JP4264540B2 - Reproducing circuit and optical disc reproducing apparatus having the same circuit - Google Patents

Description

  The present invention relates to a reproducing circuit and an optical disk reproducing apparatus having the same circuit.

  In recent years, optical disks have been widely used as large-capacity recording media capable of recording a large amount of information.

  Information recorded on the optical disc is reproduced by processing an input signal read from the optical disc using an optical disc reproducing apparatus by a signal processing circuit.

  At that time, the optical disk reproducing device generates various control signals such as a tracking control signal and a focus control signal from the input signal read from the data recording area on the optical disk, and detects a defect signal indicating a defect on the optical disk. The inside of the optical disk playback apparatus is controlled based on these control signals and defect signals (see, for example, Patent Document 1).

  In addition to the above-described data recording area for recording normal data, the optical disk has an area called a burst cutting area (BCA) for recording data for identifying individual optical disk media as a center hole. In this BCA, barcode data obtained by encoding PE-modulated (Phase Encoding) data by the RZ (Return to Zero) method is recorded (see, for example, Patent Document 2). ).

In a conventional optical disk reproducing apparatus, a defect signal generation circuit for generating a defect signal using an input signal read from a data recording area on the optical disk, and an input signal read from a burst cutting area on the optical disk A burst cutting area signal generation circuit for generating a burst cutting area signal by using each of them separately has been provided.
JP 2000-90446 A JP 2002-197665 A

  However, since the conventional optical disc playback apparatus has the defect signal generation circuit and the burst cutting area signal generation circuit separately and independently, the circuit scale inside the apparatus becomes large, and accordingly, the optical disc playback apparatus The labor, time, and cost required for manufacturing the product increased.

Therefore, in the present invention according to claim 1, in the reproduction circuit for reproducing the information recorded on the recording medium , the first analog signal read from the data recording area on the recording medium and the burst cutting area are read. a single variable a / D converter for converting the first and second digital signal at a second different sampling rates and analog signal I, a defect signal the first digital signal as an input signal produced, and the second digital signal as an input signal to have a single signal generation circuit for generating a burst cutting area signal.

Also, in the present invention according to claim 2, in the present invention according to claim 1, the variable A / D converter circuit supplies the first and second analog signals to the A / D converter circuit. In addition to being connected through two switches, the first and second switches are controlled by a control circuit that is intermittent at different sampling rates .

According to the third aspect of the present invention, in the optical disc reproducing apparatus having a reproducing circuit for reproducing the information recorded on the optical disc, the reproducing circuit reads the first analog read from the data recording area on the optical disc. A single variable A / D converter circuit for converting the signal and the second analog signal read from the burst cutting area into first and second digital signals at different sampling rates, and the first digital signal It generates a defect signal a signal as an input signal, and to have a a single signal generation circuit for generating a burst cutting area signal and the second digital signal as an input signal.

Also, in the present invention according to claim 4, in the present invention according to claim 3, the variable A / D converter circuit supplies the first and second analog signals to the A / D converter circuit. In addition to being connected through two switches, the first and second switches are controlled by a control circuit that is intermittent at different sampling rates .

  And in this invention, there exists an effect described below.

That is, in the present invention according to claim 1, in the reproduction circuit for reproducing the information recorded on the recording medium , the first analog signal read from the data recording area on the recording medium and the burst cutting area are read. a single variable a / D converter for converting the first and second digital signal at a second different sampling rates and analog signal I, a defect signal the first digital signal as an input signal generated, because you have to have a single signal generation circuit for generating a burst cutting area signal the second digital signal as an input signal, circuitry for generating a defect signal and the burst cutting area signal It is not necessary to provide a separate circuit for generating the circuit, and these circuits can be configured as a single circuit. Since wear, it is possible to reduce the circuit scale of the reproduction circuit for generating a defect signal and a burst cutting area signal.

In the present invention according to claim 2, the variable A / D converter circuit is connected to the A / D converter circuit via the first and second switches, and the first and second analog signals are connected to the A / D converter circuit. Since the first and second switches are configured to be controlled by a control circuit that is intermittent at different sampling rates, the circuit scale of the variable A / D conversion circuit can be reduced, so that the defect signal and burst cutting can be reduced. The circuit scale of the reproduction circuit that generates the region signal can be further reduced.

According to the third aspect of the present invention, in the optical disc reproducing apparatus having a reproducing circuit for reproducing the information recorded on the optical disc, the reproducing circuit reads the first analog read from the data recording area on the optical disc. A single variable A / D converter circuit for converting the signal and the second analog signal read from the burst cutting area into first and second digital signals at different sampling rates, and the first digital signal In order to generate a defect signal because it has a single signal generation circuit for generating a defect signal using the signal as an input signal and generating a burst cutting region signal using the second digital signal as an input signal It is not necessary to provide a separate circuit and a circuit for generating a burst cutting area signal separately. Since these circuits can be constituted by a single circuit, the circuit scale of the reproducing circuit for generating the defect signal and the burst cutting area signal can be reduced, and thereby the labor required for manufacturing the optical disc reproducing apparatus. And time and cost can be reduced.

In the present invention according to claim 4, the variable A / D converter circuit is connected to the A / D converter circuit via the first and second switches, and the first and second analog signals are connected to the A / D converter circuit. Since the first and second switches are configured to be controlled by a control circuit that is intermittent at different sampling rates, the circuit scale of the variable A / D conversion circuit can be reduced, so that the defect signal and burst cutting can be reduced. The circuit scale of the reproduction circuit that generates the region signal can be further reduced.

  An optical disc recording / reproducing apparatus according to the present invention incorporates a reproducing circuit for reproducing information recorded on an optical disc as a recording medium.

  This reproduction circuit has a single variable A / D conversion circuit and a single signal generation circuit.

  Here, the variable A / D conversion circuit converts the first and second analog signals read from the different first and second recording areas on the recording medium to the first and second digital signals at different sampling rates, respectively. It is a circuit for converting to.

  The variable A / D conversion circuit connects the first and second analog signals to the A / D conversion circuit via the first and second switches, and connects the first and second switches to different sampling rates. It can be configured to control with an intermittent control circuit.

  The signal generation circuit is a circuit for generating different first or second reproduction signals by using the first or second digital signal as an input signal.

  The signal generation circuit includes first and second signal detection circuits having different followability with respect to the input signal when the digital signal that is the input signal rises and falls, and the first and second signal detection circuits. The reproduction signal can be generated by comparing the first and second detection signals detected in step (b).

  For example, the signal generation circuit uses a first peak hold circuit that has high (fast) followability to an input signal as the first signal detection circuit, and low (slow) followability to the input signal as the second signal detection circuit. ) A configuration using a second peak hold circuit may be used, and the signal generation circuit, as the first signal detection circuit, is a first peak hold circuit having high (fast) followability to the input signal, and the input signal. A first bottom hold circuit that has a high (fast) follow-up performance with respect to a first difference circuit that detects a difference between a detection signal from the first peak hold circuit and a detection signal from the first bottom hold circuit. On the other hand, as the second signal detection circuit, a second peak hold circuit having low (slow) tracking ability with respect to the input signal, and a second peak holding circuit having low (slow) tracking ability with respect to the input signal. And Tom hold circuit may be configured to have a second differential circuit for detecting a difference between the detected signal of the detection signal and the second bottom hold circuit in the second peak hold circuit.

  Examples of the first and second recording areas include a data recording area and a burst cutting area. That is, the first recording area is a data recording area, the second recording area is a burst cutting area, the defect signal is reproduced as the first reproduction signal, and the burst cutting area signal is reproduced as the second reproduction signal. Can be played.

  As described above, in the reproducing circuit for reproducing the information recorded on the recording medium, the first and second analog signals read from the different first and second recording areas on the recording medium are sampled at different sampling rates. A single variable A / D conversion circuit for converting the first and second digital signals into the first and second digital signals and the first or second digital signal as input signals to generate different first and second reproduction signals, respectively. In the case of having a single signal generation circuit for performing the above, it is necessary to separately provide a circuit for generating the first reproduction signal and a circuit for generating the second reproduction signal. Since these circuits can be configured as a single circuit, the circuit scale of the reproduction circuit for generating the first and second reproduction signals can be reduced, and thereby the light with the built-in reproduction circuit can be reduced. Di It is possible to reduce labor and time and cost required for manufacturing the click reproducing apparatus.

  In particular, the defect recording is reproduced as the first reproduction signal by setting the first recording area as the data recording area, and the burst cutting area as the second reproduction signal by setting the second recording area as the burst cutting area. When the signal is reproduced, it is not necessary to provide the defect signal generation circuit and the burst cutting area signal generation circuit separately, and these circuits can be constituted by a single circuit. In addition, the circuit scale of the reproducing circuit that generates the burst cutting area signal can be reduced.

  In addition, the variable A / D conversion circuit is connected to the A / D conversion circuit via the first and second switches, and the first and second switches are connected to different sampling points. If the control circuit is configured to be controlled by a rate intermittent control circuit, the circuit scale of the variable A / D conversion circuit can be reduced. Therefore, the reproduction circuit that generates the first and second reproduction signals. The circuit scale can be further reduced.

  In addition, the signal generation circuit has first and second signal detection circuits that have different followability to the input signal when the input signal rises and falls, and is detected by the first and second signal detection circuits. When the reproduction signal is generated by comparing the first and second detection signals, it is possible that an erroneous defect signal is generated as a reproduction signal even if a bright defect occurs during reproduction. Can be prevented.

  In particular, the first peak hold circuit having high followability to the input signal is used as the first signal detection circuit, and the second peak hold circuit having low followability to the input signal is used as the second signal detection circuit. In this case, it is possible to prevent an erroneous defect signal from being generated as a reproduction signal even if a bright defect occurs during reproduction, even though it is a simple circuit. It is possible to prevent malfunction of the apparatus.

  In addition, as the first signal detection circuit, a first peak hold circuit having high followability to the input signal, a first bottom hold circuit having high followability to the input signal, and a detection signal in the first peak hold circuit And a first difference circuit that detects a difference between the detection signal in the first bottom hold circuit and a second peak hold circuit that has low followability to the input signal as the second signal detection circuit. Circuit, a second bottom hold circuit having low followability with respect to an input signal, and a second difference circuit for detecting a difference between a detection signal in the second peak hold circuit and a detection signal in the second bottom hold circuit If it is determined that the defect signal, which is a reproduction signal, is accurately generated for dark defects, interruptions, and bright defects that may occur during reproduction. Kill.

  Hereinafter, a specific configuration of the reproducing circuit according to the present invention will be described with reference to the drawings. The reproducing circuit according to the present invention can be applied to various electronic devices that reproduce information recorded on a recording medium represented by an optical disc reproducing device, an optical disc recording / reproducing device, or the like.

  As shown in FIG. 1, the reproducing circuit 1 according to the present invention includes a single variable A / D conversion circuit 2 and a single signal generation circuit 3.

  The variable A / D conversion circuit 2 reads the first and second analog signals S1 and S2 read from the different first and second recording areas 5 and 6 of the recording medium 4 shown in FIG. 2 at different sampling rates. This is a circuit for converting into first and second digital signals S3 and S4.

  Here, as shown in FIG. 2, the first recording area 5 is a data recording area in which normal data written in the recording medium 4 is recorded, while the second recording area 6 is In addition, an area called a burst cutting area (BCA) for recording data for identifying individual recording media 4 provided separately from a data recording area for recording normal data is used. The burst cutting area is formed concentrically around the center hole 7 of the recording medium 4, and is barcode data obtained by encoding PE modulated (Phase Encoding) data using the RZ (Return to Zero) method. It is recorded as.

  In addition, the signal generation circuit 3 uses the first or second digital signals S3 and S4 generated by the variable A / D conversion circuit 2 as input signals to generate different first or second reproduction signals S5 and S6, respectively. Circuit.

  Hereinafter, specific configurations of the variable A / D conversion circuit 2 and the signal generation circuit 3 will be described.

  First, the configuration of the variable A / D conversion circuit 2 will be described. As shown in FIG. 3, the variable A / D conversion circuit 2 is connected to the analog input section of the 1-input 1-output type A / D conversion circuit 8 in the channel 0. The input terminal 9 is connected via the first switch 10, and the channel 1 input terminal 11 to the channel 8 input terminal 18 are connected to the same analog input section via the second switch 19 and the switches 20 to 27 provided for each channel. Connected.

  In the variable A / D conversion circuit 2, the channel 0 output terminal 28 to the channel 8 output terminal 36 are connected to the digital output unit of the A / D conversion circuit 8 through switches 37 to 45 and registers 46 to 54. .

  Further, in the variable A / D conversion circuit 2, a control circuit 55 is connected to the A / D conversion circuit 8 and all the switches 10, 19 to 27, 37 to 45.

  The variable A / D conversion circuit 2 has nine channels to improve versatility, and inputs the first analog signal S1 to the channel 0 input terminal 9 and the first to the channel 1 input terminal 11. The second analog signal S2 is input, the first digital signal S3 is output from the channel 0 output terminal 28, and the second digital signal S4 is output from the channel 1 output terminal 29.

  The control circuit 55 generates various control signals synchronized with the system clock signal S7 to control the A / D conversion circuit 8 and the switches 10, 19 to 27, 37 to 45. Here, the control signal generated by the control circuit 55 includes an A / D clock signal S8 for driving the A / D conversion circuit 8, and a start flag signal S9 for starting the conversion in the A / D conversion circuit 8. There are switch control signals S10 to S28 for intermittently controlling the switches 10, 19 to 27, 37 to 45, and write enable signals S29 to S37 for writing data to the registers 46 to 54.

  Further, the control circuit 55 has a built-in register, and as shown in FIG. 4, various control signals are generated at a predetermined timing according to the value stored in the register.

  For example, when the binary number “000” is stored in the register, the first analog signal S1 input to the channel 0 input terminal 9 is A / D converted at a sampling rate of 2.112 MHz, and is stored in the register 46. The first digital signal S3 is output from the channel 0 output terminal 28 while being stored, while the second analog signal S2 and the like input to the channel 1 input terminal 11 to the channel 8 input terminal 18 is A at a sampling rate of 132 kHz. / D converted and stored in the registers 47 to 54, and the second digital signal S4 and the like are output from the channel 1 output terminal 29 to the channel 8 output terminal 36.

  Then, as shown in FIG. 5, the variable A / D conversion circuit 2 performs A / D conversion at the rise of the start flag signal S9, and stores data in the registers 46 to 54 at the rise of the write enable signals S29 to S37. At the same time, the signal is output from the channel 0 output terminal 28 to the channel 8 output terminal 36.

  Next, the configuration of the signal generation circuit 3 will be described. As shown in FIG. 6, the signal generation circuit 3 includes a first peak hold circuit 56, a second peak hold circuit 57, a level adjustment circuit 58, and a comparator circuit 59. It consists of and.

  The first peak hold circuit 56 has a high followability with respect to the input signal S38 (the first digital signal S3 or the second digital signal S4), that is, both when the input signal S38 rises and when it falls. It has a circuit configuration capable of following the change of S38 in a short time, and outputs a detection signal S39 substantially the same as the upper limit of the input signal S38 (FIGS. 7 to 9 (a) and (b)). reference).

  On the other hand, the second peak hold circuit 57 has low followability with respect to the input signal S38. That is, the input signal S38 changes at a predetermined time (charge time and discharge time) both when the input signal S38 rises and when it falls. And a detection signal S40 that rises or falls more slowly than the input signal S38 (see (a) and (c) of FIGS. 7 to 9). ).

  The level adjustment circuit 58 is a circuit that divides the detection signal S40 detected by the second peak hold circuit 57 into 1 / n. Here, the detection signal S41 is obtained by dividing the detection signal S40 into 1/2. (See (d) of FIGS. 7 to 9).

  The comparator circuit 59 also generates a detection signal S39 detected by the first peak hold circuit 56 and a detection signal S41 obtained by dividing the detection signal S40 detected by the second peak hold circuit 57 by the level adjustment circuit 58. In comparison, when the detection signal S39 is larger, an “L” level signal is output as the output signal S42 (first reproduction signal S5 or second reproduction signal S6), while the detection signal S39 is smaller. Outputs an “H” level signal as the output signal S42 (see FIGS. 7 to 9E).

  When the signal generation circuit 3 is configured as described above, when the first digital signal S3 based on the signal on the data recording area is used as the input signal S38, a defect signal is output as the first reproduction signal S5. When the second digital signal S4 based on the signal on the burst cutting area is used as the input signal S38, the burst cutting area signal is generated as the output signal S42 as the second reproduction signal S6. Is done.

  In addition, by configuring the signal generation circuit 3 as described above, it is possible to prevent an erroneous defect signal from being generated even if a bright defect occurs during reproduction.

  That is, in the case of a dark defect, the signal generation circuit 3 has a defect portion where the detection signal S39 is smaller than the detection signal S41 as shown in FIG. 7 (see FIG. 7D). An accurate defect signal (S42) is generated (see FIG. 7 (e)).

  In the case of interruption, as shown in FIG. 8, the detection signal S39 is always larger than the detection signal S41 (see FIG. 8D), and the defect signal (S42) is always at the “L” level. (See FIG. 8 (e)).

  In the case of a bright defect, as shown in FIG. 9, the detection signal S39 is always larger than the detection signal S41 (see FIG. 9 (d)), and the defect signal (S42) is always at the “L” level. (See FIG. 9 (e)).

  Thus, in the conventional defect signal generation circuit, the defect signal is erroneously set to the “H” level at the time of a bright defect. However, according to the signal generation circuit 3, the defect signal is erroneously “ The signal does not become an “H” level signal.

  However, the signal generation circuit 3 does not generate an accurate defect signal at the time of interruption and light defect.

  Therefore, a signal generation circuit 3 ′ having a circuit configuration capable of generating an accurate defect signal even at the time of interruption and at the time of light defect will be described below.

  The signal generation circuit 3 ′ includes first and second bottom hold circuits in addition to the first peak hold circuit 56, the second peak hold circuit 57, the level adjustment circuit 58, and the comparator circuit 59 of the signal generation circuit 3. 60 and 62 and first and second differential circuits 61 and 63 are provided.

  The first bottom hold circuit 60 has high followability to the input signal S38 (the first digital signal S3 or the second digital signal S4), that is, the input signal is both when the input signal S38 rises and when it falls. It has a circuit configuration capable of following the change of S38 in a short time, and outputs a detection signal S43 substantially the same as the lower limit of the input signal S38 (FIGS. 11 to 13 (a) and (b)) reference).

  The first difference circuit 61 detects the difference between the detection signal S39 detected by the first peak hold circuit 56 and the detection signal S43 detected by the first bottom hold circuit 60, and detects it. The signal S44 is output (see (a) and (b) of FIGS. 11 to 13).

  On the other hand, the second bottom hold circuit 62 has low followability to the input signal S38, that is, a predetermined time (charge time and discharge time) for the change of the input signal S38 both when the input signal S38 rises and when it falls. The detection signal S45 that rises or falls more slowly than the input signal S38 is output (see FIGS. 11 to 13 (a) and (c)). ).

  The second difference circuit 63 detects the difference between the detection signal S40 detected by the second peak hold circuit 57 and the detection signal S45 detected by the second bottom hold circuit 62, and detects it. The signal S46 is output (see (d) in FIGS. 11 to 13).

  The level adjustment circuit 58 is a circuit that divides the detection signal S46 detected by the second difference circuit 63 into 1 / n. Here, the detection signal S41 obtained by dividing the detection signal S46 into ½ is used. The output is made (see (e) of FIGS. 11 to 13).

  The comparator circuit 59 compares the detection signal S44 detected by the first difference circuit 61 with the detection signal S41 obtained by dividing the detection signal S46 detected by the second difference circuit 63 by the level adjustment circuit 58. When the detection signal S44 is larger, an “L” level signal is output as the output signal S42 (the first reproduction signal S5 or the second reproduction signal S6), while when the detection signal S44 is smaller, “ The H level signal is output as the output signal S42 (see (f) of FIGS. 11 to 13).

  Even when the signal generating circuit 3 ′ is configured as described above, when the first digital signal S3 based on the signal on the data recording area is used as the input signal S38, similarly to the signal generating circuit 3, When the defect signal is generated as the output signal S42 as the first reproduction signal S5, and the second digital signal S4 based on the signal on the burst cutting area is used as the input signal S38, the second reproduction signal is generated. As S6, a burst cutting area signal is generated as an output signal S42.

  In addition, when the signal generation circuit 3 ′ is configured as described above, it is possible to generate an accurate defect signal not only at the time of a dark defect but also at the time of an interruption and a light defect.

  That is, in the case of a dark defect, the signal generation circuit 3 ′ has a defect portion because the detection signal S44 is smaller than the detection signal S41 in the defect portion (see FIG. 11 (e)), as shown in FIG. Thus, an accurate defect signal (S42) is generated (see FIG. 11 (f)).

  Also in the case of interruption, as shown in FIG. 12, since the detection signal S44 is smaller than the detection signal S41 in the defective portion (see FIG. 12 (e)), an accurate defect signal (S42) in the defective portion. ) Is generated (see FIG. 12 (f)).

  Also in the case of a bright defect, as shown in FIG. 13, since the detection signal S44 is smaller than the detection signal S41 in the defective portion (see FIG. 13 (e)), an accurate defect signal (S42) in the defective portion. ) Is generated (see FIG. 13 (f)).

  Thus, the signal generation circuit 3 ′ can generate an accurate defect signal for any defect.

The block diagram which shows the reproduction | regeneration circuit. FIG. 3 is an explanatory diagram schematically showing a recording medium. The block diagram which shows a variable A / D conversion circuit. The timing chart which shows control of a switch. 6 is a timing chart showing the operation of the variable A / D conversion circuit. The block diagram which shows a signal generation circuit. Explanatory drawing which shows the detection signal at the time of a dark defect. Explanatory drawing which shows the detection signal at the time of interruption. Explanatory drawing which shows the detection signal at the time of a bright defect. The block diagram which shows another signal generation circuit. Explanatory drawing which shows the detection signal at the time of a dark defect. Explanatory drawing which shows the detection signal at the time of interruption. Explanatory drawing which shows the detection signal at the time of a bright defect.

Explanation of symbols

1 reproduction circuit 2 variable A / D conversion circuit
3, 3 'signal generation circuit 4 recording medium 5 first recording area 6 second recording area 8 A / D conversion circuit
10 First switch
19 Second switch
55 Control circuit
56 First peak hold circuit
57 Second peak hold circuit
58 Level adjustment circuit
59 Comparator circuit
60 First bottom hold circuit
61 First difference circuit
62 Second bottom hold circuit
63 Second difference circuit
S1 First analog signal
S2 Second analog signal
S3 First digital signal
S4 Second digital signal
S5 First playback signal
S6 Second playback signal

Claims (4)

In a reproduction circuit for reproducing information recorded on a recording medium,
Single for converting a first analog signal and second analog signals I read from the burst cutting area I read from the data recording area on the recording medium to the first and second digital signals with different sampling rates, respectively A variable A / D converter circuit;
Reproducing said first digital signal to generate a defect signal as an input signal, and having a single signal generation circuit for the second digital signal as an input signal to generate a burst cutting area signal circuit. The variable A / D converter circuit connects the first and second analog signals to the A / D converter circuit via first and second switches, and the first and second switches are sampled differently. The reproduction circuit according to claim 1, wherein the reproduction circuit is configured to be controlled by a control circuit that is intermittent at a rate. In an optical disc playback apparatus having a playback circuit for playing back information recorded on an optical disc,
The recovery circuit, converts the first and second digital signal and a first analog signal and second analog signals I read from the burst cutting area I read from the data recording area on the optical disk at different sampling rates, respectively A single variable A / D converter circuit for
Wherein the first digital signal to generate a defect signal as an input signal, optical disk and having a single signal generation circuit for the second digital signal as an input signal to generate a burst cutting area signal Playback device. The variable A / D converter circuit connects the first and second analog signals to the A / D converter circuit via first and second switches, and the first and second switches are sampled differently. 4. The optical disk reproducing apparatus according to claim 3, wherein the optical disk reproducing apparatus is configured to be controlled by a control circuit intermittent at a rate.

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