JPS58150137A - Optical information recording and reproducing device - Google Patents

Abstract

PURPOSE:To suppress the oscillation of a system of tracking and to enable the stable pull-in of tracking, by detecting the presence of micro spot light right above the guide tracks and the absence thereof in address information regions of sector separating information regions in the stage of pull-in of tracking and leading in the tracking at the instant of said detection. CONSTITUTION:Grooves 2a-2e of width W, pitch P and depth J are dug on the surface R side of an optical disc 1. The grooves 2a-2e constitute guide tracks and are formed concentrically or/and spirally. The guide tracks are separated from each other by the flat parts 3a-3e between the grooves. A photosensitive recording material is vapor deposited on the surface R side, thereby forming a recording layer 4. Micro spot light 5 is irradiated from, for example, the surface side of a transparent substrate 6, and focuses on the surface R, thus recording information. The places where the information is recorded are in the bottoms of the guide tracks 2a-2e. The recording bits recorded in the row of bits in varying densities recorded in the bottom of the track 2e have higher light reflectance thereof than the light reflectance in the unrecorded parts.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical TT'I' information recording/reproducing apparatus for optically recording and/or producing information on a disc-shaped information carrier, and particularly to an optical TT'I' information recording/reproducing apparatus for optically recording and/or producing information on a disc-shaped information carrier. Special feature 1a is applied to the tracking servo retracting means of the I'Fr binding carrier having nm-shaped guide tracks.

As an optical information recording/reproducing device, for example, photosensitive raw material f
: A disk-shaped signal carrier on which + is deposited or vapor-deposited is rotated completely, and a minute spot of light with a diameter of 1 μm or less from a laser light source is directed onto the front HD disk-shaped signal carrier. By irradiating the light and modulating the light output intensity with the 1D signal, a video signal is generated in real time as optical property changes such as phase changes due to irregularities, refractive index changes, or reflectance and transmittance changes on the carrier. An apparatus has been proposed that is capable of recording information such as optical signals and digital signals, and is capable of reproducing the recorded information by detecting changes in optical characteristics.

In such devices, one method for realizing high-density differentiation of recording tracks, isolated partial writing or erasing, or removal of the influence of vibration is to prepare a clear information carrier ■2 in advance for the track to be recorded. An optical disc structure has been proposed in which a recording member is coated or coated on the optical disc. Recording is carried out on this optical disk E on a flange-shaped track (hereinafter referred to as a guide track).

) is focused with the small spot light recorded on +JU, and the tracking system R4 is applied to follow the meandering of the guide track due to the eccentricity of the optical disk. Information is recorded in (4) of this guide trunk. In this way, if the optical disc is rolled for 1 second, the track density of the recording track is determined by the track pitch accuracy when forming the quotient of the guide track, regardless of the eccentricity of the optical disc, so a very effective disc can be produced.

For example, 20.00 for a 30c#11η1 disc.
0~40.000) Can accommodate concentric tracks of racks.

Such an optical disc made by Sumire Otani can accommodate 40,000 to 40,000 TV frames.

If the digital information is large enough, it has the ability to record approximately 1,000 mbytes of information. Therefore, in order to retrieve desired television images or digital information from an optical disc, it is necessary to be familiar with the information. In the case of television images, one frame of image is usually recorded on a track, so it is only necessary to add the valley track VC address information.

On the other hand, the length of digital information is not translated like that of TV images, so it is inconvenient to use only the 1st floor of a track. In order to divide the data into f\t@ areas, a sector division information area such as a sector separator is provided at the beginning of the valley sector.

It is a good idea to form such track address information and sector separator information in the form of scraps as uneven phase changes when all guide tracks are formed on an optical disk. This is because optical discs with guide tracks are produced by stamping using the same process used to manufacture playback-only discs.

Optical discs with guide tracks are unique to valley tracks.
The field and sector separator information is arranged in a circular arc form at a constant angle with respect to the center of the disk in the radial direction of the disk.

The following 1--A photosensitive material is used in the disc with the tasteful credibility.
γ has arrived, and information is to be recorded or reproduced in sector t6.

Pulling tracking control to such internal tracks (
ζt1 Every time a user searches for the track he/she wants, r-
T rope, jLru. Therefore, it is necessary to ensure the attraction of tracking city IJ + wholesalers. However, when the light spot irradiated onto the optical disk happens to not be directly above the guide track while crossing the guide track, or even if the light spot is located at the 1st stitch of the guide track, the address tlt information area or When the light spot is located on the head of the sector separation signal (lζ), if an attempt is made to pull in the tracking, the tracking system may oscillate.

When pulling in tracking, if the tqBg light spot is not at the 9th position of the guide track, the thread may hunt, or the light spot may be located in the landing information area or (d).
This is because when the sector separation information is on the head, the tracking error signal will be disturbed on the sphere, which will be described later.

The present invention detects that the minute spot light is directly above the guide track and is not in the landing information area or the sector separation information area at the time of tracking pull-in, and performs tracking pull-in at that moment, thereby improving the tracking system. The purpose of this invention is to provide a new means for suppressing start-up and performing stable tracking pull-in.

The present invention will be explained in detail below. FIG. 1 is a partial perspective view showing the groove structure of a guide track of an optical disc used in the present invention. The optical disc 1000H side has a width W,
There are m2a to 2e with pitch P and depth ■. Groove 2
a to 2e are flat portions 38 between the entire guide track grooves, which are formed in a concentric circle or/and a spiral shape.
They are separated from each other by ~3e. A photosensitive recording material is deposited on the R side to form a recording layer 4. The minute spot light 6 is emitted from the side of the transparent substrate 6, for example.
Focus on R-)H and record one report. The information is recorded at the bottom of the grooves of the guide tracks 28-2e.

Guide trunk 2e (/(is the groove) 6 logs were recorded on the bottom of the 1st part of the guide trunk 2e, and the recording pit is the unrecorded part vCχ.
1, its light reflectance increases. Guide track 2 a
~2e is usually P: 1, 6~2prn, V
i':=0.7 μm, and the groove depth δ is preferably selected from % wavelength to % wavelength in order to detect the dragging signal with a minute spot light.

Figure 2 shows an optical disc with a sector structure.
It is a format. In FIG. 2, AI and A2 are address areas where address information is recorded, S1 to S32 are sector areas where information is recorded, and 81 to B32 are sector separation information provided to divide the guide track into sectors. This is the area that is being recorded.

Arable land IH≠ has address area AI with uneven phase groove structure.

There are 6 parts recorded on A2 and cut symmetrically with respect to the center 0 of the optical disk.

It is necessary to separate the guide track of the optical disk 1 into a plurality of one official gazette recording units, so-called sectors, and to form information for 4 sectors on the guide track using phase waste cedar.

For the sector separation information mentioned above, there are two methods: one is to encode the sector number and record it in 6C, and the other is to record a special signal.
In selecting this sector separation information, it is necessary to consider two points: the characteristics and properties of the optical disc and the information recording efficiency.

Figure 3 (/i) This is an example of the 4 structure of the 4ff'j information storage area B, which is resistant to cracks and defects on optical discs and has good information recording efficiency. The guide track pieces 8ai, which have the same bit width W and track pitch pt as the guide track 7, are made by arranging flat parts 8b of equal length. The lengths of the guide track piece 8a and the flat surface 7pab are na and b. In this case, the dimensions a and b are one order of magnitude larger than the track pitch pt. FIG. 4 shows the tracking error output waveform when the optical pickup travels along the X-Al trajectory on the guide track 7. As shown in FIG. 6, the tracking error output is obtained from the reflected light from the guide track 7 by a bisecting pin photodiode placed in the far field.

That is, the tracking error output TE is the guide trunk 7
This is a photodiode 9 with a bisecting interest pin photodiode 9, which divides the deviation in the direction perpendicular to 4 in the far-field diffraction light distribution when the minute spot light from the optical pickup crosses both ends of the collar into two in the groove direction. Differential output ff of the photodiode of the photodiode: taken out from the subtracter 10.

Therefore, when the minute spot light crosses the track 7 in the table at the sector head S, a tracking error output of figure 8 as shown in FIG. 4 is generated. However, this tracking error output is greatly disturbed when a minute spot crosses the track in the sector separation information area d. This is because when the reflected light of the minute spot light cuts the track IA in the sector separation 1''# distribution area B, it is also diffracted in the direction half the direction of the guide track.Similar tracking error output 11iLn is the minute spot. It also occurs when the light crosses the track in the address area A.This is also the 7ζth point where the address signal is also provided in the same phase groove shape as the sector separation information shown in FIG. If you try to pull in the tracking when there is a minute spot light on the side, the pull-in will become unstable.

Also, if the minute spot light is directly above the guide track, the tracking error output will be almost zero (point C in Figure 4).
If the voltage is not directly above the figure 8 voltage shown in Figure 4, it will be output.

Therefore, if the voltage of this figure 8 is large during pull-in, the tracking servo system may start to oscillate. In order to prevent this nching from occurring, the tracking error output should be approximately zero. When a minute spot appears directly above the center of the track, the tracking control loop can be closed and turned on.

FIG. 6(d) is a circuit block diagram showing one embodiment of the present invention, and FIG. 7 shows output waveforms at each point shown in FIG. is o
It is a diagram of maki of ff.

The configuration of the present invention will be explained in detail with reference to FIGS. 6 and 7.

9 is a front self-dividing bin photodiode for detecting a tracking error signal. Reference numeral 11 denotes an AC amplifier for reproducing an address signal, a sector separator signal (sector separation signal), and recorded information, and its output waveform is shown in FIG. 7C. 12 is an OC angle for detecting a signal that disrupts the guide track to obtain a tracking sum output TSf:. 13 is a differential amplifier for obtaining a tracking error signal. Reference numeral 14 denotes a low-pass filter for distinguishing between the recorded news, the address signal, and the sector separator signal, and the address signal and sector separator signal having a lower band than the recorded +1 news are extracted. The extracted address signal and sector separator signal are shaped by 16 waveform shaping circuits, and become signals in sections corresponding to address signal area A and sector separator signal chain acid B, and the output of 16 inverters is as shown in FIG. I get a signal.

(The signal of (soa
) to (sof) are the waveforms when the minute spot light crosses the guide track.

Since the tracking error signal is obtained using the diffraction of the guide track, when the minute spot light crosses the guide trunk (+4), the amount of reflected light decreases and the tracking sum signal decreases. But 30b.

In the guide track where 1f roses are recorded like aof, the output signal does not change much as shown in the figure because the reflectance of the recording pit increases. Therefore, in order to detect that the reduced spot light has crossed the guide track, if information is recorded on the guide track, the information signal (FIG. 7C) reproduced by the envelope detection circuit 17 must be used. is subjected to envelope detection, and the waveform is shaped into a crab shape by the 18 waveform shaping circuits to obtain the signal shown in FIG. 7d. Note that S in FIG. 7C is an information signal reproduced from the sector header. On the other hand, in order to detect a guide track on which no news has been recorded, the output of the DC amplifier 12 is shaped by a waveform shaping circuit jN119. The output waveform is shown in FIG. 7 and 8. Therefore, the sum of values d and e in FIG. 7 is obtained by the addition ILj circuit 2o, and the theory ! J! When the full output is High, the minute spot light crosses the guide track. However, (as shown in Figure 7 d and e, it becomes uneasy when the address area and sector separation information area are crossed.Logic, fI) The output of 20 certainly represents the timing of the trunk section, but the pulse width Since the width of the pulse is wide, the rising or falling edge of the pulse does not accurately represent the four centers.The center of this pulse width is the center of the track in the stop layer.By the way, the zero crossing point of the tracking error signal is exactly the center of the track. It represents the central timing.

Therefore, when the tracking error signal shown in Fig. 7a is multiplied by i4 width by the loquat-to-hani amplifier 21, and the waveform shaping circuit 2 is processed, a pulse train indicating a cross point is generated (Fig. 79).
. However, the tracking error signal q has zero crossings not only at the center of the track, but also when the light spot crosses the instantaneous peak by one yellow. Therefore, if the logical product of the cooking sum output f that divides the above-mentioned re-interval and this zero crossing or pulse q is taken using an AND circuit, PI 3, a pulse train with exactly 4 centers will be output.

On the other hand, in the address area and sector separation information area, both the tracking error signal and the a signal become unstable. Therefore, if the AND circuit 23 is inhibited by the gate signal shown in FIG. 7F, 17. The pulse train at the center is not output, and therefore the signal shown in Figure 7 becomes a pulse train indicating that the minute spot light has come to the center of the groove within the address area and sector separation information area.

If this pulse h is used as the tracking control pull-in timing, tracking control can be started accurately at the groove center timing. By inputting the H4 center pulse (h in FIG. 7) to the RS flip-frog, the tracking ON command pulse (i) in FIG. 7 can be output in accordance with the tracking control 4 pulses in FIG. 7 (FIG. 7). Oi with (
By inputting a command pulse to the tracking drive circuit 28, tracking can be turned on during the tg period when the reduced spot light is not in the address area or the sector separation information area and is directly above the Annai track.

As shown in one embodiment of the present invention, in order to avoid address areas or sector separation information areas in which the tracking error output and tracking sum output are unstable during tracking pull-in, and to ensure further reliability, use tracks (grooves) that are unlikely to cause hunting. If the tracking control loop is closed and turned on at the moment when the small spot light comes to the center true, stable and reliable pulling of the tracking III 11 can be realized.

The optical recording and reproducing apparatus that performs recording and reproducing on a disc has been explained above, but there is also an optical reproducing apparatus that only reproduces information previously recorded on a disc. Although the description has been made using a disk as an example, the present invention can also be applied to an optical disk in which only an address area exists.

[Brief explanation of drawings]

Fig. 1 is a partial perspective view of the optical disc, Fig. 2 is a schematic plan view showing the trough area of the optical disc, and Fig. 3 A is a waveform showing the magnifier signal of 4 information areas for sectors. figure,
FIG. 6 is a summary diagram showing an example of a tracking error signal and production method, FIG. 6 is a block diagram showing one embodiment of the present invention, and FIG. 7 shows signal output waveforms of each part of FIG. 6. FIG. 1... Information carrier, 7... Guide truck,
AI, A2...address area, d1-832 sector separation information area. Name of agent: Patent attorney Toshio Nakao and one other person a1
Figure 13511 1a) 1 to 4 Figure 5

Claims (2)

[Claims] (1) Sector separation information having a concentric or spiral guide track on the surface and dividing an address information area or information recording area in which address clearing information is recorded in a part of the guide track. A disc-like shape with a bulge area! A means for rotationally driving the 4-purpose body, and an original beam for recording, /i, and reproduction are irradiated onto the guide track fL7. ), and a servo that starts the operation of the tracking servo means when the light beam is irradiated onto an area other than the address information area and the 4W information area of the guide track by sectors. An optical information recording/reproducing device comprising a starting means. (2) The servo starting means is configured to start the operation of the tracking servo means when the light beam is located at the center of the guide track. optical information recording and reproducing device.