JPS6257126A - Optical information recording medium - Google Patents

Abstract

PURPOSE:To simplify a device for recording and reproduction, by extending at least one end part of a tracking track longer than the corresponding end part of a clock track. CONSTITUTION:In an information recording area of an optical card 1, clock tracks 21, 22,... and tracking tracks 31, 32,... are placed alternately and in parallel. Also, between the clock track and the tracking track, recording areas 41, 42, 43,... for recording the information are provided. The tracking track exists extending over areas A-C of the card 1, and the clock track exists in only the area B of the card 1. That is to say, both end parts of the clock extend to the inside by only l1 and l2 from the end edge of the card 1. In this way, at the time of a seek operation of the track, it will suffice that only the tracking track is detected, and even after the seek operation, it is unnecessary to cope with both the tracks whose characteristics are different, therefore, a discriminating circuit is not required.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical information recording medium, and particularly to a card-shaped optical information recording medium provided with tracks for obtaining tracking signals and clock signals.

[Conventional technology]

2. Description of the Related Art Conventionally, various types of media such as disks, cards, and tapes have been known for recording information using light and for reading recorded information.

Among these, card-shaped optical information recording media (hereinafter referred to as optical cards) are expected to be in great demand as mediums with large storage capacities that are small, lightweight, and convenient to carry.

FIG. 10 is a schematic plan view of such an optical card 101, in which 102 is an information recording area, 103 is an information track,
104 and 104' are track selection areas, and 105 is a home position of the light beam spot.

By the way, information is recorded on the above-mentioned optical card as an optically detectable recording bit string (information track) by scanning with a light beam that is modulated according to recorded information and focused to a minute spot. At this time, in order to accurately record information without causing problems such as crossing of information tracks, the irradiation position of the light beam spot must be controlled within the optical card surface in a direction perpendicular to the scanning direction (auto tracking , hereinafter referred to as AT). In addition, in order to irradiate the light beam as a stable minute spot regardless of the bending or mechanical error of the optical card, it is necessary to control it in the direction perpendicular to the optical card surface (auto tracking, hereinafter referred to as AF). .

Furthermore, it is also necessary to obtain a clock signal to compensate for variations in scanning speed. Further, the above AT and AF are also required during playback.

Therefore, a preformat such as a tracking track or a clock track is formed on the optical card in advance.

FIG. 11 is a schematic plan view of a conventionally proposed optical card having such a preformat. A clock signal is recorded in advance on the optical card 101, and a clock track 21* is formed in an intermittent broken line shape.
2*p 2g... and a tracking track 31.3 formed in a continuous linear shape. ...are arranged alternately at equal intervals. Recording areas 41+42, 41, . . . are provided for recording information on each open track can. That is, the optical power card 1 has a recording area in the entire area between the clock track and the tracking track.

FIG. 12 is a functional diagram of the information recording/reproducing device for an optical card, and 106 is a motor for driving the optical card 101 in the direction of the arrow in the figure.

107 is a light source such as a semiconductor radar, 108 is a collimator lens, 109 is a beam splitter, 110 is an objective lens, 111 is a tracking coil, 112 is a 7-focusing coil, 113 and 114 are condensing lenses, 11
Reference numerals 5 and 116 are photoelectric conversion elements, 117 is a tracking/regulating control circuit, and 118 is a 7-order scanning control circuit. Based on the tracking signal and focusing signal detected by the photoelectric conversion elements 115 and 116, the objective is set by passing current through the focusing coil 111 and the focusing puffer coil 112 according to commands from the control circuits 117 and 118. / lens 110 is moved to perform AT and AF.

Note that a clock signal and reproduction (No. 3) are obtained from the outputs of the photoelectric conversion elements 115 and 116.

Next, a method for recording and reproducing information on the optical card using such a device will be outlined.

FIG. 13 is a partially enlarged plan view of the information recording area of the optical card.

When recording the 1°H information on the original card 101, first, the spots Sl p 81 r s = are irradiated so that S1 and the clocked track 21#S3 are located above the tracking track 3i. Then, by the relative movement of the optical head that forms these spots and the original card, the spora (81 to S1) are scanned in the direction of the arrow. Here, a clock signal is reproduced from the reflected light of the spot S1. Further, the reflected light from the spot S1 is guided to a light detection means in the optical head, and a tracking signal is detected using a well-known method such as the so-called pushinable method. Based on this tracking signal, the spots s1 + St t Ss are integrally moved in the direction perpendicular to the scanning direction, and AT is performed.

As a result, tracking track 3 is recorded in recording area 4 with Spora) Ss! Accurately record along pit 5
is being recorded. Next, when recording information on the snow in the recording area 4, the spot is set to S1'.

S, /, S;, the clock signal is reproduced from the clock track 21 at 83', the tracking signal is obtained from the tracking track 31 at 81', and while performing AT, information is recorded at 82'. I will do it. By switching operations like this, it is possible to record information in all of the J recording areas.

Although the operation for recording information has been described above, the same operation can be performed for reproducing information, and in this case, a reproduced signal is obtained based on the intensity of light incident on the photodetecting means.

[Problem that the invention seeks to solve]

In the optical card as described above, when recording or reproducing information, the light beam spot is initially located at the home button 105 shown in FIG. (seek) to find the target track N by moving it in the V direction, and then scan the track N in the r direction.

When performing the above seek operation, the light beam spot crosses the clock track and tracking track formed in the track selection area, and by counting the number of times the light beam spot crosses the clock track and tracking track formed in the track selection area, it moves to the target track. It becomes possible to reach the destination quickly.

However, in the conventional optical card described above, a clock track and a tracking track are provided also in the track selection area, so that the light beam spot crosses two types of tracks during the seek operation. Since the clock track and the tracking track have different shapes, a means for distinguishing between these two types of tracks is required for accurate track selection.9 Therefore, there is a problem in that recording and reproducing devices are complicated. was there.

[Means for solving problems]

According to the present invention, in order to solve the problems of the prior art as described above, an optical An information recording medium is provided.

〔Example〕

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic plan view showing an embodiment of an optical card which is an optical information recording medium according to the present invention.

In the information recording area of the optical card 1, there are clock tracks 2tt2s*, which are formed in an intermittent broken line shape by recording a clock signal in advance, and tracking tracks 31+31+, which are formed in a continuous line shape. are arranged alternately in parallel and at equal intervals. A recording area 41, 4sj, . . . for recording information is provided between the clock track and the tracking track.

As shown, the tracking track exists over the area A-C of the optical card 1, that is, both ends of the tracking track extend to the edge of the optical card l.
On the other hand, the clock track exists only in area B of the optical card 1, that is, both ends of the clock track extend only 4+t3 inward from the edge of the optical card l.

FIG. 2 is a partially enlarged plan view of the optical card shown in FIG. 1, particularly showing the details of the clock track 21. FIG. In the figure, 2 is a preamble area, 2b is an area indicating an encoded track number, and 2c is an original clock area.

A pattern similar to that of the pockmark area 2C is formed in the preamble area 2a.

3 and 4 are diagrams illustrating the configuration of an embodiment of an optical information recording and reproducing device for recording and reproducing an optical card according to the present invention. FIG. 3 is a perspective view, and M4 diagram is a side view. FIG.

A light beam emitted from a light source 11 such as a semiconductor radar is collimated by a collimator lens 12 and collimated by a diffraction grating 13.
It is divided into three beams by

These beams are imaged by the objective lens 14 on the information recording surface of the optical card 1 as shown in FIG.

Here, the optical card 1 is moved by an arrow R by a driving means (not shown).
The beam spot is scanned in the direction in which the tracking track and the clock track extend.

The reflected light from S3 passes through the objective lens e14 again, is reflected by the mirror 15, is projected onto the condenser lens 16, and onto photodetectors 17, 18, and 19 placed on the focal plane, respectively. be done.

These photodetectors are arranged side by side in the two directions shown in the figure, as shown in FIG. Also photodetector 17.18.1
The light receiving surfaces of 9 are A, B, and C.

It is divided into four parts as shown in D.

Next, the operation when recording optical card IK information using the above-mentioned apparatus will be explained with reference to FIG. FIG. 6 shows an enlarged plan view of the information recording surface of the optical card. First, when recording information in the recording section 41, the spot st Is! 183
21 tracks respectively.

The recording section 41 and the tracking track 31 are irradiated with light. These spots are scanned in the direction of the arrow a by the movement of the optical card 1 as described above. The reflected light from Spora) St enters the aforementioned photodetector 17, and a clock signal is reproduced. Further, the reflected light from the spot SR enters the photodetection superimposition 9, and the light is reflected from the spot SR at a location l! The tracking signal is detected by the Shuggle method. That is, the light receiving surface of the photodetector is divided into A, C, B, and D in the y direction corresponding to the length direction of the tracking track, as shown in Fig. M5.

Therefore, when the spot sg deviates from the tracking track 31, a difference occurs in the intensity of light incident on the traps A, C and B, D, and a tracking signal can be obtained by comparing the signals from these light receiving surfaces. . Based on this tracking signal, the spora) 81 #st pus is integrally moved in the direction perpendicular to the scanning direction (direction b) by a tracking means (for example, means for moving the objective lens 14 in two directions in FIG. It is moved and AT is performed. And recording section 4! The recording bit 5 is accurately recorded along the tracking track 31 by the spot S1.

Further, during the above recording, the photodetector 19 detects a focusing signal for controlling the spot to be accurately focused on the recording surface of the optical card at the same time as the tracking signal. This detection principle will be briefly explained with reference to FIG. In FIG. 7, the same members as in FIG. 4 are given the same reference numerals, and detailed explanations will be omitted.

Spot S! As shown in the figure, the incident light 20 forming the
When the spot is accurately focused on the recording surface, the light beam 2 enters the mirror 15 parallel to the incident light 20 and is guided to the detection surface 23 . However, if the recording surface is vertically shifted at points 21' and 21'' with respect to the focal position of the objective lens 14, the reflected light will be non-parallel to the incident light at points 22' and 22'', respectively. The irradiation position moves in the y direction on the detection surface 23. Therefore, a focusing signal can be obtained by detecting this gradual change in the light intensity distribution in the y direction as an output difference between the light receiving surfaces A, B and C, D of the photodetector 19 placed on the detection surface 23. . According to this focusing signal, move the objective7. Move el, 4 in the optical axis direction A
Do F.

Although the operation for recording information has been described above, the same operation can be performed for reproducing information, and in this case, a reproduced signal is obtained based on the intensity of light incident on the photodetector 18.

FIG. 8 is a graph showing the scanning speed of each beam spot on the optical card at each beam spot irradiation position during recording or reproduction as described above, where the horizontal axis represents the position of the optical card in the track direction, and the vertical axis represents the position of the optical card in the track direction. represents the absolute value of the scanning speed. In the figure, m is the speed at the time of recording, and n is the speed at the time of reproduction.

In this way, the read transfer rate is usually increased during playback compared to during recording, so the data is broken faster.

The length of the clock track t! is approximately equal to the constant speed region during reproduction shown in the graph of FIG.

The lengths tl and t of the region where only two tracking tracks exist are longer than the speed change region during reproduction shown in the graph of FIG.

Next, the process of recording information using the optical card of this embodiment as described above will be explained based on the flowchart of FIG.

First, a light spot formed on the surface of an optical card (by an information recording/reproducing device) performs a seek operation to select a desired information track from the home position. This seek operation is performed by moving the optical head of the device, and the AT/A
While maintaining the incoming light beam focus state, the F light beam advances across the tracking tracks in area A shown in Figure 1 (Stella f31), and at this time, calculate the number of tracking tracks crossed from the change in the output of the photodetector. The optical head movement is stopped when a predetermined number of tracks have been detected (step 32). At the same time, the AT is activated and the light beam spot is applied to the nearby track, and the AT sustainer circuit becomes a closed loop (AT clock).

In this way, card feeding starts in the track direction after the AT clock (Stella f33), and after reaching the constant speed region after passing through the speed change (acceleration) region shown in FIG. The preamble area 2at is scanned, and a reference clock for signal processing control during recording is generated in a PLL circuit based on a signal obtained from a corresponding photodetector. Further, the clock light beam spot scans the track number area 2b of the clock track. At this point, the reproduction reference clock issued from the PLL circuit is stable, so it is possible to accurately detect the track number based on the stable clock. The comparison circuit compares whether the detected track number is the target track (step 34).

If the detected track number is the desired one, the clock light beam spot advances along the clock track, and the recording light beam spot advances through the recording area to record information. Step 35): Record one line. After this is completed, the card feeding is reversed (Stella F36), and a verification is performed to see if the recorded information recorded on the relevant card is correct (Step 37). It is determined whether recording should be performed (step 38). That is, if the recorded information is confirmed to be correct in step 37 and there is no further information to be recorded, the process ends.

On the other hand, if it is confirmed that the recorded information is entertainment in Stella F37, or if there is JW information to be recorded, then when the track light beam spot reaches the area size, for example, the adjacent In order to jump to the tracking track, Stella f39), the card feed is reversed (Stella 7''40), and steps 34 and subsequent steps are repeated in the same manner as above.Meanwhile, the track number detected in step 34 is the target If it is not from the truck, immediately reverse the card feed (Stella F41
), then the process moves to step 39.

Note that if the recorded information is immediately confirmed to be incorrect in step 37, the information recorded in step 35 is the same information as the previous time; otherwise, the recorded information is This is new information. In this example, the track number area is provided only at one end of the clock track.) Since the track number area is not provided at the other end, the recording area must be made longer. can be secured. In this embodiment, since the track number area is provided only at one end, the track can only be confirmed at one end, but optical cards are generally used as write-once cards, and in this case It is necessary to confirm the recorded information, and if this confirmation is performed when the light beam spot is scanned in the reverse direction as described above, the information will be confirmed even if the track number can only be read at one end. There is no substantial disadvantage on the record.

Furthermore, in this embodiment, since the preamble area for clock reproduction is provided outside the track number area and in the area where the light beam spot scans at a constant speed, the track number can be detected with high accuracy. ,
Never make a mistake in selecting a track.

Although the process of recording information has been described above, the process of reproducing information can be performed in the same manner. however.

Step 35 in FIG. 9 is a playback operation, and step 37 is unnecessary.

In the above embodiment, an example is shown in which the track number area and the preamble area are provided only at one end of the clock track, but in the present invention,
A track number area and/or a preamble area may be provided at both ends of the clock track.

In this case, seek operations and track jump operations can be performed accurately in either of the two end regions of the optical card.

〔Effect of the invention〕

According to the present invention as described above, it is only necessary to detect the tracking track during the track seek operation,
Furthermore, since there is no need to deal with both the tracking track and the clock track, which have different characteristics, during auto-tracking pull-in after the seek operation, there is an advantage that a circuit for identifying the tracking track and the clock track is not required. . Furthermore, since there is no need to cross a clock track during a track jump during recording or playback, there is no crosstalk from the clock track, which has the advantage that signal processing becomes simple and reliable.

Thus, according to the optical information recording medium of the present invention, highly reliable recording and reproduction can be performed.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view of the optical information recording medium of the present invention, FIG. 2 is a partially enlarged plan view thereof, and FIGS. 3 and 4 are configurations of an example of an apparatus for recording and reproducing the medium of the present invention, respectively. 5 is a diagram showing the arrangement of photodetectors in the device shown in FIG. 3, FIG. 6 is a diagram explaining how information is recorded by the device shown in FIG. 3, and FIG. FIG. 8 is a graph showing the scanning speed of the light beam spot; FIG. 9 is a flowchart showing the recording process on the medium of the present invention; FIG. 10 11 is a schematic plan view of an optical card, FIG. 12 is a schematic configuration diagram illustrating the functions of an optical card recording/reproducing device, and FIG. 13 is a schematic diagram of an optical card recording surface illustrating the recording operation of a conventional optical card. FIG. 21 + 22 g 23...Clock track, 21...Preamble area, 2b...Track number area. 2c...Clock area, 3s t '3s...Tracking track, 41+41*4m...Recording area, sl ysl, s,...Beam spot. Agent Patent Attorney Minoru Yamashita Child 1 Figure 2 Figure 4 Figure 5 Figure 6 Figure 7 Figure 12

Claims (3)

[Claims] (1) In an optical information recording medium in which a plurality of clock tracks and tracking tracks are formed parallel to each other and information is recorded in an area sandwiched between the two tracks, at least one end of the tracking track an optical information recording medium, characterized in that the clock track extends longer than the corresponding end of the clock track. (2) A patent in which a track number area is provided at the end of each clock track on only one side of the side where the tracking track extends longer than the clock track to identify each track from other tracks. The optical information recording medium according to claim 1. (3) The optical information recording medium according to claim 2, wherein a preamble area for lock playback is provided outside the track number area in the clock track.