JPH02168470A - Optical recording and reproducing device - Google Patents

Abstract

PURPOSE:To relieve the possibility of a detection error in a bit pattern with a maximum inter-code interference by processing a digital data as a 4/11 modulation code data. CONSTITUTION:An encoder 22 provided to a recording system 20 takes a channel bit number for each byte of a digital data as 11-channel bits (CH1 - CH12). The encoder 22 converts channel bit number of logical 1 in the bits CH1 - CH12 into a 4-channel bit. Bit patterns of those patterns in the relation of mirror inversion among bit patterns of the combination of 11C4 except bit patterns in which bits CH1 - CH3 or CH9 - CH11 are [111], bits CH1 - CH4 are [1101], [0111] or [1011], and bits CH8 - CH11 are [1011], [1110] or [1101] are converted into the 4/11 modulation code data by the encoder 22.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to an optical recording and reproducing apparatus that records and reproduces digital data using an optical or magneto-optical signal recording and reproducing method.

B0 Summary of the Invention The present invention provides an optical recording and reproducing apparatus for recording and reproducing digital data using an optical or magneto-optical signal recording and reproducing method, in which the number of channel bits for each byte of the digital data is set to 11 channels. Bit (CL-
These 11 channel bits (CL
~CH11) The number of channel bits of logic (1) in 4
Of the bit patterns of 1lc4 combinations used as channel bits, a left-right symmetrical bit pattern and 3 channel bits (CHI, CHt) on the first channel bit (C1l+) side are selected from left-right inverted pairs of bit patterns.
, C1ts) or the 11th channel bit (CB1
1) side 3 channel bits (C119, CIl@, C
)Ill) is (111), and the four channel bits (CHI, CHx, C1,, CHa) on the first channel bit (CHI) side are (1101]
, [0111) or (1011), and the four channel bits (CHI, Cl1v, CHI*) on the 11th channel (CH11) side.

CL+) is (1011], [1110) or [110
1) The above digital data is converted into code data with a bit pattern excluding the bit pattern and recorded on an optical recording medium, and the playback output from the optical recording medium is converted every 11 channel bits (C■1 to CI11). The four channel bits with the higher playback output level are read as logical "L" channel bits, and the read detection output is subjected to code conversion processing corresponding to the code conversion processing in the recording system, thereby recording and playing back digital data. This can be done reliably with a simple configuration.

C0 Prior Art Conventionally, in an optical recording and reproducing apparatus that records and reproduces digital data using an optical recording medium such as a write-once optical disk or a rewritable magneto-optical disk, for example, a predetermined interval is recorded in the recording trunk of an optical disk. A so-called sampling servo control has been proposed in which a servo signal is recorded every rotation angle or every predetermined rotation angle, and the discrete servo signals are sampled when the disk is rotated to perform continuous servo control.

Furthermore, as disclosed in US Pat. No. 4,646.281, for example, as a modulation and encoding method for digital data recorded and reproduced via an optical recording medium, the number of channels per byte is set to 15, and 15 channels are used. A so-called 4/15 code modulation encoding method is adopted in which four of the channel bits are marked (logic "1"), and the playback output from the optical recording medium is sampled at the standard channel clock. A data reading method using so-called differential detection has been proposed in which four channel bits with higher levels among the channel bits are detected in units of 15 channel bits as marks.

D0 Problems to be Solved by the Invention By the way, in an optical recording and reproducing apparatus that records and reproduces digital data optically or magneto-optically via an optical recording medium, data corresponding to the digital data recorded on the optical recording medium is There is a problem in that as the bit interval becomes narrower, it is more likely to be affected by so-called code amount interference. 4/1 above
Adopting the 5-code modulation coding method in the recording system and using the differential detection described above for reading data in the reproduction system is effective in reducing the occurrence of errors due to the influence of the so-called code amount interference described above. However, it is necessary to process data from the recording system encoder to the playback system decoder at a channel clock frequency that makes the number of channels per byte 15.Furthermore, 4 channel bits out of 15 channel bits are marked (logical). "l") 4/15
In the code modulation coding method, the bit pattern with the maximum code amount interference includes a bit pattern in which there is a minimum space of two channel bits (logic "0") between marks (logic "1"), and this When performing differential detection by sampling the playback output for a bit pattern using the channel clock, errors may occur because the space (logic "0") is sampled at a position that deviates from the minimum level, as shown in Figure 4. There is a risk of detection.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional problems, the present invention aims to facilitate data processing by lowering the channel clock frequency when optically or magneto-optically recording and reproducing digital data via an optical recording medium. It is an object of the present invention to provide an optical recording/reproducing apparatus having a novel configuration that reduces the risk of detection errors in the bit pattern with the maximum amount of code interference.

83 Means for Solving the Problems In order to solve the above-mentioned conventional problems, the optical recording and reproducing apparatus according to the present invention has a recording system for recording digital data on an optical recording medium, in which one byte of the digital data is recorded. Let the number of channel bits for each channel be ll channel bits (C1l
+~CH11), this ll channel bit (C
From the left-right inverted pair of bit patterns of the 11Ca combination bit patterns in which the number of channel bits of logic "l" in H, ~CH11) is 4 channel bits, a left-right symmetric no-hit pattern and the first channel bit are obtained. (CIll) side 3 channel pit (CHl, C
Ha, CHs) or the 11th channel bit (CH
ll) side 3 channel bits (CH9, CHll, C
The bit pattern in which Hll) is (111) and the first channel bit (C1l+) side (1) 4117
Lt heat) (CL, CHt, C1hlC114) is (
11013, (0111) or (1011), and the 11th channel bit (CHl
l) 4 channel bits on the bit side (CIll.

CHa, CHll, CHa t) is (1011], [1
110) or (1101).
A reproduction system that reproduces digital data recorded on the optical recording medium is provided with an encoder that converts the pattern, and a high reproduction output level is provided for every 11 channel bits (CI+ to CH11) of the reproduction output from the optical recording medium. The other 4 channel bits are set to logic r1. The present invention is characterized in that it is provided with differential detection means for reading the channel bits of the differential detection means, and a decoder that performs code conversion processing corresponding to the encoder on the detection output of the differential detection means.

F1 action In the optical recording and reproducing apparatus according to the present invention, the encoder provided in the recording system converts the number of channel bits for each byte of digital data into 11 channel bits (CI, ~CH
z), these 11 channel bits (CH, ~CH
11) A- in Table 1 of the combination of 1 and C4 where the number of channel bits of logic "l" in is 4 channel bits
Among the 330 types of bit patterns shown in F, the left-right symmetrical bit patterns and the three channel bits (CHa, CHz, CHz) on the first channel bit (C11,) side or the first
A bit pattern in which the channel bits (CH9, Cl11°, C1l11) on the 1st channel bit (C11,) side are (111) and the above 1st channel bit (CH
, ) side 4 channel bits (CH,, C1,, CH3
,C1,) is (1101), (0111) or (1
011), and the 11th channel bit (C) 1. , ) bit side 4 channel bits (CHa, Ctl*, CHa., CI11+) are (10
11], [1110), or (1101), the digital data is converted into 4/11 modulation code data having bit patterns shown in A to H of Table 2, excluding the bit patterns of [11], [1110), or (1101).

[Margin below]

A: C C of Bipaan: B of Vipaan: D of Bipaan of: E of Bipaan of: A: 4 of Bipaan of C: B of Bipaan of Cor: C of Cor :'s El Co-Co-C margin below]'s D: Co By removing the left-right symmetrical bit pattern from the focus pattern shown in A-bow of Table 1 above, the above-mentioned left-right inverted pair of Pino) patterns can be identified. You will be able to do this. Also, the 3 channels on the 1st channel bit (C111) side and the node (C1 (+, CHg, Cll+) or the 11th
Channel bit (CI+□) side channel bit (
By excluding the focus pattern in which C1lq, CJo, CL+) is (111), there will be no more than 5 consecutive channel focuses of logic "lJ" in the continuous part of 2-byte data. (C1l+) side 4 channel bin) (C)I
, , C11□, C113, C114) is (1101
) (0111) or (1011) and the 4 channel bits (C)Is, C! on the focus side of the 11th channel bit (CH11). lq, CI
By excluding bit patterns in which I+o, CIL+) is (1011], [1110) or (1101), for example, (000 0001110) (11011
0oooooo) or ['00100001011](11
010000 00), etc., in the continuous part of 2-hyde data, the channel bit of logic "Rise" is set to the logic "R" before and after
It is possible to eliminate the risk of being confused with the logical "earth" channel bits due to code amount interference from consecutive channel bits of "l".

Then, the recording system records the digital data converted into 4/11 modulation code data by the encoder onto an optical recording medium.

Furthermore, in the reproduction system of the optical recording/reproducing apparatus according to the present invention, the differential detection means detects the reproduction output from the optical recording medium by selecting four channels having higher reproduction output levels in units of 11 channels (C1l, to CU11). The bit is read as a channel bit of logic '1', and the read detection output is subjected to decoding processing of the 4/11 modulation code decoding in a decoder to reproduce digital data.

G. Embodiment Hereinafter, an embodiment of the optical recording/reproducing apparatus according to the present invention will be described in detail with reference to the drawings.

The embodiment shown in the block diagram of FIG.
The optical disk (10) is rotated by the spindle motor (2) at a constant angular velocity while
1) The present invention is applied to a write-once type optical recording and reproducing apparatus that optically records and reproduces digital data by scanning an upper recording track with a laser beam.

The optical disc (1) has a second recording format.
As shown in the figure, concentric recording tracks (TR) centered around the central hole are provided, and one recording track is divided into 22 sectors (SC,) to (SCtz). SCI) ~ (SCz□) is 7 l sectors
It is divided into 6 segments (SGI) to (SGti), and the l segment is a 2-byte control recording area (^Rc).
and an 8-byte data recording area (ARD), and furthermore, the control recording area (^Rc) is preformatted with traverse information bits (Pa) e1''jJ (AR+).
and tracking information bits (P-+, Pwz) and clock information focus (PcK) preformat fil
It is divided into an area (ARt) and a focus information area (AR3).

In the optical recording/reproducing apparatus of this embodiment, the data recording area (A) on the recording track (TR) of the optical disc (1) is
11. ) A recording system (20) that records digital data on
is an encoder (22) into which digital data DIN to be recorded is manually input via an input/output interface (21).
), a write pulse generation circuit (23) that performs a pulse operation according to the encoded output from the encoder (22).
), a laser drive circuit (24) that pulse-drives the laser diode of the optical head (lO) according to the write pulse given by the write pulse generation circuit (23).
), encoder (22) and write pulse generation circuit (2
3) is composed of a timing generation circuit (25) that provides an operation timing clock.

The encoder (22) receives digital data (DIN) input via the input/output interface (21).
), the number of channel bits per byte (8 bits) is 11 channel bits (C11, to C) 1. ,)
As, these 11 channel bits (CH1~CH11
), the number of channel bits of logic "l" is 4 channel bits. From the left-right inverted pair of bit patterns of the combination of focus patterns in C4, a left-right symmetric focus pattern and 3 channel bits (CIll, CH,, CHI3) on the 1st channel bin) (CL) side are obtained.
Or 4 on the 11th channel bit (CIl11) side
Channel bit (CHI9.CHI., C1l11)
is [111] and the 4,000 channel bit (CHI) on the first channel bit (co+) side.
,,CHz,CH3,C! In> is (1101], [0
111) or (1011), and
4 channel bins on the 11th channel bit (CL, ) side) (CIIa, Cl1q1CL., Cl11
) is (1011), (1110) or (11
It performs encoding processing to form 4/11 modulation code data of the bit pattern excluding the bit pattern 01), and A-H in Table 2 above.
It is composed of a conversion table memory in which arbitrary 128 pairs of 4/11 modulation code data are written in advance from 131 pairs of bit patterns forming left-right inverted pairs as shown in FIG.

In the recording system (20) in the optical recording/reproducing apparatus of this embodiment, the digital data to be recorded (DIN
) is converted by the encoder (22) into the 4/11 modulation code data shown in Table 1 A to H, and the write pulse generation circuit performs a pulse generation operation according to the encoded output of the encoder (22). The laser drive circuit (24) responds to the write pulse generated at (23).
) pulse-drives the laser diode of the optical head (10) to generate the digital data (DI
N) is recorded as the above-mentioned 4/11 modulation code data in the data record 6JfJ'1 (ARo) on the recording track (TI?) of the optical disc (1).

The timing generation circuit (25) forms a channel clock for 4/11 modulation code data in synchronization with the digital data (DIN) pit clock to be recorded, and uses this channel clock as an operation timing clock for the encoder. (22) and the write pulse generation circuit (23).

Further, in the optical recording and reproducing apparatus of this embodiment, the recording system (20) reproduces digital data recorded as code data in the data recording area (ARe) on the recording track (TR) of the optical disc (1). Regeneration system (
30), the optical head (10) for detecting the return light from the recording track (TR) is connected to the optical disc (1).
The recording track (TR) is scanned with a laser beam to detect the return light from the recording track (TR), and the detection output is sent to the timing generation circuit (32) and A/D via the preamplifier (31). The output of the A/D conversion circuit (33) is supplied to a decoder (34).
).

The timing generation circuit (32) is configured to operate on the optical disc (
1) on the recording track (TR) as described above.
The control recording area (ARc) provided in advance
) A channel clock is formed based on the detected output of the clock information pit (pcK), and this channel clock is supplied as an operation timing clock to the A/Di conversion circuit (33) and decoder (34).

Further, the A/D conversion circuit (33) samples the detection output from the optical head (10) supplied via the preamplifier (31) using the channel clock as an operation timing clock. , A/D with differential detection operation in which 4 channel bits from the highest signal level are marked (logic "L") in units of 11 channel bits (CIll=CH11).
Perform the conversion process.

The decoder (34) then inputs 11 channel bits (CI+, ~CHZ) to the A/D conversion circuit (33).
) The 4/11 modulation code data read by the differential detection operation of units is converted into digital data (DouT) by performing decoding processing corresponding to the encoding processing in the encoder (22) of the recording system (20).
Reproduce.

In the optical recording/reproducing apparatus of this embodiment, the recording system (20)
1 byte 11 channel bits (CHI~C1l□
) is recorded on the recording track (TR) of the optical disc (1) as 4/1 liffl code data with the number of marks (logical "1") fixed at 4 channel focus, so the A/D of the reproduction system (30) The conversion circuit (33) converts the detection output from the optical head (10) into 11 channel focus (C)1. ~C8,,), mark the 4 channel bits from the one with the highest signal level (logic "1")
'') can perform A/D conversion processing using a differential detection operation.

In addition, the 4/II modulation code data has a longer channel bit period than the conventionally known 4/15 modulation code data, so it has a larger time margin and is suitable for use with the encoder of the recording system (20). (22) and regeneration systems (
30), the A/D conversion circuit (33), decoder (34), etc. can have a simple configuration with slow operation speed. Moreover, in the above 4/11 modulation code data, the above playback system (
In the A/D conversion circuit (33) of 30), the playback output for the bit pattern with the maximum code amount interference where there is a space (logic "0") of one channel focus between marks (logic "1") is channel When performing differential detection by sampling with a clock, as shown in Figure 3,
Since the space (logic "0") is sampled at the minimum level position, the bottom of false detection is extremely low, and highly accurate A/D conversion processing can be performed.

H0 Effect of the invention In the optical recording/reproducing apparatus according to the invention, in the recording system,
Assuming that the number of channel bits per byte of digital data is 11 channel bits (CHl, ~C1l11), these 11 channels! Levint (CH, ~cn11
) in which the number of channel bits of the logic "l" is 4 channel bits. Among the bit patterns of the combination of 11C4, a left-right symmetrical bit pattern and the first channel bit (C11
1) side 3 channel bins) (CHl, C11□, C
Hl3) or 11th channel focus (C11□)
3 channel bits on the side (CH9, C1l, ., CIl
l) is [111) and the 4 channel bits (C1ll) on the above first channel bin) (C1ll) side.
C11,, CL, CH3, CH4) is (1101], [
0111) or (1011) and the 4 bits on the 11th channel bit (CHl) bit side.
Thousand Yannel Pinto (C111, C119, C111°,
CI'l11) is (1011).

The digital data is converted into 4/11 modulation code data with a bit pattern excluding (1110) or (1101) by an encoder and recorded on an optical recording medium, and reproduced output from the optical recording medium. The differential detection means detects the ll channel bit (C111'
-CIll) unit, the four channel bits with higher playback output level are read as the channel focus of logic rlJ, and the decoder uses the decoder to
Digital data is reproduced by decoding the No. 11 modulation code data.

In this way, the number of channel bits for each byte of digital data is calculated as ll channel bits (CIll~CI!
By performing recording and reproduction as □), data processing can be easily performed by lowering the channel clock frequency, and the configuration can also be simplified. In addition, 11 channel bits (
From the left-right inverted pair of bit patterns of the combination of bit patterns 1 and C4, where the number of channel bits of logic "l" in CH+ to CH11) is 4 channel bits, a left-right symmetrical hint pattern and the first channel 3 channel bits on the hit (C) I + ) side (
CL, C11x, Cl1s) or 3 channel bits (CII*,
A bit pattern in which Cfl+o, CL+) is (Ill) and the four channel bits (CHl, Cl1g, C11x, CH4) on the first channel bit (CHl) side.
) is (1101), (Ol 11) or [101
1) and the 4 channel focus (Ctl11) bit side of the 11th channel bit (Ctl11) bit.
M,,C11,,CHl,. , CL+) is (1011]
, [1110] or (1101), which is the bit pattern excluding the focus pattern. Since digital data is recorded and reproduced as 4/l 1 modulation code data, there is a logic When performing differential detection by sampling the reproduced output for the bit pattern with the maximum code amount interference in which there is one channel bit of "0" using the channel clock,
The data in the space is sampled at the minimum level position, making it possible to reduce detection errors.

Therefore, in the optical recording and reproducing apparatus according to the present invention, recording and reproducing of digital data can be reliably performed with a simple configuration.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an optical recording/reproducing apparatus according to the present invention, FIG. 2 is a schematic diagram showing a recording format of an optical disc used in the optical recording/reproducing apparatus, and FIG.
The figure shows 4/4 reproduced from the recording track of the optical disc.
11 is a reproduced waveform diagram of the No. 11 modulation code. FIG. FIG. 4 is a reproduction waveform diagram of a 4/15 modulation code reproduced from a recording track of the conventionally known optical disc. (1)......Optical disk (10)...Optical head (20)...Recording system (22)...Encoder (23)...Write pulse generation circuit Laser drive circuit Reproduction system timing generation circuit A/D conversion circuit Decoder

Claims (1)

[Claims] A recording system for recording digital data on an optical recording medium,
The number of channel bits for each byte of the above digital data is 11 channel bits (CH_1 to CH_1_1)
As, these 11 channel bits (CH_1 to CH_
The number of channel bits with logic "1" in 1_1) is set to 4 channel bits. Among the bit patterns of combinations of _1_1C_4, a left-right inverted pair of bit patterns is selected, and a left-right symmetrical bit pattern and the first channel bit (CH_1) are obtained. side 3 channel bits (CH_1, C
H_2, CH_3) or the 11th channel bit (
3 channel bits (CH_9, C
The bit pattern in which H_1_0, CH_1_1) is [111] and the four channel bits (CH_1, CH_2, CH_3) on the first channel bit (CH_1) side
, CH_4) is [1101], [0111] or [1
011] and the 4 channel bits (CH_8, CH_9, CH_1_0, CH_1_1) on the 11th channel bit (CH_1_1) bit side.
) is [1011], [1110] or [1101], and an encoder is provided for converting the digital data into code data of a bit pattern excluding bit patterns in which the bit pattern is [1011], [1110] or [1101], and the digital data recorded on the optical recording medium is reproduced. 1 regarding the reproduction output from the optical recording medium in the reproduction system.
For each channel bit (CH_1 to CH_1_1), set the four channel bits with the higher playback output level to logic "1".
differential sensing means for reading as channel bits of ``;
An optical recording/reproducing apparatus comprising: a decoder that performs code conversion processing corresponding to the encoder on the detection output by the differential detection means.