JPH03225625A - Optical recording and reproducing device - Google Patents

Abstract

PURPOSE:To quicken a recording action and to shorten a recording time by detecting a signal recorded on a recording medium by a 1st optical means by using a 2nd optical means and performing verification. CONSTITUTION:When the recording signal is inputted in an optical disk 10 set at a specified position, encoding and error processing are performed to the recording signal by a signal processing circuit so as to divide to information in sector unit. While the optical disk 10 which rotates at a constant linear velocity is irradiated by a light beam for over-write 3a, an optical head 1 is moved from an inner periphery side to an outer periphery side to retrieve a sector and a track corresponding to a recording address and successively execute the over-write. At such a time, the readout of the recording signal by a light beam for verification 5a is performed to the adjacent track which is one track inside, and the recording signal previously detected is compared with the record ing signal recorded by the beam 3a. When they do not coincide, rerecording in an error sector or recording in an alternative sector is performed, and when they coincide with each other, the recording action to the next recording address is executed.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to an optical recording/reproducing device, and in particular, to shortening the verification time of information recorded on a write-once type and a rewritable type recording medium. The present invention relates to an optical recording and reproducing device that can quickly record information.

(Prior art) Conventionally, signals are recorded by irradiating a light beam such as a laser beam.
Optical discs are used as reproducible and erasable recording media. Known optical discs include magneto-optical discs, phase change discs, and organic dye recording film discs.

On these optical discs that allow high-speed erasing, it is possible to perform overwriting, or so-called overwriting, with a single light beam. Also, optical discs have recording tracks.
Each track is divided into sectors, and information is recorded and erased in units of sectors. Therefore,
When overriding with a single light beam,
First, a sector for recording is reproduced, and a sector and track corresponding to the recording address are searched.

Next, when a recording address is detected, overwriting is performed for the sector or track. Furthermore, the overriding sector and track are reproduced, the recorded contents are confirmed, and the series of recording operations is terminated after it is confirmed that there are no errors.

(Problems to be Solved by the Invention) As mentioned above, in the conventional recording/reproducing apparatus, when recording, a single light beam is used to perform the above-mentioned series of recording operations, so that one track can be recorded. The optical disk must be rotated at least three times to record one sector, and it is not possible to perform quick processing when sequentially overriding multiple different recording addresses, which reduces the recording operation time. It was hoped that the period would be shortened.

The present invention has been made in view of the above circumstances, and its object is to provide an optical recording/reproducing apparatus for optical discs that effectively speeds up the recording operation and shortens the recording waiting time.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the optical recording/reproducing device of the present invention includes a light emitting source that generates a light beam, and a light beam generated from the light source. a first optical means for guiding a light beam generated from the light emitting source to a recording medium and for recording a signal on the recording medium; a second optical means capable of detecting and interlocking with the first optical means; a signal relating to a light beam guided by the first optical means and a light beam detected by the second optical means; and comparison means for comparing the signals.

(Function) In the optical recording/reproducing apparatus of the present invention, a light beam generated from a light emitting source that generates a light beam, such as a semiconductor laser, is guided to a recording medium by the first optical means, and a signal is transmitted to the recording medium. Recording is done. Further, this recorded signal is reproduced by a second optical means that operates in conjunction with the optical means of the box 1, for example after approximately one revolution of the recording medium, and the reproduced signal is further compared by a comparison means. Then, a so-called verification is performed. At this time, that is, when the second optical means is performing reproduction, the first optical means is concurrently recording a signal on the recording medium at the destination of the track in the same sector, for example.

Therefore, the operation from recording to reproduction can be effectively performed in two revolutions, and at least one revolution of the recording medium is reduced.

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

FIG. 1 is a diagram showing how recording is performed on a recording medium according to an embodiment of the optical recording/reproducing apparatus of the present invention. In addition, in this embodiment, an overridable phase change optical disk (hereinafter simply referred to as an optical disk) 10 is used as a recording medium.
This will be explained using an example.

This optical disc 10 includes a recording layer 10a on which signals as information are recorded, and a recording layer 10a made of glass, polycarbonate, or P.
The disk substrate 10b is made of a transparent material such as MMA (transparent acrylic resin).
In the recording layer 10H formed on one side surface of the recording layer 10H, tracks are generally formed in a circumferential manner at intervals of 1.6 μm, and signals are formed as pits 15 on these tracks.

That is, the optical disc 10 has a group (bottom) part 13 forming a pre-group and a land part 11,
A phase-change type recording mark, that is, a pit 15, is formed by a light beam that enters the land portion 11, that is, the track, from the substrate 17 side, and recording is performed. Further, this optical disk [0] has addresses set by sectors that are divided into a predetermined number of fan-shaped areas separated by two radii. In addition, the recording signal moves from the inner circumference to the outer circumference.
and is recorded in a spiral pattern.

Next, the configuration of the optical head 1 will be explained.

The optical head 1 is located below an optical disk 10 that is rotated at high speed at a constant linear velocity by a rotational drive source such as a spindle motor (not shown), and directs light beams from two light emitting sources from the bottom of the optical disk 10 to the optical disk 10. Light beams are emitted toward the optical disc 10 from the light beam exit ports 3 and 5 arranged in parallel in the radial direction of the optical disc 10, respectively. Further, signals are recorded on and erased from the optical disc 10 by the light beam 3a irradiated on the outer peripheral side, and signals recorded on the optical disc 10 are read by receiving reflected light from the optical disc. Further, the light beam 5a that irradiates the inner peripheral side receives reflected light from the optical disc 10, and reads signals recorded on the optical disc 10. That is, the light beam 5a is used for verifying, which will be described later. As this light source, for example, a semiconductor laser that generates laser light with a wavelength of 670 nm is used.

Further, the optical head 1 is configured to be movable in the tracking direction T by a linear motor (not shown), and can be precisely driven in the tracking direction T by a tracking servo mechanism. This allows access to the track at a predetermined address and access to the optical disc 1.
Tracking of zero eccentricity is performed accurately and precisely.

Similarly, by a focusing servo mechanism (not shown), the optical disc 10, which normally exists in a range of several hundred μl, is
The focusing operation against the surface runout is performed precisely.

Next, the configuration of the optical head 1 and its peripheral devices will be explained with reference to FIG. Also, for ease of explanation, there are two light beams 3a forming the optical head 1.

Since the system 5a is constructed between two paths, the explanation will be given using the light beam system on one side as an example.

The semiconductor laser 21 is a light emitting source that generates a laser beam as a light beam, and the wavelength λ of the laser beam generated from the semiconductor laser 21 is, for example, 670 nm or 83 nm.
It is set to 0nm.

Laser light generated by this semiconductor laser 21 and emitted radially enters a collimator lens 23, is converted into parallel light, and is output to a polarizing beam splitter 25.

The polarizing beam splitter 25 splits, transmits, and reflects the incident laser beam, and makes the transmitted light and the reflected light polarized at right angles to each other.

This polarizing beam splitter 25 is connected from the semiconductor laser 21 side.
The laser beam incident on the optical disc 1 is transmitted through the polarizing beam splitter 25 and further converged by the objective lens 27.
The focus is focused on the recording layer 10a of 0.

The objective lens 27 is provided with an objective lens actuator 27a that moves the objective lens in the optical axis direction during focusing. The laser beam focused on the recording layer 10a performs recording, reproduction, or erasing on the recording layer 10a.

On the other hand, the laser beam reflected by the recording layer 10a enters the polarizing beam splitter 25 via the objective lens 27, and is directed into the direction perpendicular to the optical axis of the light beam, that is, the quarter-wave plate 2
It is reflected in the direction of 9.

This 1/4 wavelength plate 19 eliminates return light from a detection system, which will be described later, and thereby prevents an adverse effect on the semiconductor laser 21 and the optical disk 10.

The tracking servo mechanism and focusing servo mechanism that constitute the above-mentioned detection system will be explained below.

The laser beam reflected by the polarizing beam splitter 25 is given to a second polarizing beam splitter 33 via a quarter-wave plate 29 and a lens system 31, and a defocus is detected.
The focusing servo error detection system, which automatically focuses by driving the objective lens 27 using the error signal, detects the deviation between the beam spot and the track, and uses the error signal to drive various actuators to direct the laser beam to the track. The light is separated by a tracking servo error detection system. That is, the laser beam reflected by the polarizing beam splitter 33 and guided to the focusing servo error detection system is changed in shape in a cross section perpendicular to the optical axis of the beam (hereinafter simply referred to as cross-sectional shape) by the cylindrical lens 35, and then detected. The light is input to the vessel 37.

This detector 37 uses a 4-split photodetector, and when the cylindrical lens 37 is focused on the recording layer 10a of the optical disc 10, that is, in the focused state,
The photodetector is placed at a position where the cross-sectional shape of the laser beam emitted from the photodetector is a perfect circle, with the center of the perfect circle matching the center of the four-part photodetector.

Therefore, when in focus, the signal levels from the four photodetectors are the same. On the other hand, in the out-of-focus state, the position where the cross-sectional shape of the laser beam emitted from the cylindrical lens 35 becomes a perfect circle is shifted in the optical axis direction, and the laser beam with an elliptical cross-sectional shape is incident on the 4-split photodetector. Therefore, the outputs of photodetectors on the diagonal are the same, and the outputs of adjacent photodetectors are different. Therefore, when out of focus, an output corresponding to the distance to the optical disc 10 is obtained from the differential amplifier 39. The objective lens actuator 27a is driven in accordance with this output signal to obtain a focused state.

Further, the laser beam transmitted through the polarizing beam splitter 33 and guided to the tracking servo error detection system is sent to the detector 41.
is incident on the This detector 41 uses a bipolar photodetector, and when the laser beam irradiation position is on one side of the land portion 11 or group portion 13, the outputs from the two photodetectors are the same, and the laser beam When a part of the laser beam overlaps the adjacent group portion 13 or land portion 11, the laser beam is scattered, and the output of the photodetector on the side where it overlaps decreases (push-pull method).

Note that any optical system may be selected as the lens system 31 as required and may be omitted. In addition, in this embodiment, since the astigmatism method was adopted for the focus servo, a four-segment photodetector was used as the cylindrical lens 35 and the detector 37, but when the Foucault prism method is adopted, the cylindrical lens 35 is replaced. When a Foucault prism is used and the Naifezi method is employed, a Naifezi and a two-division photodetector are used, and furthermore, when a critical angle detection method is employed, a critical angle prism and a two-division photodetector are used.

Similarly, although the push-pull method is used for tracking servo, an appropriate method such as the three-spot method may be used.

Next, the operation of this embodiment will be explained according to the flowchart shown in FIG.

First, the optical disc 10 is set at a predetermined position and waits for input of a signal related to information to be recorded on the optical disc 10.

When this recording signal is input (step S1), the recording signal is encoded and subjected to error processing in a signal processing circuit, and is divided into information in units of sectors (step S2).

Next, in step S5, the optical head 1 is moved from the inner circumferential side to the outer circumferential side while irradiating the optical disk rotating at a constant linear velocity with the override light beam 3a, and searches for the sector and track corresponding to the recording address. will be carried out. When a corresponding sector or track is detected, overriding of the corresponding sector or track by the override light beam 3a is sequentially performed during the next rotation.

At this time, recording signals are successively outputted by the verification light beam 5a in the adjacent track one track inside (step S7).

In step S9, a comparison is made between the recording signal detected in step S7 and the recording signal recorded by the override light beam 3a, and if they do not match, the process advances to step Sll, where re-recording to the error sector or replacement is performed. Recording to the sector is performed.

Furthermore, in step S13 and step 9, the recording signal recorded in step Sll is compared with the recording signal recorded by the override light beam 3a, and when they match, the process advances to step S5, and the next recording address is A recording operation continues.

Next, another embodiment according to the present invention will be described using FIG. 4. As is clear from the relationship between the tracks of the recording medium and the irradiation position of the light beam shown in FIG.
The irradiation positions of the light beams are shifted to different radial positions of adjacent tracks.

That is, as shown in FIG. 2, the irradiation position 3b.

5b on the same radius, the distance between the centers of the tracks is usually narrow, for example, 1.6μ layer, so simply arranging the light beam exit ports 3 and 5 close to each other will not allow the irradiation positions 3b and 5b to be adjusted. It is difficult to align the light beam on the track, and therefore the direction of irradiation of the light beam must be tilted obliquely.In contrast, in this embodiment, the first optical head 1a having the first optical means and the second optical head 1a having the first optical means A second optical head 1b having an optical means is provided separately and independently, and the irradiation positions of these two optical heads la and lb are shifted to different radial positions of adjacent tracks, A light beam can be irradiated onto the optical disc 10 from a direction perpendicular to the optical disc 10. This facilitates fine adjustment of the irradiation directions of the two light beams during the manufacturing process and during focusing. Note that when the two optical heads la and lb are spaced apart in the circumferential direction, when the optical heads 1a and 1b are located on the outer circumference and when they are located on the inner circumference, the irradiation direction or the optical The relative positions of heads 1a and lb are finely adjusted.

As mentioned above, in the first and second embodiments,
Although two sets of optical systems were used as the light emitting sources, the present invention is not limited to this. For example, laser light generated by two semiconductor lasers is transmitted using one set of optical systems using a prism or the like. The laser beam may be focused on the recording surface.

Similarly, recording of a recording signal on the optical disc 10,
Verification is not limited to between adjacent tracks, but may be performed between tracks separated from each other. Moreover, recording of the recording signal on the optical disc 10 is performed by
It is also possible to perform the irradiation from the outer periphery toward the inner periphery; in this case, it goes without saying that the irradiation position by the first optical means is set on the inner periphery and the irradiation position by the second optical means is set on the outer periphery. not. Similarly, the optical disc 10 may be one in which recording signals are recorded concentrically.

[Effects of the Invention] As explained above, according to the present invention, the signal recorded on the recording medium by the first optical means is subsequently detected and verified by the second optical means. The operation can be effectively accelerated and the recording time can be shortened.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the general configuration of an optical recording/reproducing apparatus according to an embodiment of the present invention together with a recording medium, FIG. 2 is a diagram showing the configuration of an optical head, and FIG. FIG. 4 is a flowchart explaining the operation of the optical recording/reproducing apparatus of FIG. 1. FIG. 5 is a diagram showing the relationship between the irradiation position of the light beam and the irradiation position of the light beam. FIG. FIG. 3 is a diagram showing the relationship with position. 1... Optical head 3.5... Light beam exit ports 3a, 5a... Light beam 10... Recording medium (phase change type optical disk) 11...
Land part 13...Group part 15...Pit

Claims (1)

[Scope of Claims] A light-emitting source that generates a light beam; a first optical means that guides the light beam generated from the light-emitting source to a recording medium and records a signal on the recording medium; a second optical means capable of guiding a generated light beam to a recording medium and detecting a light beam reflected by the recording medium, and capable of interlocking with the first optical means; An optical recording/reproducing apparatus characterized by comprising a comparing means for comparing a signal relating to a light beam guided by the optical means and a signal relating to the light beam detected by the second optical means.