JPH0664857B2 - Prifo-Mat disk inspection device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a preformatted disc inspection apparatus, and more particularly to a preformatted disc inspection apparatus that detects the position of preformatted information and inspects it while protecting the preformatted information.

(Prior Art) Generally, in a magnetic disk device or the like, after a plurality of unpreformatted disk single plates are incorporated in the device, a clock on a certain disk on the disk is written in synchronization with the rotational shake of the disk and its rotation cycle is equally divided. , Preformat information is written using the clock. Therefore, in order to protect the preformat information, the protection gate can be configured with the phase accuracy using the clock. However, in an optical disc device or the like, a disc storage device is formed by exchanging one preformatted disc in which preformat information is written in advance, without incorporating a disc single plate into the device. Therefore, when inspecting a pre-formatted disc such as an optical disc device, it is necessary to detect the position of the pre-formatted information and inspect it while protecting the pre-formatted information. Need to add.

When detecting and protecting preformatted information, a single disk pre-written with preformatted information does not have a clock that divides the rotation cycle into equal angular divisions in synchronization with disk rotation shake. Has the drawbacks described below regarding the function of detecting and protecting the preformat information of the disk single plate.

(1) When an equiangular position signal is detected from the spindle on which the disk single plate is mounted to obtain the clock signal, there is a phase difference that changes depending on the mounting state of the disk single plate. Therefore, it is necessary to mount a single disk so that there is no phase difference.

(2) Since there is a medium defect in the single disk of the disk, it is impossible to distinguish the preformat information from the error pulse in level slice and the like. Therefore, a circuit for reading the preformatted information is necessary to accurately know the position of the preformatted information.

(3) When the preformat information is detected by a level slice or the like, a malfunction occurs in the phase difference raised in (1) above because of the reason (2) above.

(Object of the Invention) The present invention has been made in order to eliminate the above-mentioned drawbacks, and an object of the present invention is not to depend on the mounting state of a disk single plate, and also to prevent a malfunction due to a medium defect on the disk single plate. It is an object of the present invention to provide a preformatted disc inspection device capable of protecting format information.

(Structure of the Invention) According to the present invention, the disk single disk for a disk storage device is mounted on an encoder and rotated to protect the preformatted information of the preformatted disk previously written at an equal angle to the rotation direction. A pre-formatted disc inspection device for inspecting a pre-formatted disc, wherein the encoder is an equiangular position signal synchronized with a change in the rotation speed of the pre-formatted disc and having a period which is an integer fraction of the period of the pre-formatted information. And an equal angular position signal detection unit that outputs a selection signal that specifies a detection period of preformat information to the preformat information position detection unit, and a preformat detection unit that detects the presence of the preformat information. Pre-format information per lap A proximity equal angular position signal detection unit that selects a frequency-divided signal of the equal angular position signal that is the same as the number and has a minimum phase difference with respect to the generation timing of the preformat information, and the proximity A pre-formatted information position detection unit that measures a phase difference between an equiangular position signal and a timing at which pre-formatted information is generated, and a gate signal is generated by using the phase difference and the proximity equi-angular position detection signal to generate the pre-formatted information. There is provided a preformat disc inspection apparatus including a preformat information protection unit having a timing signal generation function for protecting and inspecting format information from rewriting.

(Example) Next, this invention is demonstrated with reference to drawings.

FIG. 1 is a block diagram showing an embodiment of a preformatted disc inspection apparatus of the present invention. In the figure, the preformat disc inspection apparatus detects an equiangular position signal 6 which is synchronized with the fluctuation of the rotation speed of the preformat disc and in which the number of clocks in one rotation of the disc single plate is an integral multiple of the number of preformat information. Using the equiangular position signal detection unit 1, the preformat detection unit 2 that detects the presence of preformat information and outputs the preformat detection signal 7, and the preformat detection signal 7 and the equiangular position signal 6 The frequency division signal of the equiangular position signal 6 having the same number as the format information and the smallest phase difference with respect to the timing at which the preformat information is generated is selected as the close equiangular position signal 8 and the close equiangular position signal 8 is selected. And the proximity equiangular position signal detection unit 3 which outputs the selection periodic signal 10 to the preformat information position detection unit 4 when the selection is made.
A pre-format information position detecting section 4 for measuring phase difference data 9 between a proximity equiangular position signal 8 and a pre-format position detection signal 7 in a portion where the selection cycle signal 10 exists in the rotation cycle of the disk single plate; A preformat information protection unit 5 that generates a gate signal using the phase difference data 9 and the proximity equiangular position signal 8 to protect the preformat information.
With.

Next, FIG. 2 is a time chart showing the operation sequence in FIG. 1, and FIG. 3 is a view showing an example of the configuration of the equiangular position signal detection unit in FIG. 1, FIGS. 4, 5, and 6. Is a proximity equiangular position signal detection unit in FIG.
It is a circuit block diagram which shows one structural example of a preformat information position detection part and a preformat information protection part.

First, the operation timing of this embodiment will be described with reference to FIGS. The proximity equiangular position signal detection unit 3 divides the equiangular position signal 6 detected by the equiangular position signal detection unit 1, and the preformat detection signal detected by the preformat detection unit 2 from the divided signals. 7 is used to select the proximity equiangular position signal 8 and the proximity equiangular position signal 8 is selected.
Is output to the preformatted-information position detector 4 and the preformatted-information protector 5. The preformat information position detector 4 detects the phase difference P between the proximity equiangular position signal 8 and the preformat detection signal 7 at the time when the selection cycle signal 10 exists, and the phase difference data 9 is sent to the preformat information protector 5. Output. The preformat information protection unit 5 generates a gate signal 11 in which a protection margin m is set based on the phase difference data 9 based on the proximity equiangular position signal 8 to protect the preformat information from rewriting. The reference symbols T ₁ and T ₂ (shown in FIG. 2) are the detection period of the preformat information and the selection time corresponding to the detection period T ₁ .

Next, referring to FIG. 3, the equiangular position signal detecting section 1 (shown in FIG. 1) includes an encoder 33 connected to a spindle 32 for mounting a disk single plate 31, and the equiangular position signal detecting unit 1 shown in FIG. The signal 6 is detected. Further, the pre-format detector 2 (shown in FIG. 1) uses the level slice read from the disc single plate 31 as shown in FIG.
Preformat detection signal 7 consisting of a pulse of preformat information 70 and an error pulse 71 due to a medium defect
To detect.

Next, if the ratio of the number of clocks of the equiangular position signal 6 and the number of pieces of information of the preformat information 70 in one rotation of the disk single plate 31 is n (where n is a positive integer of 1 or more), the proximity equal angle is obtained. As shown in FIG. 4, the position signal detector 3 includes n AND gates 421,422, to 42n, and n and frequency dividers 411,41.
2, to 41n and n D-type flip-flops 431, 432,
~ 43n, one data selector 440, and erroneous detection determination circuit
450 and a selection period setting circuit 460, if the selection period equal to the generation period of the preformat information is set and there is no error pulse due to the medium defect in the selected period, Since only the preformat information is present, the value of the D-type flip-flop is read to prevent malfunction due to an error pulse included in the preformat detection signal 7, and to divide the equiangular position signal 6 whose phase is closest to that of the preformat information. The signal is selected as the near equiangular position signal 8. That is, in FIG. 4, the equiangular position signal 6 is input to the frequency dividers 411, 412, to 41n and the erroneous detection determination circuit 450, and the divided output signals are input to one of the AND gates 421, 422, to 42n, respectively. It is also input to the data selector 440. Also divider 4
The input signal 11 is input to the selection cycle setting circuit 460, and the selection cycle signal 10 from the selection cycle setting circuit 460 set by the instruction of the erroneous detection determination circuit 450 is AND gates 421, 422,
It becomes the other input of ~ 42n. AND gate 421,422, ~ 42n
The signals logically ANDed in are input to the D terminals of the D type flip-flops 431, 432, to 43n, respectively, and the preformat detection signal 7 is input to the CLK terminal of each of the D type flip flops 431, 432, to 43n. At this time, a signal is output from the Q terminal to the false detection determination circuit 450. The data selector 440 receives the same number as the total number of preformat information 70 for each detection cycle T ₁ (shown in FIG. 2) of the preformat information from the frequency-divided signals of the frequency dividers 411, 412, to 41n according to the instruction of the erroneous detection determination circuit 450. The phase difference P having the smallest phase difference P with respect to the timing at which the preformat information 70 is generated is selected as the proximity equiangular position signal 8.

Next, as shown in FIG. 5, the preformat information position detecting section 4 is composed of a counter 52, AND gates 53 and 54, and D type flip-flops 55 and 56. Signal 7 and reset signal 12
And the selected periodic signal 10 generate a phase difference existence signal 58,
A phase difference measurement signal 59 is generated by taking the logical product of the phase difference existence signal 58 and the selected periodic signal 10, and the phase difference measurement signal 59 is generated.
The phase difference measuring clock 51 is counted by the counter 52 using 59, and the phase difference data 9 is output. Note that the reset signal
Reference numeral 12 is a signal which is in phase with the equiangular position signal 6 at one clock for one rotation of the disk. That is, in this circuit, the phase difference measuring clock 51 is input to the clock terminal of the counter 52, the selection period signal 10 is input to the AND gate 53 and each D terminal of the D type flip-flops 55 and 56, and the D type flip-flop 55 is input. The reset signal 12 is connected to each of the CLA terminals of 56 and 56, and the proximity equiangular position signal 8 and the preformat detection signal 7 are connected to each of the CLK terminals, and the Q terminal of the D type flip-flop 55 and the terminal of the D type flip-flop 56 are connected. An AND gate whose output is one input of the AND gate 53 via the AND gate 54 and the other is the selected period signal 10
The above-described operation is performed by connecting the output terminal of 53 to the count control terminal of the counter 52.

Next, as shown in FIG. 6, the preformat information protection unit 5 includes two types of counters 62 and 65 for counting the gate setting clock 61 and two types of digital comparators 63 and 65.
66 and a data setting control circuit 64. The phase difference data 9 and the pre-format length data 611 are generated by using the gate setting clock 61 with the proximity equiangular position signal 8 as a reference.
To protect the preformat information on the disc veneer from rewriting. That is,
The gate setting clock 61 is input to the clock input terminals of the counters 62 and 65, and the output of the counter 62 is input to the digital comparator 63. The digital comparator 63 uses the output of the counter 62 to compare the phase difference setting signal 67 from the data setting control circuit 64 and the proximity equal angle signal 8 and supplies the output to the AND gate 610. On the other hand, the counter 65 counts the output of the digital comparator 63 and gives an output signal to the digital comparator 66. The digital comparator 66 compares the preformat length setting signal 68 from the data setting control circuit 64 with the output signal of the counter 65 and outputs the NOT gate. 69
To the AND gate 610 via. And gate 610
Is the output signal of the digital comparator 63 and the NOT gate
The gate signal 11 is output by taking the logical product with the output signal of 69. The data setting control circuit 64 outputs a phase difference setting signal 67 and a preformat length setting signal 68 using the phase difference data 9 and the preformat length data 611.

(Effects of the Invention) As apparent from the above description, according to the preformatted disc inspection apparatus of the present invention, the phase difference between the equiangular position signal and the preformatted information which does not depend on the mounting state of the disc single plate is detected. Since the preformatted information protection gate signal is generated, the preformatted disc can be inspected by arbitrarily mounting the disc single plate without mounting it on the position having no phase difference. Further, when the phase difference is detected, the phase difference between one preformat information in one rotation of the disk single plate and the proximity equiangular position signal is detected by using the selected periodic signal. Therefore, the preformat information caused by the medium defect is detected. A large effect such that the configuration of the preformat disc inspection apparatus is simplified by preventing the malfunction of the detection protection function and by using a level slice having a simple configuration without requiring a circuit for reading the preformat information in detail is produced.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a preformatted disc inspection apparatus of the present invention, FIG. 2 is a time chart showing an operation sequence in FIG. 1, and FIG. 3 is an equiangular position signal detection unit in FIG. FIG. 4 is a diagram showing one configuration example
FIG. 5, FIG. 5 and FIG. 6 are circuit block diagrams showing one configuration example of the proximity equiangular position signal detection unit, the preformat information position detection unit and the preformat information protection unit in FIG. 1, respectively. In the figure, 1 ... equiangular position signal detection unit, 2 ... preformat detection unit, 3 ... proximity equiangular position signal detection unit, 4 ... preformat information position detection unit, 5 ... preformat information protection unit , 6 ... Equal angle position signal, 7
…… Pre-format detection signal, 8 …… Proximity equiangular position signal, 9 …… Phase difference data, 10 …… Selection period signal, 11 ・ ・ ・
… Gate signal, 12 …… Reset signal, 31 …… Disk single plate, 32 …… Spindle, 33 …… Encoder, 411,412, ～
41n ... divider, 421,422, to 42n, 53,54,610 ... AND gate, 431,432, to 43n, 55,56 ... D type flip-flop, 440 ... data selector, 450 ... erroneous detection judgment circuit, 460 ...... Selection cycle setting circuit, 51 …… Phase difference measurement clock, 52,62,65 …… Counter, 58 …… Phase difference existence signal, 59 …… Phase difference measurement signal, 61 …… Gate setting clock, 63 , 66 …… Digital comparator, 64 …… Data setting control circuit, 67 …… Phase difference setting signal, 68 …… Preformat length setting signal, 69 …… Not gate, 611 …… Preformat length data, 70 …… Pre Format information, 71 ... Error pulse.

Claims (1)

[Claims] 1. A preformatted disc is inspected while mounting a disc single disk for a disc storage device on an encoder and rotating it to protect preformatted information of the preformatted disc which is written at an equal angle to the rotation direction in advance. A preformatted disc inspection apparatus, wherein the encoder detects an equiangular position signal that is synchronized with a change in the rotation speed of the preformatted disc and has a period that is an integer fraction of the period of the preformatted information. An equiangular position signal detection unit that outputs a selection signal that specifies the detection period of the preformat information to the preformat information position detection unit, a preformat detection unit that detects the presence of the preformat information, and The same number of format information and A proximity equal angular position signal detection unit that selects a frequency-divided signal of the equal angular position signal that has the smallest phase difference with respect to the generation timing of format information as a close equal angular position signal; A pre-formatted information position detection unit that measures a phase difference from the timing at which information is generated, and a gate signal is generated by using the phase difference and the proximity equiangular position detection signal to protect the pre-formatted information from being rewritten. And a preformat information protection unit having a timing signal generation function for inspecting the preformat disk device.