JPS62279523A - Data reading method for optical card - Google Patents

Abstract

PURPOSE:To facilitate reading an optical card having various recording pitches by switching light receiving elements incorporated in one photodetector to read the optical card on which data are recorded at various pitch intervals. CONSTITUTION:The luminous flux from a light source 1 is reflected on a half mirror of a prism 2 and is converged on a laser card 10 by an objective lens 3 and is reflected there, and a part of the luminous flux goes straight on a bottom face 2b of the prism 2 and reaches a photodetector 4a. At this time, the data part an the tracking part of the card 10 are focused as images B' and C' on the photodetector 4a. Light receiving elements D1-D24 are provided in positions corresponding to images B'(1, 1), B'(1, 2)... of the data part. Light emitting elements T5 and T6 which generate a tracking error signal and clock signal elements T1-T4 which set positions of elements D1... in the X direction are provided correspondingly to images C'1, C'2... of the tracking part. Light receiving elements are selected in accordance with the data pit pitch of the card 10 to read data.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for reading data from an optical card, and particularly to an optical card in which data bits are recorded at various pitches using the same reading element. Concerning how to read cards.

[Background Art] In recent years, optical cards have been in the spotlight as information recording media. Pocket-sized cards are popular, and optical cards are expected to become popular rapidly. Information is recorded on this optical card using minute data bits. Data is read by enlarging the data bits with an optical system and focusing the enlarged image on a plurality of light receiving elements TI].

For example, if the optical system magnifies data bits by a factor of 2, data bits recorded at a pitch p/ can be read by light receiving elements arranged at a pitch p.

[Problems to be Solved by the Invention] Since optical cards are used for various purposes, the recording pitch of data bits also differs depending on the purpose. For example, if it is not necessary to record that much information on one optical card, it would be desirable to increase the pitch and keep the cost of the optical card low. On the other hand, if you want to record as much information as possible on one optical card, you can use high-precision printing technology to finely print the pitch even if it costs more to manufacture the optical card.
However, in the data reading method mentioned at the end of the article, the arrangement pitch of the light receiving elements is determined based on the recording pitch of the data bits and the magnification of the optical system. When reading optical cards with different pitches, it is necessary to prepare optical systems with different magnifications or to prepare light-receiving elements with different arrangement pitches.In this way, the reading device can be adjusted depending on the optical card to be read. Changing the optical system or the arrangement of the light-receiving elements within the device complicates the structure of the device and increases cost.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a data reading method for optical cards, which allows data to be easily read by the same reading device for various optical cards having different recording pitches of data bits.

[Means for Solving the Problems] The present invention provides a data reading method for reading information recorded on a recording medium, in which at least two or more different pieces of data recorded at different pitch intervals are incorporated into one photodetector. It is characterized by reading by switching the light-receiving elements.

[Function] According to the present invention, data is easily read from various optical cards having different recording pitches of data bits using the same optical system and the same light receiving element, since reading is performed by changing the light receiving element. Be able to do things.

[Example] An example of the format of the laser card used in the present invention is shown in FIG. 2, and FIG. 2(a) is an overall view of the card.
FIG. 5B is an enlarged partial view of one track.

FIG. 2 shows the format of the track, which consists of an address section A, a data section B, and a tracking section C.

First, to detect the desired position of the address section A, a photodetector is moved to Y.
Seek by moving in the direction.

Bits are always formed at the top (A1) and bottom (A24) of the address section A of each track. By detecting these two bits and by detecting the position by a tracking section C, which will be described later, it is known that the photodetector is correctly positioned on each track. Thereafter, data such as the track number of this trunk is read, and if this track number is a desired number, the photodetector is moved in the X direction and the data is read. In addition to the address of this track, various information such as an electronic dictionary index, information as to whether this track has been recorded or not can also be recorded in this address section A. When this part is scanned in the Y direction, the data can be read directly with the detector. The reason why the part A is extended in the X direction is that the card can be read even if the card and optical system are shifted in the X direction during scanning. In the data section B, the data to be recorded on this track is recorded as the presence or absence of data bits. Data bits are formed in the parts marked with /\ in the figure.

The tracking section C also includes troughs C1 and C, which will be described later.
2... is formed.

A number of areas B (1,1), B (1,2), B (1
, 3)...B (18, 24)... are defined. This data section B consists of two blocks with a tracking section C symmetrically sandwiched between them. Now area B
(1, 1), B (1, 2)...If the width of each area in the X direction is d, the width of each bit C1, C2... in the X direction is 2d, Beep) CL, C2...
The setting position of ・ is determined as follows. That is, area B
H, t), B (1, 2), B (1, 3)...
...First column of B (1, 24) and area B (2, 1)
, B (2,2)...Bit C1 is arranged at a position facing the two columns in the Y direction of the second column of B (2,24). Other bits C2, C3, C4...
... are recorded at pitch intervals of 4d in the X direction with the position of bit C1 as a reference. Therefore, bit C2 is in area B (5, 1).

It will be installed in a position opposite to the two columns of the 5.6th column containing B (6,1).

Next, regarding the reading detection optical system that reads the laser card.
-131 蓼1.

First, the photodetector 4a is driven in the Y direction by the address section A to seek a desired track in the address section A. That is,
When the difference between the output values of the light receiving elements T5 and T6 becomes less than a certain value, the light receiving element DI.

After confirming that the top Al and bottom A24 have been detected in D24, data such as track numbers are read.

Reference numeral 1 in FIG. 1 is a light source such as an LED, and the light beam emitted from this light source is reflected by a half mirror on the surface 2a of the prism 2, and is focused onto the laser card 10 by the objective lens 3. The reflected light from the laser card 10 is polarized by the Keer effect, passes through the objective lens 3 again, and passes through the surface 2a of the prism 2. At the bottom surface 2b of the prism 2, a part of the luminous flux continues straight and becomes light for information reading. The photodetector 4a, which reaches the photodetector 4a of the detection device 4 and reads information therefrom, is a general term for an array consisting of a plurality of light receiving elements.

A part of the other light beam is reflected by the bottom surface 2b of the prism 2, and is reflected again by the total reflection part 2c of the surface 2a, and reaches the photodetectors 4b and 4c for focus error signal detection L), thereby detecting the focal point. Make adjustments.

The solid line diagram in FIG. 3 is an enlarged partial view of the photodetector 4a for reading information. On the other hand, the broken line in the figure shows the objective lens 3.
Laser card data section B.

Data section and tracking section C showing a state in which tracking section C is imaged with no position and deviation on photodetection $4aJ:
The images formed by the photodetector 4 are shown by the symbols B' and C', and the large circle Q indicates the area irradiated by the light source 1 such as an LED. Area B' (1, 1
), B' (1,2).

B'(1,3)...B' (1,24)
A reading light-receiving element DI is placed at a position corresponding to each image formation.
, D2°D3. ...D24 is installed at pitch D.

On the other hand, the imaging of the tracking part C is C'1°C'2...
. . . Correspondingly, two tracking light receiving elements T5. T6.4 clock light receiving elements TI-T4
is located. Among these, the light receiving elements T1 to T4 are in the area B' (1, 1), the reading light receiving element D1 to D24 is
' (1, 2), B ' (1, 3)...B
'(1, 24), respectively, to generate clock signals for accurately setting positions in the X direction. These four light-receiving elements TI-T4 are arranged at a pitch D in the X direction, and among them, TI is an imaged tracking part C'
The device is arranged so that it is divided into two equal parts by the side c' iy of l in the Y direction. 2 for further generating a tracking error signal.
of light receiving elements T5. T6 is placed. Light receiving element T
The pitch interval of 5°T6 is 2D, and each element is
It is arranged so as to be divided into two by the side C'2X in the direction.

Next, a reading operation by the photodetector 4a will be explained.

First, the photodetector 4a is driven in the Y direction by the address section A of the car 1 to seek a desired track.
and T6 scans. In addition, the images of the uppermost portion A1 and the lowermost portion A24 of the corresponding card address area are detected using Di and D24 of the plurality of light receiving elements arranged in an array (
As mentioned above, bits are always formed in the address areas Al and A24 of each track), so that the photodetector 4
This means that a is set at the correct position on each track. Next, information such as the track address number is read by the light receiving element arrays D2 to D23. If the read address number is the desired number, the process moves on to reading the information in the data section B, but if it is not the desired number, the photodetector 4a is further scanned in the Y direction with the address section A, and the next track is read. seek.

Now the area B' (1, 1), B' (
1, 2).

It is assumed that the information recorded in the first column consisting of B' (1, 3), . . ., B' (1, 24) is taken once. For this purpose, each of the areas B' (1, 1), B', (
1,2), B'(1,3)...B'(1
, 24), respectively, to accurately correspond to each area.
■If the difference between the output values of T1 and T9 is detected by a differential amplifier (not shown), the X direction of the photodetector 4a will be The direction and amount of deviation can be detected. The photodetector 4a is driven in the X direction by electromagnetic driving means (not shown) so that the difference between the output values is below a certain voltage. When the output difference between the light receiving elements TI and T3 becomes below a certain voltage, a clock signal is generated and the setting to the proper position t in the X direction is completed. On the other hand, the direction and amount of deviation in the Y direction can be detected from the difference between the output values of the light receiving elements T5 and T6, and the appropriate position can be controlled using this output value by driving the photodetector 4a in the same manner as above. . With this operation, X and Y of the photodetector 4a
Directional position control is completed.

After that, the read light receiving element DI-024 sequentially or simultaneously detects the presence or absence of data bits in data section B, and areas B (1, 1), B (1, 2), B (1, 3), etc.
...B Complete reading of the first column of information consisting of (1, 24).

Area B (2,1), B (2,2),...
- Move the photodetector 4a in the X direction to read the information in the second column of B (2, 24). The detection of the clock generation signal uses the difference between the output values of the light receiving elements T2 and T4, and when the detected value is below a certain voltage, the clock generation signal is generated and reading of data is started. Area B (
3,l) ,B (3,2) ,・----B (3
, 24) (7) The x-direction tracking detection in the third row uses the light receiving elements T1 and T3 again. By alternately using these two sets of light receiving elements, clock detection in the X direction becomes possible, and the light receiving elements T5. By using T6, tracking error detection in the Y direction becomes circular.

Next, an embodiment in which the reading detection optical system shown in FIG. 1 is used to read data on a laser card recorded in a format different from that shown in FIG. 2 will be described with reference to FIG. 4.5. As shown in FIG. 4, the format for this one track consists of an address section E, a data section F, and a tracking section G, similar to the laser card described above. Compared to the format shown in Fig. 2, the data pitch in the X and Y directions of the address section and data section is doubled, and when tracking is completed, each area B' ( 1,1).

The difference is that the data section F is arranged such that the odd-numbered light receiving elements Di, D3, . The arrangement of the light receiving element of the photodetector 4a does not change, and the arrangement of the tracking section on the laser disk also does not change.

Next, a reading operation according to the format will be explained.

As described above, the image of the data portion A, etc. on the photodetector 4a is multiplied by the objective lens 3, resulting in the diagram shown by the broken line in FIG.

In this format, only the light receiving elements T1 and T3 are used to detect the clock generation signal in the X direction, and the light receiving elements T2... T4 is not used, and as described above, the photodetector 4a is adjusted so that the difference in output value between the light receiving elements T1 and T3 is below a certain voltage, and the light receiving elements T5. Position 211Q in the Y direction due to T6
Make adjustments.

After completing the tracking control in the X and Y directions using the method described above, the first column B' (1, 1) is imaged.

B'(1,2)...B' (1,12)
At the center of each area are odd-numbered light receiving elements, namely Di, D3.
. . . When reading data with D23 alone, only the odd-numbered light receiving elements D1, D3, . . . are used. In this case, the beat/beat for tracking is in the X direction and in the Y direction.
It is necessary to shift by 1/2D in both directions. Moreover, the light receiving element D
When using odd numbered light receiving elements D13 to D24 and even numbered light receiving elements D13 to D24, the tracking bit needs to be shifted by 1/2D only in the X direction. However, in this case, they are symmetrical in the Y direction.

Next, the next column, the second column, area B' (2,1)
.

B'(2,2)...B' (2,12)
In order to read the light detection element T1 and T3 until the output value becomes zero or a certain voltage or less,
move in the direction.

Hereinafter, a method for reading laser cards of two different formats using the photodetector 4a having the same configuration has been described. This reader may not be able to perform tracking in the Y direction.For example, in the third column [I area B'
(3,1), B' (3,2)...? 12
'#) ') A) e-buggy
Although T5 and T6 are separated from the tracking section C2, there is no problem because tracking control in the Y direction is performed intermittently.

Note that various shapes other than those described above are conceivable for the format of the bits CI, C2, . . . of the tracking section and the configuration of the tracking section for detecting tracking in the X and Y directions. For example, FIG. 6 shows an example of another shape. Photodetector TI, T
2 is for generating a clock in the X direction, a light receiving element T3 and T4 are a tracking detector in the Y direction.

Next, a dual-purpose head that can perform both data writing and reading functions will be described.

A semiconductor laser 7 for data writing shown in FIG. 7 is fixed at one end to the frame 5 and to the other end of two sliding leaf springs 6 whose plate surfaces are arranged in rows on the paper. Therefore, laser 7
can be moved perpendicular to the page. An enlarged ZZ' cross-sectional view of such a configuration is shown in FIG.

A pobbin 14 in which a spiral coil 15 connects two leaf springs
wrapped around. On the other hand, a cylindrical magnet 16 whose one end is fixed to the frame 5 is disposed in the pobbin 14 with a gap therebetween. Such coil 1
When the coil 4 is energized, the coil 15 is driven together with the laser 7 in the direction W in FIG. 8 by the action of the magnetic field from the magnet 16.

In FIG. 7, a beam emitted from a laser 7 is reflected by a half mirror 8 and focused onto a laser card 10 by an objective lens 9. On the other hand, a light beam emitted from a light source 11 such as a reading LED is converged onto a laser card 10 by an objective lens 12. The area of the laser card irradiated by the light beam emitted from the light source 11 is imaged on the photodetector 13 by the objective lens. FIG. 9 is an enlarged view of the photodetector 13 viewed from the direction of the objective lens 9. FIG. Two light receiving elements 18 and 19 for focusing detection are arranged with a large number of linearly arranged light receiving elements 17 for data reading (the arrangement is the same as in FIG. 3). A circle Q is an irradiation area by the laser 7.

Next, the writing and reading operations of the above head will be explained. The laser 7 is turned on based on the data signal to be written.
At the same time as turning N and OFF, a current is applied to the coil 15 to cause the laser 7 to scan in the W direction, thereby forming bits of predetermined information on the laser card 10 in a direction perpendicular to the paper surface.

When reading this written pit information, a light source 1 is placed on the area of the pit information to be read using the objective lens 12.
A single beam of light is condensed and imaged by an objective lens 9 on a photodetector 17 for reading.

Next, the focusing detection driving operation of the detection head will be explained. The position of the laser card 10 in FIG. 10(A) is assumed to be ma when in focus and c when out of focus. 10th
(a) and (b) show the image formation properties of the light beam on the photodetector 13 in correspondence with the diagram (B).

It is shown in (C). No. 1011 (The position (a) of the B-door loser card 10 is the in-focus position. When the card is in the in-focus position, the reflected light beam from the card 10 is detected by the detector 18, 19.
The optical path toward the target is shown by a solid line. At this time, the photodetector 18
The amounts of irradiated light at and 19 become zero when the difference in output between photodetectors 18 and 19 is detected by a differential amplifier. On the other hand, laser card 1
0 is displaced northward, the reflected light beam becomes a light beam indicated by a two-dot chain line, and the output of the photodetector 18 becomes larger as shown in FIG. 1O (B) (b). Conversely, when the laser card 10 is displaced downward as indicated by position mc, the reflected light beam becomes a light beam indicated by a broken line, and the output of the photodetector 19 increases as shown in FIGS. 10(B) and 10(c). In this way, the photodetector 1
The displacement direction and amount of shake of the card 10 can be detected from the difference between the outputs 8 and 19, and focusing drive control can be performed by driving the frame 5 based on this detection signal. In the non-example, driving was performed by a laser light source, but similar focusing can be achieved by driving the laser card 10 to move up and down instead.

Next, other embodiments regarding laser beam scanning will be described below.

In FIG. 11, a laser 7 is fixed to a frame 5, and a laser 20 is supported by an elastic support 6 and vibrated. The parallel light beam exiting the collimator lens 20 is converged by the objective lens 9.

Other configurations are the same as in FIG. 7. In this configuration, although the collimator lens 20 is not shown, the coil 15 is a driving means similar to that shown in FIG. The writing beam is scanned on the card 10 by driving the writing beam in a direction perpendicular to the plane of the paper by an electromagnetic driving means consisting of a combination of two magnets 16.

Furthermore, as a laser scanning mechanism, as shown in FIG. 12, the rotary mirror 21 can be slightly rotated in the Y direction by a piezoelectric element 22. In addition to the mirror drive configuration using piezoelectric elements,
As shown in FIG. 13, the mirror 21 is simply fixed to the other end of the piezoelectric element 22 fixed to the frame 5, or as shown in FIG.
It is also possible to make small rotations around the center.

Especially according to the method of stacking the voltage elements 23.

If the displacement of one piezoelectric element is made to correspond to one pitch of data bits, operation control for each pitch becomes very easy.

On the other hand, move the optical card in the X direction as shown in Figure 15,
In the case of a mechanism that scans the laser beam in the Y direction, the recording trajectory is a trajectory slightly inclined to the Y direction, that is, the recording trajectory 51 in FIG. 15. In this case, the structure of the drive mirror is such that the half mirror 21 and the piezoelectric element 22 are integrated, and the fixed axis of the piezoelectric element 22 coincides with the X direction. When the piezoelectric element 22 is driven, a half mirror? (2) is driven in the direction of arrow N.

Next, an improved mechanism for aligning the recording trajectory 51 in the Y direction will be described below.

The difference from the configuration described in L is that the fixed axis is tilted by θ. Therefore, the half mirror 21 and the piezoelectric element 22 are located at the positions indicated by the solid line instead of the broken line. When the mirror 21 is driven with this configuration, the trajectory of the laser beam becomes 52, and as a result, the trajectory of the recording beam becomes a recording trajectory 53 that coincides with the Y-axis direction.

At this time, the magnitude of the inclination angle 0 of the fixed axis is determined in relation to the moving speed of the card.

Further, FIG. 16 shows an attempt to achieve the same purpose by tilting the rotating shaft 54 of the rotating mirror 21. FIG. 17 shows a modification of FIG. 7, and FIG. 18 is a view seen from the Y direction in FIG. It is. In this case as well, by tilting the axis of the mirror, the recording locus can be set in the Y direction as described above.

[Effects of the Invention] As described above, according to the present invention, in the data reading method of an optical card, the light receiving element to be used is selected according to the data bit pitch of the optical card. This has the effect that data can be easily read using the same reading device.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of an arrangement of light receiving elements suitable for the data reading method according to the present invention, and FIG. 2 is a diagram showing the principle of reading a data format that can be read by the method according to the present invention using the method according to the present invention. FIG. 4 is a diagram illustrating another example of a data format that can be read by the method according to the present invention, and FIGS. 5 and 6 are diagrams illustrating the data format shown in FIG. 7 is a diagram illustrating an example of a head section of a data recording/reproducing device for an optical card suitable for carrying out the reading method according to the present invention, and FIG. FIG. 9 is an enlarged view of the photodetector shown in FIG. 7, and FIGS. 10 (A) and (B) are a focus adjusting section in the head shown in FIG. 7. Principle diagrams, Figures 11 to 16
The figures show various embodiments of a head section of an optical card data recording/reproducing device suitable for carrying out the method according to the invention;
FIGS. 17 and 18 are diagrams showing other embodiments for recording and reproducing data on an optical card. 1... Laser diode 2... Prism 4... Photodetector 4a, 4b, 4cm... Photodetector 5... Lens frame 6... Leaf spring 7... Writing laser 8 ... Half mirror 9 ... Objective lens 10 ... Optical card 11 ... Laser diode 12 ... Objective lens 13 ... Photodetector 14 ... Bobbin 15 ... Coil 16 ... Permanent magnets 17 to 19... Photodetector 20... Lens 21... Half mirror 22, 23... Piezoelectric elements D1 to D24... Light receiving elements T1 to T6... Light receiving element A... Address section B...Data section C...Tracking jig section E...Address section F...Data section Q...Irradiation area 3, objective lens 4, detector Fig. 4B (1.72 ) and Go ('172) Figure 5 Figure 6 Figure 7 77 7zo Figure 8 Σ Sunhaku's faction - Itoda l! 7 mountains 〒[three L! 7 Clmii
Issued) July 1986 2++ 1, Showa 1986 Patent Application No. 122892 2, Name of the invention: Method for reading data from optical cart 3, Name of the user interface 1F. Related Patent applicant address: 2-chome Hatagaya, Shibuya-ku, Tokyo] 143-2 Yumina
(037) Representative of Olympus Optical Co., Ltd.
Toshibe Shimoyama 4, agent details, column I: “Detailed description of the invention” and page 14 7
, Contents of amendment (1) From page 4, line 12 of the specification to the same page: fSl
``This is an enlarged partial view of 1 trunk,'' written up to the 3rd line. Add the description in 1 after J. ``The width of this 1 trunk in the Y direction is approximately 100 gm.'' (2rnAfB, page 7, line 11, 1-1, put 1 in card 10 (the size of card 10 is drawn as a scaled-down version of the drawing). (3) l!IF details, page 7, line 12 “rK described in 1.
"Polarized by the eer effect" is deleted. (4) Specification, 1; "Focus adjustment" described in page 8, first line +1 is corrected to "focus detection".・ Four Mr.! i Draw ``Naruto Akrotsu'' written on page 11, line 6, 11 as ``Naruto Clock''.・Page 13 of the specification, line 3, line 11 to page 4 However, the position of the data part consisting of area B (1, 1). B (1, 2)... is opposite to the direction and Y
Both are shifted in parallel by d/2 in the opposite direction. ” he corrected. C7) Correct "IJI Detailed Work, Page 16, No. 12" to "Objective Lens 9". (8) Delete "Although the collimator lens 20 is not shown" written from line 4 on page 19 of the specification to line L1 on line 5 of the same page. (9) "Small in the ■ direction" described in page 19, line 11 +1 of the specification is corrected to "slight in the V direction with the rotation axis 24 as the center of rotation." (10) Figures 2 (a), (b), Figures 3 and 4. Figures 5, 6, 10 (B), and 12 are corrected as shown in the attached sheet. 8. Inventory of attached category 3 (1) Drawings 1 copy Figure 4 B (7.12) B (5!-72/ Figure 5)

Claims (1)

[Claims] In a data reading method for reading information recorded on a recording medium, at least two or more different recorded data recorded at different pitch intervals are read by switching a light receiving element incorporated in one photodetector. A method for reading data from an optical card.