JPS61198466A - Method for detecting home position - Google Patents

Abstract

PURPOSE:To detect the home position of an optical head for an optical card by moving the optical card or an optical head along the arranging direction in the unit of tracks in the optical card to read a reference line. CONSTITUTION:Clock tracks 3a-3c and tracking tracks 4a, 4b are arranged alternately at an equal pitch in the inside of a data area 6 on the optical card 1 and data tracks 2a-2d exist between the pitches. Automatic tracking is applied by using a spot 8a in three beam spots at, e.g., data recording, and while generating a clock by a spot 9a, the data is recorded by a spot 7a. On the other hand, at reproduction while automatic tracking is applied by a spot 7b, the data is reproduced at the same time by using both the spots 8b, 9b. It is possible to apply automatic focusing by using any of the three spots. Thus, it is possible to discriminate the kind of an optical card and the home position is detected by a simple means.

Description

Detailed Description of the Invention (Technical Field) The present invention relates to a recording and reproducing device for a card-shaped recording medium (hereinafter referred to as an optical card) that performs recording and reproducing using a light beam. This invention relates to a so-called home position detection method in which relative positioning of an optical head and an optical card is performed so that the optical head section is located at a predetermined position on the optical card. In this application, the term "recording-playback device" refers to only recording or playback, or recording and playback.
This refers to a device that performs both reproduction and reproduction.

(Prior Art) In recent years, with the progress of informationization in society, optical cards have been attracting attention as a means of storing information. The main characteristics of optical cards are that their card shape is easier to carry and handle than optical disks, optical tapes, etc.
It has a large storage capacity compared to magnetic cards, IC cards, etc.

By the way, when recording and reproducing data via a storage medium such as an optical card, generally before starting the above operation, a table of contents provided in the optical card that describes the data status etc. in the optical card is prepared. In many formats, information in the area is read and operations are performed based on that information. Therefore, in order to reduce the time required for data recording and reproduction, the optical head and optical card must be quickly connected after the optical card is inserted into the device. It is necessary to move the relative position so that the information in the table of contents area can be reproduced. In this application, for example, such a state in which the optical head is positioned relative to the optical card is referred to as the home position of the optical head.

On the other hand, a further requirement for the recorded fist reproducing device is that it has a certain degree of versatility. In other words, although the data recording format (format) is the same,
For example, it is preferable to be able to record and reproduce data on and from different types of optical cards in which the table of contents area is set at different positions due to differences in recordable capacity. For example, there are methods in which a marking is placed at a specific position on an optical card to identify the card type, and this mark is read using an optical system dedicated to identifying the mark. ), and detecting this with a detection sensor, but both methods require a dedicated means for card discrimination, which increases the number of parts per unit, and is not necessarily a preferable method.

SUMMARY OF THE INVENTION An object of the present invention is to provide a vehicle-enabled method for detecting the home position of an optical head relative to an optical card by simple means.

In the home position detection method according to the present invention, when writing data to or reading data from an optical card having a reference line provided for an information track, the track in the optical card is The type of optical card is determined by moving the optical card or the optical head along the direction in which the units are lined up and reading the reference line, and based on this information, the position of the optical head relative to the optical card becomes the home position. Set as desired. Hereinafter, the present invention will be explained in detail using the drawings.

(Example) Based on the contract signed between the applicant and Drexler Technology Corporation of the United States, the technical report disclosed to the applicant by Drexler Technology Corporation includes data. A plurality of track units on which recording or reproduction is performed are arranged in a predetermined data area, and a reference line corresponding to the track unit is provided outside the data area in the traveling direction of the track in the track unit. An example of an optical card is shown. The track unit here refers to a row of data tracks on which data is written, as well as tracking tracks for reliable data writing and reading.
This means a combination of the minimum necessary various tracks, including a clock track, etc.

FIG. 1 is a diagram showing an embodiment of such an optical card, where 1 is an optical card, 2a, 2b, 2c, and 2d are data tracks, and 3
a, 3b, 3c are clock tracks, 4a, 4b are tracking tracks for tracking, 5a
, 5b, 5c.

5d indicates a reference line, 6 a data area, and 7 a reference line area. (7a, 8a, 9a), (7b,
8 b and 9 b) respectively indicate the beam spots of the light beams projected from the optical head to the optical card in order to record data on the optical card 1 or read data from the optical card 1. In this case, when recording or playing back,
Three beam spots are formed on the optical card simultaneously. As shown in FIG. 1, inside the data area 6 on the optical card 1.

Clock tracks 3a, 3b, 3c and tracking tracks 4a, 4b are arranged alternately at equal pitches, and data tracks 2a, 2b, 2c are arranged between them.

2d exists. For example, when recording data, auto-tracking is performed with spot 8a of the three beam spots, and recording is performed with spot 7a while generating a clock with spot 9a. On the other hand, during reproduction, it is also possible to perform auto-focusing using any one of the three spots, by performing auto-tracking with spot 7b and simultaneously reproducing with both slots 8b and 9b.

In the above example, data tracks 2a, 2b.

When recording on tracks 2c and 2d, clock track and tracking track pairs (3a94a) and (3b
, 4a), (3b, 4b).

(3c, 4b), and for convenience of explanation, (
2a, 3a, 4a), (2b, 3b.

4a), (2c, 3b, 4b), (2d, 3c.

4b) will hereinafter be referred to as a track unit.

The reference lines 5a, 5b, 5c, and 5d correspond to the track units, and are provided in a reference line area 7 outside the data area 6 where data is recorded and reproduced.

FIG. 2 shows the state of relative movement between the optical head and the optical card during an initial operation before recording/reproducing data in a recording/reproducing apparatus using the home position detection method according to the present invention.

As in FIG. 1, a data area 6 and a reference line area 7 are provided on the optical card 1. In the state before data is reproduced or recorded, the optical head lla is located outside the reference line area 7. The position of this optical head is always at this position during initial operation.The optical head 11a and the optical card 1 are relative to each other in the reference line area 7 in the direction in which the reference lines are lined up. It is possible to count the number of reference lines by moving them to different positions. The number of reference lines varies depending on the type of card, and if the number of reference lines depending on the type of card is known in advance, the card can be identified by counting the number of reference lines. In this way, it is possible to discriminate between optical cards that have the same data recording format but different types. Based on this identified information, the optical head is moved to the home position.

By increasing the length of the reference line 5 shown in FIG. 1 in the horizontal direction to a certain extent, it is possible to prevent the reference line from being omitted even if the card is installed diagonally in the initial state, which is convenient. be. In FIG. 1, the explanation is given using an example in which the track unit and the number of reference lines are in one-to-one correspondence, but the invention is not necessarily limited to this. It is possible to change the number of lines, such as 2:1 or 3:1. In this case, the above objective can be achieved by detecting the period of the reference line read when the optical head 11 moves relative to the optical card 1 from lla to flb in FIG. becomes possible.

Figures 3 and 4 are diagrams for explaining this content.
Figures (A), (B), and (C) sequentially show reference lines 1 corresponding to the track units at a ratio of 1:1.2:1.3:1.
2, 13, and 14 are shown. As the optical head moves from the position lla to the position llb relative to the optical card on each reference line, the 6 reproduction signal t* obtained by the optical head 184 (A), (B ), (C)
is obtained. The frequency of this reproduction signal is determined by the pitch of the reference line, and by detecting the difference in frequency, the type (A) of the card can be determined.

It is possible to distinguish between (E) and (C).

FIG. 5 is a schematic diagram showing an embodiment of an optical card recording/reproducing apparatus using the method according to the present invention.

Sensor 2 detects that optical card 1 is inserted first
1 gives a detection signal to the pulse motor driver 22, and based on this signal, the pulse motor driver 22 drives the pulse motor 23 to move the optical radar 11 to a predetermined initial position, for example, the position lla shown in FIG. . When the sensor 24 detects that the optical radar 11 has moved to the position Lla, it resets the counter 25 and simultaneously gives a detection signal to the pulse motor 22, which causes the pulse motor driver 22 to drive the pulse motor 23. , as mentioned above, move the optical head 11 from the lla position to the llb shown in FIG.
Move to the position. Furthermore, at this time, the sensor 24 also sends a reading command signal to the Hikari Rad 11, and the Hikari Rad 11 reads the reference line while operating the AF@ function during the movement from the above-mentioned lla to flb, and the signal is counter 2
5, and then the comparator 26 compares it with a numerical value given from the setting circuit 27, which has been set in advance, thereby determining the type of the optical card I. When the sensor 28 detects that the optical head 11 has come to the position llb.

This is for stopping the counting operation of the counter 25. The pulse calculation circuit 28 moves the optical head 11 near the reference line corresponding to the table of contents area in the optical cart 1, which is different for each type, based on the type signal from the comparator 26 and the set value of the setting circuit 29. In the explanation using FIG. 5, an example is shown in which the optical head is moved, but the optical card may also be moved.The specific configuration of the circuit shown in the block diagram can be understood by those skilled in the art. Since it is easily manufactured, the explanation will be omitted. Furthermore, although FIG. 3 shows an example in which a series of operations is started upon detection of the insertion of an optical card into the device, the invention is not necessarily limited to this.
It's not a thing.

In other words, even when an optical card has already been inserted into the device, data has been recorded or reproduced, and the operation is temporarily interrupted, the youngest son's method can be applied even when starting recording and reproduction again.

As described above, in the home position detection method according to the present invention, before recording or reproducing data, the optical card and the optical head are moved relative to each other in the direction in which the reference lines are lined up as necessary, and the optical head is used to refer to the reference line. It is possible to determine the type of optical card by playing the line.
The home position can be detected by a simple means.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of the format of an optical card suitable for the method according to the present invention, FIG. 2 is a diagram for explaining the method according to the present invention, and FIGS. FIG. 5 is a diagram for explaining one means for identifying an optical card in the method according to the invention, and FIG. 5 is a diagram showing an embodiment of an optical card recording/reproducing apparatus to which the method according to the invention is applied. 1-11 optical card, 2a, 2b, 2c, 2d---data track. 3a, 3b, 3cm--clock track, 4a, 4b
--1 Tracking track, 5a, 5b, 5c, 5
d--One reference line. 6---Data area, 7---Reference line area. 11a, 1lb--one light head. 12.13.14-m-Reference line.

Claims (1)

[Claims] (1) When recording or reproducing data on the optical card, the step of adjusting the relative positional relationship between the optical card and the optical head to a predetermined initial state, the step of aligning the optical head and the optical head in the track alignment direction of the optical card changing the relative positional relationship of the cards and reading a reference line of the optical card with the optical head; determining the type of the optical card from the information obtained by reading the reference line; and determining the type of the optical card from the information obtained by reading the reference line. A home position detection method comprising the step of: relatively moving the optical head and the optical card so that the optical head is located near the home position based on the type information.