JPS61160838A - Optical information recording and reproducing device - Google Patents

Abstract

PURPOSE:To discriminate the type of a recording medium and to attain the stable recording, reproducing and erasing operations, by detecting the reflected or transmitted light of the light irradiated to a reflector or a transmitter which is provided to a recording medium and shows different reflection or transmission factors according to the type of the recording medium. CONSTITUTION:The laser beam delivered from a light source 2 is irradiated to a reflector 23 of a disk 7 prior to a recording, reproducing or erasing operation. The laser beam reflected by the reflector 23 is polarized by a polarized beam splitter 4 and supplied to a photoreceptor 10 to be converted into electric signals. Then a disk type detecting circuit 22 decides the type the disk 7. A laser modulator 14and a spindle motor control circuit 20 are controlled to the laser power and the revolving speeds optimum to the disk 7 by the control signal given from a controller 21. At the same time, the controller 21 sends the control signals to a focus/tracking control circuit 16 and a demodulation circuit 15. Then an optical head 1 is shifted for start of operations of record, reproduction and erasion with high stability.

Description

[Detailed description of the invention] [Field of industrial use] The present invention relates to an optical information recording/reproducing device.

The present invention is applied to an optical information recording and reproducing device used in a home recording and reproducing device, a document 7 eyering device, and the like.

[Prior art]

As an optical information recording/reproducing device, there is a method of recording, reproducing, and erasing information by shining a radar light onto an optical information recording medium (hereinafter referred to as a disk). ROM type) disk, disk that can be recorded only once (DRAW type), disk that is erasable and can be recorded and played back multiple times (E-DRAW type)
There are discs such as discs. The ROM tag disk has small holes formed in advance in accordance with the information, and the information signal is reproduced based on changes in the amount of transmitted or reflected light by the laser beam. In a DRAW type disk, a radar beam is applied onto the disk surface to create unevenness corresponding to the information to be recorded, and an information signal is reproduced by changing the amount of transmitted light or reflected light. E-DRAW type disks use laser light to cause magnetization reversal (recording and erasing is performed, and reproduction is performed using the magnetic Kerr effect, etc.).These disks are selected depending on the purpose of the information to be recorded. If the decision has been made and there is a need for mass production and long-term storage, RO
M-type disks are used, DRAW type disks are used when the required quantity is small and must be stored for a long period of time, and g-DRAWROM is used when information may be erased later and is used as a temporary buffer. Type disk is available.

These types of disks have almost the same basic configuration for recording, reproducing, and erasing information, and it is desirable to use a common drive device.

However, such discs usually have different recording sensitivities depending on the type of disc, and in order to prevent accidents such as loss of recorded information due to playback light and to perform recording and playback in good condition, it is necessary to adjust the recording sensitivity depending on the type of disc. Therefore, it was necessary to change the radar/4' power or the number of rotations of the disk. In addition, information signals, tracking error signals, and
The focus error signal has a difference in signal level due to differences in the reflectance of the disk surface, differences in detection principle, and the like. In particular, the level of the information signal component varies by several tens of times depending on the type of disc. This same recording, playback,
When attempting to record, reproduce or erase information using an erasure system,
If a small signal is used as a reference, a huge dynamic range is required, and if a large signal is used as a reference, it becomes difficult to detect small signals and noise problems arise. Therefore, in order to stably record, reproduce, and erase data on different types of discs, it is necessary to switch the signal input and signal gain depending on the type of disc. Therefore, in order to solve these problems, it has been desired that an optical information recording/reproducing apparatus has a function of easily determining the type of disc.

[Purpose of the invention]

In view of the problems of the prior art described above, the purpose of Honkotomei is to provide an optical system that can easily and reliably identify the type of recording medium and stably record, reproduce, and erase multiple types of recording media using the same device. The purpose of the present invention is to provide a type information recording/reproducing device.

[Summary of the invention]

In order to achieve the above object, the present invention directs light from the optical head to a discrimination area provided on the recording medium and having a reflectance or transmittance that differs depending on the type of recording medium, prior to a recording, reproducing, or erasing operation. It is characterized by providing means for determining the type of recording medium by irradiating the recording medium and detecting the reflected light or transmitted light.

[Embodiments of the invention]

Embodiments of the present invention will be described in detail below with reference to the drawings. Here, a case will be described in which a disc is provided with a discrimination area made of a reflector.

FIG. 1 is a block diagram of an embodiment of an optical information recording/reproducing apparatus according to the present invention. In Fig. 1, 1 is an optical head;
2 is a laser light source, 3 is a collimator lens that makes the light beam from the radar light source parallel, 4 is a polarizing beam sinter that reflects the reflected light from the disk 7, 5 is an objective lens, and 6 is the objective lens. This is an actuator that drives the objective lens 5 in order to focus and track the light beam passing through the disk 70 to a predetermined position on the surface of the disk 70. 8 is an analyzer, 9 is a condensing lens, and 10 is a light receiving element. A spindle motor 11 rotates a disk 7 attached to a turntable 12 by a flang 13. In the recording operation, the image information signal is sent to the laser modulator 1.
4, the laser light is converted into an optical signal by a laser light source 2, and the laser light is passed through a collimator lens 3 and a polarizing beam snorritator 4.
, are focused on the disk 7 through the objective lens 5 and recorded. In the reproduction operation, a laser beam with a constant output is emitted from the laser light source 2, and the laser beam is irradiated onto the disk 7 in the same manner as in the recording process described above. -4, and passes through the analyzer 8 and condensing lens 9 to the light receiving element 1.
Enters 0. The amount of reflected light is converted into an electrical signal by the light receiving element 10, and reproduced into image information by the demodulation circuit 15. At the same time, the output from the light receiving element 10 is also sent to the focus control and tracking control circuit 16, and the objective lens 5 is driven by the actuator 6 to perform focus control and tracking control. In the erasing operation, a laser beam of constant output is output from a radar light source, and the laser beam is irradiated onto the disk 7 in the same manner as in the recording operation described above, thereby erasing the information recorded on the disk 7. Optical head 1 is feed motor 1
7 provides access in the radial direction of the disk. Reference numeral 18 denotes a control circuit for the feed motor 17, which controls the position of the optical head 1 in accordance with the output of the head position sensor 19. Reference numeral 20 denotes a spindle motor control circuit, in which a signal indicating the type of disk is sent from a disk type detection circuit 22 to a controller 21, and the spindle motor 11 is rotated at a rotation speed suitable for the type of disk instructed by the controller 21.

A controller 21 controls the timing of the above circuit.

FIG. 2 is a plan view of a disk used in the optical information recording/reproducing apparatus according to the present invention. 7 is a disk, and a discrimination area 23 made of a reflector is provided on the surface of the disk. The reflectance of this reflector varies depending on the type of disc. For example, for a ROM type disk, the reflectance is 01, for a DRAW type disk, the reflectance is 25 inches, and for a g-DRAW type disk, the reflectance is 50 inches.

Next, the determination operation will be explained using the operation flowchart of FIG. 3 for determining the disc type.

First, the disk 7 is placed on the turntable 12, and when the power is turned on and started, the spindle motor 11 on which the disk 7 is placed starts rotating (24). Next, the feed motor control circuit 18 drives the feed motor 17 in accordance with the instruction from the controller 21 so that the optical axis of the objective lens of the optical head 10 is placed above the discrimination area 23 (accessed).

After that, turn on Rade light source 2 (26) and turn on the autofocus sensor. Close the loop and operate autofocus (27). Now, the reflectance of the reflector attached to the disc is selected to be within the range where Auto 7 Orcus is applied. A laser beam emitted from a radar light source 2 passes through a collimator lens 3, a polarizing beam sinter 4, and an objective lens 5, and is reflected onto a disk 70 by a reflection lens 23. The laser beam reflected by the reflector is passed through an objective lens 5, a polarizing beam sinter 4,
It passes through the analyzer 8 and the condensing lens 9 and enters the light receiving element 10.
The amount of reflected light is converted into an electrical signal by the light receiving element 10. Next, the disk type detection circuit 22 determines the type of disk (28), and according to the control signal from the controller 21, the laser modulator 14 and spindle motor control circuit 20 respectively control the speed and rotation of the disk to suit the loaded disk. Adjusted to speed. At the same time, a control signal is sent from the controller 21 to the focus control and tracking control circuit and the demodulation circuit to switch to the optimal autofocus gain, autotracking gain, and signal gain (29). Then, move the optical spatula F″1 and start playback.

FIG. 4 is a circuit diagram of a disc type detection circuit in the embodiment. In FIG. 4, 24 is a bias resistor, 25 is a light-receiving bin photodiode, 26 is a preamplifier for amplifying the received signal, 27.degree. 28 is a comparator, and 29.30 is a variable resistor.

The detection operation of the embodiment will be described below with reference to the drawings.

Laser light emitted from the radar light source 2 is reflected by a reflector 23 provided on the disk 7 and enters a bin photodiode 25, which is a light receiving element, and an optical signal is converted into an electrical signal. This electrical signal is further transmitted to a preamplifier 26
Amplification and current-to-voltage conversion are performed by. Comparator 27
．． The potential of each inverting input terminal ←) of variable resistor 2
9.30, and as shown in FIG. The voltage value (vl) between the output [(V, ) from the amplifier 26
) and the voltage value (v2) between the output [(V, ) and the output f[(VC) from the preamplifier 26 when the reflector has a reflectance of 50 cm. Comparators 27 and 28 compare the voltage value of the inverting input terminal ←) set as described above with the voltage value of the non-inverting input terminal (G) connected to the output of the preamplifier 26. R with a reflector with a reflectance of Ochi
For OM type disks, v, < v, < v2
Therefore, the outputs of comparators 27 and 28 are both LOW level, and in the case of a DRAW type disc equipped with a reflector with a reflectance of 25%, V, (V, (V2), so the output of comparator 27 is H1gh level. , the output of the comparator 28 becomes Low V level.Since the E-DRAW type equipped with a reflector with a reflectance of 50 cm is v, 〈v2〈vc, the outputs of the comparators 27 and 28 are both at the H1gh level. As above, the output signal of type 311 is output and 3
It is possible to detect different types of disks.

Above, we have explained the case where a disc is provided with a discrimination area made of a reflector, but in a device using a transmissive disc that reproduces information using transmitted light, a transmissive material with different transmittance depending on the type of disc is used on the disc surface. A similar operation can be performed by providing a discrimination area consisting of .

〔Effect of the invention〕

As explained in detail above, according to the optical information recording and reproducing apparatus of the present invention, light is irradiated onto a reflector or a transmitter that is provided on a recording medium and has a reflectance or transmittance that differs depending on the type of recording medium, Since the type of recording medium is determined by detecting the reflected light or transmitted light, reliable determination of the type is possible. In addition, since the discrimination is performed using an optical head, there is no need for a special device for discrimination, and with a simple configuration, multiple types of discs can be stably recorded, played back, and erased with the same device. An optical information recording/reproducing device can be provided.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of an optical information recording/reproducing apparatus according to the present invention. FIG. 2 is a plan view of a disk used in the optical information recording/reproducing apparatus according to the present invention. FIG. 3 is an operation flow diagram for determining the type of disc. FIG. 4 is a circuit diagram of a disc type detection circuit in the embodiment. FIG. 5 is a diagram showing voltage values at the non-inverting input terminal and the inverting input terminal of the comparator in the above circuit diagram. 1... Optical head, 2... Laser light source, 3...
Collimator lens, 4...Polarizing beam sinter, 5
...Objective lens, 6...Actuator, 7...
Disc, 8... Analyzer, 9... Condensing lens, 10
···Light receiving element. 1st Flash Figure 2

Claims (1)

[Claims] In an optical information recording/reproducing device equipped with an optical head that performs an operation of recording, reproducing, or erasing information by irradiating light onto an optical information recording medium, prior to the operation, a The present invention is characterized by providing means for irradiating light from the optical head onto a discrimination area having a reflectance or transmittance that differs depending on the type, detecting the reflected light or transmitted light, and discriminating the type of recording medium. Optical information recording and reproducing device.