JPS63228417A - Data recording method - Google Patents

Abstract

PURPOSE:To always record desired data without fail by projecting the writing beam of an actually different light quantity to another area to a recording area prior to recording, and reproducing and checking the writing condition and determining and recording the light quantity of a suitable writing beam. CONSTITUTION:Prior to the writing to a prescribed frame 16 of data, the light quantity of a writing beam is determined. For this reason, the writing beam of respectively different light quantities is successively projected from a semiconductor laser 7 to four writing positions 20-1-20-4, the writing condition in respective writing positions 20-1-20-4 is reproduced after writing and the result is stored into a CPU 26. Next, in the same way, the writing beam is successively projected to four writing positions 20-5-20-8, the writing condition is reproduced and the result is stored into the CPU 26. Next, the CPU 26 selects the driving current of the writing beam of a minimum light quantity from the writing beam of 8 different light quantities and records it to the corresponding frame 16. Thus, without being influenced by the temperature, sensitivity and ambient temperature of a light card, the desired data can be always recorded without fail.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for recording data on an optical recording medium such as an optical card, an optical disk, or a magneto-optical disk.

[Prior Art] As a method for recording data on an optical recording medium, there is a method described, for example, in Japanese Patent Application Laid-Open No. 61-208671.

This conventional example employs the so-called read-after-write method in which data is checked for playback after it has been recorded. If the data is not recorded in the desired state as a result of the playback check, the following sector is blanked and the next sector is The same data is re-recorded.

[Problem that the invention seeks to solve]

However, in the conventional example described above, after data is recorded, it is played back and checked.
It takes a long time to record, and if there is a recording error, it is necessary to leave one sector open and re-record in the next sector.
There is a problem in that the usage efficiency of the recording medium is poor and the overall recording capacity is reduced. Further, the amount of the writing beam emitted from the semiconductor laser varies depending on the temperature, and there are also differences in temperature and sensitivity between recording media, so there is a problem that desired data cannot always be recorded reliably. The above-mentioned temperature difference between recording media is significant, especially in optical cards, which are usually carried around.

The present invention was made in view of these conventional problems, and aims to provide a data recording method that can always reliably record desired data in a short period of time without reducing the capacity of a recording medium. purpose.

[Means and operations for solving the problem] In order to achieve the above object, the present invention projects a writing beam multiple times with different light intensities onto a portion of a recording medium other than the area where desired data is recorded. The recorded state is reproduced and checked, thereby determining the appropriate light intensity of the writing beam, and desired data is optically readably recorded in the corresponding recording area by the writing beam of the appropriate light intensity.

〔Example〕

FIG. 1 is a perspective view, partially cut away, showing the structure of a main part of an example of a head section of an optical card recording/reproducing apparatus embodying the present invention. The holding member 1 is movable in the tracking direction via four wires 2 so as to be displaceable in a focus direction which is a normal direction to an optical card (not shown) and in a tracking direction perpendicular to the track direction of the optical card. It is supported by a slider (not shown). This holding member 2 holds all optical systems including a light emitting diode 3, lenses 4 and 5, a photodetector 6, a semiconductor laser 7, a mirror 8, and a lens 9, and also processes the output signal of the photo disk 6. and an IC for driving control, focusing and tracking control of the semiconductor laser 7
Retain l0 and 11. Here, light emitting diode 3
The semiconductor laser 7 is attached to a mounting frame integrally provided on the holding member 1, the lenses 4, 5 and 9 are fitted and held on the bottom surface 1a of the holding member 1, and the mirror 8 is attached to the holding member 1 via the bimorph 12. At the same time as installing the photodetector 6
and ICl0.11 are held on the same flexible substrate and attached to the holding member 1.

In this way, in this example, the illumination light from the light emitting diode 3 is projected diagonally onto the optical card via the lens 4 to illuminate the track, and the reflected light is incident on the photodetector 6 via the lens 5. An image of the track is formed on the top, and the light from the semiconductor laser 7 is reflected by a mirror 8 and then projected onto the track via a lens 9. A part of the reflected light passes through the lens 5 and enters a photodetector 6. Let them do it. Note that the semiconductor laser 7
By driving the bimorph 12 and displacing the mirror 8, the light is moved in a direction perpendicular to the track within the spot illumination area by the light emitting diode 3 on the optical card, as will be described later.

Further, a focus coil 13 is wound around the outer periphery of the holding member 1, and tracking coils 14 made of bent flat coils are attached to each of the four corners around which the focus coil 13 is wound. By supplying a focus error signal and a tracking error signal to the sensor, focus control and tracking control are performed in cooperation with a magnetic field generating means (not shown).

FIG. 2 shows an example of the track format of an optical card. In this example, a plurality of frames 16 are provided on one track 15, and data is written in frame units. Each track 15 is divided almost equally into 20 lines, and black and white clock patterns 17 for clock generation, focus error detection, and tracking error detection are extended in the track direction at equal intervals on the 10th line counting from the top. At the same time, a black frame synchronization line 18 for detecting a frame synchronization signal is formed on the 20th line. Constructs a byte of bits.

Furthermore, a frame number section 19 representing a frame number is provided at the beginning of each frame 16.

In this example, frame numbers are formed in the 12th to 19th lines in the frame number section 19, and a writing section 20 for determining the light intensity of the writing beam from the semiconductor laser 7 is formed in the 1st to 4th lines. This writing section 20 has each line 2
A total of eight writing positions 20-1 to 20-8 are provided, and a writing beam is projected onto these writing positions with different amounts of light.

Note that the portion written by the semiconductor laser 7 in each frame 16 and the frame number portion 19 has a material with low reflectance forming the background portion and a material with high reflectance representing binary data “1”, and is irradiated with the writing beam. The binary data “0”
The recording medium is composed of a gelatin layer having a silver-based coloring agent that exhibits a low reflectance, and this recording medium is exposed in a circular shape from the background.

FIG. 3 shows the configuration of the photodetector 6.

The photodetector 6 is connected to lines 1 to 8 of the track and
Light receiving areas 21-1 to 21-17 are arranged in the width direction of the track corresponding to each of lines 2 to 20, and these light receiving areas are symmetrical with respect to the arrangement direction and arranged in the track direction corresponding to the clock pattern 17. Four pairs of light receiving areas 22-1 to 22-8 for clock generation, and similarly a light receiving area 21-1.
Two pairs of focus and tracking light receiving areas 23-1 to 23-4 are symmetrical with respect to the arrangement direction of 21-17 and spaced apart in the track width direction so as to be able to respectively receive images of the plurality of clock patterns 17. It consists of:

FIG. 4 is a block diagram showing the configuration of an example of a signal processing circuit. Light receiving areas 21-1 to 21- of photodetector 6
17 is supplied to the binarization circuit 24, and the outputs (b+ to ba) of the light receiving areas 22-1 to 22-8 are supplied to the clock generation circuit 25.Clock generation circuit 2
5, the light receiving area 22- is controlled by the CPU 26.
1.22-3.22-5 and 22-7 output sum,
Light receiving areas 22-2.22-4.22-6 and 22-8
A clock signal is generated based on the difference between the sum of the outputs of , and is supplied to the CPU 26 and the binarization circuit 24 . In the binarization circuit 24, the light receiving areas 21-1 to 21-17 are synchronized with the clock signal from the clock generation circuit 25.
The outputs are binarized, latched in a latch circuit 27, and supplied to a CPU 26 and an error correction circuit (ECC) 28.

The FCC circuit 28 corrects errors in data read under the control of the CPU 26 during data reproduction.
This error-corrected data is stored in the RAM 29.

Further, the output (Ct) of the light receiving area 23-1 is output from the adder 30.
and 31, the output (C2) of the light receiving area 23-2 is sent to the adders 30 and 32, and the output (C3) of the light receiving area 23-3 is sent to the adders 30 and 32.
is the output of the light receiving area 23-4 (
C4) is supplied to adders 33 and 32, respectively, and the difference between the outputs of adders 30 and 33, that is, the light receiving area 23-
A comparator 34 detects the difference between the sum of the outputs of the light-receiving areas 23-3 and 23-2 and the sum of the outputs of the light-receiving areas 23-3 and 23-4, and supplies the difference output to the focus determination circuit 35. Also,
The outputs of the adders 31 and 32 are supplied to a comparator 36, where the difference between the two human power signals, that is, the light receiving areas 23-1 and 23-1 is calculated.
The sum of the outputs of 3-3 and the light receiving areas 23-2 and 23-4
and the sum of the outputs thereof is detected, and the difference output is supplied to the tracking determination circuit 37. In this way, the focus determination circuit 35 controls the comparator 3 under the control of the CPU 26.
A focus error signal is obtained based on the output of 5 and is supplied to the focus coil 13 to perform focus control.
Under the control of U26, a tracking error signal is obtained based on the output of the comparator 36, and this is sent to the tracking coil 14.
to perform tracking control.

On the other hand, the light emitting diode 3 is driven via the light emitting diode drive circuit 38 under the control of the CPU 26 to drive the light emitting diode 3 to the optical card 39.
is spot-illuminated, and the semiconductor laser 7 is C
Laser drive control circuit 40 and D under the control of PU26
The drive is controlled via the /A converter 41 so that desired data is recorded on the optical card 39.

Note that the binarization circuit 24, clock generation circuit 25, latch circuit 27, adders 30 to 33, and comparators 34 and 36 are ICs.
10, and a focus determination circuit 35
, the tracking determination circuit 37, the light emitting diode drive circuit 38, the laser drive control circuit 40, and the D/A converter 41.
ctt, and these ICl0.11 are arranged near the photodetector 6 in the holding member 1. In this way, by arranging ICl0.11 constituting the signal processing circuit near the photodetector 6, the influence of noise can be reduced.

Next, the operation of the above-mentioned recording and reproducing apparatus will be explained.

In this recording/reproducing apparatus, while relatively moving the holding member 1 and the optical card 39 in the track direction, synchronization is performed with a clock signal obtained by processing the outputs of the light receiving areas 22-1 to 22-8 of the photodetector 6. Record and play back data. In the reproduction mode, the semiconductor laser 7 is turned off and the light emitting diode 3 is driven to illuminate the optical card 39 with a spot as shown by reference numeral 42 in FIG. -1~
The light receiving area 21 is controlled in synchronization with a clock signal obtained based on the outputs of the light receiving areas 22-1 to 22-8 while performing focus and tracking control based on the output of the light receiving area 23-4.
-1 to 21-17 are read to obtain a data signal and a frame synchronization signal, and the data signal is stored in RAM 29 via ECC circuit 28.

In the recording mode, the light emitting diode 3 is driven to perform focus and tracking control in the same manner as in the reproduction mode described above, and a clock signal is obtained, and writing from the semiconductor laser 7 is performed in synchronization with this clock signal. The beam is modulated with the data to be recorded to record the data in a predetermined frame 16, but before writing this data into the predetermined frame 16, the light intensity of the writing beam is determined. Therefore, the write section 20 of the number section 19 corresponds to the predetermined frame 16 in which data is recorded.
While driving the bimorph 12 and swinging the mirror 8, the semiconductor laser 7 is placed in the four writing positions 20-1 to 20-4.
At the same time, the output of the light receiving areas 21-1 to 21-4 after writing is binarized to reproduce the writing state at each writing position 20-1 to 20-4. The results are stored in the CPU 26. Next, similarly, the next four writing positions 2 of the writing section 20 are
Writing beams of different light intensities are sequentially projected onto 0-5 to 20-8, their writing states are reproduced, and the results are stored in the CPU 26.

Therefore, in this example, eight laser drive currents (digital values) for projecting write beams of different light intensities are set in advance in the laser drive control circuit 40, and the semiconductor laser 7 is controlled at each write position using the corresponding drive current. D/A
It is driven through transducer 41 to project the writing beam. In addition, in projecting this writing beam, the semiconductor laser 7 is driven with a current lower than the above-mentioned eight drive currents to project light that cannot be written, and this light is used to drive the bimorph 12 to shake the mirror 8. By scanning in a direction perpendicular to the track, write position 20-1 is scanned.
When the light receiving areas 21-1 to 21-4 corresponding to ~20-4 and 20-5 to 20-8 receive the reflected light of the non-writable light from the semiconductor laser 7, the semiconductor laser 7 is programmed. A writing beam is projected at the writing position by driving with a driving current corresponding to the position.

Next, the CPU 26 selects the drive current of the writing beam with the minimum light intensity, which is binarized from the reproduction signal representing the writing state by the writing beams with eight different light intensities, that is, the binary signal becomes "0". The semiconductor laser 7 is driven by this drive current, and its write beam is modulated by the data to be recorded, thereby recording the data in the corresponding frame 16. Note that in recording this data, the semiconductor laser 7
21-1 to 21-8 corresponding to each writing position. At the time when 21-9 to 21-16 receive the reflected light of the non-writable light from the semiconductor laser 7, depending on the data to be written to the writing position,
That is, when writing the binary signal "0", the semiconductor laser 7 is driven with the above-selected drive current to write data.

In this way, prior to recording data, write beams of different light intensities are actually projected onto the optical card, the writing conditions are replayed and checked to determine the appropriate light intensity of the write beam, and the determined light intensity is used for writing. By recording data with a beam, desired data can always be recorded reliably without being affected by the temperature and sensitivity of the optical card or the ambient temperature. Therefore, there is no reduction in the recording capacity of the optical card.

FIG. 6 shows the configuration of another example of the optical system in the recording/reproducing apparatus described above. In this example, the light from the light emitting diode 3 is transmitted through the mirror 8 and then projected obliquely onto the optical card through the lens 4 to illuminate the track, and the reflected light is made to enter the photodetector 6 through the lens 5. The light from the semiconductor laser 7 is reflected by a mirror 8 and then projected onto an optical card via a lens 4, and the reflected light is similarly made to enter a photodetector 6 via a lens 5. The mirror 8 is displaced by the bimorph 12 so that the light from the semiconductor laser 7 is moved in the direction perpendicular to the track within the spot illumination area by the light emitting diode 3 on the optical card as described above.

With this configuration, the comparison lens 9 is not required in the optical system shown in FIG. 1, so the number of parts is reduced accordingly.
It has the advantage of being less expensive and easier to assemble.

FIG. 7 shows the configuration of yet another example of the optical system.

In this example, the light from the light emitting diode 3 is transmitted through the mirror 45 and then projected diagonally onto the optical card through the lens 4 to illuminate the track, and the reflected light is transmitted through the lens 5 and mirror 8 and is directed to the photodetector 6. At the same time, the light from the semiconductor laser 7 is reflected by a mirror 8 and then projected onto an optical card via a lens 5.The reflected light is reflected by a mirror 45 via a lens 4, and then a photodetector 4.
It is designed to receive light at 6. The mirror 8 is displaced by the bimorph 12 as described above,
Thereby, the light from the semiconductor laser 7 is moved in the direction perpendicular to the track within the spot illumination area by the light emitting diode 3 on the optical card. In addition, the photodetector 46 that receives the light from the semiconductor laser 7 reflected by the optical card has a light receiving area corresponding to the writing position,
That is, the light receiving areas 21-1 to 21 of the photodetector 6
-16, and when each light receiving area of this photodetector 46 receives non-writable light from the semiconductor laser 7, the semiconductor laser 7 selectively projects a writing beam. do it like this.

In this way, if the writing beam from the semiconductor laser 7 is projected onto the optical card from the reflected optical path side of the illumination light from the light emitting diode 3, even if there is a slight focus shift, it will be at the correct position in synchronization with the clock signal. , i.e. the second
In the figure, data can be written at a position that exactly matches the black and white clock pattern 17 in the direction perpendicular to the track.

FIG. 8 shows another example of the track format of the optical card. This optical card 51 has tracks 53 each consisting of one line defined by a guide track 52.
Each track 53 has a plurality of sectors identified by a sector start pattern 54 and a sector end pattern 55.

In another embodiment of the present invention, prior to recording data in a predetermined sector, for example, while moving the optical card 51 to the left in the figure, the end pattern 55 of the previous sector and the start pattern of the predetermined sector are recorded. Writing beams with different light intensities are sequentially projected into the space between the pattern 54 to form written portions 56 to 59, and the written state of these parts is reproduced and checked to determine the appropriate light intensity of the writing beam. Data is written to a predetermined sector using a writing beam of a certain amount of light.

FIG. 9 shows an example of an optical system in this case, in which light from a light emitting diode 60 is transmitted through a mirror 61 and then projected obliquely onto an optical card 51 via a lens 62 to illuminate the track. Light is made to enter a photodetector 64 through a lens 63, and a writing beam from a semiconductor laser 65 is reflected by a mirror 61 and then projected onto an optical card 51 through a lens 62.

As shown in FIG. 10, the photodetector 64 has light-receiving areas 66-1 to 66-5 for reproduction corresponding to successive tracks arranged in a direction perpendicular to the tracks, and is symmetrical with respect to the arrangement direction of these light-receiving areas. A pair of reproduction light receiving areas 67-1 and 67-2 arranged corresponding to the tracks;
Similarly, two pairs of focusing and tracking light receiving regions 68-1 to 68-4 are arranged symmetrically with respect to the arrangement direction of the light receiving regions 66-1 to 66-5 and spaced apart in the track width direction.
It consists of:

In this way, the light emitting diode 60 illuminates the optical card 51 as shown by the reference numeral 69 in FIG.
The image is formed on the photodetector 64, and focus and tracking control is performed based on the outputs of the light-receiving areas 68-1 to 68-4 in the same manner as in the embodiment described above. The writing beam is sequentially projected, and the resulting writing portions 56 to 59 are reproduced in the light receiving area 67-1 to determine the appropriate light amount of the writing beam. Note that the light receiving area 6
7-2 is used to reproduce the written portions when writing beams of different amounts of light are projected while moving the optical card 51 to the right in FIG.

Therefore, in this embodiment, as in the above-described embodiments, desired data can always be recorded reliably without reducing the recording capacity of the optical card 51.

It should be noted that the present invention is not limited only to the embodiments described above, and can be modified or modified in many ways. 20-1 to 20-8 can also be arranged in a direction perpendicular to the track. In addition, the number of changes in the light intensity of the writing beam can be set to an arbitrary number, and
Changes in light intensity are not limited to changes in semiconductor laser drive current;
It can also be changed by the irradiation time and the intervention of optical members such as filters. Furthermore, the present invention is not limited to data recording on optical cards, but can also be effectively applied to data recording on other recording media such as optical disks and magneto-optical disks. Furthermore, in each of the embodiments described above, the written state written with different light intensities by the semiconductor laser is illuminated and reproduced by the light emitting diode. You can also play them by letting them play.

〔Effect of the invention〕

As described above, according to the present invention, prior to recording desired data, a writing beam of a different amount of light is actually projected onto an area other than the area where the data is recorded, and the writing status is checked for reproduction. Then, the appropriate amount of light of the writing beam is determined, and the desired data is recorded in the corresponding area using the determined amount of writing beam.
Desired data can always be recorded reliably without being affected by the temperature or sensitivity of the recording medium or the ambient temperature, and without reducing the recording capacity of the recording medium.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view showing the structure of the main part of an example of the head section of an optical card recording/reproducing apparatus embodying the present invention; FIG. 2 is a diagram showing an example of the track format of an optical card; 3 is a diagram showing the configuration of the photodetector shown in FIG. 1, FIG. 4 is a block diagram showing the configuration of an example of a signal processing circuit, and FIG. 5 is a diagram showing the configuration of the optical card and photodetector shown in FIGS. 2 and 3. Corresponding figures, FIG. 6 is a perspective view showing another example of the optical system in the recording/reproducing apparatus shown in FIG. FIG. 9 is a perspective view showing an example of an optical system in a recording/reproducing apparatus using the optical card shown in FIG. 8; FIG. 10 is a photodetector shown in FIG. 9; 11 is a diagram showing the optical card and photodetector shown in FIGS. 8 and 10 in correspondence. 1... Holding member 2... Wire 3...
Light emitting diode 4.5...Lens 6...Photodetector 7...Semiconductor laser 8...Mirror 9...Lens 10.11...IC
12... Bimorph 13... Focus coil 1
4...Tracking coil 15...Track
16... Frame 17... Clock pattern 18... Frame synchronization line 19... Frame number 20... Writing section 20-1 to 20-8...
Writing position 21-1~21-17.22-1~22-8°23-1
~23-4... Light receiving area 24... Binarization circuit 25... Clock generation circuit 26... CPU 27... Latch circuit 28... ECC circuit 29... RAM3
0 to 33...Adder 34.36...Comparator 3
5... Focus judgment circuit 37... Tracking judgment circuit 38... Light emitting diode drive circuit 39... Optical card 40... Laser drive control circuit 41... D/A converter Fig. 1 Fig. 4 Figure 8 Figure 9

Claims (1)

[Claims] 1. When projecting a writing beam onto a recording medium to record desired data in an optically readable manner, a plurality of writing beams are applied to a portion other than the area where the desired data is recorded, each with a different light intensity. The method is characterized in that, after determining the appropriate light amount of the writing beam by reproducing and checking the recording state at each of these light amounts, the desired data is recorded in the recording area by the writing beam of the appropriate light amount. Data recording method.