JPS61273748A - Recording and reproducing device for optical card - Google Patents

Abstract

PURPOSE:To read out data accurately and continuously by handling several tracks as a unit when data is retrieved and moving a light spot to a next track after a read of one track is finished when data is read. CONSTITUTION:A main scan is made forward and backward once on one track 43 and returns to a line part 45a. The main scan is stopped and the light spot 15 is moved to the line part 45a of an adjacent track 54 by a jumping means 37 after the stop is confirmed. For the purpose, a jump pulse 53 is applied to a sub-scanning mirror driving circuit 51 from a jumping pulse generating circuit 52 while a tracking servo circuit 50 is turned off, and the jump pulse 53 is inverted in polarity when a tracking error signal 48 crosses the zero level to obtain a brake pulse, stopping the light spot 15 on the adjacent track. This operation is repeated as many time as tracks in an array 44, which is read completely. Thus, a continuous stable reproducing signal is obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an information recording/reproducing device using an optical card optical recording medium that can record and reproduce information at high density using laser light. It is.

[Conventional technology]

Conventionally, such a device has a configuration shown in FIG. 5. In the figure, (1) is a semiconductor laser that is a laser light source, and (2) is a driver that drives the laser (1) in accordance with an input signal (3). (4) is a collimator lens that converts the emitted light (5) from the semiconductor laser (1) into a parallel light beam (6), and (7) and (8) respectively represent a parallel light beam (6) from the collimator lens (2). ) is a plano-concave cylindrical lens and a plano-convex cylindrical lens for converting the beam (9) into a circular beam (9), and (10a) is a galvano mirror 1 for reflecting the circular beam (0) described below downward.
@ is a condensing lens that condenses the luminous flux from the power mirror (10a), for example an f-θ lens, and α field is a card that is an optical card-like recording medium; The area surrounded by the dashed line in the figure shows the recording optical spot or the reproducing optical spot (G) on the card αΦ in the main scanning direction α.
A scanning means (lIη) is configured to scan in the direction Q. The direction of rotation of the galvano mirror (10a) for this scanning is indicated by the direction of rotation of the galvano mirror (10a). ) is allowed to pass through as it is, and the galvano mirror (1
0a) is a beam splitter that reflects the reflected light downward as a luminous flux αυ, and ■ is a photodetector that converts the light from the beam splitter 19 into an output signal. ) is the column of bit I211, (to) is the feeding direction of the card α, and (to) is the light spot during playback (
This is the reflected light from card α4 due to

Next, the operation will be explained.

The luminous flux (
5) is collimated by a collimator lens (4) into a parallel light beam (6
), the light beam is made into a circular light beam (9) with a circular shape by a plano-concave norindrical lens (7) and a plano-convex nolindrical lens (8). Then this circular beam (9)
The O galvano mirror (10a) passes through the beam splitter (19) and enters the galvano mirror (10a).
) and is deflected downward, becoming an irradiation light beam (to). This irradiation light flux α is incident on the condensing lens (6),
The light is focused on the card α to form a focused spot (g) and information is recorded as dot-like bits. At this time, the optical path of the light beam 01) incident on the galvanometer mirror (10a) is deflected by the rotation of the galvanometer mirror (10a) in the four directions of the arrows, so that the condensed spot α on the card α is , the card is swung in the main scanning direction αQ over the card α, and the locus of the condensed spot (A) forms a dotted bit string. Then, when the card α is moved by a card feeding system (not shown) in a direction crossing this main scanning direction α, for example, in a sub-scanning direction perpendicular to this, the sixth
As shown in the figure, dot-shaped bit strings α9 (2) are formed aligned in the -1 scanning direction.

Information on the input signal (3) will be recorded.

In order to record the information of the input signal (3) as dotted bits c2υ on the card α, the entire input signal (3) is input to the driver (2) of the semiconductor laser (1). At this time, the output of the semiconductor laser (1) is changed depending on the strength of the input signal (3), or when recording a point-like hit t2υ on the card α, the output of the semiconductor laser (1) is The recording speed is increased to a level higher than the predetermined threshold value shown in FIG. or reduce the power below a predetermined threshold.

On the other hand, the dotted Hila l recorded on card (2)! 11
When reading and reproducing information from the IS, as shown in FIG. 6, an optical spot is used to trace the dotted bit string in the direction of the arrow IS. This light spot α
Q is similar to the case of information recording described above, in which the light beam (5) emitted from the semiconductor laser (1) as a light source is transmitted through a collimator lens (4), a plano-concave silica/trical lens (7),
Plano-convex cylindrical lens (8), beam splitter α9, galvano mirror (10a) and condensing lens (6)
When reading and reproducing information, the output of the semiconductor laser (1) is lowered to a reproducing power below a predetermined threshold shown in FIG. 7(b).

The light spot (to) enters the beam sinter 119 through the optical path opposite to the case of recording 1# information of dotted bits on the card αφ, that is, through the condensing lens (6) and the galvanometer mirror (10a). be done. The light beam incident on the beam splitter α9 has its optical path deflected downward by the beam splitter α9 and enters the photodetector (1), thereby reproducing the information converted into the output No. 1g.

That is, the light spot (g) is located on the galvano mirror (10a
c
The intensity of the reflected light flux changes depending on the presence or absence of 2D.

Correspondingly, the intensity of the output signal of photodetector I also changes,
This means that information can be read and reproduced from the card α-hiro.

[Problem that the invention seeks to solve]

However, in order to accurately follow and scan the light spot (a) on such a dot-shaped hit train, it is necessary to correct the deviation between the direction of the dot-like hit train) and the direction of the light spot αI-ne following. At the same time, it is necessary to increase the accuracy of feeding the optical card α◆ in the sub-scanning direction.

Conventional optical card recording and reproducing devices are structured as described above, so in order to accurately record and reproduce information, it is necessary to increase the dimensional accuracy of the optical card α4.
It was also necessary to improve the feeding accuracy of the feeding system of the optical card α field, and therefore, the disadvantage was that the feeding system required a large scale device.

This invention was made to solve the above-mentioned problems, and since it is possible to follow and scan a light spot or a data track, it is a compact device that can sufficiently reproduce signals even if the dimensional accuracy of the card or the feeding accuracy of the feeding system is poor. The purpose is to obtain a device for

[Means for solving problems]

The optical card recording/reproducing device according to the present invention scans and records a light spot on a recording medium, and one track is composed of three areas: a line part, a data part, and a line part,
Data searches are performed using these several tracks as a unit, and data reading is performed by scanning each track with a light spot, and after reading one track, the source spot is moved to the next track. This allows the data to be read out accurately and continuously.

[Function] The data track according to the second aspect of the present invention consists of two line parts and a data part sandwiched between them, and when reading data, one of the line parts crosses the head of the first track, and After starting the operation of following the data track, the light spot scans and reproduces the signal while following the data section, and when it reaches the other line section, it reverses the scanning direction while performing the following operation, By repeating a series of operations such as returning to the first line group and moving the light spot to the adjacent track, data can be read out accurately and continuously.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG.

FIG. 1 shows an embodiment of the invention. In the figure, the same reference numerals as in Figure 5 indicate the same or corresponding parts.
0b) is a sub-galvano mirror that reflects the circular light flux from the plano-convex cylindrical lens (8) downward and also moves the circular light flux in the sub-scanning direction. , a scanning means for scanning the recording and reproducing light spot 4 on the card αΦ in the main scanning direction α and the sub-scanning direction.

In addition, gradient is a feeding device that moves the card α◆ in the sub-scanning direction, and (to) is an information recording means, which uses the scanning means (4) to convert the input signal 4 into multiple rows of tracks. Record it on the card α. 3D is a feeding device driving means that causes the feeding device to move an arbitrary distance (to the recording medium) according to an external command (9). (To) is a track start means, and after receiving the end signal (To) from the feeder driving means 31), the above-mentioned scanning means (To) moves the reproduction light spot (To) to the line on the card α4, which will be described later. position the light spot αυ in the card feeding direction, detect the reflected light from each line section described later, and after a certain period of time after it becomes undetectable, reverse the moving direction of the light spot (c). let

After the returning light spot (to) detects the first line, it stops moving. (to) is a track following means,
After receiving the end signal (7) from the track start means (to), the operation is started, and the above scanning means (to) scans in the scanning direction α while giving negative feedback to the output of the photodetector. Then, a mirror (
10b). (b) is a jumping means which, after scanning one track, moves the original spot α to an adjacent track or several optical tracks, and operates a track following means (to). For this purpose, a signal (to) is received between the track following means (to), and a signal (to) is received from the track following means (to).
send.

. . is a data reproducing means, which receives the output signal (6) from the photodetector through the track following means (to) and reproduces the data.

Next, the operation will be explained.

The light (5) emitted from the semiconductor laser (1) as a light source is
A galvanometer mirror (10b) that moves the light beam (9) in the sub-scanning direction after being shaped into a parallel circular beam (9) by the lens systems (4), (7) and (8), and a main-scanning direction. A galvanometer mirror that moves the source beam to α (
10a), and is focused on the card α4 by the condenser lens (2).

To explain the case of recording information, the information is recorded in the information area of the card α in the shape shown in FIG. 82. This recording is performed by causing the information recording means (to) to scan the scanning means (to), and the minimum unit of information is a track row consisting of several tracks. The second line part (45a) is recorded, and subsequently data is recorded in the data part. Then, a life part (45b) of a certain length is recorded at the lower end. The length of the line portions (45a) and (45b) is 0.
1 to 0.5 m+ is appropriate. The smallest unit track column (
The appropriate distance between (b) is 3 to 5 times the track pitch.

When reproducing data, as shown in FIG.
(See Figure 2) and stop so that the light spot (g) is on top. Thereafter, the light spot for reproduction is moved to the position of the line part (4-) of the track row by the scanning means (e), and then the light spot (to) is moved to the position of the line part (4-) by the scanning means (to).
to move in the sub-scanning direction. As the light spot (G) moves, the reflected light from each line part (45a) can be detected, and after a certain period of time, the moving direction of the light spot (4) is reversed, and the first line is detected immediately after the first line is detected. , the movement is stopped and the track following means (to) is operated.

FIG. 3A shows an example of the structure of the track following means.

Various methods have been proposed as sensor systems for detecting track deviation, and here, a method called a three-beam method will be used for explanation.

The laser beam is divided into three by the diffraction grating η, and irradiated onto the bit string on the card α so as to be arranged as shown in FIG.
(20c) is detected. If the hit train moves and the track shifts, this causes an imbalance in the detection power between the detectors (20a) and (20c) at both ends.
A tracking error signal is extracted as a difference signal between both detectors (20a) and (20c) using a differential angle. The reproduced signal (transformation) is extracted from the central zero dimension (15b). This error signal) is amplified between the servo circuits,
Kane compensation and phase compensation are performed and transmitted to the tracking mirror (axis scanning mirror) drive circuit (51), and the mirror (10
b), so that the zero-order light spot (15b) is always positioned on the track while moving in the mechanical scanning direction.

In this device, the optical switch (L19) is moved in the main scanning direction α (
In order to reproduce the signal by shaking it again, the direction of shaking must be changed. Since it is only possible to maintain the scanning speed of the light spot at a constant value during the time before and after changing the direction of shaking, the time axis of the reproduced signal fluctuates.

Also, when tracking is applied, if the track is not present at all times, the tracking will be lost, so the track must also be present when changing the direction of swing. In the past, by providing line parts (45a) and (45b) before and after the data part (45a) and (45b), and performing main scanning from the line part (45a) to (45b), the data part could be scanned at one speed, and the stability was 1. ; Tracking can be applied.

The main scan is performed once for each track, and data is not read during the return scan, and when the main scan returns to the line portion (45a) after the return scan, the main scan is stopped. After confirming the stop, the jumping means (b) moves the light spot (g) to the line part (45a) of the adjacent truck. An explanatory diagram of the jump pink operation is shown in FIG.

Jumping is performed by turning off the tracking servo circuit and at the same time sending a jump pulse (53) from the jumping pulse generation circuit (52) to the secondary scanning mirror drive circuit (51).
), and when the tracking error signal crosses zero, the polarity of the jump pulse (53) is reversed and used as a brake pulse to stop the light spot on the adjacent track. These operations are repeated for the number of tracks included in the track sequence θ→+j, the reading of that track sequence (b) is completed, and the next command is waited.

3. In the above embodiment, a galvanometer mirror is used as the main scanning mirror, but a rotating mirror may also be used.

Further, in the above embodiment, C uses a three-beam method as an example of a tracking servo sensor method, but a tracking servo sensor method (such as a push-pull method) that is generally used in optical discs may also be used.

〔Effect of the invention〕

As described above, according to the present invention, an information track is recorded using an optical spot scanning means so as to consist of two line parts and a data part, and the data is reproduced using a track following means and a track jumping means. So,
This has the effect of providing a continuous and stable reproduction signal.

[Brief explanation of drawings]

Fig. 1 is a block diagram of an optical card recording/reproducing device according to an embodiment of the present invention, Fig. 2A is a plan view showing the entire recording medium in this embodiment, and Fig. 2B shows details of the track row. 3 is a diagram explaining the configuration and operation of the track following means, FIG. 4 is a diagram explaining the operation of the track jumping means, FIG. 5 is a configuration diagram of a conventional optical card recording/reproducing device, and FIG. The figure is a pattern diagram showing a bit string recorded by this conventional device, and FIG. 7 is a diagram showing the power level during recording and reproduction in this conventional device. In the figure, (1)...V-the light source, α-i...recording medium (optical card), (g)...light spot, wire...
Scanning means, ... feeding device, (to) ... information recording means, 3D ... feeding device driving means, (to) ... track head means, (to) ... track following means ,(B)
... Jumping means, (G) ... Data reproducing means, ■ ... Track, (B) ... Track row, (45
a). (4Sb)...Line section, -...Data section. Note that the same reference numerals in the figures indicate the same or equivalent parts. Figure 4 Figure 5

Claims (1)

[Claims] (1) A scanning means for scanning a recording light spot obtained by focusing a light beam from a laser light source or a reproduction light spot of a different intensity on a card-shaped recording medium, and moving the recording medium in a predetermined direction. and a feeding device for sequentially recording information on a plurality of mutually parallel tracks on the recording medium or reproducing the recorded information,
Each of the tracks is composed of first and second line parts for causing the light spot to follow and scan the tracks during reproduction, and a data part for recording the information, which is sandwiched between the first and second line parts, and the data part for recording the information. information recording means for recording a series of the above information of a predetermined length as a track train consisting of a predetermined number of continuous tracks using a scanning means; a feeding device driving means for moving the recording medium by moving the recording medium; a track starting means for finding the first track of the track array after the moving of the recording medium; track following means for performing follow-up scanning along the track and reproducing data recorded on the track; and track jumping means for moving the light spot to an adjacent track after following-scanning one of the tracks. Optical card recording/playback device.