JPS6254832A - Recording structure in optical information recording medium - Google Patents

Abstract

PURPOSE:To prevent a change causing external disturbance to a servo system at a boundary by changing the shape of a pit and a groove in the vicinity of the boundary of adjacent areas so as to connect smoothly the adjacent areas. CONSTITUTION:The track 1a consists of a pre-address pit part 2 and a pre- groove part (guide groove) 3 and the address of a succeeding pre-groove part 3 is recorded in advance to the pre-address pit part 2. A transition section 6 consists of a pit 10 and the length (or both the length and width) of the pit is changed gradually by the recording beam modulation to connect the pre- address pit part 2 with the pre-groove part 3 thereby smoothing the change in the returned light quantity.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Application of the Invention The present invention relates to a recording structure in an optical information recording medium.

"Prior Art" A typical example of this type of optical information recording structure in the past is the structure shown in FIG.

FIG. 5 is a plan view of the signal surface of the optical information recording medium.
The recording thin film layer formed on the surface is omitted.

In the drawing, A is an optical information recording medium, and this optical information recording medium A has a plurality of tracks A1, A2 . A3
... is formed, but in the drawing there is only one track A.
Only 1 and A2 are shown.

Each track A1, A2 is composed of a pre-address bit part B and a pre-group part (guide groove) C, and the address of the following pre-group part C is recorded in advance in the pre-address pit part B. There is. Further, an information signal is later recorded in the pregroup portion C, and a recording portion F is formed after the non-recording portion E as shown in track A2. Note that the track At shows a state in which no information signal is recorded in the pregroup section C.

G is a light spot used for reading out the information signal, recording the information signal, erasing the information signal, etc.

Briaddress bit part B and pregroup part C are usually 1,
These areas are formed in advance when the optical recording medium A is created, and the boundaries of each area are clearly divided into a pre-address bit area B and a pre-group area C, as shown in FIG.

Also, when an information signal is later recorded in the pre-group area C by the optical spot G, it is recorded in the form of a pit on the pre-group area C, so the boundary between the non-recorded area E and the recorded area F is clearly separated. In other words, one track A1 is divided into two or three different types of areas, and the boundaries of the respective areas are discontinuous. Then, the light spot G is on the track A1. When tracing on A2, the DC of the amount of returned light! The pre-address bit section B and pre-group section C differ in number, and the non-recording section E and recording section F also differ. In this case, the magnitude relationship of the DC component of the amount of returned light is largely influenced by the recording shape of each area.

"Problems to be Solved by the Invention" As mentioned above, in the conventional recording structure, the boundaries between adjacent areas are discontinuous, so that the light spot G is
When tracing the top, at the boundary, the amount of return light D
The C component changes rapidly. As a result, the level of the focusing error signal, tracking error signal, etc. suddenly changes, and in some cases, the focusing servo or tracking servo may become out of order.

"Means to Solve the Problem" The present invention has been made to solve the above-mentioned drawbacks. The purpose of this invention is to provide an optical information recording structure that smoothly connects regions and prevents changes that would cause disturbance to the servo system at the boundaries.

"Structure of the Invention" The present invention will be described based on embodiments of the drawings. 1, 2, 3, and 4 are plan views of main parts showing different embodiments of a recording medium to which the recording structure of an optical information recording medium according to the present invention is applied, and each of them is a The recording Fj film layer formed on the surface is omitted.

In the drawings from FIG. 1 to FIG. 4, 1 is an optical information recording medium, and this optical information recording medium 1 has a plurality of tracks la, lb, lc... Here, only one track la is shown.

The track 1a in FIGS. 1 and 2 is composed of a pre-address pit part 2 and a pre-group part (guide groove) 3, and the pre-address bit part 2 has a pre-address pit part 2 and a pre-group part (guide groove) 3. The address has been recorded in advance.

Further, the track 1a shown in FIGS. 3 and 4 is constituted by a pre-group portion (guide groove) 4. As shown in FIG.

5 is a light spot used for reading information signals, recording information signals, erasing information No. 48, and the like.

Therefore, FIGS. 1 and 2 show examples in which the pre-address bit section 2 and the pre-group section 3 are smoothly connected by the transition section 6. 3 and 4 are examples in which the pre-group non-recording section 7 and the pre-group recording section 8 on the pre-group section 4 are smoothly connected by a pre-group transition section 9.

Note that "smooth" here means that when the optical scrubber 5 traces the track la, the DC component of the amount of returned light changes smoothly (without discontinuities).

To give an additional explanation about the recording device, FIG. 6 shows an embodiment of the recording device for recording as shown in the drawings of FIGS. 1 to 4 above. Only the main parts of the apparatus are shown. In the figure, the recording beam 11 is modulated in intensity and irradiation time by an optical modulator 12, expanded in beam diameter by a beam expander 13, and then sent to a beam splitter. Pass through 14 and mirror 15
The shape of the pit or group reflected by the light modulator 1 and recorded on the recording medium 17 by the condensing lens 16 is
The beam intensity and irradiation time are modulated by 2.

An example of a method for modulating the beam intensity and irradiation time for recording transition sections such as those shown in FIGS. 1 to 4 is shown in FIGS. 7 to 1O.

Figure 7 shows a case where the beam intensity is constant and the irradiation time is lengthened, Figure 8 shows a case where the beam intensity is increased continuously, and Figure 9 shows a case where the beam intensity and irradiation time are constant but the irradiation interval is gradually increased. In FIG. 10, the irradiation time and irradiation interval are constant and the beam intensity is gradually increased.

Next, the operation of the above embodiment will be explained.

First, in FIG. 1, the transition section 6 is composed of pits 10, and the
The length of the pit (
By gradually changing both the length and width and connecting the preaddress section 2 and the pregroup section 3, the amount of returned light changes smoothly.

In addition, Fig. 2 shows the transition section 6 as a pre-group (guide groove) 1.
1, recording is performed by gradually changing the width of the pre-group by recording beam modulation as shown in FIG. This is what I did.

Furthermore, FIG. 3 shows recording by gradually changing the interval of the pits 12 recorded in the group transition section 9 on the pre-group section 4 by recording beam modulation as shown in FIG. The group recording section 8 is connected to the device so that the amount of returned light changes smoothly.

In addition, in Figure @4, recording is performed by gradually changing the size of the pit 12 recorded in the group transition section 9 of the pre-group part 4H by adjusting the recording beam as shown in Figure 1θ. and the pre-group recording section 8, so that the amount of returned light changes smoothly.

"Other Embodiments" In the above embodiments, each of the embodiments was treated individually, but in actual cases, multiple embodiments may be used together. For example, FIG. 3 and FIG. 4 may be used together. A similar effect can be expected even if both the size and interval of the pits 12 are gradually changed.

In addition, in the above embodiment, the size of p) 10.12,
Although the explanation has been limited to the amount of change in terms of the interval and the width of the pre-group, the depth of the pit or pre-group, or if the record of the pit is of a reflectance-varying type, the reflectance of the pit is also one of the amounts of change. By gradually changing them in the transition section, it is also possible to smoothly connect adjacent regions and obtain the same effect as in the above embodiment.

"Effects of the Invention" As described above, the present invention provides track l of the optical recording medium 1.
When a, lb, lc, etc. are composed of multiple areas with different recording formats, the recording shape of one or both information signals near the boundary of each adjacent area is changed, so that the optical When the spot 5 traces the tracks 1a, 1b, lc, . . . , the amount of returned light changes smoothly. Therefore, playability such as focusing and tracking near the boundary does not undergo sudden changes, and a stable state can be maintained.

[Brief explanation of the drawing]

1, 2, 3, and 4 are plan views of main parts showing different embodiments of optical recording media to which the optical information recording structure according to the present invention is applied, and FIG. FIG. 6 is a plan view of the main parts of an optical recording medium according to an optical information recording method, FIG. 6 is a schematic diagram of the main parts of a recording apparatus for recording shown in the embodiment, and FIGS. 7 to 10 are FIG. 4 is a plan view of different embodiments showing methods of recording beam modulation and time modulation as shown in the drawings of FIGS. 1 to 4; 1... Optical recording medium, la, lb, 1c...-track, 2... Pre-address pit section, 3.4... Pre-group section, 5... Light spot, 6... Transition Section, 7... Pre-group non-recording section, 8... Pre-group recording section, 9... Pre-group transition section. Patent applicant Pioneer Corporation Figure 6 Figure 11! l

Claims (1)

[Claims] A recording structure in an optical information recording medium, which includes a first recording track area in which a DC component of the amount of return light with respect to the light irradiated onto the information recording surface is relatively large, and a D of the amount of return light.
A second recording track area in which the C component is relatively small, and a second recording track area is formed between the first recording track area and the second recording track area, and the DC component of the amount of returned light is in the second recording track area. A recording structure in an optical information recording medium, characterized in that it has a transition track area that sequentially changes from a value to the relatively small value.