JPH0576112B2 - - Google Patents

Description

[Detailed description of the invention]

Industrial Application Field The present invention provides compatibility between reproduction of a read-only optical disc, recording/reproduction of a recordable/reproducible optical disc, or recording/reproduction/erasure of a recordable/reproducible/erasable optical disc. The present invention relates to an optical recording and reproducing device that can be used in a system that includes a device that records or reproduces information, such as an external memory for a computer, an audio recording and reproducing system, a video recording and reproducing system, etc. It is something. Conventional configuration and its problems Conventional devices that play reflective playback-only optical discs are equipped with functions for detecting the presence or absence of a disc and detecting the front and back sides of the disc. Devices that perform erasing were also equipped with similar functions. However, when configuring an optical recording/playback device that can function independently for playback of read-only optical discs and recording, playback, or erasing of recordable optical discs, conventional methods cannot be used. There was a problem in that it was not possible to automatically distinguish between a dedicated optical disc and a recordable optical disc. Purpose of the Invention The present invention solves the above-mentioned conventional problems, and allows reproduction of a read-only optical disc and recording/reproduction or erasing of a recordable optical disc to function independently and with compatibility. An object of the present invention is to provide an optical recording and reproducing device that can automatically distinguish between a read-only optical disc and a recordable optical disc. Structure of the Invention The present invention comprises: a first optical disc having a reproducible property; a second optical disc having a reflectance different from that of the first optical disc and capable of recording, reproducing, and erasing; With a configuration having a discriminating means for discriminating between a state in which there is no disc, playback of the first optical disc and recording/playback or erasing of the recordable second optical disc function independently and with compatibility. It is something that can be done. DESCRIPTION OF THE EMBODIMENTS FIG. 1 is a block diagram of an optical recording/reproducing apparatus according to an embodiment of the present invention. In FIG. 1, numeral 1 denotes a disk, which is either a read-only optical disk or a recordable optical disk that is used to function. 2 is a light source that makes a light beam enter the disk 1;
A photodetector 3 receives reflected light from the disk 1, and both are placed near the disk 1. 4 is a voltage amplifier that amplifies the signal P from the photodetector 3; 5A and 5B are reference voltages V ₁ of different values;
Variable resistors 6A and 6B set V ₂ are reference voltages V ₁ and V ₂ set by variable resistors 5A and 5B,
This is a voltage comparator that compares the output voltage V _P from the voltage amplifier 4. 7 is a judgment circuit, and a voltage comparator 6
The disk 1 to be used is determined based on the output signals Q and R from A and 6B. Reference numeral 8 denotes a display means for displaying the content determined by the determination circuit 7. The operation of the optical recording/reproducing apparatus of this embodiment configured as described above will be explained below. First, a light beam from a light source 2 is made incident on a reflective disk 1, and the light reflected by the disk 1 is received by a photodetector 3. A signal P from the photodetector 3, which is proportional to the reflectance of the disk 1, is sent to a voltage amplifier 4.
voltage _comparator 6A,
It is input to 6B. Furthermore, the reference voltage V ₁ set by the variable resistor 5A and the reference voltage V ₂ set by the variable resistor 5B are input to voltage comparators 6A and 6B, respectively, and compared with the output voltage V _P from the voltage amplifier 4. be done. Figure 2 is an output characteristic diagram showing the relationship between disk reflectance and output voltage, where the horizontal axis is disk reflectance γ,
The vertical axis indicates the output voltage V _P from the voltage amplifier 4. In FIG. 2, disk 1 _x is a read-only optical disk with a reflectance _γ
Output V _x . Further, the disk 1 _y is a recordable/reproducible optical disk or a recordable/reproducible/erasable optical disk having a reflectance γ _y and outputs a voltage V _y from the voltage amplifier 4 . In this way, under the condition that γ _x > γ _y holds true in the reflectance, and therefore the relationship V _x > V _y holds true, the reference voltages V ₁ and V ₂ are set to an appropriate value that holds the relationship V ₁ < V ₂ . If the value is set to a certain value, it can be determined from the output voltage whether the disk 1 is a read-only optical disk _1x or a recordable/readable/erasable optical disk _1y .
At this time, V _x > V ₂ > V _y > V ₁ holds true. Therefore, in the determination circuit 7, the voltage comparator 6
When the output signal Q indicating V _P >V ₁ is output from A and the output signal R indicating V _P >V ₂ is output from the voltage comparator 6B, it can be determined that the disk 1 _x is being used. In addition, the output signal Q indicates V _P > V ₁ ,
If the output signal R indicates V _P <V ₂ , it is determined that the disk 1 _y is being used. Furthermore, the output signal Q
When V _P <V ₁ and the output signal R indicates V _P <V ₂ , it is determined that the disk 1 does not exist. As described above, according to this embodiment, the difference in the output signal from the photodetector based on the difference in reflectance between a read-only optical disc and a recordable optical disc is used to determine which disc is to be used for functioning. It can be performed. Furthermore, the content determined by the determination circuit 7 is displayed by the display means 8. Also, based on the discrimination signal output from the determination circuit 7 and the selection signal corresponding to the operation to be performed among recording, playback, and erasure, it corresponds to the time of playback of a read-only optical disk and the time of recording, playback, or erasure of a recordable optical disk. By providing a means for switching the servo gains for focus control and tracking control, and the degree of modulation of the light source, etc. to optimal values that have been set in advance according to each state, a read-only optical disk can be produced using a single optical head. playback and recording/playback or erasing of a recordable optical disc can function independently and with compatibility. Output voltage V _P from voltage amplifier 4 and reference voltage V ₁ ,
The relationship between V ₂ and the operating state of the display means 8 are summarized in the table below.

[Table] In the above table, the ○ mark indicates that the display function is in the operating state, and the × mark indicates that the display function is in the stopped state. In this embodiment, variable resistors 5A and 5B provide 2
Although the reference voltages V ₁ and V ₂ are provided in stages, if the number of variable resistors is further increased to set reference voltages in two or more stages, it will be possible to improve the function of detecting the front and back sides of the disc and the ability to record/play back the light. It can even be equipped with a function to distinguish between a disc and a recordable, reproducible, and erasable optical disc. Effects of the Invention The present invention comprises: a first optical disc having a reproducible property; a second optical disc having a different reflectance from the first optical disc and capable of recording, reproducing, and erasing; By providing a discriminating means for discriminating between a state in which there is no disc and a state in which there is no disc, it is possible to detect the front and back sides of an optical disc and to discriminate between various types of optical discs.In addition, focus control and tracking control can be performed in accordance with the discrimination signal of this discriminating means. , comprising a switching means for switching a constant of the light source modulation degree, and one transporting means for transporting one optical head in the radial direction of the optical disc, and the reproducing means for reproducing the first optical disc and the second optical disc. By independently functioning recording, playback, and erasing of the first optical disk, it is possible to play back the first optical disk even though it is a single optical recording/playback device consisting of one optical head. It becomes possible to record, reproduce, and erase information on the second optical disk, and also has a cost reduction effect, for example, the present device can be configured at approximately the same cost as a recording/reproducing device that targets only the second optical disk. This makes it possible to realize an excellent optical magnetic recording and reproducing device that provides the following effects.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an optical recording/reproducing apparatus according to an embodiment of the present invention, and FIG. 2 is a characteristic diagram showing the relationship between reflectance and output voltage of the same disk. 1... Disk, 2... Light source, 3... Photodetector, 4... Voltage amplifier, 5A, 5B... Variable resistor, 6A, 6B... Voltage comparator, 7... Judgment circuit, 8... Display means.

Claims (1)

[Scope of Claims] 1. A first optical disc having a reproducible property; a second optical disc having a reflectance different from that of the first optical disc and capable of recording, reproducing, and erasing; a discriminating means for discriminating whether there is no disk; a switching means for switching between focus control, tracking control, and a constant of the light source modulation degree in accordance with a discriminating signal from the discriminating means; 1. An optical recording and reproducing apparatus, comprising one transporting means for transporting the first optical disc, and independently functioning reproducing the first optical disc and recording, reproducing, and erasing the second optical disc. 2. The determining means includes a light source that makes a light beam incident on the optical disk, and a photodetector that receives reflected light from the optical disk, and the photodetector detects the reflected light from the first optical disk and the second optical disk. 2. The optical recording and reproducing apparatus according to claim 1, wherein a discrimination signal is output in accordance with a difference in the amount of light received by the photodetector caused by a difference in rate.