JPS60234233A - Optical recording and reproducing device - Google Patents

Abstract

PURPOSE:To attain the record/reproduction of disks having different recording systems through the same recording/reproducing device, by controlling the polarity of a record signal based on the result of detection of a polarity deciding mark for record signal provided to an optical disk. CONSTITUTION:When an optical disk is loaded to a disk motor 7, a controller (not shown in the figure) consisting of a microcomputer detects the loading of the disk. Then a command of revolution is delivered to the motor 7. An FF21 is cleared by the rise of said command. If a polarity reverse mark 17 exists to show that the optical disk has an erasion function, a photodiode 19 detects the mark 17. This detection signal is compared with the reference voltage VTH by a comparator 20 and delivered in the form of a pulse. This pulse output latches FF outputs Q and Q'. Then the output of a modulator is inverted and delivered by a logic signal reverse logic 22. Thus even an optical disk of an erasable whitening record system can obtain the reproduction signal output of the same polarity as the output of the modulator obtained in a record mode. As a result, the stable reproduction is possible with a preamplifier, a signal processing circuit and a demodulator which have systems equal to a blackening record system.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an optical recording and reproducing apparatus that focuses a laser beam into a minute spot light and applies a thermal change to an optical disk to record and reproduce signals.

Conventional configuration and its problems In recent years, signals have been recorded and reproduced on optical discs by focusing laser light to about 1 μm. In particular, devices have come into use that record by depositing a recording material onto an optical disk and subjecting it to thermal changes using laser light.

Below, with reference to the drawings, a conventional optical recording/reproducing device U
An example will be explained.

FIG. 1 shows the configuration of a conventional optical recording/reproducing device. The laser beam of the semiconductor laser 1 passes through the condensing lens 2
The beam is converted into a parallel beam by the total reflection mirror 4 and is incident on the aperture lens 5vC. The diaphragm lens 5 focuses this incident light onto the optical disk 8 into a minute spot of φ17 mm and 100 mm. The reflected light from the optical disk 8 is again guided to the beam splitter 3 via the aperture lens 5 and the total reflection mirror 4, and is received by the photodetector 6. 7 rotates a disk 8 with a disk motor. A preamplifier 9 amplifies the photodetector output signal, and the signal is inputted to a demodulator 11Vc via a signal processing circuit 10. Reference numeral 12 denotes a semiconductor laser 1 driving circuit which drives the semiconductor laser 1 at a current value such that its output is greater than the sensitivity of the recording material in accordance with the signal from the modulator 13.

FIG. 2L shows a state in which a signal is recorded on the guide track 14 in the shape of a concave or groove formed in advance in a phase structure on the optical disk 8.

Figure 2b (1) shows the waveform of the output signal of the preamplifier when the pits recorded in this manner are reproduced.

When a recording material on an optical disk is irradiated with a minute spot of light, a thermal change occurs as shown in FIG. 2, causing the recording material to turn black. In the blackened portion, the reflectance increases, as shown by the reproduced signal in Figure 2. In other words, the portion that is blackened and has a high reflectance is the portion where the signal is recorded. This type of recording method is called blackening recording.

TeOx-based materials are used as materials that correspond to blackening records. Although recording is possible with TeOx-based materials, erasing is difficult.

On the other hand, FIG. 3 is a diagram illustrating a recording material used in a recording method called whitening recording.

Similar to FIG. 2, a pit is recorded on the guide track 14. In FIG. 3a, when a minute spot of light is irradiated onto the recording material of the disk, a thermal change occurs and the material becomes white. The whitened portion has a reduced reflectance as shown in Figure 3. In other words, the portion where the reflectance is low is the portion where the signal is recorded. This type of recording method is called whitening recording.

The TeGexOy system is used as a material that corresponds to this, and is capable of recording and reproducing.

As explained above, due to the difference in recording material, the polarity of the reproduced signal output waveform obtained from the lid disk when recording signals of the same polarity differs. However, one recording/reproducing device does not necessarily use only optical discs using one type of recording material. The problem in such a case is that, as mentioned above, the polarity of the reproduced signal when recording signals of the same polarity differs depending on the recording material. The configuration of the optical recording and reproducing apparatus as shown in FIG. 1 has the disadvantage that recording and reproduction cannot be performed on an optical disc using recording materials in which the polarity of the reproduction signal is different.

Purpose of the Invention The Invention (C) Disadvantages (2) In view of the above, an optical recording and reproducing apparatus capable of stably recording and reproducing even an optical disc in which the polarity of a reproduction signal differs when recording a signal of the same polarity depending on the recording material, especially an optical disc with an erasing function and an erasing function. The present invention provides an optical recording and reproducing device that can record and reproduce information on both non-functional and non-functional disks.

Structure of the Invention 6/゛The present invention provides a means for recording and reproducing signals by focusing a light source such as a laser beam into a minute spot light and applying a thermal change to an optical disk, and determining the polarity of a signal recorded on the optical disk. An optical recording/reproducing device is provided with a recording signal polarity determination mark, detects the determination mark, and changes the polarity of a signal recorded on an optical disk to normal or reverse based on the detection result. The same recording and reproducing device can handle both erasable optical discs and non-erasable original discs.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 4 shows the structure of an optical disc of an optical recording/reproducing apparatus according to an embodiment of the present invention. In FIG. 4, %8 is an optical disk, and 15 is an information recording area in which recording and reproduction is performed by concentrating a laser beam into a minute spot beam. Guide tracks are formed in the information recording area 16 in a concentric, spiral, or spiral shape. 16 is a recording signal polarity determination mark area provided inside the information recording area. 1
7 is a recording signal polarity determination mark, and the structure of this part is shown in 5th
As shown in the figure. As shown in FIG. 5, it is possible to optically detect a VC by providing a phase structure of concave and convex grooves similar to the guide track of the information recording area in a part of the circular arc of the judgment mark area 16. The phase structure is +1, and like the guide track of the information recording area, it can be formed when the master disc is cut.

The recording signal polarity determination mark can be easily detected using a simple reflective photodetector that combines a light emitting diode and a photodiode, in addition to a light source such as a laser beam that performs recording and reproduction in the information recording area. When the recording signal polarity determination mark portion having the groove structure is irradiated with light from a light emitting diode or the like, the light is diffracted and reduced to reflected light. Changes in reflected light can be detected with inexpensive photodiodes.

The recording signal pole 1 (1 judgment mark is provided, for example, at the edge of the whitened record as shown in FIG. 3, and is not provided on the material VrC of the blackened record as shown in FIG. 2. When the mark is detected, If not, the polarity of the modulator output signal is left as is, and if a mark is detected, the polarity of the modulator output signal is controlled to be inverted.By doing this, the polarity of the reproduced signal is controlled to match the recording charge of the optical disc. Regardless, it will be the same.

FIG. 6 shows the configuration of an optical recording/reproducing apparatus according to an embodiment of the present invention. In FIG. 6, the components denoted by the same numbers as in FIG. 1 are the same as in FIG.

18 is a light emitting diode, and 19 is a photodiode. These two constitute a reflection type photodetector to detect the presence or absence of a recording signal polarity determination mark.

FIGS. 7a to 7e show signal waveforms at each point &-el shown in FIG. In FIG. 6, a comparator 20 converts the detected recording signal polarity determination mark into a pulse (FIG. 7b). This pulse is passed through flip-flop 2
When input to the preset terminal 1, the /ζ signal (FIG. 7C) is output (latched from the output). 22 is the logic for reversing the polarity of the recording signal;
The inverted C1 is controlled to be the Q and Q outputs of the flip-flop 21.

When an optical disk is mounted on the disk motor 7, a controller (not shown) comprising a microcomputer detects this and outputs a disk motor rotation command to the disk motor. At the rising edge of this rotation command, the knob flop 21 is cleared.

If there is a polarity reversal mark as shown in FIG. 517 indicating that the optical disc has an erasing function, the photodiode 19 detects a waveform as shown in FIG. 7a.

This signal is compared with the reference voltage VTR by the comparator 20 and outputted, and is converted into a pulse (FIG. 7b). Flip-flop outputs Q and Q are latched by this pulse output. Q,
When the φ-ratio output is latched, the recording signal inversion logic 22 inverts the modulator output.

The state of recording signal polarity reversal is shown in FIGS. 8a to 8d.

a is the output signal of the modulator, and b is its inverted output. C
d shows the state of the recorded pits, and d is the reproduction 107, -2 signal output of the preamplifier when the recorded pits are reproduced.

In this way, even with an erasable whitening recording type optical disc, it is possible to obtain a reproduced signal output having the same polarity as the modulator output during recording. Therefore, stable playback is possible using the same preamplifier, signal processing circuit, and demodulator as in the black recording method. As another embodiment of the present invention, a recording signal determination mark may be provided on the disc cartridge.

Effects of the Invention As described above, the present invention provides a recording signal polarity determination mark that can determine the polarity of a recording signal on an optical disc, detects this determination mark to determine the polarity of the signal to be recorded, and performs recording based on the determination result. By controlling the polarity of the signal to be normal or inverted, it is possible to record and reproduce optical discs with different recording methods, such as erasable and non-erasable optical discs, using the same recording and reproducing device. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a conventional optical recording/reproducing device, and FIG. 2 shows an optical disk 11 using a black recording method. FIG. 3 is a diagram showing how signals are recorded on an optical disc using the whitening recording method and the reproduced signal waveform. FIG. FIG. 5 is a plan view showing the structure of an optical disc of an optical recording/reproducing device in an embodiment, FIG. 5 is a perspective view showing an example of the structure of a recording signal polarity determination mark, and FIG. 6 is an optical recording/reproducing device in an embodiment of the present invention. Block diagram showing equipment purchasing, No. 7
The figure is a waveform diagram showing the signals at each part of FIG. 6, and FIG. 8 is a diagram illustrating recording signal polarity inversion and reproduction signal. 1... Semiconductor laser, 8... Optical tisf,
13...Modulator, 17...Recording signal polarity determination mark, 18...Light emitting diode, 19...Photodiode. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3

Claims (5)

[Claims] (1) A means for recording and reproducing signals by focusing a light source such as a laser beam into a minute spot light and applying a thermal change to the optical disk, and a recording polarity of the optical disk provided on the optical disk or a disk jacket that houses the optical disk. Optical recording characterized by comprising a mark detection means for detecting a mark for determination, and a control means for controlling the polarity of a recording signal to normal rotation or inversion based on the mark detected by the mark detection means. playback device. (2) The optical recording and reproducing apparatus according to claim 1, wherein the mark is provided on either an erasable optical disc or a non-erasable optical disc. (3) Claim 1, characterized in that the mark is provided on either one of the disc jacket housing the erasable optical disc and the disc jacket housing the non-erasable original disc. optical recording and reproducing device. (4) The optical recording and reproducing apparatus according to claim 1, wherein the mark is provided inside or outside the information area of the optical disc. (5) The optical recording and reproducing apparatus according to claim 4, wherein the mark is provided by a phase structure formed by unevenness of the groove.