JP2005302083A - Optical disk recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To exactly and promptly discriminate types of optical disks in which reflection levels are mutually approximate in an optical disk recorder. <P>SOLUTION: The optical disk recorder calculates the reflection levels at a plurality of parts of an optical disk, when its variation is smaller than a first threshold (small in #11), whether it is a DVD-R (unrecorded) or a DVD-RW (unrecorded) is determined (#12) according to the magnitude of the reflection levels. When the variation of the reflection levels is larger than a second threshold (large in #11), whether it is a DVD-ROM (single layer) or a DVD-ROM (double layer) is determined (#18) according to the magnitude of the reflection levels. When the variation of the reflection levels is above the first threshold and below the second threshold (middle in #11), whether it is a DVD-R (recorded) or a DVD-RW (recorded) is determined (#15) according to the magnitude of the reflection levels. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical disc recorder having a function of discriminating the type of optical disc.

  2. Description of the Related Art Conventionally, an optical disc recorder that records a television broadcast signal on an optical disc such as a DVD (Digital Versatile Disc) has been put into practical use. For example, in addition to DVD-ROM (Pre-Mastered Disc or Stamp Disc) that can only read data, DVD-R (Recordable) that can write data only once or DVD that can rewrite data There are multiple types such as -RW (Rewritable). Such an optical disc has a significantly different reflection level with respect to the laser beam for each type of disc. Therefore, when an optical disc is loaded, the optical disc recorder first determines the type and irradiates the laser beam with the optimum output for that type. Thus, data is written or read.

  In conventional optical disk recorders, the disc type is discriminated based on the wobble signal and the reflection level of the laser beam after adjusting the servo signal, and then the disc type is logically determined by reading the control data recorded on the optical disc. ing.

In addition to such a conventional optical disc recorder, there is known an optical disc apparatus that discriminates the type of an optical disc based on the level (pull-in level) of a signal detected by an optical pickup or the peak level of a focus error signal. (For example, refer to Patent Document 1). Also, there is known an optical disc apparatus that compares the reflection level of a loaded optical disc with the reflection level of a read-only optical disc as a reference, and discriminates the type of the optical disc (for example, see Patent Document 2).
JP 2003-217137 A JP 2001-101658 A

  However, for example, in the case of DVD-R and DVD-RW, the control data including the discriminating code and the like of the type of the optical disc is formed by aluminum embossing, so this area is equivalent to DVD-ROM (single layer) Has reflectivity. Therefore, in the above-described conventional optical disc recorder, if the servo signal is adjusted in the recorded area before reading out the control data, for example, the tracking error signal is saturated due to the drop in reflectance, resulting in the control data being There may be a problem that it cannot be read. In such a case, it is necessary to readjust the servo signal, and it takes time to determine the disk type.

  Further, in the optical disk apparatus disclosed in Patent Document 1 or Patent Document 2, since the type of the optical disk is determined based only on the reflection level, the type and recording state of the optical disk whose reflection levels are close to each other can be accurately determined. It becomes difficult.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an optical disc recorder that can accurately and quickly determine the types of optical discs whose reflection levels are close to each other.

  In order to achieve the above object, according to the first aspect of the present invention, in an optical disc recorder corresponding to a plurality of types of optical disc recording media, the recording surface of the loaded optical disc is irradiated with a laser beam a plurality of times while changing the emission intensity, and the reflection is performed. The type of optical disk loaded and the recorded or unrecorded disk from the received light and the tendency of the change in the reflection level with respect to the variation in the reflection level, the magnitude of the reflection level, and the change in the emission intensity of the laser beam It can be discriminated without controlling the rotational speed of the optical disk.

  According to a second aspect of the present invention, in an optical disc recorder corresponding to a plurality of types of optical disc recording media, the recording surface of the loaded optical disc is irradiated with laser light, the reflected light is received, and the reflection level variation and the reflection level are reduced. The type of the optical disk loaded and whether it is an already recorded disk or an unrecorded disk can be discriminated from the size.

  According to a third aspect of the present invention, in an optical disc recorder corresponding to a plurality of types of optical disc recording media, the recording surface of the loaded optical disc is irradiated with a laser beam a plurality of times while changing the emission intensity, and the reflected light is received to obtain a reflection level. Before the servo signal is adjusted to determine whether or not data is recorded on the recordable optical disk, and the adjustment target value of the servo signal is set in either the recorded area or the unrecorded area. The error signal can be changed to a level that does not saturate.

  According to a fourth aspect of the present invention, in an optical disc recorder corresponding to a plurality of types of optical disc recording media, the recording surface of the loaded optical disc is irradiated with a laser beam a plurality of times while changing the emission intensity, and the reflected light is received to obtain a reflection level. From this variation, it is determined whether or not data is recorded on a recordable optical disc without using an RF signal.

  According to the first aspect of the present invention, the type of the optical disc and the recorded disc are obtained from the variation in the reflection level on the recording surface of the optical disc, the magnitude of the reflection level, and the tendency of the change in the reflection level with respect to the change in the emission intensity of the laser beam. Therefore, even if the optical disks have similar reflection levels, the type or the like can be accurately determined. In addition, since it is not necessary to control the rotation speed of the optical disk in order to detect a wobble signal or the like, it is possible to quickly determine the type of the optical disk, and recording / playback operations can be performed after the user loads the optical disk. Can be shortened.

  According to the second aspect of the present invention, since the type of the optical disk and whether it is a recorded disk or an unrecorded disk are determined from the variation in the reflection level on the recording surface of the optical disk and the magnitude of the reflection level. The type and the like can be determined quickly and accurately.

  According to the invention of claim 3, from the variation in the reflection level on the recording surface of the optical disk, for example, it is determined before adjusting the servo signal that the loaded optical disk is a recorded DVD-R or DVD-RW. Therefore, the adjustment target value of the servo signal can be changed to a level at which the error signal is not saturated. As a result, the probability of failing to acquire control data or the like can be greatly reduced, and the time until the discriminating result of the optical disc is determined can be shortened.

  According to the fourth aspect of the present invention, it is determined from the variation in the reflection level on the recording surface of the optical disk, for example, that the loaded optical disk is a recorded DVD-R or DVD-RW without using an RF signal. Therefore, the time required for discriminating the optical disk can be shortened.

  An optical disk recorder according to the best mode for carrying out the present invention will be described with reference to the drawings. FIG. 1 shows a configuration of a DVD recorder that records a television broadcast signal on a DVD (Digital Versatile Disk) as an example of an optical disk recorder. The optical disc recorder has a back end 1 that performs processing as the entire recorder, and a front end 2 that writes data to or reads data from the optical disc.

  The back end 1 includes a tuner 3 that receives a television broadcast signal via an antenna 30, and an MPEG encoder 5 that compresses and encodes the broadcast signal received by the tuner 3 into a signal that conforms to the MPEG (Moving Picture Experts Group) standard. The buffer 6 that temporarily stores the signal compressed and encoded by the MPEG encoder 5, the MPEG decoder 7 that combines the signal stored in the buffer 6, and the monitor device 20 that outputs the signal combined by the MPEG decoder 7 A D / A converter 8 that converts the signal into a possible analog signal, a control unit 9 that controls each part of the back end 1, a remote control device (not shown) for inputting various commands to the optical disc recorder, and timer recording The timer part (not shown) etc. which perform the process for are comprised. The tuner 3 may be compatible with digital broadcasting or analog broadcasting. When the tuner 3 is compatible with analog broadcasting, an A / D converter for converting the analog signal received by the tuner 3 into a digital signal is separately required.

  On the other hand, the front end 2 has a buffer 11 that passes signals to and from the buffer 6, and an EFM (Eight) that modulates a signal (8-bit signal) accumulated in the buffer 11 into a 14-bit signal suitable for writing to the optical disc. (Fourteen Modulation) modulator 12, a spindle motor 13 for rotationally driving the optical disk, an optical pickup 14 for writing or reading a signal by irradiating the optical disk rotated by the spindle motor 13 with a laser beam, The EFM demodulator 15 that modulates the 14-bit signal read by the optical pickup 14 into an 8-bit signal, and the control unit 16 that receives control signals output from the control unit 9 and controls each part of the front end 2 are configured. ing.

  The control unit 9 of the back end 1 and the control unit 16 of the front end 2 are connected so as to be able to transmit and receive various control signals to each other. The buffer 6 of the back end 1 and the buffer 11 of the front end 2 are The MPEG encoded signals can be transmitted and received with each other.

  2 shows six types of optical disks ((1) DVD-ROM (double layer), (2) DVD-ROM (single layer), (3) DVD-RW (unrecorded), and (4) DVD). -RW (already recorded), (5) DVD-R (unrecorded), (6) DVD-R (already recorded)) when laser light is irradiated multiple times while changing the light emission power (read power) to 6 levels The relationship between the light emission power of the light emitting element of the optical pickup 14 and its reflection level is shown. The reflection level indicates the output voltage of the light receiving element of the optical pickup 14 normalized by the light emission power.

  FIG. 3 shows the average value of the standard deviation of the reflection level calculated for each of the light emission powers at each stage and the evaluation of the variation in the reflection level for the above six types of discs. According to FIGS. 2 and 3, of the six types of discs, (3) DVD-RW (unrecorded) and (5) DVD-R (unrecorded) have no pits formed on the recording surface. Further, it can be seen that the reflection level variation is small, and (5) DVD-R (unrecorded) has a particularly large reflection level compared to other discs in the region where the light emission power is small. Also, (2) DVD-ROM (single layer) has a very large variation in reflection level compared to other disks. Furthermore, (1) DVD-ROM (double layer), (2) DVD-ROM (single layer), (3) DVD-RW (unrecorded) and (4) DVD-RW (already recorded) emit light power. Increasing the value tends to increase the reflection level (particularly, (2) DVD-ROM (single layer) has a tendency for the reflection level to increase remarkably with increasing light emission power), and (5) DVD-R (unrecorded). Has a substantially constant reflection level regardless of the light emission power. (6) It can be seen that DVD-R (already recorded) tends to decrease the reflection level when the light emission power is increased. .

  In the optical disk recorder of this embodiment, paying attention to the characteristics of each type of optical disk described above, the variation and size of the reflection level are compared with a predetermined threshold value, so that the type of the loaded optical disk and the recording state are determined. I try to distinguish.

  The operation of discriminating the type of optical disc by the optical disc recorder of this embodiment will be described with reference to FIG. When the optical disc is loaded (# 1), the optical disc recorder performs chucking of the optical disc (# 2). Then, the optical disk recorder rotates the optical disk by rotating the spindle motor 13 (# 3), irradiates laser light from the optical pickup 14 at a plurality of locations while changing the light emission power, receives the reflected light, and receives the electric signal. The reflection level is calculated (# 4), and the process shown in FIG. 5 described later is executed to determine the type of the optical disk (# 5). The calculation of the reflection level (# 4) and the discrimination of the optical disk (# 5) are performed by the control unit 9 or the control unit 16.

  When the optical disk is discriminated, the final target value used when adjusting the servo signal is changed based on the discriminating result (# 6), and the servo signal is adjusted according to the target value (# 7). Here, the servo signal to be adjusted is, for example, a focus error signal, a focus gain signal, a tracking error signal, a tracking gain signal, an RF gain signal, a wobble signal, or the like. By adjusting these servo signals to a level that does not saturate the error signal, the control data can be read normally (# 8). The control data is acquired by reading pits formed in the control data zone on the innermost circumference of the disc. The pits for recording the control data are usually formed by aluminum embossing at the time of manufacturing the optical disc. Therefore, if the servo signal is adjusted normally, the unrecorded DVD-R and DVD-RW can be used normally. Can be read. Thus, when the control data is successfully acquired (YES in # 9), the discriminating result of the optical disc in # 5 is confirmed based on the discriminating code regarding the optical disc type included in the control data. If the surface of the optical disk is dirty or scratched, there is a possibility that it cannot be accurately determined only by the determination in # 5. Therefore, the type of the optical disk is confirmed using the discrimination based on the discrimination code. If the discrimination result based on the reflection level in # 5 and the discrimination result based on the discrimination code included in the control data in # 8 and 9 match, it is determined that the discrimination of the optical disk is successful (YES in # 10). The process ends. If they do not match and it is determined that the determination of the optical disk has failed (NO in # 10), the process returns to # 4 and the reflection level is calculated again. Also, as described above, the pits for recording the control data are formed with aluminum embossing, so the reflectivity is high, and the pits cannot be read normally depending on the adjustment of the servo signal in # 7. (No in # 8). Thus, even if acquisition of control data fails, the process returns to # 4 and the reflection level is calculated again. If the loaded optical disc is a DVD-R (unrecorded) or DVD-RW (unrecorded), the power is adjusted to a level at which the RF signal can be read during OPC (Optimum Power Control), so writing must fail. Basically, it is at a level that can be read without problems.

  Next, an optical disc discrimination process will be described with reference to FIG. When the variation in the reflection level calculated in # 4 is smaller than a predetermined threshold (first threshold) (small in # 11), it is determined that no pit is formed on the loaded optical disk, and # 12 When the variation in the reflection level is larger than the predetermined threshold (second threshold) (large in # 11), the process proceeds to # 18. Furthermore, when the reflection level variation is not less than the first threshold value and not more than the second threshold value (middle in # 11), the process proceeds to # 15. In # 12, # 15, and # 18, as described later, the reflection level is compared with a threshold value determined in each step.

  First, in # 12, when the reflection level is greater than a predetermined threshold (third threshold) (large in # 12), the optical disc recorder is (5) DVD-R (unrecorded). (# 13), and when the reflection level is equal to or lower than a predetermined threshold (third threshold) (small in # 12), the optical disc recorder is (3) DVD-RW (unrecorded). (# 14).

  If the reflection level is greater than the predetermined threshold value (fourth threshold value) in # 15 (large in # 15), the optical disc recorder is (6) DVD-R (already recorded). (# 16), and when the reflection level is equal to or lower than the fourth threshold value (small in # 15), the optical disk recorder determines that the loaded optical disk is (4) DVD-RW (already recorded). (# 17).

  In # 18, when the reflection level is greater than a predetermined threshold (fifth threshold) (large in # 18), the optical disc recorder is (2) a DVD-ROM (single layer). (# 19), and when the reflection level is equal to or lower than the fifth threshold value (small in # 18), the optical disk recorder determines that the loaded optical disk is (1) DVD-ROM (two layers). (# 20). The first to fifth thresholds may be set as appropriate so that each optical disc can be determined by irradiating various optical discs with laser light and calculating variations and levels of reflection levels.

  In the optical disk recorder of the present embodiment, when discriminating the type of the optical disk based on the above-described dispersion of the reflection level and the size of the reflection level, the tendency of the change in the reflection level with respect to the change in the emission intensity of the laser light is investigated. The type of the optical disc is confirmed from the above. That is, when the reflection level is substantially constant without depending on the light emission power, the loaded optical disk is (5) DVD-R (unrecorded), and when the light emission power is increased, the reflection level decreases. The recorded optical disk is (6) DVD-R (already recorded). When the light emission power is increased, the reflection level also increases. The loaded optical disk is (1) DVD-ROM (two layers), (2 ) DVD-ROM (single layer), (3) DVD-RW (unrecorded), and (4) DVD-RW (recorded). Further, when the tendency of the reflection level to increase is remarkable, it is determined that the loaded optical disk is (2) DVD-ROM (single layer).

  As described above, according to the optical disc recorder of the present embodiment, the type of optical disc and whether it is a recorded disc or an unrecorded disc can be determined from the variation in reflection level on the recording surface of the optical disc and the magnitude of the reflection level. Therefore, even if the optical disks have similar reflection levels, the type and the like can be accurately determined. In addition, since the tendency of the change in the reflection level with respect to the change in the emission intensity of the laser light is investigated and the type of the optical disk is confirmed based on the result, the type of the optical disk is more accurately determined. It can be. Further, since it is not necessary to control the rotational speed of the disc in order to detect a wobble signal or the like, it is possible to quickly determine the type of the optical disc and the like, and recording / playback operations can be performed after the user has loaded the optical disc. Can be shortened.

  In addition, before adjusting the servo signal, it is possible to determine the type of the loaded optical disk and whether it is a recorded disk or an unrecorded disk from the variation in the reflection level on the recording surface of the optical disk. Can be changed to a level at which the error signal does not saturate. As a result, the probability of failure in acquiring control data or the like (corresponding to NO in # 9) can be greatly reduced, and the time until the discriminating result of the optical disc is determined can be shortened. In addition, since the type of the loaded optical disc is discriminated without using the RF signal, the time required for discriminating the optical disc can be shortened.

  The present invention is not limited to the configuration of the above embodiment, and various modifications can be made. For example, the disc for discriminating the type and the like is not limited to the above-described six types of optical discs, but can be widely applied to various CDs (Compact Disks) and next-generation optical discs as well as DVD + RW.

1 is a block diagram of an optical disc recorder according to an embodiment of the present invention. The figure which showed distribution of the reflection level when a laser beam is irradiated to various optical disks while changing the light emission power. The figure which showed the standard deviation and dispersion | variation evaluation of the reflection level of various optical disks. The flowchart which shows operation | movement of the recorder when an optical disk is loaded. The flowchart which shows the operation | movement of the recorder when discriminating the kind of optical disk.

Explanation of symbols

3 Tuner 5 Encoder 6 Buffer 9 Control Unit 13 Spindle Motor 14 Optical Pickup 16 Control Unit

Claims (4)

In an optical disc recorder that supports multiple types of optical disc recording media,
The recording surface of the loaded optical disk is irradiated with laser light multiple times while changing the light emission intensity, and the reflected light is received, and the reflection level variation, the size of the reflection level, and the reflection level with respect to the laser light emission intensity An optical disc recorder characterized by being able to determine the type of an optical disc loaded and whether it is an already recorded disc or an unrecorded disc without controlling the number of revolutions of the optical disc from the tendency of change. In an optical disc recorder that supports multiple types of optical disc recording media,
The recording surface of the loaded optical disk is irradiated with laser light, and the reflected light is received. The type of the loaded optical disk and the recorded disk are recorded or not recorded based on the variation in the reflection level and the size of the reflection level. An optical disc recorder characterized in that it can be discriminated whether it is a disc or not. In an optical disc recorder that supports multiple types of optical disc recording media,
The recording surface of the loaded optical disk is irradiated with laser light multiple times while changing the light emission intensity, and the reflected light is received to determine whether data is recorded on the recordable optical disk from the variation in the reflection level. Before adjusting the signal,
An optical disc recorder characterized in that an adjustment target value of a servo signal can be changed to a level at which an error signal is not saturated in any of a recorded area and an unrecorded area. In an optical disc recorder that supports multiple types of optical disc recording media,
The recording surface of the loaded optical disc is irradiated with laser light a plurality of times while changing the emission intensity, the reflected light is received, and whether or not data is recorded on the recordable optical disc from the variation in the reflection level is determined by RF An optical disc recorder characterized by discriminating without using a signal.

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