JPS5842526B2 - kilokutantai - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a record carrier having a hatched area for detecting scanning deviation from a recording section.

BACKGROUND OF THE INVENTION Rotating record carriers on which image signals such as T and V signals are recorded usually have information recorded thereon in a spiral or concentric manner, such as on an audio record.

In a record carrier on which information is recorded at high density, the pitch of spiral lines or concentric circles in the radial direction is several μm or less, and in order to reproduce information favorably, scanning of the recording portion must be performed accurately.

Purpose The present invention achieves the above-mentioned objects by providing a diagonal line part having a certain angle with respect to the radial direction of a part of a record carrier and obtaining a spectral pattern for detecting scanning deviation from the diagonal line part. It is something to be achieved.

DESCRIPTION OF EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is for explaining the principle of operation. Reference numeral 11 indicates a recording plate, and on this recording plate there are marks indicated at 12° and 13. As shown, two types of multiple parallel line portions with different inclinations are recorded.

Now, when this recording plate 11 is irradiated with a coherent parallel light beam 14 such as a laser beam, the focal plane of the lens 15 placed behind the recording plate 11, As is well known, the Fourier spectrum of the recording plate 11 is generated at the position of the rear focal length f.

That is, the line indicated by 16 in FIG. 1 is the multiple parallel line portion 1.
3 is the Fourier spectrum, and the line 17 is the Fourier spectrum due to the multiple parallel line portion 12.

Now, the parallel light beam 14 (it does not necessarily have to be a parallel light beam, but if it is not a parallel light beam, a pattern similar to the multiple line parts 12 and 13 will be formed shifted from the rear focal plane of the lens 15) is recorded. The right half of the plate 11, that is, the multiple parallel line portion 13
When only the multiple parallel line portion 12 is irradiated with the parallel beam 14, only the pattern 16 is generated on the rear focal plane (X-Y plane) of the lens 15, and when the parallel beam 14 is irradiated only on the multiple parallel line portion 12, the pattern 17 is generated on the X-Y plane. only occurs.

Conversely, by observing the Fourier spectrum pattern formed on the X-Y plane, the irradiated portion of the recording plate 11 can be determined.

The multiple parallel line portions on the recording plate may be recorded as black and white patterns, or may be recorded by deforming the surface of the recording plate, or by changing the refractive index of the recording plate.

Figure 2 shows a part of a rotating record carrier in which a multiple line section is provided on the record carrier in order to enable the signal detection head to accurately follow the signal track of the record carrier. An information recording section 19 is formed in a spiral shape on one surface of the record carrier 18 formed in the same direction, and on both sides of the information recording section there are different fixed sections with respect to the straight line 0-r in the radial direction of the record carrier. Two types of multiple diagonal lines 20 having angles α and β
21 are arranged respectively.

The pitch of each diagonal line in this multiple diagonal line portion does not necessarily have to be equal, but better results can be obtained if the pitch is equal.

Further, it is preferable that the distance between the pitches is narrower than the width of the beam 22 that is irradiated to read out the signal from the recording section 19.

In addition, when the recording section 19 is configured in a spiral shape, the radial angle differences α and β of the multiple diagonal lines are determined on one side of the spiral (in the case of the embodiment, the point that coincides with the radius C-C). The recording unit 19 sends a switching signal (for example, T
The configuration is such that when a V signal is recorded, a vertical synchronizing signal, etc. are also recorded.

Therefore, when reading the information on the record carrier 18, it is preferable to use a device as shown in FIG.

That is, the turntable 24 is rotated by a motor 23, and the feed screw 25 provided in the radial direction of the turntable is rotated by a motor 26.

The feed screw 25 has a moving portion 27 that is screwed into the feed screw 25.
will be established.

This moving unit 27 has an optical system (
(not shown) and a moving means (not shown) for moving the beam irradiated onto the record carrier 18 from the moving unit 27 in the radial direction of the record carrier 18. When a control signal is applied to the terminal 30 of the section 27, the beam irradiated onto the record carrier 18 is moved in the direction of the rotation center axis of the record carrier 18, and when a control signal is applied to the terminal 31, the beam irradiated onto the record carrier 18 is moved. This is to move the beam irradiated upward in the direction opposite to the central axis of rotation.

Reference numeral 32 designates a half mirror 134 that introduces the reflected light into the demodulator 33, and 35 represents a detection unit.
has detection elements 36 and 37, and their respective outputs are connected to the terminal 3 of the moving section 27 via a switching circuit 38 controlled by the control output from the demodulator 33.
0.31.

In the tracking device configured as described above, the record carrier 18 is placed on the turntable 24 and the motor 23 is rotated to rotate the record carrier 18. 26 and move the moving part 27 at a constant pitch equal to the pitch of the recording part 19 according to the rotation of the feed screw, and the beam source 2
A case in which a beam is generated from 8, reflected by a half mirror 29 and introduced into the moving section 2.gamma., and the beam introduced into the moving section is irradiated onto a recording medium will be described in detail below.

Now, when the beam irradiated onto the recording medium is irradiated onto the recording section 19 where information is recorded, as shown at 22 in FIG.
, reaches the half mirror 32 via the half mirror 29,
A part of it is introduced into the demodulator 33 to demodulate the information contained in the reflected beam, and the other part is introduced into the detection section 35 via the lens 34.

However, since the reflected beam only contains information, it is only focused at point P, and the detection element 3
6,3775= get any output, so terminal 30,
No control signal is applied to 31 either.

Also, in contrast to this, if the irradiated beam shifts to the outside of the recording section 19 as shown at 40 in FIG. 2B, the detection section 35 will obtain a Fourier spectrum as shown at 41. Therefore, an output is obtained only from the detection element 36, a control signal is applied to the terminal 30, and as described above, the beam irradiated onto the record carrier from the moving unit 27 moves in the direction of the rotation center axis of the record carrier. beam 2
When it has moved to a substantially normal position as shown at 2, the application of the control signal is stopped.

Conversely, if the beam irradiated onto the record carrier deviates to the inside of the recording section 19 as shown at 39 in FIG. 2, a Fourier spectrum as shown at 42 will be obtained at the detection section 35. Therefore, an output is obtained only from the detection element 37, and therefore a control signal is applied to the terminal 31, and the irradiation beam moves in the counter-rotation axis direction, and when it moves to approximately the normal position as shown by the beam 22, the application of the control signal is stopped. be done.

As described above, in this embodiment, since the scanning deviation from the recording section can be detected accurately, the recording section can be accurately tracked by the beam.

Further, since the recording section 19 is configured in a spiral shape, the direction of the diagonal line is changed every time the recording carrier 18 rotates once.

Therefore, if the signal detected by the detection section 35 is applied to the terminal as it is, the moving section will be controlled in the opposite direction every other rotation.In order to solve this problem, the switching circuit 38 is connected to the demodulator every one rotation. Switching is performed by a switching signal (for example, a vertical synchronization signal, etc.) from 33.

For example, when the beam is scanning the recording section 19a in FIG.
．． If the switching circuit 38 is controlled such that the voltage is applied to the detection element 36 in the next recording section 19b,
, 37 is applied to the husband terminals 31 and 30.

FIG. 4 shows another embodiment of the rotating record carrier according to the present invention, which differs from the above embodiment in that two types of recording parts are provided between the recording parts 19 provided in a spiral shape on the record carrier 18. Multiple hatched portions 41 and 42 are provided.

This shaded area also has a fixed angle αβ different from the straight line o − r in the radial direction of the record carrier, as described in FIG.
It is desirable to have the following.

By arranging the two kinds of diagonal lines between the recording parts in this way, the area of the recording part on the recording button body is reduced, but in the tracking device as shown in FIG. 3, the switching circuit 38 Therefore, the signal recorded on the recording section does not need to include a switching signal.

FIG. 5 shows another embodiment of the record carrier according to the present invention, in which on one record carrier 18, an area 43 where a recording part is provided and an area 44 where multiple hatched parts are provided are provided separately. It is something.

Therefore, when reproducing information from such a record carrier, two types of beams are required: one for irradiating the recording portion and the other for irradiating the multiple hatched area.

The multiple hatched portions of such a record carrier are constructed as shown in FIG. 5B, with three hatched portions 46, 4 corresponding to one recording portion.
7 and 48, when the beam is irradiating the recording section, the second beam irradiates the multiple hatched area 47, and when the beam deviates from above the recording section, the second beam irradiates the multiple hatched area 47 according to this deviation. By configuring the two beams so that the second beam is also located in the multiple hatched area 46 or 48, it is possible to accurately detect the scanning deviation from the recording section, and therefore it is possible to control the recording section so that the beam accurately tracks the recording section. It is something.

In the above embodiment, the recording section and the multiple diagonal lines are provided at separate positions, but in the record carrier as described in FIGS. 2 and 3, the multiple diagonal lines as described above are provided over the recording section. It is also possible to provide a section.

Since the record carrier according to the present invention is provided with optically diagonal portions having different inclination angles as a tracking pattern,
The tracking pattern can be formed at the same time as the recording section is formed.

Further, since the optical diagonal lines do not need to have equal pitches, there is no need to perform highly accurate equal pitch control when forming the optical diagonal lines, making it easy to create a tracking pattern.

Furthermore, in the present invention, when detecting scanning deviation, it is of course possible to detect it while moving the record carrier as in the embodiment, but basically it can be detected by the existence of optical diagonal lines itself. Scanning deviation can be detected even in a stationary state.

Therefore, it is not necessary to move the record carrier or move it at a constant speed in order to detect scanning deviation, and there is an advantage that the scanning deviation detection device, etc. to which such a record carrier is applied is not subject to the above-mentioned limitations. It is something.

Furthermore, when performing scanning deviation detection using such a record carrier, it is basically only necessary to provide the number of detection sections corresponding to the types of diagonal lines, so it is necessary to set the frequency in order to obtain the scanning deviation detection signal. This does not require complicated circuits such as separation, and can be made into a simple control circuit.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram for detecting positional deviation using the record carrier according to the present invention, in which 11 is a recording plate, 12°, 13 is a multiple parallel line part, 14 is a parallel light beam, 15 is a lens, and 16,
17 is a Fourier spectrum. 2 shows a record carrier according to the invention, FIG. 2A is a top view and FIG. 2B is a partial perspective view, 18 is a record carrier, 1
9 is a recording section, 20, 21 is a multiple hatched area, 22, 39.4
0 is the irradiation beam, respectively. FIG. 3 shows a tracking device applied to a record carrier according to the present invention, 27 is a moving part, 29 and 32 are half mirrors, 128 is a beam source, 33 is a demodulator, 34 is a lens, 41 and 42 are Fourier, spectrum, 36 and 37 are detection elements, 38 is a switching circuit, and 30 and 31 are terminals for applying control signals. FIG. 4 shows a record carrier according to another embodiment of the present invention, in which FIG. 4A shows a front view and FIG. 4B shows a partial perspective view, 41,
42 are multiple hatched parts. FIG. 5 shows a record carrier according to another embodiment of the invention, 4
3 is the area where the recording section is provided, 44 is the area where the diagonal line is provided,
46, 47 and 48 are multiple hatched areas.

Claims (1)

[Claims] 1. In a record carrier that has a recording section in which signals are recorded in a spiral or concentric pattern and the recording section is scanned for signal reproduction, a spectral pattern is formed for detecting scanning deviation from the recording section. Therefore, a first diagonal area having a plurality of optical diagonal lines is scanned when the scanning of the recording section is shifted toward the center of the record carrier, and a second diagonal section having a plurality of optical diagonal lines that are scanned when the record carrier is scanned; A record carrier characterized by being formed at fixed angles that are different from each other.