JPH0522295B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an optical recording/reproducing device for recording information on a disc-shaped recording medium (disc) that can be recorded and reproduced, and for reproducing the recorded information from the disc. .

Conventional technology As a conventional optical recording/reproducing device, for example, Japanese Patent Laid-Open No. 59
-11546. FIG. 3 shows a block diagram of this conventional optical recording/reproducing apparatus.
In the figure, an optical disk 1 is connected to a disk motor 2.
It is rotated by 0. Light emitted from a light source 21 such as a semiconductor laser is collected by a condenser lens 22, and focused by an aperture lens 23 onto the optical disk 1 into a light spot of about 1 μm in diameter. The reflected light from the optical disk 1 is separated by a λ/4 plate 24 and a polarizing beam splitter 25, and then sent to a two-split photodetector 26.
guided by. This photodetector 26 is connected to the optical disk 1
The dividing line is arranged parallel to the upper track. A tracking error signal 27 from the two-split photodetector 26 passes through a tracking/jumping control circuit 28 to drive the aperture lens 23 in a direction perpendicular to the track, thereby subjecting it to tracking control. Further, the reproduction signal output 29 is used for reproduction of recorded signals and reproduction of track addresses.

A light source 21 such as a semiconductor laser is set to read power or write power by a drive circuit 30.
A recording signal such as a digital signal or a video signal is generated by a recording signal generation circuit 31, and modulates the power of the semiconductor laser during recording.

FIG. 4 is a diagram showing signal waveforms at various parts when track jump occurs. b to e in FIG. 3 are observation points of signal waveforms b to e in FIG. 4. A is a cross-sectional view of the track in the scanning direction of the light beam, as seen from the light beam. Reference numeral 40 represents a groove track, and 41 represents a flat portion between grooves, and their respective levels are shown. 3 represents the track currently being recorded, and the blackened portion represents the photosensitive state. When track jump 8 occurs, it indicates that the track 4A and 4B are crossed and the tracking servo is applied to the jump destination track 5. FIG. 4b shows the output waveform of the tracking error signal 27, which becomes the track crossing signal. 27A, 27B groove track 4
When the tracking servo is on 0, the 4th
As shown in FIG. b, the level of the error signal is naturally close to zero. In this way, by detecting the moment when tracking deviates from track 3 currently being recorded, that is, the falling edge of the waveform of 27A, it is possible to detect track jump 8 without scanning the recording beam on other tracks. If the waveform of the error signal 27 shown in FIG. Track jump detection signals 44, 45 shown in FIGS. c and d are obtained.

In FIG. 3, the track jump pulse signals c and d in FIG. 4 are logically summed by an OR gate 34. Then, the flip-flop 35 is set with the output, the analog gate 36 is opened, and the recording signal generation circuit 31 and the semiconductor laser drive circuit 30 are cut off.
In addition, the optical power of the semiconductor laser drive circuit 30 is reduced from recording power to reproducing power. Figure 4 e
represents the optical output waveform of the semiconductor laser.

Problems to be Solved by the Invention However, in the above configuration, if the threshold values of the comparators 32 and 33 are not set correctly, or if the input level of the track crossing signal becomes lower than the initial setting, track jumping may occur. Accurate detection becomes impossible, and it is impossible to completely detect erroneous recordings and double recordings. In addition, the digital circuit 34 configuring the write protection function,
Even when a failure occurs in 35 or 56, the switching from recording power to reproducing power cannot be controlled, resulting in the problem that erroneous recording and double recording cannot be completely prevented.

In view of this point, the present invention provides track jump detection,
It is an object of the present invention to provide an optical recording and reproducing device that can reliably prevent erroneous recording and double recording by performing self-diagnosis of a write protection means.

Means for Solving the Problems The present invention provides means for detecting track skipping using a track crossing signal, write protection means for reducing optical power from recording power to playback power by track jumping detecting means, track jumping detecting means, and The present invention is an optical recording/reproducing device equipped with self-diagnosis means for confirming that the write protection means is operating normally.

According to the above-described configuration, the present invention generates a pseudo write gate at the time of resetting the device, etc., and generates a track crossing signal by starting a track jump during the pseudo write gate generation period. Self-diagnosis is performed to confirm that the protection means operates normally, and erroneous recording and double-free recording caused by track skipping are reliably prevented.

Embodiment FIG. 1 shows a configuration diagram of an optical recording/reproducing apparatus in an embodiment of the present invention. The same components as those in FIG. 3, which shows the configuration of the conventional example, are given the same numbers.

When the write gate signal k is output from the CPU, the recording signal 1 is inputted from the recording signal generation circuit 31 to the semiconductor laser drive circuit 30 to modulate the recording light.
FIG. 2 is a signal waveform diagram at each part of FIG. 1. The write gate signal k is input to the AND gate 60, and the track crossing signal is input to the comparator 32,
The signal g binarized by 33 can be input to the flip-flop 35. If a track jump occurs here, the track crossing signal (27A, 2 in Figure 2)
7B), the flip-flop 35 is set and its Q output becomes L level as shown in FIG. 2h. Therefore, the AND gates 61 and 62 are turned OFF, the write gate signal k and the recording signal 1 are no longer input to the semiconductor laser drive circuit 30, and the recording state changes to the reproducing state at the same time as track skipping, thereby preventing double recording and erroneous recording. Ru. The write protect signal h is
The track address currently being reproduced by the track address reproducing circuit 38 is sent to the CPU 37 and, after confirmation, is canceled by the reset signal i. (FIG. 2 63) Next, a self-diagnosis method for detecting track skipping and checking the operation of the write protect function will be explained. When the power of the optical recording/reproducing device shown in Fig. 1 is turned on or
Activate this self-diagnosis function when resetting the CPU. The CPU 37 outputs a pseudo write gate signal m from the out port. Next, one track jump is forcibly performed to confirm the detection of track jump. For this purpose, the CPU 37 inputs a truck jump start signal j to the truck jump control circuit. Here, a track crossing signal 64 is generated by one track jumping, and the binarized signal g passes through the AND gate 60, which is enabled for input by the pseudo write gate signal, sets the flip-flop 35, and outputs the Q output (write signal). The protect signal h) becomes L level. The CPU reads this write protect signal h from the import, confirms that the track jump detection and write protect functions are operating normally, and outputs a write protect reset signal i. At this time, the pseudo write gate signal m is not input to the semiconductor laser drive circuit 30, and the recording power state is not established. Therefore, it is possible to perform self-diagnosis by detecting track skipping and checking the write protection function without actually putting the semiconductor laser into the recording mode.

As described above, according to this embodiment, a track crossing signal is generated by generating a pseudo write gate signal and activating a track jump during the period in which the pseudo write gate signal is generated, and the track jump detection and write protection functions are performed normally. By providing a self-diagnosis function to confirm that the
Self-diagnosis is possible without actually setting the semiconductor laser to a recording power state, and erroneous recording and double recording caused by track skipping can be reliably prevented.

Effects of the Invention As explained above, according to the present invention, the self-diagnosis function for confirming that the track skipping detection means and the write protection means are operating normally can be used to actually record a track without causing track skipping. It can be operated using a pseudo write gate signal, has highly reliable track jump detection and write protection functions, and can completely prevent erroneous recording and double recording caused by unexpected track jumps. The reliability of the above recorded data can be dramatically improved.

[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, FIG. 2 is an operating waveform diagram of the same embodiment, FIG. 3 is a block diagram of a conventional optical recording/reproducing apparatus, and FIG.
The figure is an operational waveform diagram of the conventional example. 1... Optical disk, 21... Laser light source, m
...Pseudo light gate signal.

Claims (1)

[Claims] 1. Optical recording and reproducing means for recording or reproducing information by focusing a laser light source on an optical disk equipped with a guide track, and a track-crossing system that detects the occurrence of track skipping from the guide track on which information is being recorded to another guide track. track jump detection means for detecting by a signal; write protection means for changing the optical power of a laser light source from a recording state to a non-recording state by means of the track jump detection means; and a write protection means for changing the optical power of a laser light source from a recording state to a non-recording state. A pseudo write gate signal that does not enter the recording state is generated at certain time intervals during the operation of the device, and a track crossing signal is generated by activating a track jump during the pseudo write gate signal generation period to detect a track jump. An optical recording/reproducing device comprising a self-diagnosis means for confirming that the means and the write protection means operate normally.