JP2839191B2 - Signal evaluation device for information recording media - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal evaluation apparatus for selecting a specific signal from a large amount of signals recorded on an information recording medium and automatically evaluating the selected signal.

[Conventional technology]

2. Description of the Related Art Conventionally, a recording area is divided into a large number of sectors, a sector mark indicating a sector delimiter for each sector, a VFO (variable frequency oscillator) section for generating a clock unique to each sector, and an address indicating an address of each sector. Section, a sync pattern indicating a break between the VFO section and the address section,
An optical recording medium in which a data part and the like are pre-formatted is known.

In this type of optical recording medium, if the above-mentioned various preformat signals cannot be read correctly, the optical spot cannot access a desired sector, and cannot record or reproduce information. Therefore, it is necessary to read the preformat signal before shipping the product and evaluate whether or not the signal amplitude and the pulse width are correctly formed. Further, the above signal evaluation is indispensable for studying an optical recording medium on which a more accurate preformat is formed.

Heretofore, as a signal evaluation means for this purpose, a means has been adopted in which an optical spot is accessed to a track including a desired sector and a signal read therefrom is observed with a CRT oscilloscope.

In the above description, the evaluation of the preformat signal of the optical recording medium has been described as an example. However, the same means can be applied to the evaluation of the write signal on the optical recording medium or the signal evaluation of another information recording medium such as a magnetic recording medium. Has been adopted.

[Problems to be solved by the invention]

However, when the above-described evaluation means is employed, only the average value of the accessed track can be detected, and the signal evaluation of the specific sector included in the track or the specific value included in one sector is performed. There is a problem that the signal cannot be evaluated.

In addition, the signal amplitude, pulse width, waveform distortion, etc. of each signal must be measured from the signal waveform displayed on the CRT oscilloscope, and the data obtained in this way must be statistically processed. Therefore, there is a problem that the efficiency is low and the method cannot be applied to a production line.

Accordingly, an object of the present invention is to provide a signal evaluation device capable of selecting a specific signal from a large amount of signals recorded on an information recording medium and automatically evaluating the selected signal.

[Means for solving the problem]

In order to achieve the above object, the present invention firstly provides:
A reproducing device for reproducing a signal recorded on an information recording medium,
An analog / digital converter for quantizing a reproduced signal read by the reproducing apparatus, a memory for storing the quantized data, a memory controller for controlling a start time of a storage operation of the memory, In the signal evaluation device for an information recording medium, comprising: an arithmetic processing unit that extracts data stored in a memory unit and performs a predetermined signal evaluation, the memory control unit detects a predetermined signal pattern from the reproduced signal. A pattern detection unit that generates a synchronization signal, and a timer unit that is activated by the synchronization signal, generates a trigger signal after a predetermined time, and starts a storage operation of the memory unit, and The arithmetic processing unit is configured to be able to select and extract operation target data from the data stored in the memory unit.

Secondly, in a signal evaluation device for an information recording medium having a similar configuration, the memory control unit detects a predetermined signal pattern from the reproduced signal to generate a synchronization signal, The timer unit is activated by the synchronization signal, generates a trigger signal after a predetermined time, and starts a storage operation of the memory unit, and recognizes an address pre-formatted on the information recording medium, and specifies a pre-designated address. An address recognizing unit that outputs an address match signal when the address of the specified address area matches the address read by the playback device; and the memory unit when the trigger signal and the address match signal are output. And an AND gate for starting a storage operation of a signal recorded in the specific address area. Was a configuration that can be taken out by selecting the data to be processed from among the data stored in the memory unit.

[Action]

The lengths (time lengths) of the sector marks, the VFO section, the address section, the sync pattern, the data section, and the like preformatted on the information recording medium are all known. Accordingly, each time from when a specific signal selected from each of these preformat signals is read to when each subsequent signal is read can be calculated.

Therefore, by setting in advance the time from when the specific signal is read to when the signal to be evaluated is read to the memory control unit, the signal of the specific sector or the signal in the specific sector is read. Only signals in a specific area can be stored in the memory, and the signals can be selectively evaluated.

In addition, data measurement such as signal amplitude and pulse width and processing of data thus obtained can be automatically performed according to a program stored in the arithmetic processing unit, so that signal evaluation is made more efficient. And the range of data processing can be expanded.

〔Example〕

Hereinafter, an embodiment of the present invention will be described using a signal evaluation apparatus for a disk-shaped optical recording medium as an example.

FIG. 1 is a program diagram of the signal evaluation apparatus according to the first embodiment, which mainly includes a reproduction apparatus 1, an analog / digital conversion section (hereinafter abbreviated as an A / D conversion section) 2, and a memory section 3. , A memory control unit 4, an arithmetic processing unit 5, a display 6, and a printer 7.

As shown in FIG. 2, the reproducing apparatus 1 includes a rotary spindle 11, an optical head 12, a head driving unit 13, a focus control circuit 14, a tracking control circuit 15, and a reproduction signal amplifying circuit 16. A signal is optically reproduced from a disk-shaped optical recording medium 17 mounted on the rotary spindle 11. Disk-shaped optical recording medium 17
The recording area is divided into a number of sectors 21a, 21b, 21c,... As schematically shown in FIG. VFO unit 23, which generates a clock of the address, an address unit 24 for displaying the address of each sector, the VFO unit 23 and the address unit 2
Sync pattern 25 indicating the division of 4 and data section 26
Is pre-formatted.

The memory control unit 4 includes a pattern detection unit 8 and a timer unit 9 as shown in FIG.

As shown in FIG. 4, the pattern detector 8 comprises a binarization circuit 31, a VFO 32, a shift register 33, a pattern comparator 34, and a memory 35, and the binarization circuit 31VFO32
The reproduction signal r read out by the reproduction device 1 is input to the input section of the reproduction device 1.

The VFO 32 generates a clock c from the VFO pattern read from the VFO section 23 of the disk-shaped optical recording medium 17 and converts the reproduced signal d which has been binarized by the binarization circuit 31 and synchronized by the clock c. Register in the shift register 33. In the memory 35, the same pattern as the sync pattern 25 pre-formatted on the disc-shaped optical recording medium 17 is set in advance, and the pattern of the reproduction signal registered in the shift register 32 and the pattern set in advance are set. The signal patterns are sequentially compared with each other, and a one-shot synchronizing signal s is generated when they coincide with each other.

The timer section 9 is started by the synchronization signal s output from the pattern detection section 8 and counts the time from when the synchronization signal s is output until immediately before the sector mark of the next sector is read out. At the same time, a one-shot trigger signal is generated. The set time of the timer unit 9 is set by the arithmetic processing unit 5.

The A / D converter 2 quantizes the reproduction signal read from the optical disk 17 by the reproducing apparatus 1. The memory unit 3 starts the storage operation together with the output of the trigger signal, and stores the quantized reproduction signal waveform.

The arithmetic processing unit 5 stores the preformat of the disk-shaped optical recording medium 17, and sets the time from when the sync pattern 25 is read until immediately before the sector mark of the next sector is read to the timer unit 9. ing. Also,
From the data stored in the memory unit 3, the address range of the data related to the sector mark is obtained, and the data is taken out. For example, signal vibration width measurement, pulse width measurement, various types of data, etc. Performs data processing such as statistical processing.

Hereinafter, the operation of the signal evaluation apparatus according to the embodiment will be described with reference to FIG.

FIG. 5 (a) shows a reproduction signal pattern read from the disk-shaped optical recording medium 17, and includes a sector mark signal 41a, a VFO signal 42a, a sync pattern signal 43a, an address signal 44a, a data signal 45a, and a next signal. Are sequentially read out.

When the pattern detector 8 detects the sync pattern signal 43a, the synchronization signal s is output from the pattern comparator 34 (FIG. 5 (b)).

When the synchronization signal s is output, the timer unit 9 operates,
Count the time set in advance. In this example, the time is set slightly shorter than the time from when the synchronization signal s is output to when the sector mark signal 41b of the next sector is read, so that the sector mark signal 41b of the next sector is read. The trigger signal t is output immediately before (FIG. 5 (c)).

Thereby, the reproduction signal can be stored in the memory unit 3, and the reproduction signal after the trigger signal is output is stored in the memory unit 3. If the storage capacity of the memory unit 3 is set so as to store not only the sector mark signal 41b but also a part of the VFO signal 42b, the sector mark signal 41b and the VFO signal 42
Part of b is stored {FIG. 5 (b)}.

Since the sampling frequency of the A / D converter 2 and the time length of the sector mark are known, it is possible to determine which range of the memory address is the data of the sector mark signal 41b. The arithmetic processing unit 5 reads out the data of the sector mark area from the data stored in the memory unit 3, and measures the signal amplitude, pulse width, waveform distortion, and the like of the sector mark signal 41b. The statistical processing of the data obtained as described above is performed.

In the same manner, the signal evaluation of the sector mark signal of each sector can be continuously performed.

In the signal evaluation device of the above embodiment, the data stored in the memory unit 3 is controlled by the memory control unit 4. Therefore, the signal evaluation is performed on the sector mark of the specific sector in the track where the optical spot is accessed. Can be performed, and the accuracy of signal evaluation can be improved.

In addition, since data measurement, data processing, and the like are performed according to a program stored in the arithmetic processing unit 5, signal evaluation can be automatically performed. The range of processing can be expanded.

Next, a second embodiment of the present invention will be described with reference to FIG.

FIG. 6 is a block diagram of the signal evaluation apparatus according to the second embodiment, in which 51 is an address recognition unit, 52 is an AND gate, and the same reference numerals are used for the other devices corresponding to those shown in FIG. Is displayed.

The address recognizing section 51 recognizes an address preformatted on the disk-shaped optical recording medium 17 and compares the address specified by the arithmetic processing section 5 with the address read by the reproducing apparatus 1. And outputs an address match signal when the address specified by the arithmetic processing unit 5 matches the address read by the playback device 1.

The AND gate 52 receives the address match signal and the timer 5
AND operation with the trigger signal output from the memory unit 3 to start the storage operation of the memory unit 3.

The configuration and operation of each unit of the apparatus other than those described above are the same as those of the first embodiment, and thus description thereof is omitted.

In the signal evaluation device of the second embodiment, since the memory control unit 4 is provided with the address recognition unit 51 and the AND gate 52, the signal recorded in the desired sector can be selectively evaluated, and the address and the address can be evaluated. The correlation with the signal recorded in the sector can be evaluated.

In each of the above embodiments, the sync pattern 25 is used as a signal pattern for generating the synchronization signal s. However, any signal pattern can be used as long as it can be distinguished from other signal patterns. The signal can be arbitrarily selected from various signals pre-formatted on the disk-shaped optical recording medium 17.

In each of the above embodiments, the time from when the trigger signal t is generated in the timer unit 9 until immediately before the sector mark of the next sector is read is set, and the signal evaluation of the sector mark of the next sector is performed. However, the set time of the timer unit 9 can be arbitrarily changed according to a signal to be evaluated.

Further, the signal to be evaluated is not limited to the sector mark signal, and it is possible to perform signal evaluation on an arbitrary preformat signal preformatted on the information recording medium and an arbitrary recording signal additionally written on the information recording medium. it can.

Furthermore, in each of the above embodiments, the signal evaluation device for a disk-shaped optical recording medium has been described as an example, but the present invention can also be applied to a signal evaluation device for other types of optical recording media such as a card-shaped optical recording medium. . Further, the present invention can be applied to signal evaluation of a magnetic recording medium after pre-formatting.

〔The invention's effect〕

As described above, according to the present invention, only a signal of a specific sector or a signal of a specific area in a specific sector can be selectively evaluated. And high efficiency can be achieved. In addition, by changing the set time of the timer section and the range of the data to be calculated, the signal evaluation for an arbitrary area on the information recording medium can be performed with an arbitrary time length, so that the versatility is excellent. Further, since the signal evaluation is automatically performed according to the program stored in the arithmetic processing unit, the signal evaluation can be made more efficient, and the range of data processing can be expanded.

[Brief description of the drawings]

FIG. 1 is a block diagram of a signal evaluation apparatus according to a first embodiment,
FIG. 2 is a block diagram of a reproducing apparatus, FIG. 3 is an explanatory view schematically showing a preformat of a disk-shaped optical recording medium, FIG. 4 is a block diagram of a pattern detecting section, and FIG. FIG. 6 is a block diagram of the signal evaluation apparatus according to the second embodiment. 1: playback device, 2: A / D converter, 3: memory, 4: memory controller, 5: arithmetic processor, 6: display, 7: printer, 8: pattern detector, 9: timer, 51 : Address recognition unit, 52:
And gate.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-1945 (JP, A) JP-A-62-6180 (JP, A) JP-A-62-88175 (JP, A) JP-A 62-88 212975 (JP, A) JP-A-63-98574 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G11B 20/18 G11B 5/00

Claims (5)

(57) [Claims] 1. A reproducing apparatus for reproducing a signal recorded on an information recording medium, an analog / digital converter for quantizing a reproduced signal read by the reproducing apparatus, and a memory for storing the quantized data. Unit, a memory control unit for controlling a storage operation start time of the memory unit, and an arithmetic processing for extracting data stored in the memory unit and performing a predetermined signal evaluation. A memory control unit, a pattern detection unit that detects a predetermined signal pattern from the reproduction signal and generates a synchronization signal, and is activated by the synchronization signal and generates a trigger signal after a predetermined time. And a timer unit for starting the storage operation of the memory unit.
A signal evaluation device for an information recording medium, wherein the arithmetic processing unit is configured to select and extract operation target data from data stored in the memory unit. 2. A reproducing apparatus for reproducing a signal recorded on an information recording medium, an analog / digital converter for quantizing a reproduced signal read by the reproducing apparatus, and a memory for storing the quantized data. Signal evaluation device for an information recording medium, comprising: a memory control unit that controls a storage operation start time of the memory unit; and an arithmetic processing unit that extracts data stored in the memory unit and performs a predetermined signal evaluation. A pattern detection unit that detects a predetermined signal pattern from the reproduction signal and generates a synchronization signal, and generates a trigger signal after a predetermined time, which is activated by the synchronization signal. A timer unit for starting a storage operation of the memory unit, and recognizing an address preformatted on the information recording medium, and specifying a specific address designated in advance. An address recognition unit that outputs an address match signal when an address of an area matches an address read by the playback device; and the identification to the memory unit when the trigger signal and the address match signal are output. And an AND gate for starting a storage operation of a signal recorded in the address area, and the arithmetic processing unit can select and retrieve operation target data from data stored in the memory unit. A signal evaluation device for an information recording medium, characterized in that: 3. The signal evaluation device for an information recording medium according to claim 1, wherein the arithmetic processing unit detects the synchronization signal in the timer unit and generates the trigger signal. The signal evaluation time of the information recording medium is variably set in accordance with the recording position of the signal taken into the memory unit. 4. The signal evaluation device for an information recording medium according to claim 1, wherein said information recording medium is an optical recording medium. 5. The signal evaluation device for an information recording medium according to claim 1, wherein said information recording medium is a magnetic recording medium.