JPH0492220A - Optical recording and reproducing device - Google Patents

Abstract

PURPOSE:To set a recording and reproducing starting point with high accuracy by correcting a relative position of an optical recording medium to an optical head based on a read data from the optical recording medium as against an output signal from a carrier means for carrying the optical recording medium. CONSTITUTION:A source position clock 51 is corrected by a position clock correcting control circuit 47 upon receipt of a coincidence signal from a comparator 46, and a load signal and a position clock signal are outputted to a position counter 48. The clock 51 and also an output signal of a comparator 42 are inputted to this circuit 47. An output of the position counter 48 is inputted to a 3rd comparator 49, to which a prescribed value corresponding to a sector partitioned position on an optical card is inputted as well in response to a format selecting signal 36 from a format selector 50, and when both output values are coincident with each other, a sensor position detecting signal 37 is outputted to a controller 30.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical recording/reproducing apparatus provided with means for correcting the relative position of an optical recording medium with respect to an optical head based on data read from the optical recording medium. .

[Prior Art] A data recording/reproducing device using an optical card as a recording medium includes an optical card having a plurality of mutually parallel tracks, and an optical head for optically recording and reproducing data on the optical card. Data is recorded and reproduced by relatively reciprocating movement in the track direction and in a direction orthogonal thereto. FIG. 6 shows an example of the configuration of an optical card used in such an optical card recording/reproducing device. The optical card 1 has a track 2 extending in the longitudinal direction of the card.
It has multiple pieces parallel to the card width direction.

In optical cards, the amount of data recorded at one time varies depending on the application. Therefore, in order to effectively use the limited recording area, it is necessary to prepare a rack format with a sector size suitable for the application.

On the other hand, in an optical card recording and reproducing device, in order to shorten access time, it is desirable to record and reproduce data in both directions of relative reciprocating motion between the optical card and the optical card.

Japanese Patent Application No. 1-30809 proposes an optical card recording and reproducing apparatus that satisfies the above requirements. Here, the relative position of the optical card with respect to the optical head in the direction in which the track extends is detected by the output from the means for transporting the optical card, and the recording/reproduction start point is arbitrarily selected based on the detected result. This makes it possible to format tracks of any sector size, and to record and reproduce data in both directions of relative reciprocating motion between the optical card and the optical head.

[Problems to be Solved by the Invention] In the data recording and reproducing apparatus described above, means for transporting the optical card, which determines the relative position of the optical card with respect to the optical head;
That is, the detection is based on the output clock signal from the encoder attached to the optical card transport motor, and the data recording/reproducing start point is determined based on the detection. Such an encoder number is normally used with a force of about 200 μm.

In reality, the clock signal output at this interval is
A clock signal which is multiplied and generated every 50 μm converted to the length on the optical card is generated and used. Therefore, the positioning accuracy of the data recording/reproducing start point is approximately 50 μm.

However, in this type of data recording and reproducing device (2), positioning is not performed in consideration of the position information on the optical card, so data recording and reproducing cannot be performed depending on the mounting state of the optical card on the optical card transport means. There was a problem that the starting point would change.

In addition, when recording and reproducing even higher density data, 50
Although the positioning accuracy on the order of μm is insufficient, there was a problem with using a high-precision encoder, which would increase the cost of the device.

The present invention has been made in view of the above-mentioned points, and enables highly accurate recording/playback positioning without the need for a high-precision encoder and regardless of the mounting state of the optical card on the optical card transport means. The purpose of the present invention is to provide an optical recording/reproducing device that achieves the following.

[Means and effects for solving the problem] In the present invention, data is recorded and/or reproduced by an optical recording medium including a track area on which data is recorded, and a relative movement between this optical recording medium and an optical head. In an optical recording and reproducing apparatus that performs the following, an optical recording medium conveying means for moving the optical recording medium relative to an optical head, and a position signal indicating a relative position between the optical head and the optical recording medium conveying means. a position detection means for detecting a position, a correction means for correcting the generation timing of the position signal based on a signal corresponding to a track area of the optical recording medium detected by the optical head, and a position corrected by the correction means; By setting the data recording/reproducing position based on the signal, the data recording/reproducing position can be set with high precision.

[Example] Hereinafter, the present invention will be specifically explained with reference to the drawings.

1 to 5 relate to one embodiment of the present invention, FIG. 1 shows the configuration of an optical card recording/reproducing device of the first embodiment, and FIG.
The figure shows an example of a recording format of a track of an optical card, FIG. 3 shows the configuration of a sector position detection circuit, FIG. 4 shows timing charts 1 to 1 for explaining the operation of FIG. 3, and FIG. 5 shows a flowchart when accessing a sector of a specific track.

As shown in FIG. 1, an optical card recording/reproducing device W2 according to an embodiment
0 records and reproduces data by moving the optical card 1 as an optical recording medium in the 1-to-rack direction and the optical head 21 in a direction perpendicular to the trunk. The hook is attached to a predetermined position on the conveyor belt 23, and the optical card 1 is conveyed back and forth in the trunk direction by driving a motor 25 whose drive is controlled by a motor drive circuit 24. An encoder 26 for detecting the position of the optical card 1 with respect to the optical head 21 is attached to the motor 25, and its output is supplied to a sector position detection circuit 27.

The optical helad 21 includes a laser diode 21. It is configured to project the writing or reading light from the optical card 1 onto the optical card 1 via an optical system 21b composed of a beam splitter, an objective lens, and the like. Detector 21c
The output is supplied to the demodulation circuit 28 to obtain a readout signal 35, and is also supplied to two focus/track servo circuits, so that the incident light always follows the optical head 21 in the focus and track directions. Control as follows.

The read signal 35 is supplied to the controller 30 to detect a data reproduction signal and track address information.

When reproducing data, the controller 30 first outputs a format selection signal 36 indicating the type of track format to the sector position detection circuit 27, and selects the track format based on how many sectors one track consists of. Then, the laser diode 21a outputs a low-power reading light via the laser drive circuit 31, controls the drive of the motor drive circuit 24, and outputs the track address information demodulated by the demodulation circuit 28 and the sector position detection circuit 27. Based on the sector position detection signal 37 according to the track format, a desired sector of a desired track is sought and data is reproduced. In addition, when recording data, the format selection signal 36 is first output to the sector position detection circuit 27 in the same way as described above.
After selecting a track format and seeking a desired sector of a desired track on which data is to be recorded, the high-power writing light from the laser diode 21a is modulated by the data to be recorded and output via the laser drive circuit 31. data is recorded in the sector.

The optical card 1 used in this embodiment is the same as the one shown in FIG. 6, and this optical card 1 has a plurality of tracks 2 extending in the card longitudinal direction formed in the card width direction. Each track 2 is composed of one sector or a plurality of sectors.

FIG. 2 shows an example of the structure of a track record format. This track has ID sections 3a at both ends.
, 3b and a data section 4 for recording data therebetween. The left side ID section 3a has PLL synchronization patterns (also referred to as PLL synchronization patterns) 5a, 9a, 14b, 17a,
Byte synchronization patterns 6a, 10a, 14a that indicate the beginning of the ID when reading from the left side, IDs 7a, lla, 15a in which track addresses etc. are recorded, and byte synchronization pattern 8a that indicates the beginning of the ID when reading from the right side. 12a and 16a.

Similarly to the left side ID section 3a, the right side ID section 3b also has bit synchronization patterns 5b, 9b, 13b, 17b, and byte synchronization patterns 6b, 1 that indicate the beginning of the ID when reading from the left side.
0b, 14b, I where track addresses etc. are recorded
D7b, llb, 15b, and byte synchronization patterns 8b, 12b, which indicate the beginning of the ID when reading from the right side.
16b. In this embodiment, in order to increase the reliability of the track address, the ID sections 3a at both ends.

3b, each ID is written three times.

In addition, each ID has an I ID to distinguish it from other IDs.
The D number is recorded together with the track address. Further, since a byte synchronization pattern and a bit synchronization pattern are arranged on both sides of each If), reading from both directions is possible.

Next, the sector position detection circuit 27, which is a feature of the present invention, will be explained.

The sector position detection circuit 27 outputs a sector position detection signal when the optical head approaches a position on the optical card corresponding to a sector division according to the track format selected by the format selection signal 36 from the controller 30. It is.

FIG. 3 is a block diagram of the sector position detection circuit.

FIG. 4 is a time chart for explaining the operation of the sector position detection circuit 27.

The feature of this sector position detection circuit 27 is that the source position clock 51 (fourth clock) is obtained by multiplying the output clock from the encoder by four, which is unrelated to the reference position on the card shown in FIG. 4 (see FIG. 4(a)). (see Figure (b)), a position clock is generated that is corrected so that it always occurs at each reference position on the card, and a sector position detection signal 37 is generated based on this corrected position clock as a reference for starting recording or playback. There is a place to do it.

Reference numeral 40 in FIG. 3 is a correction start position register that stores data indicating a correction start position, and correction start position data is inputted from the controller 30.

The data of this correction start position register 40 is inputted as reference data to a first comparator 42, and the count value of a bit counter 43 for counting the PLL clock signal 38 is also inputted to this comparator 42. This bit counter 43 is reset by three byte synchronization pattern detection signals from the demodulation circuit 28 (see FIG. 4(c)).

The comparator 42 compares the output of the correction start position register 40 and the output of the bit counter 43, and outputs a match signal to the correction amount register 44 if they match. This correction amount register 44 receives the output of a correction amount counter 45 that is reset every time the source position clock 51 is generated and counts a reference clock (for example, a clock with a frequency of about 256 times the frequency of the source position clock 51). When the matching signal is output, the output value of the correction amount counter 45 is stored.

The outputs of the correction amount counter 45 and the correction amount register 44 are input to a second comparator 46, and when the Okayama force values match, a match signal is output to the position clock correction control circuit 47.

The position clock correction control circuit 47 includes a comparator 4
6, corrects the source position clock 51 and outputs a load signal and a position clock signal to the position counter 48.

This position clock correction control circuit 47 also receives the source position clock 51 and the output signal of the comparator 42 as input. This position clock control circuit 47 is controlled by the controller 30.

The output of the position counter 48 is sent to the third comparator 4.
9, and a predetermined value corresponding to the sector separation position on the optical card 1 is also input to this comparator 49 in accordance with the format selection signal 36 from the format selector 50, and when the Okayama force value matches, A sector position detection signal 37 is output to the controller 30.

Next, the operation of this sector position detection circuit 27 will be explained below with reference to FIG.

This description is for example forward access, part 10 3a
The left end of the position counter 48 is controlled so that it becomes 100H. First, when the optical head 21 approaches the ID section 3a, a PLL clock signal 38 corresponding to the bit on the optical card 1 is output from the demodulation circuit 28. Bit counter 43 counts this PLL clock signal 38. Additionally, a byte synchronization pattern detection signal (
When 39-1) in FIG. 4(C) is output, the bit counter 43 is reset as shown in FIG. 4(d) and continues counting the PLL clock signal 38 again. That is, the value of this bit counter 43 corresponds to the position of a bit on the optical card 1 (with the period being the arrangement of the bit synchronization pattern 5a, byte synchronization pattern 6a, etc.). At this time, the controller 30 uses the demodulation circuit 28 to
7a and outputs correction start position data (N in FIG. 4) corresponding to the ID number to the correction start position register 40. This value N is prepared in advance in correspondence with the ID number, and in this example, it is the value corresponding to the seventh reference position on the card from the left as shown in Figure 4 (a). Since the correction start position data requires time to read and judge the ID section, data corresponding to the reference position after this ID judgment and before reaching the next ID section is actually prepared.

Subsequently, when the output value of the bit counter 43 reaches N, the fourth
A match signal is output from the comparator 42 as shown in FIG. 4(e). On the other hand, the correction amount counter 45 is reset every time the source position clock 51 is generated, as shown in FIG. 4 (f>), and a counting operation is always performed.

When a match signal is generated from the comparator 42, the output value of the correction amount counter 45 at that time is stored in the correction amount register 44 (M in FIG. 4(g)). At the same time, the position clock correction control circuit 47 sends a load signal and a load value (preset) to the position counter 48.

(in this example, it is 106H, and if you go back to the beginning of optical card 1, it will be 100H.), and
8 to load the load value. Until this point, the position clock correction control circuit 47, which had given the source position clock 51 as it is to the position counter 48 as a position clock (see FIG. 4(i)), starts from this point when the optical head 21 is connected to the ID section 3b on the opposite side. 2°C 1, which operates to provide the position counter 48 with a position clock corrected for the period until it passes through the
:3 The position clock is generated in the position clock correction control circuit 47 as follows. That is, the output value of the correction amount counter 45 and the content of the correction amount register 44 (that is, M)
are compared by a comparator 46, and when they match, a corrected position clock (see FIG. 4(h)) is output. By doing this, the position counter 48 counts at each reference position on the card in FIG. As shown in Figure 4 (j), 106H is preset from the controller 30, and from this value the correction position clock synchronized with the reference position is counted), so that the optical card 1 is in the attached state on the conveyor belt 23/\. Yes, the recording/reproducing start point can be made constant. Furthermore, since the positioning accuracy in this case is based on the PLL clock signal 38, it is on the order of 1 bit formed on the optical card 1.

The output of this position counter 48 and the format selector 50
The output values of are compared by a comparator 49, and when they match, a sector position detection signal 37 is output.

FIG. 5 shows flowcharts 1 to 1 when a specific sector of a specific track is accessed in the above-described optical card recording/reproducing apparatus 20 using the optical card 1 having a track in the pre-record format shown in FIG. First, in step S1, a format selection signal 36 is applied to the sector position detection circuit 27 in order to select the track format of a target specific track. Next, the ID section shown in FIG. 2 is read, and the optical radar 21 is sought to a specific track to be accessed (step S2>).

That is, when the optical card 21 moves from left to right in the track direction with respect to the optical card 1 shown in FIG.
"Forward direction" means ID7 of the ID section 3a shown in FIG.
When moving from right to left by reading a, lla, and 15a and determining the track address by majority logic (hereinafter,
(referred to as "reverse direction") is ID1 of the ID section 3b shown in FIG.
5b, 11b, and 17b are read and the track address is determined by majority logic. Subsequently, in step S3, the optical card 1 is moved in the track direction on a specific track, and the sector position detection signal 37 output from the sector position detection circuit 27 is counted. A counter for counting this sector position detection signal 37 is reset in advance every time the direction of movement changes.

It is determined in step S4 whether or not the value matches the target sector number, and when they match, the sector is accessed as shown in step S5.

Here, the sector number is recognized as follows.

That is, for example, when accessing a track in a track format in which one track is composed of four sectors,
For forward access, Karan 1 to value -1 goes to sector number -1, count value = 2 goes to sector number -2, count value = 3 goes to sector number -3, count value = 4 goes to sector number -4 , respectively. Also, for reverse access, count value = 1 is assigned to sector number -4, count value 2 is assigned to sector number = 3, count value = 3 is assigned to sector number = 2, count value = 4 is assigned to sector number = 1. , correspond to each other. *It can be easily recognized by the motor drive circuit 24 whether the direction access is the reverse direction access.

[Effects of the Invention] As described above, according to the present invention, the relative position of the optical recording medium with respect to the optical head is read from the optical recording medium in response to the output signal from the conveyance means that conveys the optical recording medium. Since the correction is based on the data, it is possible to position the minimum recording unit of the optical recording medium without depending on the installation state of the optical recording medium on the transport means, and the recording and playback start point can be determined with extremely high precision. Can be set.

[Brief explanation of the drawing]

1 to 5 relate to one embodiment of the present invention, FIG. 1 is a configuration diagram of an optical card recording/reproducing device of one embodiment, and FIG. 2 is an explanatory diagram showing an example of preformatting an optical card. Third
The figure is a block diagram of the sector position detection circuit, Figure 4 is a timing chart for explaining the operation of Figure 3, Figure 5 is a flowchart showing the processing content when accessing a specific sector, and Figure 6 is an optical card. FIG. 1... Optical card 2... Track 20.
- Optical card recording/reproducing device 21... Optical head 27... Sector position detection circuit 8... Demodulation circuit 9... Focus/track servo circuit 0... Controller 0... Correction start position register 2.46. 49... Comparator 3... Bi-soto counter 44... Correction amount register 5... Correction amount counter 7... Position clock correction control circuit 8... Position counter O... Format selector No. 5 Figure 6

Claims (1)

[Scope of Claims] An optical recording and reproducing apparatus that records and/or reproduces data by means of an optical recording medium including a track area on which data is recorded, and a relative movement between this optical recording medium and an optical head, comprising: an optical recording medium transport means for moving an optical recording medium relative to the optical head; a position detection means for detecting a position signal representing a relative position between the optical head and the optical recording medium transport means; a correction means for correcting the generation timing of the position signal based on a signal corresponding to a track area of the optical recording medium detected by an optical head; and a correction means for correcting the recording/reproducing position of the data based on the corrected position signal. An optical recording/reproducing device characterized in that: