is to use the position information contained in the pre-groove wobble signal (hereinafter referred to as the wobble signal) to determine the type of DVD. According to DVD specifications, DVD-ROM does not have a wobble signal, while DVD- and DVD+ have wobble signals in addition to normal tracks. Please refer to Figure 1 for its source. When the optical disc rotates in the DVD player, the read/write head 101 will slide out along the track 102 . As shown in the figure, at this time, the four areas A, B, C, and D of the photo diode IC (photodiode integrated circuit) of the read-write head 101 are arranged as shown in Figure 1, and each will sense signals of different intensities, and swing The signal is obtained according to the following formula:

G×[g1×(A+D)-g2×(B+C)]

Wherein G, g1 and g2 are adjustable gain values (gain).

DVD- and DVD+ each have a set of positioning methods that are mixed in the wobble signal, and the current position information can be obtained after being interpreted by the logical operation circuit. FIG. 2 shows the wobble signal of DVD+. The wobble signal 201 contains a plurality of phase change regions 202. After the wobble signal is interpreted by a logic circuit, position information can be obtained. As for the wobble signal of DVD-, please refer to FIG. 3 . The wobble signal 301 contains a plurality of land pre-pit 302. Similarly, the position information can be obtained through logic circuit calculation and interpretation. It can be seen from Figure 2 and Figure 3 that the wobble signals of DVD+ and DVD- are different, and the interpretation functions of the logical operation circuit are also different, so they can be used to judge the type of DVD.

FIG. 4 is a flow chart of a currently used method for determining the type of a digital versatile disc. First, step 402 will first guess that the disc inserted by the user is DVD+, so set the relevant parameters used by DVD+, and then step 404 will try to read the current location information, if the reading is successful, step 406 will determine the type of the disc for DVD+. Otherwise, the next step 408 will guess that the optical disc is DVD-, and set the relevant parameters used by DVD-, and then step 410 will try to read the current position information again, if successful, step 412 will determine the type of optical disc is DVD -, otherwise step 414 will determine that the type of the optical disc is DVD-ROM.

The disadvantage of this method is that the relevant parameters used by DVD+ and DVD- must be able to cover most of the discs, especially the discs that have been burned, the quality of the position information on them will deteriorate, and it is often easy to misjudge. Therefore, we need a method to solve this problem to reduce the misjudgment probability of DVD+ and DVD-.

Contents of the invention

The invention provides a method for judging the type of a digital multifunctional optical disc, which overcomes the shortcoming of easy misjudgment in the prior art and improves the correct judgment rate of DVD+ and DVD- discs.

One embodiment of the present invention is a method for judging the type of a digital versatile disc, the main steps of which are: first set relevant parameters, and then read a pan-wobble signal (including a wobble signals and other signals that can be read simultaneously). Here, the magnitude of the wobble signal can also be adjusted to a preset standard value. Then, read the maximum sustained value and minimum sustained value of the pan-swing signal to obtain the peak-to-peak voltage value (usually the result after converting analog to digital). Finally, if the peak-to-peak voltage value is greater than a predetermined threshold, it is determined that the type of the digital versatile disc is DVD-, otherwise it is determined that the type of the digital versatile disc is DVD+. Of course, if the peak-to-peak voltage value is zero or less than another predetermined threshold, it can be determined that the type of the digital versatile disc is DVD-ROM.

There may be another variation of the above-mentioned embodiment, after reading the pan-oscillation signal, the magnitude of the pan-oscillation signal may be adjusted to another preset standard value. Then, read the maximum sustained value and the minimum sustained value of the swing signal, so as to obtain the peak-to-peak voltage value. Finally, as in the above-mentioned embodiment, the peak-to-peak voltage value is compared with the other two preset threshold values to determine whether the type of the digital versatile disc is DVD-, DVD+, or DVD-ROM.

The method for judging the type of digital versatile disc proposed by the present invention is based on the peak-to-peak voltage value of the wobble signal or pan-wobble signal to distinguish DVD- and DVD+, which are two types of digital versatile discs, not based on the prior art. The current position information contained in the wobble signal is sufficient to overcome the shortcomings of the prior art and improve the correct judgment rate of the type of the DVD disc.

In order to make the above and other contents, features and advantages of the present invention more comprehensible, preferred embodiments will be described in detail below together with the attached drawings.

Description of drawings

Figure 1 is a schematic diagram of the source of the wobble signal.

FIG. 2 is a schematic diagram of a wobble signal of DVD+.

FIG. 3 is a schematic diagram of a DVD-wobble signal.

FIG. 4 is a flow chart of a previous method for determining the type of a DVD.

FIG. 5 is a flowchart of an embodiment of a method for determining the type of a digital versatile disc proposed by the present invention.

FIG. 6 is a flow chart of another embodiment of the method for determining the type of a digital versatile disc proposed by the present invention.

A, B, C, D: The four areas of the read/write head of the optical disc drive

101: Read/write head for DVD player

102: Tracks on a DVD disc

201: Wobble signal for DVD+

202: The phase change area contained in the wobble signal of DVD+

203: Size range and peak-to-peak voltage value of DVD+ wobble signal

204: The maximum duration of the wobble signal of DVD+

205: The minimum duration of the wobble signal of DVD+

301: DVD-wobble signal

302: Emboss preset holes included in DVD-pan wobble signal

303: Size interval of DVD-wobble signal

304: Peak-to-peak voltage value of pan-swing signal of DVD-

305: Maximum duration of pan-wobble signal of DVD-

306: Minimum sustained value of pan-wobble signal for DVD-

402: Set related parameters used by DVD+

404, 410: Have you read the current location?

406, 516: DVD+

408, 502: Set DVD-related parameters used

412, 514: DVD-

414, 520: DVD-ROM

504: Read pan swing signal

508: Read the maximum and minimum duration values

510: Obtain the peak-to-peak voltage value

512: Is the peak-to-peak voltage greater than the critical value?

518: Is the peak-to-peak voltage greater than another critical value?

Detailed ways

The key of an embodiment of the present invention is to read the pan-swing signal (including the swing signal and other signals that can be read together) and find out its maximum hold value (peak hold value) and minimum hold value (bottom hold value), Then obtain the peak-to-peak voltage value (peak-to-peakvoltage) of the pan-swing signal (for example, the gap between a maximum continuous value and an adjacent minimum continuous value, and is usually the result after converting analog to digital), And according to the size of the peak-to-peak voltage to distinguish between DVD+ and DVD- (even DVD-ROM). As for the difference between the peak-to-peak voltage values of these two DVDs, please refer to Figure 2 and Figure 3.

FIG. 2 shows a pan-wobble signal of DVD+, which only includes a wobble signal 201, and a plurality of phase change regions 202 are included in the wobble signal 201. Referring to FIG. The maximum sustained value of the wobble signal 201 is marked as 204 in the figure, and the minimum sustained value is marked as 205 in the figure. The two sustained values are the uppermost edge and the lowermost edge of the wobble signal 201 respectively, and the peak-to-peak voltage value 203 is the maximum sustained value 204 minus the minimum sustained value 205 , that is, the size range of the wobble signal 201 itself. Of course, for simplicity, the peak-to-peak voltage value 203 may be the difference between an uppermost edge and a lowermost edge adjacent to each other.

As for the DVD-pan-wobble signal shown in FIG. 3, it is more complicated. As shown in Figure 3, because the pan-wobble signal of DVD-contains a wobble signal 301 and a land pre-pit 302 attached to the wobble signal 301 at the same time, the maximum sustain value 305 is the land pre-pit at the top. The tip of the embossed preset hole, while the minimum persistence value 306 is located at the tip of the embossed preset hole below. Also because of this, the gap between the two continuous values, that is, the peak-to-peak voltage value 304 of the pan-oscillating signal, is larger than the size range 303 of the oscillating signal 301 itself (ie, the peak-to-peak voltage value of the oscillating signal 301 ). Of course, for simplicity, the peak-to-peak voltage value 304 may be the difference between an upper predetermined relief hole and a lower predetermined relief hole.

As mentioned above, the present embodiment distinguishes DVD+ and DVD- according to the magnitude difference between the peak-to-peak voltage value 203 of DVD+ and the peak-to-peak voltage value 304 or 303 of DVD-. Here, the pan-wobble signal of DVD- has embossed preset holes, while the pan-wobble signal of DVD+ has no embossed preset holes, which can make the peak-to-peak voltage values of DVD- and DVD+ significantly different, and provide A pipe to identify the type of Digital Versatile Disc. In particular, this embodiment can also adjust the size of the wobble signal in the pan-wobble signals from different digital versatile discs to a preset standard value, so as to eliminate the size difference caused by different digital versatile discs, and make the peak-to-peak The difference in voltage value is almost all due to the existence of embossed preset holes, and it is obviously easier to distinguish DVD- from DVD+ than the conventional technology.

For the detailed flow of another embodiment of the present invention, please refer to FIG. 5 . First, assume that the type of the unknown optical disc is DVD-, so step 502 will set the relevant parameters used by DVD-, and then step 504 will use the relevant parameters set in step 502 to read the pan-wobble signal from the unknown optical disc, Next step 508 is to read the maximum duration and minimum duration of the swing signal in the pan swing signal. Then, step 510 obtains the peak-to-peak voltage value of the swing signal according to the two continuous values. At this time, if the unknown optical disc is indeed DVD-, although the influence of the embossed preset hole is not considered at this time, the peak-to-peak voltage values of the wobble signals of the two are different due to the different properties of DVD- and DVD+, so By choosing an appropriate threshold, DVD- and DVD+ can still be distinguished by the peak-to-peak voltage value of the wobble signal. Therefore, step 512 will determine whether the peak-to-peak voltage value is greater than a preset critical value, if yes, step 514 will determine the type of the unknown optical disc is DVD-, otherwise step 516 will determine the type of the unknown optical disc is DVD+.

It can be seen from the above description that the method for judging the type of digital versatile disc proposed by the present invention is based on the magnitude of the peak-to-peak voltage value of the wobble signal to distinguish between DVD- and DVD+, which are two types of digital versatile discs, not based on the prior art. The current position information contained in the wobble signal is sufficient to overcome the shortcomings of the prior art and improve the correct judgment rate of the DVD disc type.

And further, utilizing the feature that DVD-ROM has no wobble signal, that is, the size and amplitude of its wobble signal is zero, another embodiment of the present invention can also modify the flow chart of FIG. 5 to that shown in FIG. After the peak-to-peak voltage value is less than the first critical value, it is not judged to be DVD+ immediately, but whether the judgment peak-to-peak voltage value in step 518 is greater than the second critical value (less than the first critical value and can be driven closer to zero, such as 0.03 volts), if it is not less than, it is judged as DVD+, and if it is less than, it is convenient for step 520 to judge as DVD-ROM.

In the above-mentioned embodiment, before step 508 to read the maximum and minimum duration values of the wobble signal, the size of the entire pan-wobble signal can be adjusted to a preset standard value, so as to eliminate the size caused by different digital discs. difference.

In the above-mentioned embodiment, the disc type is judged by the peak-to-peak voltage value of the wobble signal, but in another embodiment of the present invention, the judgment is made by the peak-to-peak voltage value of the entire pan-wobble signal. The flow of this embodiment can be illustrated by using FIG. 6 , except that what is read in step 508 is the maximum sustained value and the minimum sustained value of the entire pan-oscillation signal, and what is obtained in step 510 is the peak-to-peak voltage value of the entire pan-oscillation signal. . Next, as shown in FIG. 6 , the peak-to-peak voltage value is compared with the two preset critical values to determine whether the type of the digital versatile disc is DVD-, DVD+, or DVD-ROM. However, the two preset thresholds in this embodiment are not necessarily the same as those used in the previous embodiment. Moreover, before step 508 reads the maximum and minimum duration values of the entire pan-wobble signal, the size of the wobble signal in the pan-wobble signal can also be adjusted to a preset standard value, so as to eliminate the difference caused by different digital discs. size difference. The preset standard value here is not necessarily the same as that used in the previous embodiment.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, this The scope of protection of the invention shall be defined by the scope of the appended patent application.

Claims (13)

1. a method for determining type of digital versatile disc is characterized in that it comprises the following steps:

(a) receive a general swinging signal, this general swinging signal comprises a swinging signal at least, and can be included in the signal that can be read in the lump when this digital versatile disc reads this swinging signal again;

(b) this general swinging signal is tried to achieve a peak to the peak magnitude of voltage certainly; And

(c) if this peak to the peak magnitude of voltage greater than one first preset critical, the kind of then judging this digital versatile disc is DVD-, otherwise the kind of judging this digital versatile disc is DVD+, and if this peak to the peak magnitude of voltage less than one second preset critical, the kind of then judging this digital versatile disc is DVD-ROM.

2. method according to claim 1, it is characterized in that wherein said peak to the peak magnitude of voltage for the peak of this general swinging signal to the peak magnitude of voltage.

3. method according to claim 2 is characterized in that it more is included in step (a) afterwards and between the step (b), carries out step (d):

Adjust size to the preset standard value of this swinging signal.

4. method according to claim 3, it is characterized in that in above-mentioned steps (d) can also be with this other signal in general swinging signal according to the resize ratio of this swinging signal, equal proportion adjustment.

5. method according to claim 2 is characterized in that wherein step (b) more comprises:

Read a maximum persistent value and a minimum persistent value of this general swinging signal; And

According to the gap between this maximum persistent value and this minimum persistent value, the peak of trying to achieve this general swinging signal is to the peak magnitude of voltage.

6. method according to claim 2 is characterized in that when this digital versatile disc is DVD-, and this peak is to preset difference mutually between the hole for a default hole of the top burr in this general swinging signal and an adjacent below burr to the peak magnitude of voltage.

7. method according to claim 1, it is characterized in that wherein said peak to the peak magnitude of voltage for the peak of this swinging signal to the peak magnitude of voltage.

8. method according to claim 7 is characterized in that it more is included in step (a) afterwards and between the step (b), carries out step (d):

Adjust size to the preset standard value of this general swinging signal.

9. method according to claim 7 is characterized in that wherein said step (b) more comprises:

Read a maximum persistent value and a minimum persistent value of this swinging signal; And

According to the gap between this maximum persistent value and this minimum persistent value, the peak of trying to achieve this swinging signal is to the peak magnitude of voltage.

10. method according to claim 7 is characterized in that when this digital versatile disc is DVD-, and this peak is to be the difference mutually between upper limb in this swinging signal and the adjacent lower edge to the peak magnitude of voltage.

11. method according to claim 1 is characterized in that when this digital versatile disc is DVD+, this peak is to be the difference mutually between upper limb in this swinging signal and the adjacent lower edge to the peak magnitude of voltage.

12. method according to claim 1 is characterized in that it more is included in step (a) before, carries out step (e) earlier:

Set correlation parameter, to read this general swinging signal from this digital versatile disc.

13. method according to claim 12 is characterized in that wherein said step (e) more comprises:

Set the correlation parameter that DVD-uses, to read this swinging signal from this digital versatile disc.

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