JPS61137275A - Discriminating method of recording medium - Google Patents

Abstract

PURPOSE:To discriminate the kind of a recording medium easily by forming a reflector changing its reflection factors in accordance with a part of kinds in a recording medium cartridge including plural kinds of recording media having different driving conditions and detecting the reflected light from the reflector. CONSTITUTION:The potential levels of respective inverted input terminal (-) of comparators 12, 14 are adjusted by variable resistors 13, 15 so that the potential levels are adjusted to a voltage value V1 between the output value Va of a pre-amplifier 11 when a reflection seal has 0% reflection factor and the output value Vb of the pre-amplifier 11 when the reflection seal has 25% reflection factor and to a voltage value V2 between the output value Vb and an output value Vc outputted from the pre-amplifier 11 when the reflection seal has 50% reflection factor. The comparators 12, 14 compare the voltage values of the inverted input terminals (-) with the voltage values of non-inverted input terminals (+) connected to the outputs of the pre-amplifiers 11. In case of a ROM type disk adhering the reflection seel having 0% reflection factor, Va<V1<V2 is formed, so that the outputs of the comparators 12, 14 are in the Low level. Thus, three kinds of different disks can be detected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording medium identification method, and more particularly to a method for identifying types of recording media with different driving conditions.

The present invention is applied to information recording and reproducing devices such as optical disk memories and video disks.

[Prior art]

As an information recording and reproducing device, there is a laser ♂ deo disc device that optically records information. Recording media (hereinafter referred to as disks) include read-only R, 0M type disks, RAW type disks that can be recorded only once, and E-DR that is erasable and can be recorded and played multiple times.
Although there are disks such as AW type disks, these disks have almost the same basic configuration for recording, playback, and erasing, and it is possible to use a common drive device. However, due to differences in the reflectance of the surface of each disk and differences in the reproduction principle, the driving conditions must be changed for each disk, so it is necessary to identify the disks in order to operate them with a common drive device. .

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for easily identifying the type of recording medium in view of the above-mentioned demands from the prior art. According to the present invention, it is possible to drive multiple types of recording media with different driving conditions using a common information recording/reproducing device.

[Summary of the invention]

In order to achieve the above object, the present invention provides a part of a recording medium cartridge containing a plurality of types of recording media with different driving conditions, and includes a reflector having various reflectances depending on the type, and The method is characterized in that the recording medium is identified by detecting reflected light.

[Embodiments of the invention]

Embodiments of the present invention will be described in detail below with reference to the drawings.

As an embodiment of the recording medium identification method according to the present invention, a case of a disk device will be described.

FIG. 1 is a perspective view of an optical disk device to which the present invention is applied. In FIG. 1, 1 is a disk, 2 is a disk cartridge into which the disk is placed, 3 is a guide rail for inserting the disk cartridge into a drive device (not shown), and 4 is a reflective seal attached to the disk cartridge. The reflective seal 4 changes its reflectance depending on the type of disc.

For example, for ROM type discs, attach a reflective sticker with a reflectance of 0, for DRAW type discs, attach a reflective sticker with a reflectance of 25, and for E-DRAW type discs, attach a reflective sticker with a reflectance of 50%. . 5 is a photo interrupter.

FIG. 2 is a circuit diagram of the optical disk device shown in FIG. 1.

In FIG. 2, 7 is an LED, 6 is a current limiting resistor, and 10 is an LED driving transistor. 8 is bias resistance,
9 is a pin photodiode, and 11 is a preamplifier that amplifies the received signal. 12.14 is a comparator, 1
3.15 is a variable resistor.

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

When an input signal enters the pace of the LEDffi driving transistor 10, the LED driving transistor 10 is turned on, current flows, and the LED 7 is generated.

The light emitted from the LED 7 is reflected by the reflective seal 4, enters the bin photodiode 9, and is amplified and current-to-voltage converted by the preamplifier 11. The potential of each inverting input terminal (→) of the comparator 12.14 is adjusted by a variable resistor 13.15, and as shown in FIG. The output value from (
Va) and the output value (Vb) from the preamplifier 11 when the reflective seal has a reflectance of 25 cm and the output value (Wb) and when the reflective seal has a reflectance of 50 cm. The voltage value (vc) between the output value (vc) from the preamplifier 11 of
v2). Comparators 12 and 14 compare the voltage value of the inverting input terminal (c) set as above and the preamplifier 1.
A comparison is made with the voltage value of the non-inverting input terminal (G) connected to the output of No. 1. In the case of a ROM type disk with a reflective sticker with a reflectance of 0%, since va<vl<v2, the outputs of comparators 12 and 14 are both low level, and in the case of a DRAW type disk with a reflective sticker with a reflectance of 25 cm. In this case, since Vl<Vb<V2, the output of the comparator 12 is at H1gh level, and the output of comparator 14 is at Low level.

Since Vl<Vz<Vc for the E-RAW type with a reflective sticker with a reflectance of 50ch, the outputs of the comparator 12 are both at I (i gh level).As mentioned above, three types of output signals are output. It can detect three different types of discs.

〔Effect of the invention〕

As explained in detail above, according to the recording medium identification method according to the present invention, by providing a part of the recording medium cartridge with a reflector according to the type of recording medium, it is possible to easily identify the recording medium, and the driving conditions It becomes possible to drive a plurality of types of recording media with different values using a common information recording/reproducing device.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an optical disk device to which the method of the present invention is applied. FIG. 2 is a circuit diagram of the optical disk device shown in FIG. 1. FIG. 3 is a diagram showing voltage values at the non-inverting input terminal and the inverting input terminal of the comparator of the circuit shown in FIG. 2. 1...disk, 2...disk cartridge, 3
...Guide rail, 4...Reflective sticker, 5...Photo interrupter

Claims (1)

[Claims] A reflector having a different reflectance depending on the type is provided in a part of a recording medium cartridge containing a plurality of types of recording media with different driving conditions, and the recording medium is identified by detecting the reflected light of the reflector. A recording medium identification method characterized by: