JPH01311425A - Recording and reproducing device for optical recording medium - Google Patents

Abstract

PURPOSE:To contrive the secure movement to a target track by moving relatively an optical system and an optical recording medium in such a direction that a light beam by the optical system is parallel with the track on the optical recording medium. CONSTITUTION:Data from the outside are recorded to an optical recording card 1 by driving a laser in an optical head 24 via a CPU 40 and a laser driving circuit 41. A driving motor 26 is rotated by the CPU 40 in accordance with an output of a track moving control circuit 47 so as to make the head 24 correspond to the track corresponding to a recording and reproducing position from the outside, while a driving motor 22 is rotated to enable the head 24 to follow the prescribed track when the head 24 corresponds to this track. An objective lens is moved in order to adjust its distance from the card 1 by a focusing servo circuit 43 with an output of a photoelec tric transducer, whereas the tracking is performed by a tracking servo circuit 44. A target track from the CPU 40 and the present track position decided by a signal from a binarization circuit 42 are compared with each other by the circuit 47 to calcu late a track moving amt. By this method, the secure and prompt movement to the objective track can be performed.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention is directed to recording information on an optical recording medium called an optical recording card using, for example, a laser beam. The present invention relates to a recording and reproducing device for an optical recording medium that reproduces recorded information.

(Prior Art) FIG. 5 shows an optical recording card that has already been proposed. In the recording section 2 of the optical recording card 1, a plurality of guidelines 3 are provided in advance along the longitudinal direction of the optical recording card 1, and the space between these guidelines 3 is called a track, and the information 5 is stored on this track 4. recorded.

Also, on the left side of each track 4, . . .
As shown in Figure 6, a clock data code CC for synchronizing when recording and reproducing information 5 and each track 4
,... Track number code TNC for identifying
A pre-format data code PC is recorded in advance, which is composed of an identification code called ``1'', and a start code SC indicating the start position of the unrecorded portion.

FIG. 7 shows a recording and reproducing apparatus for the optical recording card. The transport system 20 holds the optical recording card 1 and reciprocates the optical recording card 1 in its longitudinal direction. A guide shaft 21 passes through the transport system 20 and is rotated by a drive motor 22. A screw bolt 23 is screwed together. Further, the optical head 24 is
It is provided opposite to the transport system 20. This optical head 24 irradiates light onto the optical recording card 1 held in the transport system 20 to record information, irradiates the optical recording card 1 with light, and detects reflected light from the optical recording card. By doing so, information recorded on the optical recording card 1 is read. A guide shaft 25 passes through the optical head 24, and a screw bolt 27 rotated by a drive motor 26 is screwed into the optical head 24. The optical head 24 moves in a direction perpendicular to the conveyance system 20 to move any track 4. It is possible to record and play.

FIG. 8 shows the structure of the optical head 24. As shown in FIG. For example, light output from a semiconductor laser 30 is made into parallel light by a correction lens 31 called a so-called collimation lens, and then collimated by a grating plate (diffraction grating).
32, and is divided into three light beams consisting of 0th order light PO1+1st order light P+1 and -1st order light P-1. These three light beams are guided to an objective lens 35 via a beam splitter 33 and a λ/4 wavelength plate 34, and are irradiated onto the optical recording card 1 by this objective lens 35. The three light beams reflected on the optical recording card 1 are each reflected by the beam splitter 33, guided to the photoelectric conversion element 37 via the imaging lens 36, and read.

Since the objective lens 35 has a narrow track pitch of about 10-odd micrometers, it can be moved vertically (10-curlens) and horizontally (tracking) by a moving mechanism (not shown) that can move minutely for precise control. It is about to be moved.

As shown in FIG. 10, the photoelectric conversion element 37 is composed of photodetection cells 37 a s 37 b s 37 c. The light beam p+1 is placed on the photoelectric conversion element 37.
, POlP-1 forms an optical image. Here, the photodetection cell 37a is composed of a four-split light receiver in order to realize a well-known focus detection called astigmatism method using a cylindrical lens as the condensing lens, and the photodetection cells 37b and 37c are This method is used for a well-known tracking detection called the three-beam method.

When recording and reproducing information, as shown in FIG. The optical head 24 is configured to irradiate the guideline 3
While moving the optical recording card 1 in the lateral direction of the card, the transport system 20 is moved in the longitudinal direction of the optical recording card 1, and information is recorded or read using the zero-order light PO in the center.

For example, the light reflected from the card surface by the ±1st order lights P+1 and P-1 is photoelectrically converted by the photodetection cells 37b and 37c,
The objective lens 35 in the optical system 24 is moved in the longitudinal direction of the optical recording card 1 in accordance with the difference in these photoelectric conversion outputs.

That is, when the light beam by the objective lens 35 moves above the track, the difference in the photoelectric conversion output becomes negative, the light beam by the objective lens 35 moves below the track 4, and the O-order light PO moves to the track 4. Move to the center of 4. Conversely, when the light beam by the objective lens 35 moves below the track 4, the difference in the photoelectric conversion output becomes positive, and the light beam by the objective lens 35 moves above the track 4, and the zero-order light PO moves to the center of track 4.

In addition, when recording information on the optical recording card 1, it is necessary to check whether the destination beam is on the track to be recorded and to know the starting position of the unrecorded portion before recording. However, this is done as follows.

First, after reading the clock data code CC of the optical recording card 1 shown in FIG. 6 and establishing synchronization for recording and reproduction,
The track number code TNC is read to confirm the recording track. Immediately after reading the start code SC, the encoded information is recorded.

Also, during playback, the +1st order light p+1, -
The transport system 20 is moved while controlling the optical head 24 using the primary light P-1, the reflected light of the zero-order light PO is received by the photoelectric conversion element 37, and the information received is decoded. At this time, after synchronizing with the clock data code CC for decoding, reading the track number code TNC and reading the start code is the same as in recording.

As described above, the optical recording card 1 is moved back and forth in its longitudinal direction to perform upward recording and reproduction. For this reason, compared to optical disks that perform upward recording and reproduction through rotational movement, the movement speed changes continuously before and after the reversal of the reciprocating movement, which tends to cause vibrations to the objective lens 35. There is. Therefore, since the track pitch is as narrow as 10-odd μm, when moving to another track 4 (when moving between tracks), focusing and tracking are performed immediately due to the vibration of the objective lens 35. As a result, there was a drawback that it was not possible to move quickly and reliably to the target track.

(Problem to be Solved by the Invention) This invention eliminates the drawback that when moving a light beam between tracks, it is not possible to move it to the target track quickly and reliably. It is an object of the present invention to provide a recording/reproducing device for an optical recording medium that can quickly and reliably move to a target track when moving between tracks.

[Structure of the Invention] (Means for Solving Problems) The recording and reproducing apparatus for an optical recording medium of the present invention allows the optical system to record the optical information by moving the optical recording medium and the optical system relatively. In a device that records or reproduces information on a plurality of tracks formed as information recording units in a direction substantially parallel to the end surface of a recording medium, the light beam from the optical system and the track on the optical recording medium are approximately parallel to each other. a first moving means for scanning a predetermined track with a light beam from the optical head by relatively moving the optical system and the optical recording medium in parallel first directions;
And while the movement by the first moving means is stopped, the optical system and the optical recording medium are moved relative to each other in a second direction where the light beam from the optical system and the track on the optical recording medium intersect. The second moving means moves the optical head to correspond to a predetermined track.

(Function) This invention provides a plurality of tracks formed as information recording units in a direction substantially parallel to the end surface of the optical recording medium by the optical system by relatively moving the optical recording medium and the optical system. The optical system and the optical recording medium are moved relative to each other in a first direction in which the light beam from the optical system and the track on the optical recording medium are substantially parallel to each other. By moving to
The first moving means scans a predetermined track with a light beam from the optical head, and when the first moving means stops moving, the light beam from the optical system and the track on the optical recording medium are scanned. By relatively moving the optical system and the optical recording medium in a second intersecting direction, the light beam from the optical head is made to correspond to a predetermined track.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 2 shows the main part of the electric circuit for the optical recording card recording/reproducing apparatus of the present invention.

That is, the photoelectric conversion element 3 in the optical head 24
The output from the photodetection cell 37a of No. 7 is binarized by a binarization circuit 42, and the binarized data is output as reproduction (read) data to an external device (not shown) via the CPU 40. It has become so. Further, recording data supplied from an external device is supplied to the laser drive circuit 41 via the CPU 40. Thereby, the semiconductor laser 30 in the optical head 24 is driven by the output of the laser drive circuit 41, and a laser beam spot is irradiated onto the optical recording card 1, thereby recording data.

The CPU 40 also causes the optical head 24 to move to a track corresponding to a recording position or a reproduction position from the external device.
According to the output of the track movement control circuit 47, the driver 46 is driven and the drive motor 26 is rotated so as to correspond to the output of the track movement control circuit 47. Furthermore, the CPU 40 is
When the optical head 24 corresponds to a predetermined track,
The driver 45 is driven to rotate the drive motor 22 so as to follow the track.

The forcing servo circuit 43 calculates four outputs from the four-divided detection cell 37a of the photoelectric conversion element 37, and moves the objective lens 35 based on the result, thereby moving the objective lens 35 and the optical recording card. This is to adjust the distance.

The tracking servo circuit 44 includes the photodetection cell 37b.
, 37c, by supplying a current corresponding to the difference in detection outputs from the optical head 24 to a coil (not shown).
Tracking is performed by moving the objective lens 35 in the left-right direction (horizontal direction).

The track movement control circuit 47 receives the target track from the CPU 40 and the two signals supplied from the binarization circuit 42.
The amount of truck movement is calculated by comparing the current track position determined by the digitized signal, and the calculated value is output by subtracting this amount of movement by the binary signal of the track crossing signal. As shown in FIG. 3, amplifiers 51, 52, differential amplifiers 53, and low-pass filters 54.
It is composed of a binarization circuit 55, a down counter 56, a trunk position determination circuit 57, and a subtraction circuit 58.

That is, the output signals from the photodetection cells 37b and 37c are amplified by amplifiers 51 and 52, and then supplied to the differential amplifier 53. This differential amplifier 53 is connected to the photodetector cells 37b and 3 supplied from the amplifiers 51 and 52.
It outputs the output difference from 7c, that is, a track deviation detection signal. The track deviation detection signal from the differential amplifier 53 is waveform-shaped by a low-pass filter 54 as a track crossing detection signal, as shown in FIG. 4(b), and then supplied to a binarization circuit 55. This binarization circuit 55
As shown in FIG. 3C, the binarized signal is supplied to one input terminal of the down counter 56.

Further, the binarized signal from the binarization circuit 42 is supplied to a track position determination circuit 57. This track position determination circuit 57 determines the track position currently facing the beam of the optical head 24 based on the binary signal supplied from the binary conversion circuit 42, and outputs this determination result to the subtraction circuit 58. It has become.

This subtraction circuit 58 detects the difference between the track number to be accessed (target track) supplied from the CPU 40 and the track position (target track number data, movement amount) from the track position determination circuit 57, and calculates the result of the subtraction. It is designed to be output to the other input terminal of the down counter 56.

The down counter 56 counts down the number of tracks (travel amount) from the subtraction circuit 58 for each pulse of the binarized signal from the binarization circuit 55, that is, the track crossing signal, and the count value is It is output to the CPU 40. The CPU 40 rotates the drive motor 26 until the number of tracks from the down counter 56 becomes "0".

Next, the operation of such a configuration will be explained with reference to the flowchart shown in FIG. For example, right now, CP
U40 is a drive motor 2 when the optical recording card 1 is inserted from an insertion slot (not shown) and held by the conveyance system 20.
6, the optical head 24 is moved to a predetermined track. Further, the CPU 55 operates the focus servo by the focus servo circuit 43.

When the optical head 24 is positioned on a predetermined track, the CPU 40 activates the tracking servo by the tracking servo circuit 44 and rotates the drive motor 22, thereby causing the optical head 24 to start scanning the track.

By this scanning, the read signal from the photodetection cell 57a is outputted to the track position determination circuit 57 via the binarization circuit 42. As a result, the track position determination circuit 57 determines the track position currently facing the light beam of the optical head 24 based on the binary signal supplied from the binarization circuit 42 .

In this state, the track number to be accessed is supplied to the CPU 40 from an external device (not shown). Then, the CPU 40 stops the track scanning by the drive motor 22, and also supplies the track number to be accessed to the subtraction circuit 58.

Further, at this time, the track number (current position) determined by the track position determination circuit 57 is supplied to the subtraction circuit 30. As a result, the subtraction circuit 58
The value obtained by subtracting the current track supplied from the track position determination circuit 57 from the target track supplied from the track position determination circuit 57, that is, the target track number data (travel amount) is output to the down counter 56.

As a result, the number of tracks set in the down counter 56 is output to the CPU 40. Then, if the count from the down counter 56 is other than "0", the CPU 40 rotates the drive motor 26 to move the optical head 24, that is, the light beam, to traverse the track.

By sequentially crossing the tracks in this manner, the down counter 56 is sequentially counted down as described above.

Then, the count value from the down counter 56 is "0"
When this occurs, the CPU 40 stops the movement of the drive motor 26, that is, the light beam. At this time, the light beam reaches the target track.

Then, by rotating the drive motor 22, the CPU 40 starts track scanning by the optical head 24, and records or reproduces information.

Note that when the target track is reached, the track number may be read and it may be determined whether or not it matches the track number from an external device.

As mentioned above, the light beam is moved between tracks while the optical head stops scanning the tracks, that is, the light beam stops moving back and forth with respect to the optical recording card. , since there is no vibration of the objective lens caused by the reciprocating movement of the optical recording card.
It is easy to reliably move a light beam between tracks, and the light beam can be quickly and reliably moved to a target track.

In the above embodiment, when the optical recording card is inserted, a predetermined track is scanned and the track number facing the light beam is checked. You can check the track number after that.

In addition, although the case where the movement of the light beam between tracks is performed by a drive motor has been described, the invention is not limited to this.
This may be performed by controlling the objective lens in the vertical direction, or by a combination of a drive motor and controlling the objective lens in the vertical direction. In this combination, when the amount of movement is large, the drive motor is used to move, and when the amount of movement is small, the object is moved using the objective lens.

[Effects of the Invention] As detailed above, according to the present invention, when a light beam is moved between tracks, it is possible to immediately and reliably move a light beam to a target track. We can provide playback equipment.

[Brief explanation of the drawing]

FIG. 1 is a flowchart for explaining the operation of an embodiment of the present invention, FIG. 2 is a block diagram for explaining the configuration of a recording/reproducing apparatus, and FIG. 3 is a block diagram for explaining the configuration of a track movement control circuit. , FIG. 4 is a signal waveform diagram showing the signal waveforms of the main parts in FIG. 3, FIG. 5 is a plan view showing the configuration of the optical recording card, and FIG. 6 shows the recording state of preformat data codes in the tracks. 7 is a perspective view schematically showing a recording/reproducing device for an optical recording card, FIG. 8 is a configuration diagram showing the configuration of an optical head, and FIG. 9 is a diagram showing a state of irradiation of a light beam onto an optical recording card. , FIG. 10 is a diagram for explaining the positional relationship between the light beam and the photodetection cell. 1. Optical recording card (optical recording medium), 4... Track, 20... Transport body, 22. 26... Drive motor, 24... Optical head, 40... CPU, 42.
55... Binarization circuit, 47... Track movement control circuit, 56... Grand counter, 57... Track position determination circuit, 58... Subtraction circuit. Applicant's representative Patent attorney Takehiko Suzue Figure 1. 13 The 5th “7j 6th Shinobi:

Claims (1)

[Claims] By relatively moving the optical recording medium and the optical system,
In a recording/reproducing apparatus for an information recording medium, which uses the optical system to record or reproduce information on a plurality of tracks formed as information recording units in a direction substantially parallel to an end surface of the optical recording medium, the optical system comprises: By relatively moving the optical system and the optical recording medium in a first direction in which the light beam and the track on the optical recording medium are substantially parallel, the optical beam of the optical head tracks a predetermined track. 1st to scan
moving the optical system and the optical recording medium in a second direction where the light beam from the optical system and the track on the optical recording medium intersect with each other while the first moving means stops moving. a second moving means that causes a light beam from the optical head to correspond to a predetermined track by relatively moving the optical head.