JPS63140425A - Optical disk recording information confirming circuit - Google Patents

Abstract

PURPOSE:To confirm the recording information of an optical disk in a short access time by obtaining an OR signal of the writing confirming data and the error confirming data and obtaining error data with a noncoincidence signal to an AND signal. CONSTITUTION:A reference signal CCK, a writing signal W/D and a reproducing RF signal are inputted to an error confirming circuit 13, the level of a reflecting light quantity is a prescribed error reference voltage ECV or below and error confirming data EDD to show a scratch are detected. Next, when writing confirming data WDD and the error confirming data EDD are inputted to an OR gate 14, an OR signal DD to show a normal bit formation and a scratch detection is detected and outputted to a comparator 15. The data DD and an AND signal WCD from an AND gate 11 are compared, and error data E/D to show the writing defect and the scratch detection at the time of noncoincidence is outputted. Thus, simultaneously with an information writing action to an optical disk, recording information can be read and confirmed and the access time can be shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an optical disk recorded information confirmation circuit, and particularly to an optical disk device in which information is stored on an optical disk.An optical disk generally stores a large amount of digital information such as original images and audio in a spiral or concentric circle. It can be written as desired and read as desired.

Conventionally, an optical disc recorded information confirmation circuit in this type of optical disc device reads the written information from the beginning after writing information on the entire disc when writing on the optical disc in a spiral shape, and on the other hand, when writing in a concentric circle, It was configured to read the information written on each track to check whether it was recorded accurately or not, and to detect the presence or absence of defects on the optical disc.

Problems to be Solved by the Invention However, with such a configuration, there is a problem that access time becomes long because information is written to the entire optical disc or each track and then read out.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide an optical disc recorded information confirmation circuit that can confirm recorded information on an optical disc in a short access time.

Means for Solving the Problems In order to solve the above problems, the present invention includes a first detection means for detecting a point in time when information is written on an optical disc and the amount of light reflected from the optical disc decreases; a second detection means for detecting that information has been written normally when the amount of light reflected from the optical disc falls below a writing reference level while the writing means is in operation; a third detection means for detecting a defect in the optical disk when the amount of reflected light is less than an error detection reference level; and performing a logical OR operation on the data from the second detection means and the data from the third detection means. A circuit, and a fourth detection means for comparing the data from the first detection means and the data from the OR circuit, and detecting a write failure or defect in the optical disc if they do not match. shall be.

Operation The present invention can read and confirm recorded information at the same time as the information writing operation to the optical disc is performed by using the above-described configuration, so that the access time can be greatly shortened.

EXAMPLES Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of an optical disk recording information confirmation circuit according to the present invention, and FIG. 2 is a timing chart of main signals of the circuit shown in FIG.

First, in the upper part of FIG. 2, the input signals of this circuit will be explained. CCK is a reference signal, W/D is a write signal output to a semiconductor laser (not shown) for writing information to an optical disk (not shown), and RF is: This is a signal obtained by reflecting laser light emitted from a semiconductor laser from an optical disk and photoelectrically converted by a light receiving element (not shown), that is, a reproduction signal read out simultaneously with information being written to the optical disk.

As shown by the first, second, and fourth waveforms in FIG. 2, the reproduced RF signal is leveled by the reflected light of the semiconductor laser when information is written by the semiconductor laser driven by the write signal W/D. is the predetermined write reference voltage WC
When the voltage rises above V and a normal bit is formed, the write signal W/D increases as shown by the first and fourth waveforms.
Even if the semiconductor laser light is emitted while the peak is at a high level, the waveform will fall.On the other hand, if no pit is formed, the reflected light from the semiconductor laser will be detected as is, as shown by the second waveform. Also, information is not written):
If there is a scratch on the optical disc, the waveform becomes lower than a predetermined error reference voltage, as shown by the third waveform.

Returning to FIG. 1: C. This circuit performs an AND operation between the reference signal CCK and the write signal W/D, and outputs the AND gate 11 shown in the lower part of FIG. 2, and the write signal W/D. When D is high level, reference signal CCK
A write confirmation circuit 12 compares the RF multiplied signal voltage with the write reference voltage WCv in synchronization with the write confirmation data WDD shown in the lower part of FIG.
The error checking circuit 13 compares the RF multiplied signal voltage with the error reference voltage EC■ in synchronization with the reference signal CCK when the voltage is at a low level, and outputs the error checking data EDD shown in the lower part of FIG. 2.

This circuit also includes an OR gate 14 that performs a logical sum operation on write confirmation data WDD from the write confirmation circuit 12 and error confirmation data EDD from the error confirmation circuit 13, and outputs a logical sum signal DD shown in FIG. , AND game)
The comparator 15 compares the AND signal WCD from 11 and the OR signal DD from the OR gate 14 and outputs error data E/D.

Next, the operation of the embodiment according to the above configuration will be explained.

First, the basic signal CCK and the write signal W/D shown in the upper part of FIG. 2 (-) are ANDed by the AND gate 11,
Comparator 1 outputs a logical product signal WCD that indicates the time interval in the latter half of the write signal W/D, which is the point in time when information is written to the optical disk and the amount of light reflected from the optical disk decreases.
5 is output.

On the other hand, the reference signal CCK, the write signal W/D and the reproduction R
When the F signal is input to the write confirmation circuit 12, the reproduction RF
The write signal W as shown by the first and fourth waveforms of the signal
In the latter half of the time interval /D, the amount of reflected light decreases from the write reference voltage WCv, and write confirmation data WDD indicating normal bit formation is detected and output to the OR gate 14.

Furthermore, when the reference signal CCK, write signal W/D and reproduction RF signal are input to the error confirmation circuit 13, the reproduction RF
As shown by the third waveform of the signal, error confirmation data EDD in which the level of the amount of reflected light is below a predetermined error reference voltage ECV and indicates a flaw is detected and output to the OR gate 14.

Next, write confirmation data WDD and error confirmation data E
When DD is input to the OR gate 14, data (OR signal) DD indicating normal bit formation and flaw detection is detected and output to the comparator 15.

The data DD output to the comparator 15 and the AND signal WCD from the AND gate 11 are compared, and if they do not match, the error data E/D indicates a write failure and scratch detection.
is output. That is, a write failure is detected because the amount of reflected light does not decrease from the write reference voltage WCV in the latter half of the time interval of the write signal W/D when a normal bit is not formed.

As explained above, in the above embodiment, the reference signal CCK
and write signal W/D, and obtain write confirmation data and error confirmation data by comparing the voltages of the reproduced R and F signals with the write reference voltage WCV and the error reference voltage ECV, respectively. It is configured to obtain a logical sum signal DD of both data, and to obtain error data E/D based on a mismatch signal between the logical product signal WCD and the logical sum signal DD.

DETAILED DESCRIPTION OF THE INVENTION As described above, the present invention includes a first detecting means for detecting a point in time when information is written on an optical disk and the amount of reflected light from the optical disk decreases, and a first detecting means for detecting a point in time when information is written on an optical disk and the amount of reflected light from the optical disk decreases; a second detection means for detecting that information has been written normally when the amount of reflected light from the optical disk falls below a writing reference level; and when the information writing means is not in operation, the amount of reflected light from the optical disk falls below a writing reference level a third detection means for detecting a defect in the optical disc in the following cases; a circuit for performing an OR operation of data from the second detection means and data from the third detection means; A fourth device that compares the data from the means and the data from the OR circuit, and detects a write failure or defect in the optical disc if they do not match.
Since the optical disc is equipped with a detecting means, it is possible to read and confirm the recorded information at the same time as the information writing operation to the optical disc, and therefore, the access time can be greatly shortened.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of an optical disk recording information confirmation circuit according to the present invention, and FIG. 2 is a timing chart of main signals of the circuit shown in FIG. 11...AND gate, 12...Write confirmation circuit, 13...Error confirmation circuit, 14...OR gate,
15...Comparator.

Claims (1)

[Claims] a first detection means for detecting a point in time when information is written on the optical disk and the amount of light reflected from the optical disk decreases; and a first detection means for detecting a point in time when the amount of light reflected from the optical disk decreases from a writing reference level while the means for writing information on the optical disk is in operation. a second detection means for detecting that information has been written normally; and a third detection means for detecting a defect in the optical disc when the amount of reflected light from the optical disc is below an error detection reference level when the information writing means is not in operation. detection means;
a circuit that performs an OR operation of the data from the second detection means and the data from the third detection means, and compares the data from the first detection means and the data from the OR operation circuit; An optical disc recorded information confirmation circuit having a fourth detection means for detecting a writing failure and a defect in the optical disc in the case of a mismatch.