JPS58108041A - Optical information recording and reproducing device - Google Patents

Abstract

PURPOSE:To improve an S/N ratio during reproduction by making feed intervals of a driving means shorter than those of a recording bit string, and detecting the position of the recording bit string through a reproducing means and controlling the driving means. CONSTITUTION:The movement starting position A of the reproducing means 8 is almost on a recording bit string 17a and a recording medium 11 rotates to scan a light beam on the circular recording bit string 17a. Then, the reproducing means 8 moves to a position B through the driving means to retrieve a recording bit string by the light beam. If a recording bit is not present within a tracking range, the reproducing means 8 sends a driving signal, moves to a succeeding position C immediately, and retrieves it again by the light beam to obtain the recording bit string 17b; and the light beam scans on this recording bit string and thus this operation is repeated to reproduce recording bit strings on the recording medium 1 successively.

Description

Detailed Description of the Invention: The present invention relates to an optical information recording and reproducing device.More details-When reproducing information on a medium, a light beam efficiently scans a recorded bit string (track). The present invention relates to an optical information recording/reproducing device having a controlled drive system.

An optical information recording/reproducing device records information as a time-series signal on a recording medium using a single source, or uses a light beam to pass over a signal train recorded in a concentric spiral shape on the recording medium. It is a device that reproduces information by scanning it with %
Original disks ~ party magnetic disks, etc. are known. Here, a case where recording bit strings are formed concentrically on a magnetic disk will be explained with reference to FIG. 1. In Figure 1, 1#i recording medium, 2 playback device, 3#i movable mirror, 4
1 is an original beam, 5F1 objective lens, 6 is a recording means, and 7 is a recording bit string. Here, the recording bits are recorded by the recording means 6 as a reversal of the magnetization direction, forming a recording bit string 7 concentrically spaced at equal intervals.

Scan with 4. This light and the reflected light of 4 are received by a light receiving element in the reproducing device to reproduce information. At this time, the interval between the recorded bit strings, that is, the track pitch, is about 2 m, and the two playback devices have recording bit position detection means, and by driving the movable mirror 3, the light beam 4 moves over the recorded bit string. It is controlled to scan accurately. 11 Fis for reproducing another recorded bit string A reproducing means such as a reproducing device is moved in the radial direction by a driving means (not shown).

A method of moving the reproducing means for the magneto-optical disk will be explained with reference to FIGS. 2(1) and 2(b). Figure 2 (1)
.

(b) is a side sectional view of each of the magneto-optical disks, in which 8 company reproduction means, 11#i recording medium, and 17 indicate a recording bit string. Reproducing means 8#1 is usually moved by a Stellar Pin l motor (not shown) at the same interval as the distance between recording bit strings as shown in FIG. 2 (1), and irradiates the recording bit string 17 with the original beam. However, if a positional shift occurs when the recording medium 11 is loaded, the starting point of the reproducing means 8 will shift from directly above the recorded bit string 17, as shown in FIG. 2(b). Further, since the driving means does not have a control means for such a deviation, the reproducing means 8 is moved with the deviation. In this case as well, since the reproducing means 8 includes means for detecting recorded bits and tracking the original beam with a movable mirror or the like as described above, it is possible to correctly scan the recorded bit string with the original beam. However, in order to prevent the original beam from being reflected in unnecessary directions and to perform efficient reproduction, it is desirable that the amount of tracking be small. Therefore, if the positional deviation of the reproducing means is large, the amount of tracking increases and the efficiency of reproduction decreases.

In view of the above-mentioned points, an object of the present invention is to provide an optical information recording/reproducing apparatus which can obtain reflected light with high efficiency and can reproduce information with a high S/N ratio.

The present invention moves the reproducing means to the position closest to the recorded bits by making the moving interval of the reproducing means smaller than the interval between recorded bit strings and controlling the drive of the reproducing means based on the detection signal of the recorded bits, thereby reducing the amount of tracking. The above purpose is achieved by making the size small.

Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 3 (1), (b)ii is a side lIr side view showing an embodiment of the present invention, in which 8 is a reproduction means, 11 is a recording medium,
17m=17b and 17C are recording bit strings, respectively. Here, the eight reproducing means are moved by a driving means (not shown) at intervals of 1/2 of the distance between the recorded bit strings. Furthermore, when the reproducing means tracks the original beam and correctly scans the recording bit string, it sends a signal to the driving means to perform reproduction when there are no recorded bits within the tracking range with the same interval as the feed pitch of the driving means. It moves the means to the next position.

3a(M), the movement start position of the reproducing means 8 indicated by a person is approximately on the recording bit string 17a, and as the recording medium 11 rotates, the circular recording bit string 17
A is scanned with the original beam. Next, the reproducing means 8 moves to the position shown in B by the driving means and searches for the recorded bit string using the original beam.

If there is no recorded bit within the tracking range, the reproducing means 8 sends a signal to the drive signal to immediately move to the next position C, searches again with the original beam to obtain the recorded bit data IJ17b, and retrieves the recorded bit data IJ17b. The recording bit string is scanned with the original beam. Repeat the above operations to create recording medium 1.
1 is used to reproduce the recorded bit string on the face.

Here, as shown in FIG. IS3 (b), if the movement start point position of the reproduction means 8 is thick from the top for the recording bit string 12 (if it deviates, then if there is no recorded bit string within the tracking range at the position of the person, the reproduction The means 8 immediately moves to position B and scans the recording bit string 17a without exceeding this range. Therefore, compared to the conventional example shown in Fig. 8g2 (ah (b)),
The amount of tracking can be kept small.

In this embodiment, the feed interval of the driving means is set to 1/2 of the interval between recording bits, but the value is not limited to this value. It is possible to obtain the effect. In addition, although a magneto-optical disk is used as an example here, the defective disk of the present invention, etc.
It can be widely used in optical information recording and reproducing devices.

As explained above, the present invention has the effect of improving the 8/N ratio during reproduction in a conventional optical information recording/reproducing apparatus by reducing the tracking amount of the light beam.

[Brief explanation of the drawing]

Figure 1: A perspective view showing the outline of the company's magneto-optical disk 1 kWt.
, Figures 2 (1) and (b) are 6 volumes, and Figures 3 (a) and (b) are cross-sections showing the movement of the conventional regeneration means.
) tJ is a side sectional view showing the movement of the reproducing means of the present invention. 8. Fist - Reproduction means % 11 @*@@ Recording medium,
IL17m-17b*17c 6866e recorded bit string. Applicant Canon Co., Ltd. kj + blood, → hand? Open (t)) Aro diagram (α) (F))

Claims (1)

[Claims] (1) A recording medium in which recording bit strings are formed concentrically, a means for rotating the wrinkled recording medium, a reproducing means for reproducing information from the recording bit string; In an optical information recording and reproducing apparatus comprising a driving means that relatively moves at a constant distance in the radial direction, the feeding interval of the driving means is smaller than the interval between the recording bit strings, and the recording by the reproducing means 1. An optical information recording and reproducing apparatus, characterized in that the position of a bit string is detected and the driving means is controlled.