JPH03116443A - Misrecording preventing device for optical disk memory device - Google Patents

Abstract

PURPOSE:To preclude misrecording due to disturbance, the flaw of an optical disk, etc., by monitoring an RF signal, an Fe signal, and a Te signal and comparing them with respective reference values, and deciding whether recording operation is carried on or interrupted. CONSTITUTION:The subject device is provided with comparator parts 20 - 22 which compare the RF signal with its reference value, the focus error signal (Fe signal) with its reference value, and the tracking error signal (Te signal) with its reference value and TTL level signal conversion parts 23 - 25 which convert the signals from the comparator parts 20 - 22 to TTL levels. Then the device is provided with a recording decision part 26 which decides misrecording with the comparison result signals of those TTL levels and outputs a control signal for interruption control over the recording operation to the main control circuit of the optical disk memory device. Consequently, misrecording due to the disturbance, the flaw of the optical disk, etc., and erroneous recording due to variation and deviation in the control value of servo control are precluded.

Description

[Detailed description of the invention] [Industrial application field] This invention records information on an optical disc, and.

The present invention relates to an erroneous recording prevention device used in an optical disk memory device that can read information from an optical disk, and more specifically to an erroneous recording prevention device for an optical disk memory device that prevents erroneous recording due to disturbances, defects in the optical disk, etc. be.

[Conventional example] In recent years, optical discs have significantly developed from read-only and write-once types to rewritable types, and devices for recording information on optical discs and reproducing information.

For example, various optical disk memory devices have been proposed.

In the optical disk memory device 1, for example, as shown in FIG. 5, the optical disk 1 is irradiated with a laser beam,
In addition, an optical head is provided to detect the reflected light from the optical disc l. This optical head includes a laser beam output device 2, a collimator lens 3, a prism 4, a polarizing beam splitter (PBS) 5, and a λ/4 wavelength plate (
QυP) 6, an objective lens 7, a detection lens 8, a cylindrical lens 9, and a photodetector (PD) 10.

That is, the laser beam from the laser beam output device 2 is transmitted to the collimator lens 3, the prism 4, the polarizing beam splitter 5. λ
The light is focused on the recording surface of the optical disc 1 through the /4 wavelength plate 6 and the objective lens 7, and the reflected light from the optical disc 1 is transmitted to the objective lens 7, the λ/4 wavelength plate 6, the polarizing beam splitter 5. The light passes through the detection lens 8 and the cylindrical lens 9, enters the photodetector 10, and is converted into an electrical signal.

Although not shown, the optical disk memory device is provided with a focus error detection circuit that obtains a focus error signal based on the amount of light detected by the photodetector 10, a tracking error detection circuit that obtains a tracking error signal, and the like. Focus control and tracking control are performed by the signal.

That is, unless the laser light from the laser light output device 2 is focused on the recording surface of the optical disc 1 and accurately follows the tracks of the optical disc 1, information will not be recorded or reproduced accurately. .

[Problems to be Solved by the Invention] By the way, in the optical disc memory device described above, if there is a disturbance or a defect (for example, a scratch) on the optical disc 1, track skipping may occur, and information may be recorded in the wrong area of the optical disc 1. Furthermore, depending on changes or deviations in the focus control value, incorrect information may be recorded on the optical disc 1 or may not be recorded partially.

As described above, an optical disk on which erroneous recording has occurred may become unusable even if track skipping does not occur, and there is a problem in that the write-once optical disk in particular becomes unusable.

This invention was made in view of the above problems, and its purpose is to provide an optical disk memory that can prevent erroneous recording due to disturbances, defects in the optical disk, etc., and erroneous recording due to changes and deviations in control values of servo control. An object of the present invention is to provide a device for preventing erroneous recording of a device.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an optical disc memory device that performs focus control and tracking control when recording information on an optical disc and reproducing the information. a comparison means for comparing the RF multiplied signal with a reference value for the focus control, comparing the focus error signal for the focus control with the reference value, and comparing the tracking error signal for the tracking control with the reference value; Based on the results, determine if there is a recording error,
and recording determination means for outputting a control signal to stop recording the information if at least one of the determination results results in an erroneous recording state, and the plurality of reference values are within an allowable range for the recording conditions. Set based on
The gist is that the above judgment is made based on whether or not the above permissible range is exceeded.

[Function] With the above configuration, during the recording operation in the optical disk memory device, the RF multiplied signals Fe signal and Te signal are compared with their respective reference values. In the comparison results, the signal degradation is multiplied by RF.

It is determined whether a defocus state or track skipping occurs. Then, based on the comparison results, it is determined whether to continue or stop the recording operation. That is, if a track skip occurs, control is performed to stop the recording operation, regardless of other comparison results. *Ta. Even if no track skip occurs, if a defocus state or RF signal deterioration occurs, or if both occur simultaneously, control is performed to stop the recording operation.

[Example] Hereinafter, an example of the present invention will be described based on FIGS. 1 to 4. Incidentally, please refer to FIG. 5 for the optical head of the optical disk memory device.

In FIG. 1, the erroneous recording prevention device of the optical disk memory device compares the RF multiplied signal with the reference value, compares the focus error signal (Fe signal) with the reference value, and compares the tracking error signal (Te signal) with the reference value. A comparator section 20.21.
22, a TTL level signal converter 23, 24, 25 that converts the signals from these comparator units 20, 21, 22 to TTL level, and a comparison result signal of these TTL levels to determine erroneous recording. It also includes a recording determination section 26 that outputs a control signal for controlling the abort of the recording operation to the main control circuit (microcomputer) of the optical disk memory device. Note that, like the conventional example, the optical disk memory device is equipped with a focus error detection circuit for obtaining a focus error signal and a tracking error detection circuit for obtaining a tracking error signal.

Here, reference values that can be set in the comparator sections 20, 21, and 22 will be explained.

(1) When erroneous recording occurs during a recording operation, the RF multiplied signal during recording includes, for example, the portions shown at A and B in FIG. 2. Therefore, at the time of the erroneous recording, a predetermined tolerance level exceeding the RF multiplied signal is determined, and this level is used as a reference value.

(2) If the control value of the focus control changes or shifts, a defocus state occurs, that is, the objective lens 7 and the optical disc 1 are too close, or if the objective lens 7 and the optical disc 1 are not brought back together, the RF signal deteriorates and erroneous recording occurs. As shown in FIG. 3, the focus control may become sloppy and the predetermined focus control range may deviate. Therefore, the deviation is compared with an allowable range of focus control during recording, a predetermined allowable range exceeding this allowable range is determined, and this range is used as a reference value.

(3) If track skipping occurs due to disturbances, defects in the optical disc 1, etc., erroneous recording will occur.

At this time, as shown in FIG. 4, the tracking error signal includes a track cross signal.

Therefore, at the time of the erroneous recording, a predetermined tolerance level that the Te signal exceeds is determined, and this level is used as a reference value.

Then, from the comparator section 20.21.22, R
Comparison signals are output in accordance with the comparison results of the F-fold signals Fe signal and Te signal and their respective reference values.

These comparison signals are converted to TTL level by TTL level signal converters 23, 24, 25, and outputted to recording determination section 26. Then, in the recording determination section 26, the T
A determination is made as to whether to continue or stop the recording operation based on the TL level comparison signal. At this time, it is not necessary that the three signals mentioned above exceed their respective reference values, and the determination to stop the recording operation is made based on a combination of the signals exceeding the reference values or even on a single signal. Based on this determination result, the recording determination section 26 outputs a control signal to continue/stop the recording operation to the main control circuit of the optical disk memory device. In this main control circuit, if it is stopped by the control signal,
For example, since control is performed to stop laser modulation of the laser light output device 2, the recording operation of the optical disc 1 is stopped.

In this way, the RF multiplied signals Fe signal and Ta signal are monitored, that is, these signals are compared with their respective reference values, and the recording operation is continued or stopped based on the comparison results. Therefore, for example, even when no track skipping occurs (that is, the Te signal does not exceed the reference value), a defocus state occurs (
The recording operation is stopped when the Fe signal exceeds the reference value) or when the RF multiplied signal deteriorates (the RF multiplied signal exceeds the reference value). That is, for example, if the control value of focus control changes or deviates, track skipping will not occur, but it will cause erroneous recording. In addition, if a track skip occurs due to disturbance or a defect in the optical disk, the recording operation will be stopped even if the other Fe signals and RF multiplied signals do not exceed their respective reference values, since the 1゛e signal includes a track cross signal. This prevents unnecessary defects from forming on the optical disc 1.

[Effects of the Invention] As explained above, according to the error recording prevention device for an optical disk memory device of the present invention, the RI” signal, the Fe signal, and the Te signal are monitored, and these signals are compared with their respective reference values. Since the signal of this comparison result is used to determine whether to continue or stop the recording operation, it is possible to prevent track skipping from occurring not only when a track skip occurs due to external disturbances or a defect in the optical disk, but also when a track skip occurs during the recording operation. If the optical disc is not in use, for example, if erroneous recording occurs due to a defocus state or RF signal deterioration, the recording operation will be stopped, making it possible to prevent or prevent erroneous recording and eliminating the need to waste optical discs. .

[Brief explanation of drawings]

FIG. 1 is a schematic circuit diagram of an erroneous recording prevention device for an optical disk memory device showing an embodiment of the present invention, FIGS. 2 to 4 are diagrams for explaining the erroneous recording prevention device, and FIG. FIG. 2 is a schematic block diagram of an optical head of an optical disk memory device. In the figure, 1 is an optical disk, 2 is a laser light output device, 20, 2
1.22 is the comparator section, 23.24.25 is TT
The L level signal conversion section 26 is a recording determination section.

Claims (1)

[Claims] (1) In an optical disk memory device that performs focus control and tracking control when recording information on an optical disk and reproducing information, the RF signal at the time of recording is compared with a reference value, and the RF signal for the focus control is compared with a reference value. Comparing means for comparing a focus error signal with a reference value and comparing the tracking error signal and reference value for the tracking control; recording determination means for outputting a control signal to stop recording the information if at least one of the determination results indicates an erroneous recording state, and the plurality of reference values are set based on an allowable range for recording conditions. An apparatus for preventing erroneous recording in an optical disk memory device, wherein the judgment is made based on whether or not the permissible range is exceeded.