KR20000013999A - Discriminating apparatus and method of optical disk type - Google Patents

Abstract

PURPOSE: A discriminating apparatus of an optical disk type is provided to discriminate a kind of an optical disk according to an amplitude value of a detected focus error signal. CONSTITUTION: The apparatus comprises a detector for detecting a focus error signal outputted by moving an optical signal reader to a vertical direction of an optical disk surface, a sensor for sensing size variation of the detected focus error signal, a comparator for comparing any value of the sensed size with a preset fixed value, and a discriminator for discriminating a kind of the optical disk according to the comparing result.

Description

Optical Disc Type Discrimination Device and Discrimination Method

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc type discrimination apparatus and a discrimination method for accurately determining the type of a mounted optical disc, and more particularly to a focus error signal detected by vertically moving an objective lens of an optical pickup with respect to a reading surface of an optical disc. By comparing the maximum value of with the predetermined constant value, it is possible to determine the read-only optical disc (hereinafter referred to as CD) and the recordable optical disc (hereinafter referred to as CD-RW) in a short time. The present invention relates to an optical disc type discrimination apparatus and a discrimination method.

A typical optical disk player includes a pick-up section 11 for reading a recording signal by injecting a light source into the optical disk 10 as shown in FIG. An R / F unit 30 for filtering the high frequency analog signal read out and input; An amplifier (40) for amplifying a focus error (F.E) signal output from the optical pickup (11); A zero crossing signal detector 60 for detecting a zero crossing signal FZC from the amplified focus error signal; A microcomputer (50) for variably controlling the amplification ratio of the amplifier (40) according to whether the zero crossing signal is detected, and determining the type of the optical disc (10) based on the detection time point of the zero crossing signal; And moving the optical pickup 11 through the drive unit 70 under the control of the microcomputer 50, and tracking and focusing the optical pickup 11 from the tracking error TE and the focus error FE. It is configured to include a servo unit 20 for adjusting the.

The method for determining the type of optical disc player optical disc configured as described above is performed as follows. First, the microcomputer 50 applies a voltage (about 6V) to a focusing actuator (not shown) of the optical pickup 11 through the servo unit 20, thereby providing a certain type of objective lens of the optical pickup 11. The optical disk recording pit is also vertically moved to a proximate position Lu which can be detected. Thereafter, the objective lens of the optical pickup 11 enters a light source while moving from the proximal position Lu to the lowest position Ld as shown in FIG. 2, so that the pit of the optical disk 10 The optical signals reflected from the listed surfaces are detected and converted into electrical signals, and the R / F unit 30 filters and outputs the electrical high frequency signals.

The amplifier 40 amplifies the focus error signal read out from the disk surface by the optical pickup 11 to a predetermined level, and the zero crossing signal detector 60 zeros based on the amplified focus error signal value. The cross signal FZC is detected. Accordingly, as shown in FIG. 2, the optical pickup 11 is vertically moved from the proximal position Lu to the lowest position Ld, that is, a predetermined time (approximately 25 ms) after the voltage is applied to the focusing actuator. In the elapsed time, the level of the zero crossing signal is increased at the zero crossing of the focus error signal detected from the optimum position Lx, and the zero crossing signal detector 60 detects this and informs the microcomputer 50. From this, the microcomputer 50 recognizes the type of the mounted optical disk as a general CD.

Further, even after the optical pickup 11 moves to the lowest position Ld, if the level of the zero crossing signal detected by the zero crossing signal detector 60 does not change, the microcomputer 50 may include a servo unit ( By controlling the focusing actuator of the optical pickup 11 through 20), the above-described process is repeated twice more. If the level of the detected zero crossing signal does not change after this, as shown in FIG. 3, the microcomputer 50 increases the amplification factor of the amplifier 40 by about 12 dB (about 3 times) and repeats the same operation. Done. Accordingly, when the level of the zero crossing signal is raised and changed by the zero crossing signal detector 60, the microcomputer 50 determines the type of the seated optical disk as CD-RW.

In addition, if the level of the zero crossing signal does not change even after the amplification rate is increased as described above, it is additionally performed twice as in the above-described case, and if there is no change, the microcomputer 50 does not have a seated optical disk ( No Disc).

However, if a servo operation is performed to move the objective lens of the optical pickup to the proximate position Lu, which can discriminate all types of optical disks (takes about 280 msec), and the level of the zero crossing signal does not rise and change during the servo operation, After moving the objective lens to the lowest position (Ld) again, the servo operation is repeated three or more times. If the level is not increased, the optical disc is judged to be a CD-RW. There was a problem.

In addition, even when the seated optical disc is a CD-RW, the level of the zero crossing signal is increased and changed in the initial servo operation so that the disc is abnormally discriminated as a general CD. When noise is inserted into the focus error signal by relying on the zero crossing time point, there is a problem in that an error of discrimination occurs due to a change in the zero crossing point time point.

Accordingly, an object of the present invention is to provide an optical disc type discriminating apparatus and a discriminating method for discriminating an optical disc type according to the amplitude value of a detected focus error signal.

Fig. 1 shows the configuration of an optical disc reader in an optical disc player,

Fig. 2 shows the focus error signal F.E and the zero crossing signal FZC which are generated at the positive focus position in order.

3 shows a comparison between the focus error signal F.E and the zero crossing signal FZC detected according to the type of the mounted optical disk,

Fig. 4 shows the structure of an optical disc reading unit in the optical disc player according to the present invention,

Figure 5 shows the flow of one embodiment of an optical disc type discrimination method according to the present invention.

※ Explanation of code for main part of drawing

10: Optical Disc 11: Optical Pick-up

20: Servo section 30: R / F section

40: Amplifier 50, 500: MICOM

60: zero crossing signal (FZC) detector 70: drive unit

80: memory 81,83: A / D converter

82: comparator

An optical disc type discriminating apparatus according to the present invention for achieving the above object comprises: detecting means for detecting a focus error signal output from a rotation driving means while moving an optical signal reading means in a vertical direction of an optical disk surface; Sensing means for sensing a change in magnitude of the detected focus error signal; Comparison means for comparing an arbitrary value of the sensed magnitude with a predetermined constant value; And discriminating means for discriminating the type of the optical disk according to the comparison result.

In addition, the optical disc type determination method according to the present invention comprises a first step of detecting a focus error signal output while moving the optical signal reading means in the vertical direction of the optical disk surface; And a second step of determining the type of the optical disk according to whether the detected signal exceeds a predetermined constant value.

In the optical disc type discriminant and discriminant method according to the present invention constructed and configured as described above, first, the detection means detects a focus error signal while moving the optical signal reading means in a vertical direction of the optical disc surface, and the detection means The change in the magnitude of the detected focus error signal is continuously detected. At this time, the magnitude value of the detected focus error signal is continuously compared with a preset reference signal, and the discriminating means determines the type of the optical disc according to whether the focus error signal magnitude value exceeds the reference signal. Will be determined.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Hereinafter, an embodiment of an optical disc type determining apparatus and a method according to the present invention will be described in detail with reference to the accompanying drawings.

4 is a block diagram of an embodiment of an optical disc type determining apparatus according to the present invention. The optical disc type discriminating apparatus of FIG. 4 samples the focus error signal detected by the optical pickup 11 without using the amplifier 40 and the zero crossing signal detector 60 as in the conventional apparatus of FIG. A first A / D converter (81) for converting the signal to the first; A comparator (82) which compares the applied focal error data with a reference value; A second A / D converter 83 for converting a high frequency signal detected by the optical pickup 11 into digital data; And a memory 80 storing a reference value for determining an optical disc. In the present invention, the microcomputer 500 reads the reference value from the memory 80 and applies the reference value to the comparator 82. The type of optical disc is determined according to the comparison result of 82.

Hereinafter, the flow of an optical disc type determination method according to the present invention of FIG. 5 will be described in detail with reference to the configuration of FIG.

In the optical disc type determining apparatus and the determining method according to the present invention, as in the prior art, the microcomputer 50 supplies a voltage (about 6 V) to a focusing actuator (not shown) of the optical pickup 11 through the servo unit 20. The optical disk 10 seated by the optical pickup 11 is applied while the objective lens of the optical pickup 11 is vertically moved from the lowest position Ld to the proximal position Lu (S01, S02). The focus error signal extracted from the amount of light read out from) is sequentially input to the A / D converter 81 (S10).

At this time, the A / D converter 81 samples the focus error signals sequentially input at a predetermined period, and the focus error signal is converted into digital data corresponding to the value as a result of the sampling and comparator 82. It is applied to (S11). The microcomputer 500 reads a reference value (1.8mV) for determining the type of the optical disk stored in the memory 80 and applies it to the comparator 82, and is the comparator 82 sequentially. The digital data is continuously compared with the reference value input from the microcomputer 500. When the digital data is smaller than the reference value, a signal having a 'low' level is output. The signal of the 'high' level is output (S12).

Accordingly, the microcomputer 500 has a predetermined time until the objective lens of the optical pickup 11 reaches the proximal position Lu from the lowest position Ld, that is, a predetermined time after the voltage is applied to the focusing actuator. When the output value of the comparator 82 changes to a 'high' level, the optical disc currently seated is discriminated as a normal CD (S21).

On the contrary, if the output value of the comparator 82 is maintained as 'low', the microcomputer 500 may temporarily determine the optically seated optical disc as a CD-RW (S31). If the pickup 11 reads the recorded data of the optical disc and confirms that the high frequency signal is not read from the data digitally converted by the R / F unit 30 and the A / D converter 83 (S32), The microcomputer 500 judges that the optical disc is not seated (No Disc) (S41).

The apparatus and method for discriminating the optical disc type according to the present invention, which is constructed and constructed as described above, is further determined by determining whether the type of the optical disc is CD or CD-RW from the signal detected while moving the optical pickup only once in the vertical direction. The type of optical disc seated in a short time can be determined.

In addition, the present invention is based on the signal level value, unlike the conventional conditions, the type of signal noise level is unexpectedly generated in the device, even if there is a change in the zero crossing of the focus error signal affects the signal level discrimination It is a very useful invention that can achieve the result of type determination of an accurate optical disk without error.

Claims (5)

A first step of detecting a focus error signal output while moving the optical signal reading means in the vertical direction of the optical disk surface; And And determining a type of the optical disk according to whether the detected signal exceeds a predetermined value. The method of claim 1, The second step is characterized in that the optical disk type discrimination method characterized in that it is determined that the recordable optical disk when the predetermined constant value is not exceeded. The method of claim 1, The second step, the optical disk type discrimination method characterized in that it is determined as a read-only optical disk when the predetermined value is exceeded. Detection means for detecting a focus error signal output from the rotation driving means while moving the optical signal reading means in the vertical direction of the optical disk surface; Sensing means for sensing a change in magnitude of the detected focus error signal; Comparison means for comparing an arbitrary value of the sensed magnitude with a predetermined constant value; And And an discriminating means for discriminating the type of the optical disk according to the comparison result. The method of claim 4, wherein And the random value compared by said comparing means is a maximum value of a focus error signal.