JPS61158079A - Optical information recording and reproducing device - Google Patents

Abstract

PURPOSE:To detect a recording error generated due to defective recording medium, adhesion of dust or dirt by adopting the constitution that a reflected light reflected from a recording medium is detected by a photodetector so as to detect the changing state of the detected signal thereby detecting the recording state of the light at recording. CONSTITUTION:The light is reflected in a recording film 3 of a recording medium 1 and detected by the photodetector 11. The light detected by the photodetector 11 is amplified by a preamplifier 23. If the recording medium 1 is defective, dust is adhered onto the surface or dirt exists, the luminous amount irradiated to the recording film 3 is changed due to the defect or dust, and the luminous amount reflected from the recording film 3 and the luminous amount reaching the photo-etector 11 in the reflected luminous amount are changed, then an output of the preampliifer 23 is a signal whose amplitude and envelope of amplitude are changed in response to the defect or adhesion of dust. Thus, the recording state is checked by detecting the amplitude change in the output of the preamplifier 23.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an apparatus for recording and reproducing information signals on an optical recording medium.

Conventional technology FIG. 3 shows a conventional optical information recording/reproducing device.

The disc-shaped optical recording medium 1 (hereinafter abbreviated as the recording medium) is composed of a protective base material 2.4 and a recording film 3, and is equipped with a driving motor (
(not shown) at a constant rotational speed. A light beam 6 emitted by the semiconductor laser 5, a condenser lens 7, a polarizing beam splitter 8, 3A person plate 9. The recording film layer 3 of the recording medium 1 is irradiated through the aperture lens 10. The light beam 6 irradiated onto the recording film layer 3 is reflected by the recording film layer 3, passes through the aperture lens 10°K large plate 9, enters the polarizing beam splitter 8, is polarized along the optical path by the polarizing beam splitter 8, and is detected. It is projected onto the vessel 11. The photodetector 11 uses a conventionally known method to detect a recording signal based on the amount of light reflected from the recording film 3, and to detect a focus error detection signal and a focus error detection signal for detecting the condensation state of the light beam 6 on the recording film 3, and pre-caulk the recording medium 1. A tracking error detection signal indicating the misalignment between the provided recording position guide groove and the light beam 6 is generated. The focus error detection signal detected by the photodetector 11 is amplified by the amplifier 12, and is applied to the drive element 14 for moving the aperture lens 1o in the axial direction of the light beam 6 through the focus control circuit 13, so that the light beam 6 is accurately The light is controlled to be focused onto the recording film 3. Further, the tracking error detection signal detected by the photodetector 11 passes through an amplifier 15 and a tracking control circuit 16 to a light beam 6.
In order to move the focal position on the recording film 3 in the radial direction of the recording medium 10, the driving element 17 provided in the aperture lens 1o moves the focal position of the light beams on the recording film 3 in the radial direction of the recording medium 10.
It is controlled to accurately track the guide groove provided in the guide groove. During recording in this device, the information processing circuit 18 composed of a microprocessor, etc. gives a recording mode signal to the switching circuit 2Q through a mode command line, and controls the switching circuit 2o so that the contact point is connected to the R contact point. do. The signal to be recorded is given from a memory circuit in the information processing circuit 18 or a signal source of an external device, and is encoded by a modulation circuit 21 so as to be a signal suitable for optical recording, and sent through a switching circuit 2° to emit light from the semiconductor laser 5. It is added to the laser drive circuit 19 for control. The laser drive circuit 19 turns on and off the light emission of the semiconductor laser 6 according to the output signal of the modulation circuit 21, and separates the state change area (which causes an optical change such as a change in reflectance) and the non-change area on the recording film 3 into two areas (7). It is made into a shape and the signal is recorded. On the other hand, during reproduction, the contact of the switching circuit 20 is connected to the P terminal by the information processing circuit 18, the output signal of the reproduction light amount setting circuit 22 is applied to the laser drive circuit 19, and the amount of light generated by the semiconductor laser 6 is set to a constant value. The light beam 6 is accurately focused and tracked onto the recording film 3 at the position of the previously recorded guide groove, and the signal is reproduced. The reproduced signal is detected by the photodetector 11, amplified by the preamplifier 23, decoded by the demodulation circuit 24, converted to the original signal, applied to the information processing circuit 18, subjected to signal processing, and then transmitted to an external device etc. . As shown in FIG. 4, the recording medium 1 used for recording and reproducing information signals has concentric or spiral recording position guide grooves in the usage area 26, and the guide grooves guide the recording of information signals into appropriate blocks. It is divided into units of appropriate length (called sectors) so that it can be carried out separately.
At the beginning of each sector, a sector address signal 27 for indicating the position of the sector is recorded in advance as a code signal, so that the recorded signals can be easily managed. At the time of reproduction, this sector address signal is detected by the address signal detection circuit 25, and the detected address signal is applied to the information processing circuit 18 and used for searching for recording signals and the like.

In the above apparatus, even if there is a defect, foreign matter, or dust attached to the recording medium 1, there is no problem as long as it is small, and the signal can be recorded correctly and reproduced accurately. However, when a large defect or dust is attached, the amount of recording/reproducing light decreases or is blocked, resulting in an error in signal recording/reproducing.

For this reason, although some devices have error detection and correction capabilities, there is a limit to the error length that can be corrected, resulting in errors occurring. Therefore, in order to prevent the occurrence of errors in the recording and reproduction of data signals, where the occurrence of errors is a particular problem, first, for example, the recording area is irradiated with the amount of reproduction light and inspected for defects, foreign matter, dust, etc. ), a method was used in which the address of a sector containing a defect, etc. was checked, and the signal was recorded while avoiding that sector. However, this method has the disadvantage that it takes time to record the signal.

Problems to be Solved by the Invention In view of the above points, the present invention provides a means for detecting recording errors caused by defects, adhesion of dust, dirt, etc. on a recording medium during information recording and reproduction.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides an optical type having means for detecting the occurrence of recording errors due to defects existing in the recording medium and dust attached to the recording medium during recording. The present invention provides an information recording and reproducing device, in which recording error occurrence is detected by using a photodetector to detect the reflected light of the recording light reflected from the recording medium during recording, and detecting the state of change in the detection signal. It is.

Operation: The recording location (sector address) detected by the recording error occurrence detection means is stored in memory by the information processing circuit, or the recording error occurrence sector address is recorded in a specific location of the optical recording medium to clearly indicate it.

As described above, the present invention detects the occurrence of an error during recording, stops recording when an error is detected, switches to playback mode, and causes the laser beam to scan the sector where the error has occurred again. In order to prevent the recording signal in the sector where the error occurred from being mistaken for a normal recording signal, a demark signal is recorded (overwritten) in this sector, and the information signal that should be recorded in the sector where the error occurred is recorded in the sector following the sector where the error occurred. Then, normal recording continues. Therefore, it is possible to stop one-step recording only when an error occurs, record a demark signal in the sector where the error occurred after one rotation of the recording medium, and continue continuous recording.
It is possible to prevent the occurrence of errors without providing any special time required for checking the cause of the occurrence of recording errors.

Embodiment FIG. 1 is a block diagram showing an embodiment of the optical information recording/reproducing apparatus of the present invention. Components in FIG. 1 that are the same as the conventional example shown in FIG. 3 are given the same numbers. The information processing circuit 1B is connected to the switch/edge circuit 2o by the mode command line.
Connect the contact to the R terminal. Therefore, the semiconductor laser 6 is turned on and off according to the modulation circuit 21, and generates a luminous flux according to the recording signal. This recording light is reflected by the recording film 3 of the recording medium 1 as explained in FIG.
Detected by The recording light detected by the photodetector 11 is amplified by the preamplifier 23.

If the recording medium 1 is free of defects, dust, dirt, etc., the signal detected by the preamplifier 23 will be a signal with a substantially flat amplitude envelope as shown in FIG. 2a. If the recording medium 1 has a defect, has dust attached to its surface, or is dirty, the recording film 3 may be damaged due to the defect or dust.
As the amount of light irradiated on the recording film 3 changes, the amount of light reflected from the recording film 3 and the amount of light that reaches the photodetector 11 among the reflected light amounts also change, so the output of the preamplifier 11 changes depending on defects, dust, etc. As shown in Figure 2, the resulting signal has a changed amplitude and amplitude envelope.

Therefore, by detecting changes in the amplitude of the output of the preamplifier 23, the recording state can be checked, and recording errors due to defects in the recording medium, adhesion of dust, etc. can be detected. The output of the preamplifier 23 is transmitted to a positive envelope detection circuit 102 and a negative envelope detection circuit 104.
In addition to detecting the envelope voltage of each polarity. The outputs of the respective detection circuits 102 and 104 are connected to the comparator 1, respectively.
Add to o3゜106. Comparators 103 and 105 compare the envelope voltage with a threshold level (S+l5- in Figure 2) at which a recording error occurs, and when the positive envelope voltage is less than S, the negative envelope voltage is S. - Generates a negative pulse when the level is exceeded (Figure 2C). Each comparator 103
, 105 is applied to the output pulse width detection circuit 106 to detect the negative pulse width of Riki Okayama. The output of this pulse width detection circuit 106 is detected by the information processing circuit 18. When the information processing circuit 18 detects the output pulse of the pulse width detection circuit 106, it connects the connection terminal of the switch 2o to the P terminal via the mode command line to enter the playback mode, and also sets the recording sector address at the time of stop (Fig. 4, 32). ). Then, at the next sector address, the address information of the previous sector address where recording was stopped and information indicating that the information recorded at that address is incorrect are recorded. Then, in the next sector, information that should have been recorded two addresses earlier (information for which recording was stopped midway) is recorded, and normal recording is sequentially performed. Therefore, even if erroneous data is detected when reproducing information in a sector where recording was stopped midway due to a defect, information indicating that the reproduced information is erroneous will be reproduced in the next sector, and the erroneous data will be immediately reproduced in the next sector. Erroneous data is erased, corrected to correct data to be reproduced in the next sector, and normal information is reproduced sequentially thereafter.

Effects of the Invention As described above, according to the present invention, errors in information signals caused by defects, adhesion of dust, dirt, etc. on a recording medium can be detected without requiring special time for detecting defects, adhesion of dust, etc. It can accurately prevent errors, quickly correct disturbances in information signal recording due to their effects, correct the negative effects of recording stoppage due to defects, and extremely reduce the occurrence of errors, which has a great practical effect. It is something.

[Brief explanation of drawings]

Fig. 1 is a block diagram of an optical information recording/reproducing device according to an embodiment of the present invention, Fig. 2 is a waveform diagram for explaining recording error detection of the same device, and Fig. 3 is a conventional optical information recording/reproducing device. FIG. 4, a block diagram of the apparatus, is an explanatory diagram of the optical recording medium and recording state of the apparatus. 24... Demodulation circuit, 26... Address signal detection circuit, 102... Positive envelope detection circuit, 103... Positive direction comparator, 1
o4... Negative envelope detection circuit, 105
...Negative direction comparator, 106...
Pulse width detection circuit, 18... Information processing circuit, 21... Modulation circuit, 22... Reproduction light amount setting circuit, 19... Laser drive circuit , 2Q・
...Qui 1. H, 5... Semiconductor laser,
11......Photodetector. Name of agent: Patent attorney Toshio Nakao Haga 1st person
2ryJ Figure 3 Figure 4

Claims (2)

[Claims] (1) An optical system equipped with an optical recording medium for recording information signals, a recording means for recording signals on this optical recording medium, and a means for detecting recording errors when recording signals by this recording means. type information recording and reproducing device. (2) The optical information recording and reproducing apparatus according to claim 1, wherein the means for detecting a recording error uses the amount of light reflected from the optical recording medium of the recording light by the recording means.