JPS63117323A - Optical recording and reproducing device - Google Patents

Abstract

PURPOSE:To place a gap section in a uniform crystal state and to hold a stable recording film even when erasure and recording are carried out repeatedly by imposing DC modulation on the head and tail ends of an erasure beam with maximum power with which the recording film does not enter a liquid phase state and scanning the beam. CONSTITUTION:Plural tracks on a disk are divided by plural sectors and addresses are recorded in the respective sectors previously by a cutting method, etc., and the addresses are reproduced at the time of recording and erasure and digital data are recorded and erased in sectors identified with their addresses and gap sections are provided between recording sections of addresses and digital data. In this case, the head and tail ends of a semiconductor laser control gate signal 23-a are provided in each gap section at the time of the erasure and the ON area of the semiconductor laser control gate signal 23d is an area excluding an address part at the time of the recording; and the DC modulation is imposed in the gaps section with the maximum power with which the recording film does not enter the liquid phase state. Consequently, the recording film becomes stable at the head and tail end parts of the erasure and is tolerant to the recording and erasure even when used repeatedly.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an optical recording/reproducing apparatus for optically recording, reproducing, and erasing information on an optical recording medium.

BACKGROUND OF THE INVENTION In recent years, optical recording and reproducing devices have been proposed that use two light sources with different wavelengths to irradiate substantially circular and oval beams onto a recording medium to record and reproduce video signals and digital signals concentrically or spirally. ing. As shown in FIG. 2, the conventional optical recording/reproducing apparatus has a configuration in which recording is performed using a beam 19 while erasing using a beam 20. A semiconductor laser drive signal generating circuit 23 generates a semiconductor laser control gate signal 23-& for erasing. , modulation signal 23 for erasure
-'b, semiconductor laser power control signal for erasing, semiconductor laser control gate signal for recording 2
3-d, the recording modulation signal 23-0 and the recording semiconductor laser power control signal 23-f are transmitted to the erasing semiconductor laser drive circuit 21 and the recording semiconductor laser drive circuit 22, respectively, as shown in FIG. Recording and erasing was performed by supplying data by typing. That is, erasing is performed by providing a starting end and an ending end in the gap section 26, and performing the recording with such power that the recording film is once in a liquid phase and gradually cooled down, and recording is performed by modulating the recording film with a digital signal recorded only during the data area 26. This was done with the power to bring it into a liquid state.

Problems to be Solved by the Invention However, when simultaneous erasing is performed at such timing, there is a steep gradient of heat at the beginning and end of erasing, and the state of the recording film remains partially uneven, resulting in repeated erasing. There was a problem in that the recording film would break when recording was performed.

Means for Solving the Problems The present invention provides an optical recording/reproducing apparatus that records digital data on a disk using a change in reflectance using recording light modulated by digital data. A plurality of tracks is divided into a plurality of sectors, an address is recorded in advance for each sector by a method such as cutting, and the address is reproduced at the time of recording and erasing, and the location identified by the address is recorded. In the sector, the digital data can be recorded and erased, and a gap section is provided between the address and the recording section of the digital data, and when erasing, the start and end of the semiconductor laser control gate signal are Each is provided within the gap section, and during recording, the semiconductor laser control gate signal ON area is set to the area excluding the address section, and the gap section is recorded and reproduced by performing NC modulation at the maximum power that does not cause the recording film to enter a liquid phase state. , to perform erasure.

Effect of the Invention With the above-described configuration, the present invention scans the beginning and end portions of the erasing beam 20 by DC modulating the recording beam 19 at the maximum power that does not cause the recording film to enter a liquid phase state, thereby making the gap section uniform. It becomes a crystalline state and can maintain a stable recording film even after repeated erasing.

Embodiment FIG. 1 is a timing diagram of an embodiment of the present invention, 24 is an address, 25 is a gap section, 26 is a data area, and FIG. 2 is a configuration diagram, which is the same as the conventional example, and 1 and 2 are wavelengths, respectively. Different light sources, 3 and 4 are condensing lenses, 5 is a cylindrical lens that shapes the beam of light emitted from light source 2, 6 is an expanding prism that shapes the beam of light that is emitted from light source 1, 7 is a polarizing beam splitter, 8 and 9 is a λ/4 wavelength plate, 10
1 is a filter that separates light from light source 1 and light source 2; 11 is an aperture lens; 12 is a recording medium; 13 is a right-angle prism; 14 is a convex lens; 16 is a dividing mirror; 16 is a photodetector for tracking control; 17 is a focus Photodetector for control, 1
8 is a track groove for recording information, and 19 is a substantially circular beam formed on the disk 12 by the light source 1. 2Q is an oval beam formed on the disk 12 by the light source 2.

21 is a drive circuit that drives light source 2; 22 is a drive circuit that drives light source 1;
The driving circuit 23 is a semiconductor laser control gate signal 23-a for erasing, a modulation signal 23-b for erasing, and a semiconductor laser power control (N number 23c) for erasing, to the drive circuit 21. This is a drive control signal generation circuit that supplies a recording semiconductor laser control gate signal 23-d, a recording modulation signal 23-e, and a recording semiconductor laser power control signal 23-f, respectively.

The operation of the optical recording/reproducing apparatus configured as described above will be explained below. The laser beam emitted from the light source 1 passes through the condensing lens 3, is beam-shaped by the magnifying prism 6, and enters the aperture lens 11 via the polarizing beam splitter 7 and the λ/4 wavelength plate 9, where it is projected onto the disk 12 into a substantially circular shape. A beam 19 is formed. On the other hand, the reflected light from the beam 19 from the recording medium 12 is reflected by the aperture lens 11. The polarization direction is rotated by 90 degrees through the λ/4 wavelength plate 9, separated by the polarizing beam splitter 7, and then passed through the λ/4 wavelength plate 8° filter 10.
A photodetector 16.1 passes through the rectangular prism 13, convex lens 29, and divided power 15 to read out servo signals for known focus and tracking control.
Guided by 7.

On the other hand, the laser beam emitted from the light source 2 passes through a condensing lens 4, is beam-shaped by a cylindrical lens 6, and is sent to a filter 1o via a polarizing beam splitter 7 and a λ/4 wavelength plate 8.
The polarization direction is rotated by 90 degrees through the λ/4 wavelength plate 8 again, separated by the polarizing beam splitter 7, passed through the λ/4 wavelength plate 9, and then sent to the recording medium by the diaphragm lens 11. 12 to form an oblong beam 20. On the other hand, the polarization direction of the beam 20 reflected from the recording medium 12 is rotated by 90 degrees through the aperture lens 11°λ/4 wavelength plate 9, separated by the polarizing beam splitter 7, and directed toward the magnifying prism 6.

Next, at the timing shown in FIG. 1, five drive control signals 23-& to 23-c for erasing are generated and while erasing, immediately after that, drive control signals 23-d to 23-f for recording are generated to record. do. That is, erasing is performed with a starting end and an ending end in the gap section 25 as before, and the recording film is once brought into a liquid state and is slowly cooled, and recording is performed at the maximum power in which the recording film does not go into a liquid state in the gap section 25. The data area 26 is scanned with a power that modulates the data area 26 with a digital signal to be recorded and brings the recording film into a liquid phase state.

By performing the drive control as described above, the erase start and end portions existing in the gap section 26 are aligned with the recording beam 1.
It will be annealed at 9.

Effects of the Invention As described above, according to the present invention, the recording film becomes stable at the beginning and end of erasing, is resistant to repeated erasing, and is extremely effective as an optical recording/reproducing device.

[Brief explanation of the drawing]

Fig. 1 is a timing diagram of a semiconductor laser drive control signal in an embodiment of the present invention, Fig. 2 is a principle diagram of an optical recording/reproducing device in a conventional example, and Fig. 3 is a timing diagram of a semiconductor laser drive control signal in a conventional example. It is a diagram. 1...First light source, 2...Second light source, 3, 4...Condensing lens, 5...Cylindrical lens, 6... ... Magnifying prism, 7.
...Polarizing beam splitter, 8,9...
λ/4 wavelength plate, 1o...filter, 11...
...Aperture lens, 12...Recording medium, 13 pa. ...Right angle prism, 14... Convex lens, 16
. . . Split mirror, 16 . . . Photodetector for tracking control, 17 . . . Photodetector for focus control, 18- Track groove for recording information, 19.
. . . Substantially circular beam, 2o . . . Oval beam, 21 . . . Drive circuit for light source 2, 22 .
...Drive circuit for light source 1, 23...Drive control signal generation circuit, 23-1L...Semiconductor laser control gate signal for erasing, 23-b...For erasing modulation signal, 23-C... semiconductor laser power control signal for erasure, 23-d...
・Semiconductor laser control gate signal for recording, 23
-6...Modulation signal for recording, 23-4...
...Semiconductor laser power control signal for recording. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
figure

Claims (1)

[Claims] In an optical recording and reproducing device that records digital data on a disk using a change in reflectance using recording light modulated by digital data, a plurality of tracks on the disk are divided into a plurality of sectors, An address is recorded in advance in each sector by a method such as cutting, and the address is reproduced during recording and erasing, so that the digital data can be recorded and erased in the sector identified by the address. In a configuration in which a gap section is provided between the address and the recording section of the digital data, the start and end ends of the semiconductor laser control gate signal are respectively provided within the gap section during erasing, and the semiconductor laser control gate signal is set within the gap section during recording. An optical recording/reproducing apparatus characterized in that the laser control gate signal ON region is an area excluding the address section, and the gap section is DC-modulated at a maximum power that does not cause the recording film to enter a liquid phase state.