JPH10261227A - Optical information reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reproduce information while performing AT control for each track by moving a light spot between a tracking track and an information track during relative reciprocating movements in an optical card difference in width between the tracking track and the information track. SOLUTION: When a pulse motor 91 is rotated, a rotary encoder 90 is also rotated, and its rotating amount is measured by a detected signal waveform. The rotating command of a specified amount is given to the pulse motor by the MPU light spot moving command of an MPU and, following the rotation of the pulse motor, an optical card loading base 93 is moved vertically to a tracking track via a connecting section 92. Thus, a light spot is moved by a specified amount between the tracking track and an information track. During this movement, AT control is switched from closed control to open control and, after the movement of a specified amount, the AT control is switched again to the closed control and then the AT control is continued.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information reproducing apparatus for reproducing information recorded on an optical information recording medium.

[0002]

2. Description of the Related Art Hitherto, various types of recording media for optically reproducing recorded information, such as discs, cards, and tapes, are known. In order to obtain information from these information recording media, a light beam of a constant power is focused at such an intensity that recording is not performed on the recording medium, irradiated as a minute spot onto the information pit array, and scanned. Thus, the reflected light or transmitted light from the recording medium is detected, and the recorded information is reproduced based on the obtained detection signal.

[0003] Such an optical head used for reproducing information from a recording medium is relatively positioned with respect to the recording medium in an information track direction composed of information pits in the information area and in a direction crossing the information track. The light spot is accessed to a desired information track by the relative movement in both directions, and the information track is scanned.

[0004] The optical head is provided with a focusing lens for focusing the light beam and narrowing it down to a minute light spot of a fixed size. In particular, an objective lens is used as this lens. The objective lens is held by the optical head so that it can move independently in the optical axis direction (focus direction) and in the direction perpendicular to the information track of the recording medium (tracking direction). Such holding of the objective lens is generally performed via an elastic member, and movement of the objective lens in the focusing and tracking directions is generally realized by driving an actuator using magnetic interaction. is there.

FIG. 25 is a schematic plan view of a write-once optical card. A large number of information tracks 2 and tracking tracks 4 are arranged on the information recording surface of the optical card so as to be alternately arranged. Also, the optical card is provided with a home position 3 which is a reference position for accessing the information track 2. Then, the information track 2 is 2-1 2-2, 2-
3,... Are arranged in this order. As shown in FIG. 25, tracking tracks are arranged in the order of 4-1, 4-2, 4-3,... Adjacent to each of the information tracks 2. These tracking tracks are used as guides for auto tracking (hereinafter abbreviated as AT control) for controlling the light spot so as not to deviate from the target information track at the time of light spot scanning during reproduction of recorded information. .

[0006] Such AT control is performed by a servo control circuit. Here, a deviation (AT error) of a light spot from an information track is detected by an optical head, and this detected information is used as an object information. Feedback is provided to a tracking actuator that drives the lens in the tracking direction. That is, by moving the objective lens with respect to the optical head body in the tracking direction (D direction) of the recording medium, control is performed so that the light spot does not deviate from the target information track.

[0007] Further, at the time of information reproduction, when an information track is scanned by a light spot, a light beam is irradiated (focused) so as to form a small spot of an appropriate size on the recording surface of the optical card. For the objective lens,
Auto focus (hereinafter, abbreviated as AF control) is performed. In such AF control, a deviation (AF error) of a light spot from a focused state is detected in an optical head, and this detection signal is fed back to a focus actuator that moves an objective lens along an optical axis direction. Thus, the objective lens can be moved in the focus direction with respect to the optical head body, and as a result, control is performed so that the light spot is focused on the recording layer of the optical card.

FIG. 26 shows light spots S1, S2 and S3 irradiated on the optical card 1. Among them, AT control is performed by using the light spots S2 and S3 that partially cover the tracking tracks 4-2 and 4-3. Also, AF control and reading of information pits are performed using the light spot S1. In the figure, 5
-1 to 5-3 are information pit strings, and 6-1 to 6-3 are track numbers (addresses) arranged on both sides of the information pit strings 5-1 to 5-3, respectively. Each information track is provided with a track number indicating which track the position is.

As shown in the figure, the width of the information track 2 which is an information area is wider than the width of the tracking track 4, and according to the standard, the width of the tracking track 2 is about 3 μm.
m, the width of the information track 4 is 9 μm, and the width of the information pit is about 3 μm. The diameter of the light spot is not specified in the standard, but is related to AT and reproduction signal characteristics.
It is about 3 μm, which is almost the same as each track width.

FIG. 27 is a schematic diagram showing an example of an optical information reproducing apparatus using an optical card as an information recording medium. Here, reference numeral 10 denotes a semiconductor laser which is a light source. 11 is a collimator lens, 12
Denotes a beam shaping prism, 13 denotes a diffraction grating, and 14 denotes a polarization beam splitter. Further, 15 is a quarter-wave plate, 1
6 is an objective lens, 17 is a spherical lens, 18 is a cylindrical lens, and 19 is a photodetector. The light detector 19 is
As shown in FIG. 27, the light receiving element 19-
1, 19-2, 19-3, and 19-4, and two light receiving elements 19-5 and 19-6.

The light beam emitted from the semiconductor laser 10 is
A divergent light beam enters the collimator lens 11, is collimated by the collimator lens 11, is converted by the beam shaping prism 12 into a substantially circular beam cross section, and is incident on the diffraction grating 13. I do. The diffraction grating 13 is split into three effective light beams (0-order diffracted light and two ± 1st-order diffracted lights).

The three split light beams enter the polarization beam splitter 14 as P-polarized light beams, pass through the same, and are converted into circularly polarized light when passing through the quarter-wave plate 15. . The three light beams converted into the circularly polarized light are converged on the optical card 1 by the objective lens 16, and at this time, are narrowed to the shape of a minute light spot. This converged light forms a small light spot S2 (+1
Order diffraction light), S1 (0th order diffraction light), S3 (-1st order diffraction)
It is. As described above, the light spot S1 is used for reproduction and AF.
The light spots S2 and S3 are used for AT control.

The position of the spot on the optical card 1 is
As shown in FIG. 26, the light spots S2 and S3
Are located on two adjacent tracking tracks, and the spot S1 is located on the information track 2 which is an information area between the tracking tracks. The degree of the light spots S2 and S3 on the tracking track is as follows.
It is controlled by rotating the diffraction grating 13 about the optical axis, and the rotation is finely adjusted so that desired AT control can be performed.

In this manner, the optical card 1 is irradiated with the light spot, and a part of the light spot is reflected on the optical card surface and enters the objective lens 16. This reflected light is again transmitted to the objective lens 16.
, Is converted into a light beam whose polarization direction has been displaced by 90 degrees in the direction of rotation as compared with that at the time of incidence. Then, the light enters the polarization beam splitter 14 as an S-polarized beam, and is reflected by the detection optical system side and separated from the light beam from the semiconductor laser 10 due to its characteristics.

The detection optical system includes a spherical lens 17, a cylindrical lens 18, and a photodetector 19. The combination of the spherical lens 17 and the cylindrical lens 18 performs AF control by an astigmatism method. The three light beams reflected from the optical card 1 are detected by a photodetector 19 composed of a plurality of light receiving elements.

FIG. 28 is a circuit diagram showing a signal processing circuit of the above optical information reproducing apparatus. In FIG.
Reference numeral 9 denotes the photodetector shown in FIG. 27, which is composed of the light receiving elements 19-5 and 19-6 and the four divided light receiving elements 19-1 to 19-4, as described above. Light spots S1, S2, S on the light receiving surface of the optical card of each light receiving element
3, the reflected light from the optical card is shown. That is, the AT control light spots S2 and S3 are received by the light receiving elements 19-5 and 19-6, respectively.
The light spot S1 for F control and reproduction is received by the four-divided light receiving elements 19-1 to 19-4.

The output signals of the light receiving elements 19-5 and 19-6 are output to a subtraction circuit 122, and the subtraction circuit 122 detects the difference therebetween to generate an AT control signal. The output signals of the four-divided light receiving elements 19-2 and 19-4 are added to the adder circuit 111 by the adder circuit 111.
The outputs of 1 and 19-3 are added by an adding circuit 112, respectively. The output signals of the adding circuits 111 and 112 are subtracted by a subtracting circuit 121, and the difference between them is output as an AF control signal. Also, the adders 111 and 11
The outputs of 2 are further added by an adding circuit 113, whereby a sum signal of the four-divided light receiving elements is created and output as an information reproduction signal RF.

FIG. 29 is a diagram showing a moving range of a moving body (for example, an optical card or an optical head) and a moving speed at that time when each light spot is relatively moved with respect to the optical card 1. Since the moving body reciprocates, a stop / reverse position always occurs. Further, information needs to be reproduced at a constant interval or length, and therefore, the moving speed in the vicinity of the information reproduction area must be constant. In addition, of course, in order to reach the target speed from the stop / reverse position, or to stop /
In order to invert, there is always an acceleration / deceleration area in the figure.

Although the conventional example in which the information medium is an optical card has been described above, another conventional example is the case where the information medium is an optical disk. This case will be described below. FIG. 30 shows the relationship between one light spot S5 on the optical disk surface and the information tracks 3'-1, 3'-2. FIG. 31 is a sectional view taken along a broken line E in FIG. As shown in FIG. 31, the optical disc comprises a concave portion 3 'and a convex portion 8, and the width of the concave portion 3'
The widths of the parts are almost the same (1.5 to 1.6 μm). The concave portion 3 ′ is an information track having information pits, and has a diameter such that the light spot slightly overlaps the convex portion 8. In the AT / AF method often used in this case, the AT is a one-beam push-pull method, and the AF is an astigmatism method. Both methods are too well-known techniques, and a description thereof will be omitted.

FIG. 32 shows the relationship between one light spot S 6 on the disk surface of the same light and the information track 9. The difference from the above-mentioned optical disc is that there is no uneven portion for performing the AT control. In this case, AT control is performed using continuously existing information pits as guide tracks. Incidentally, the AT control is a one-beam push-pull system.

[0021]

However, the above-mentioned conventional optical information reproducing apparatus has the following problems.

First, in the above-mentioned conventional example shown in the reproduction of an optical card, a diffraction grating is required to generate three light spots. Therefore, a fine adjustment mechanism is required to align the space between the diffraction grating and the diffraction grating in the optical head, which not only hinders miniaturization and weight reduction of the optical head, but also this diffraction grating and the fine adjustment mechanism. This causes an increase in assembly time and man-hours.

In the photodetector, two light receiving surfaces for AT are required in addition to the four-divided light receiving element. Since the interval between the three light beams incident on the photodetector is constant, the interval between the respective light receiving surfaces needs to be constant in accordance therewith, which complicates the management of the manufacturing apparatus in manufacturing.

On the other hand, in the conventional example shown by an optical disk, there is one light spot, and the above-mentioned problem is eliminated. However, according to the conventional technique, it is not possible to reproduce information of an optical card by using a single optical head (hereinafter, referred to as a one-beam optical head) as it is with a light spot frequently used on an optical disk. This is because the width of the information area is about three times the width of the tracking track of the optical card, and information cannot be reproduced while performing AT control using the tracking track.

The optical card reproduces information by a relative reciprocating movement. In this movement, an acceleration / deceleration area always exists. Therefore, in an area where the speed is not constant, such as the acceleration / deceleration area, It is very difficult to generate information stably, and therefore, generally, information pits are not arranged in such an acceleration / deceleration area. for that reason,
One beam PP · A using only information pits shown in the conventional example
T control cannot be performed.

In an information track having no information pits in an acceleration / deceleration area of several mm, a conventional one-beam PP
Even if the AT control is performed, the signal level does not change until the light spot is applied to the adjacent tracking track, so that the position of the light spot cannot be strictly guaranteed during the light beam irradiation process.

The present invention has been made in order to solve the above-mentioned conventional problems, and an object of the present invention is to relatively move a light spot such as an optical card and an information medium back and forth so as to reciprocate information. When playing back the information medium,
An object of the present invention is to provide an optical information reproducing apparatus that can perform stable AT control and information reproduction using a one-beam optical head.

[0028]

According to the present invention, there is provided an information recording medium comprising a plurality of tracking tracks and a plurality of information areas interposed between the tracking tracks. A light beam from a light source is converged by an objective lens and irradiated as a single light spot on the surface of the information recording medium, and the information recording medium and the light spot are moved in the tracking track direction while performing auto tracking control. Relative reciprocating movement, the optical spot scans an information track composed of information pits in the information area by the light spot and reproduces recorded information. And a transition means for transitioning the light spot between the tracking track and the information track. And wherein the Rukoto.

The optical card and the light spot are relatively reciprocated in the track direction while performing auto-tracking control, and during the reciprocal movement, the light spot is moved to the information track composed of the tracking track and the information pits in the information area. By using the transition means for transitioning between and, the information track is scanned with the shifted light spot,
In an optical information reproducing apparatus that reproduces recorded information, the amount of movement of a light spot on an optical card is equivalent to the amount of movement of an objective lens. Thus, the objective lens can be moved in a direction orthogonal to the tracking track.

The amount of movement of the objective lens is determined from the reference position of the objective lens, for example, the amount of displacement from its neutral position, based on the output of a position detector as optical means comprising a light source and a sensor. It is also possible. The performance of the position detector using such optical means enables measurement in sub-micron units, and there is no problem in use as the performance for measuring the amount of movement of the objective lens.

As described above, in the optical information reproducing apparatus capable of measuring the moving amount of the objective lens using the position detector,
It is very effective to use the output value of the position detector to control the light spot transition means. That is, by the transfer command for the light spot, the auto tracking control is switched from the closed control to the open control, and in order to move the objective lens by a predetermined amount, the current is injected into the auto tracking actuator in the open control state, The movement of the objective lens is performed.

At this time, whether or not the objective lens has moved by a predetermined amount is monitored by the output of the position detector, and when it is confirmed that the objective lens has moved by a predetermined amount, the control is switched again to the closed control,
By pulling in the control, the movement of the objective lens, that is,
The transfer of the light spot can be completed. Thereby, it is possible to reproduce information while performing AT control with one light spot.

Further, the optical card and the light spot are relatively reciprocated in the track direction while performing the auto tracking control, and the light spot is moved between the tracking track and the information pit in the information area during the relative reciprocation. In an optical information reproducing apparatus which is provided with a transition means for transitioning to an information track consisting of: scanning the information track with a light spot shifted thereby to reproduce recorded information, If the tracking track in the case of the light spot transition from the information track to the information track is the same as the tracking track in the case of the light spot transition from the information track to the tracking track, the adjacent information track will be reproduced continuously. Then, near the stop / reversal position, the adjacent tracking track On which to shift the light spot on,
The light spot must be scanned. Therefore, the access time becomes longer.

In such a system, the tracking track in the case of the light spot transition from the tracking track to the information track and the tracking track in the case of the light spot transition from the information track to the tracking track are mutually separated. Differently, each of the transitions reduces the access time in the information reproduction when a plurality of information tracks are continuously reproduced, except for the necessity of the transition of the light spot from a tracking track to an adjacent tracking track. It is very effective in terms of. As a result, the speed of information reproduction can be increased while performing AT control with one light spot.

Further, in the present invention, in an apparatus for reproducing information by reciprocating an optical card and a light spot relatively, an information pit row in an information track is not always continuous. That is, it is also possible to manage information in units of information pits, that is, sectors, according to the purpose of use. When such sector management is performed, a method of managing a difference between sectors, for example, a physical address is usually employed. Here, information for managing a physical address of a sector in which information exists is provided in an optical card. Thus, by reproducing the management information in advance at the time of reproducing the information, it is possible to manage which address sector has the information.

In such an apparatus, one beam PP
In a sector portion having no information pits in which AT control is difficult, a light spot bearing an information signal is shifted to a tracking track based on sector management, and accurate and stable one-beam PP / AT control is performed in the tracking track. It is possible.

Further, for example, in a system using a linear motor as the moving means of the optical card, the error of the moving speed can be controlled accurately so as not to cause a problem in use. Therefore, the light spot is shifted from the information track to the tracking track. After that, when shifting from the tracking track to the sector having the information pits in order to reproduce the information again, the movement time obtained from the movement speed of the optical card and the sector width is added to the timing of the light spot transfer instruction. Even if you use
It is valid.

According to the above, the light spot is shifted between the information track and the tracking track in the information track according to the management information for managing the information pit group (sector) in the information track area. Even when there is no information pit in the information track, it is possible to reproduce information while performing stable one-beam PP • AT.

[0039]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) Hereinafter, an embodiment of the present invention will be described with reference to FIG.
17 will be described with reference to FIG. FIG. 1 is a configuration diagram showing a first embodiment of the optical information reproducing apparatus of the present invention.
In FIG. 1, the same parts as those of the conventional apparatus of FIGS. 25 to 32 are denoted by the same reference numerals. That is, the semiconductor laser 10,
The collimator lens 11, the beam shaping prism 12, the polarization beam splitter 14, the quarter-wave plate 15, the objective lens 16, the spherical lens 17, and the cylindrical lens 18
Both are the same as those described in the related art.

The photodetector 20, as shown in FIG. 2, is a quadrant photodetector composed of four light receiving surfaces 20-1 to 20-4. Reference symbol S0 denotes a light spot for reproduction and AT / AF control on the optical card 1, which is a photodetector 20.
It is also an upward projection image. Further, FIG. 2 shows a signal processing circuit for generating a reproduction signal and each of the AT and AF control signals based on each signal from the photodetector 20, where reference numerals 114 to 118 denote addition circuits. , 123 and 124
Is a subtraction circuit.

The AT method of the present invention is a one-beam push-pull (hereinafter, referred to as one-beam PP), and the AF method is
The astigmatism method is used as in the conventional example. In the figure,
x 'and y' indicate the moving direction of the light spot S0 on the optical card 1, x 'is the relative reciprocating direction (tracking track direction) between the light spot S0 and the optical card 1, and y' is Indicates the direction perpendicular to the tracking track direction. Note that the AF control signal generation circuit is the same as that of the conventional example, and a description thereof will be omitted.

The AT control signal generation circuit will now be described. Here, of the four light receiving surfaces, signals from each of the two light receiving surfaces divided into two in the tracking track direction x 'are added to adders 114 and 117, respectively. , And subtraction of the signals of the addition circuits 114 and 117 from each other is performed by a subtraction circuit 123.
The light spot S0 on the optical card 1 is moved in the direction y 'perpendicular to the tracking track so that the output of the subtraction circuit 123 always becomes 0. The movement of the light spot S0 is achieved by moving the objective lens 16 in a direction y 'perpendicular to the tracking track.

The optical element shown in FIG. 1 is integrated as an optical head and irradiates an optical card as an information recording medium with one light spot. In the figure, reference numeral 70 denotes a linear encoder, and 71 denotes a speed detector. The optical card 1
It is mounted on a carriage (not shown), and the carriage is moved by a moving mechanism such as a linear motor (not shown).
By reciprocating in the information track direction, the optical head is reciprocated relative to the information track direction. As described above, information is reproduced by reciprocally scanning the spot of light from the optical head on the information track.

This device is provided with a linear encoder 70 for detecting the moving speed of the optical card 1 and a speed detector 71. The linear encoder 70 is shown in FIG.
As shown in the figure, the window portions 80 are formed at intervals of the same pitch P along the scanning direction of the optical card 1,
A material exhibiting a light shielding property is used for portions other than the window portion 80.

As shown in FIG. 4, the speed detector 71 comprises a pair of light sources 72 provided so as to sandwich the linear encoder 70, and an optical sensor 73 for receiving light from the light source 72. The optical card 1 is fixed to the carriage on which the optical card 1 is placed, and moves relatively to the linear encoder 70 with the movement of the carriage. At this time,
The light from the light source 72 of the speed detector 71 passes through the window 80,
Since light is shielded at other locations, the light receiving signal of the optical sensor has a sine waveform.

The light receiving signal of the optical sensor 73 is binarized by an MPU (not shown) and converted into a periodic signal of 1 and 0. The MPU detects the moving speed V of the optical card 1 from the obtained cycle T of the binarized signal and the pitch P of the window 80 of the linear encoder 70. That is, the moving speed V of the optical card 1 is obtained by an equation of V = P / T.

FIG. 5 shows an encoder pulse signal obtained by binarizing the output signal of the speed detector 71, the moving speed of the optical card 1,
FIG. 4 is a diagram showing a relative relationship between reproduction zone signals for instructing start and end of information reproduction from the MPU. As is clear from the figure, when the optical card 1 is moved in the L direction, it accelerates linearly from the stop / reverse position A. The cycle of the encoder pulse signal in this acceleration region gradually decreases. The MPU monitors the moving speed of the optical card, and when the moving speed reaches a preset target speed v, performs speed control so as to maintain the moving speed at a constant speed.

For this speed control, a system is employed in which feedback control is performed so that the moving speed becomes the target speed based on the difference between the moving speed by the speed detector 71 and the target speed v. Thus, in the constant speed region, the cycle of the encoder pulse signal is constant. When the optical card 1 stops and starts accelerating from the reversing position A, and after a predetermined time has elapsed, the MPU applies a brake to the movement of the optical card 1 to decelerate. The outward movement of the card 1 is completed. Further, in the deceleration region, the period of the encoder palace signal gradually increases.
When the optical card 1 is moved in the F direction, control of acceleration, constant speed, and deceleration is performed in the same manner as described above.

Next, the relationship between the acceleration / deceleration / constant speed area, the data area, and the non-data area in FIG. 5 will be described. The moving speed of the optical card 1 needs to be reliably maintained at a constant speed in order to perform stable information reproduction in the data area. For this purpose, a speed switching position between the acceleration / deceleration region and the constant speed region is arranged outside the data region so that the constant speed region completely includes the data region. As a result, when the light spot is located in the data area of the optical card 1, the moving speed of the optical card 1 becomes constant.

The data area and the non-data area shown in the figure are executed by a reproduction zone opening / closing command from the MPU. Generally, an optical card has a risk that dust or the like may be mixed into a recording medium portion during its manufacture, and that the surface of the optical card may be scratched later. There is a risk of misidentification.

As a countermeasure, in order to eliminate the influence of dust and scratches other than the track number portion and the information portion of the optical card, a reproduction zone (open state) is provided in the track number portion and the information portion to be reproduced. In other places, a masking (closed state) method is adopted. That is, even if there is a dimensional error at the time of manufacturing the optical card 1, an expansion / contraction error due to a change in the environment of the optical card, or an error in the moving speed of the optical card 1, the opening / closing position of the reproduction zone is not within the track number portion or the information portion. After calculating the respective error factors, the reproduction zone is opened / closed with some margin on both outer sides of the track number portion or the information portion so as not to cause the above.

In a device for reproducing information based on such relative movement between an optical card and a light spot, a means and a method for shifting a light spot during relative movement, which is a main technique of the present invention, will be described below. Will be described.

FIG. 6 is a diagram showing the transition of the light spot S0 from the tracking track to the information track.
Here, reference numerals 2-1 to 2-3 represent information tracks, and 4-1 to 4-1.
4-4 is a tracking track, 5-1 to 5-3 are information pit strings, and 6-1 to 6-3 are information pit strings 4 respectively.
Track number portions arranged on both sides of -1 to 4-3.

When the card 1 starts moving with respect to the light spot to reproduce information, the light spot S0 is irradiated on the tracking track 4-3, and the AT control is performed on the tracking track 4-3. Do. Optical card 1
The light spot S0 moves relatively to the optical card 1 with the movement of the optical card 1. As shown in the figure, a predetermined amount of information The process moves to the track 2-2. The light spot S0 relatively moves in the L direction at a constant speed even after the transition, and performs AT control with a pit signal of the track number section 6-2 irradiated immediately after the transition.

When shifting from the tracking track to the information track by a predetermined amount, the AT control is switched from the closed control to the open control by the shift command, and after shifting by the predetermined amount, the AT control is switched again to the closed control. , AT control. Thereafter, after the reproduction of the information is completed, the AT control is performed by the information pit train including the track number portion and the information pit portion until the light spot S0 is shifted to the tracking track again by the command to close the reproduction zone.

FIG. 7 is a diagram showing a state in which the light spot S0 moves from the tracking track 4-3 to the information track 2-2 at the transition point a together with the command to open the reproduction zone. Note that the reproduction zone signal is a binary signal of 1 and 0. Incidentally, when the zone signal is 0, it indicates a closed state, and when the zone signal is 1, it indicates an open state.

FIG. 8 is a diagram showing the transition of the light spot S0 after the information reproduction is completed. Here, the light spot S0 includes the information pit row 5-2 and the track number section 6-
After the reproduction in step 2, the information track 2-2 moves to the tracking track 4-3 together with the reproduction zone closing command at the transition point b. At the time of the transition, the AT control is switched from the closed control to the open control, and after the transition, the AT control is switched again to the closed control to perform the AT control with the tracking track.

Next, the light spot shifting means will be described below. FIG. 9 shows a mechanism for moving the optical card 1 in a direction perpendicular to its tracking track. Here, reference numeral 90 denotes a rotary encoder, 91 denotes a pulse motor, and 92 denotes a rotation axis of the pulse motor 91 and an optical axis. A connection portion of the table on which the card 1 is mounted, 93 is an optical card mounting table, 9
Reference numeral 4 denotes a light source unit of the detection system, and 95 denotes a sensor unit of the detection system.

The rotary encoder 90 has a small light transmission window 96 along the circumferential direction as shown in FIG. 10, and the width of the light transmission window 96 and the width of the light shielding portion between the light transmission windows are determined. Are approximately the same. When the pulse motor 91 rotates, the rotary encoder 90 fixed to the rotation shaft of the pulse motor 91 also rotates, and the amount of rotation is measured from the signal waveform detected by the detection system. The narrower the width of the light transmission window 96 and the width of the light shielding portion, the higher the resolution of the rotation.

In the present invention, a predetermined amount of rotation command is issued to the pulse motor by the light spot transfer command of the MPU. With the rotation of the pulse motor, the optical card mounting table 93 moves in the direction perpendicular to the tracking track via the connection section 92. Accordingly, the light spot moves by a predetermined amount between the tracking track and the information track. In addition, when the light spot shifts from the tracking track to the information track by a predetermined amount, the AT control is switched from the closed control to the open control by the shift instruction of the MPU, and after the shift by the predetermined amount, the AT control is switched again to the closed control. Perform AT control. The shift amount of the light spot at the time of the above-described shift is set in advance. That is, it corresponds to a distance of 6 μm between the center of the tracking track and the center of the information track.

(Second Embodiment) As shown in the first embodiment, in an apparatus for reproducing information by relatively reciprocating an optical card and an optical spot, a linear reciprocating means is used. In a system using a motor, the moving speed of the moving body is constantly controlled by a linear encoder and a speed detector.
Detection and control of the moving speed can be performed. In such a system, the error in the speed of the moving body is so accurate that it does not pose a problem in use, and it is also effective to simply perform the light spot transition timing based on the moving speed.

Therefore, a second embodiment of the optical information reproducing apparatus according to the present invention, which is characterized by this point, will be described below. FIG. 11 is a diagram showing the correlation among the encoder pulse signal, the moving speed of the optical card, and the transition point of the light spot shown in the first embodiment. In FIG.
The moving speed V of the optical card is obtained by the equation V = P / T based on the period T at a position where the encoder pulse signal is present and the pitch P of the window 80 of the linear encoder shown in FIG. The MPU constantly monitors the moving speed of the optical card from the start of the movement, and switches to the constant speed control when the moving speed V reaches the target speed v (transition point a). At time point v, the light spot is shifted from the tracking track to the information track.

That is, in the acceleration region, one-beam PP / AT control is performed on the tracking track, and in the constant speed region, information is reproduced while performing one-beam PP / AT control on the information pit train. After the information reproduction, the MPU outputs a deceleration command (transition point b) from the MPU to stop the optical card. At the same time, the light spot is shifted from the information track to the tracking track. Performs one-beam PP / AT control. The means for shifting between the tracking track and the information track is the same as that in the first embodiment.

As described above, even when the relative movement speed between the optical card and the optical spot is used for the transition timing of the optical spot, the reproduction of information is performed while performing the one-beam PP / AT control on the optical card. It is possible to

(Third Embodiment) As shown in the first embodiment, in an apparatus for reproducing information by relatively reciprocating an optical card and an optical spot, a linear motor is used as a moving means. In the system using the system, since the error of the moving speed can be controlled accurately so as not to cause a problem in use, the error of the distance reached after a predetermined time from the start of the movement does not matter in use. In such a system, it is effective to use the movement time as the timing of the light spot shift command.

A third embodiment of the optical information reproducing apparatus according to the present invention, which is characterized in this point, will be described below. FIG. 12 is a diagram showing the clock signal generated by the MPU at the start of the movement of the optical card, the movement time of the optical card 1, and the transition point of the light spot. FIG.
Assuming that the optical card 1 starts moving in the L direction in 2, the MPU generates a clock signal having a fixed period simultaneously with the start of the movement of the optical card, and keeps counting the clock signal while the optical card 1 is moving.

The MPU commands the shift of the light spot when the counted number N ′ of the counted clock signal reaches the target counted number N. That is, the clock count number N1 from the start of movement (target time T1: transition point a)
The light spot is shifted from the tracking track to the information track by a predetermined amount, and after the information reproduction is completed, the light spot is shifted from the information track to the tracking track when the clock count N2 (target time T2: shift point b) is reached. A predetermined amount is shifted. The time measurement from the clock signal is obtained by the time T = N · t. t is a clock cycle.

The AT control is as follows. That is, from the start of movement to the transition point a, one-beam PP / AT control is performed on the tracking track, and from the transition point a to the transition point b, information is reproduced while performing one-beam PP / AT control on the information pit train. Perform After the information reproduction is completed, one-beam PP / AT control is performed on the tracking track after the transition point b. Note that the means for shifting between the tracking track and the information track is the same as in the first embodiment.

As described above, even when the relative movement time between the optical card and the optical spot is used for the transition timing of the optical spot, information is reproduced while performing one-beam PP / AT control on the optical card. It is possible to

(Fourth Embodiment) As described in the first embodiment, in an apparatus for reproducing information by relatively reciprocating an optical card and a light spot, a reciprocating means is used as a reciprocating means. Using a linear motor, a linear encoder and a speed detector always detect the moving speed of the moving body, and in a system that controls the moving speed, by counting the encoder pulse signal of the linear encoder,
The moving distance of the moving body can be measured within an error range that does not cause a problem in use. In such a system, it is effective to use the moving distance of the moving body for the timing of the light spot transfer command.

Therefore, a fourth embodiment of the optical information reproducing apparatus of the present invention characterized in this point will be described below. FIG. 13 shows an encoder pulse signal obtained from the linear encoder and the speed detector, a moving distance of the optical card,
FIG. 4 is a diagram illustrating a relationship between light spot transition points. Here, the optical card 1 is moved from the stop / reverse position A to L
Assuming that movement has started in the direction, the MPU counts the encoder pulse signal and detects the moving distance of the optical card 1 based on the count value.

Since one cycle of the encoder pulse signal corresponds to the pitch P of the window 80 of the linear encoder 70 as shown in FIG. 3, the moving distance D is equal to the count value N of the encoder pulse signal and the linear encoder 70. Pitch P
From the distance D = N · P.

The MPU instructs the shift of the light spot when the target movement distance is reached. That is, the light spot is shifted by a predetermined amount from the tracking track to the information track by the count value N1 of the encoder pulse signal (target movement distance D1: shift point a) from the start of the movement, and after the information reproduction is completed, the encoder pulse signal is counted. When the value reaches the value N2 (target moving distance D2: transition point b), the light spot is moved from the information track to the tracking track by a predetermined amount.

The AT control is performed at the transition point a from the start of the movement.
Up to this point, one-beam PP / AT control is performed by the tracking track, and from the transition point a to the transition point b, information is reproduced while performing one-beam PP / AT control by the information pit train. After the information reproduction is completed, after the transition point b, 1
Beam PP / AT control is performed. The means for shifting between the tracking track and the information track is the same as in the first embodiment.

As described above, even when the relative movement distance between the optical card and the optical spot is used for the transition timing of the optical spot, information is reproduced while performing one-beam PP / AT control on the optical card. It is possible to

(Fifth Embodiment) As described in the first embodiment, in an apparatus for reproducing information by relatively reciprocating an optical card and a light spot, a single light spot is used. In a system that reproduces information while performing AT control, it is also possible to detect an information pit, for example, a track number part, in a part of the light spot, and shift the light spot at the time of the detection. In such a system, it is effective to use the light spot itself for the timing of the light spot transfer command.

Therefore, a fifth embodiment of the optical information reproducing apparatus of the present invention having this feature will be described below. FIG. 14 is a diagram showing the relationship between the tracking track 4 and the information track 2 of the optical card 1 and the light spot S0. Here, the difference from the first embodiment is the diameter of the light spot S0 on the optical card 1. In other words, the diameter of the light spot S0 is set to a size such that a part of the light spot overlaps the information pit while the AT is being controlled by the tracking track 4 in order to achieve the purpose.

Next, the shift of the light spot S0 will be described. When an information reproduction start command is output by the MPU, the optical card 1 moves to the tracking track 4-3 in FIG.
In the same manner as in the second to fourth embodiments, the movement is started from the stop / reverse position A while performing the AT control. The light spot S0 is controlled at a constant speed in the constant speed region.
When the track number portion 6-2 is detected in a part of the
The information track 2-2 is moved to almost the center by the U transfer command. After that, information is reproduced while performing AT control with the information pit string. After the information reproduction, the light spot S0 is shifted to the tracking track 4-2,
After that, it is decelerated and moved to the stop / reverse position B. Note that the means for shifting between the tracking track and the information track is the same as in the first embodiment.

FIG. 15 shows a modification of the fifth embodiment. The difference from the above embodiment is that the light spot S
The spot shape is 0 ', and by reducing the diameter of the information pits in the arrangement direction, crosstalk between adjacent information pits is reduced and the signal efficiency from the information pits is improved. The shift of the light spot S0 'is the same as in the above-described embodiment, and the description is omitted.

Next, in a system in which the transition is performed when information is detected by the light spot, a transition means for adding an electric offset can be used in the auto tracking control as described below. Thereby, the object of the present invention can be achieved even if the diameter is the same as the light spot shown in the first embodiment.

FIG. 16 shows how the light spot S0 shifts from the tracking track 4-3 to the track number section of the information track 2-2 by applying an electrical offset to the AT control. FIG. 17 is a diagram showing the relationship between the one-beam PP / AT control signal and the position of the objective lens.

In FIG. 17, the control of the AT is always
This is performed so that the output becomes 0. For example, if the center of the light spot deviates from the center of the tracking track, the AT control output will have an S-shaped waveform shown in FIG. 17 depending on the amount and direction. A in this case
In the T control, a current is applied to the AT control coil so that the AT control output becomes 0, the objective lens is moved, and the center of the light spot coincides with the center of the tracking track. This is always performed by AT control. In this AT control method, as shown by i in FIG. 17, when a predetermined amount of current is added and an electric offset amount i is given in the AT control circuit system, the objective lens moves to the position of j. In this state, it is held at that position.

As described above, the light spot shifting method according to the present invention is performed by utilizing the electrical offset. That is, as shown in FIG. 16, the light spot S0 is one beam PP.multidot.
When the MPU determines that the relative movement has been performed to a predetermined position in advance while performing the AT control, the MPU
Provides an electrical AT offset to the AT control circuit. The AT offset amount may be such that a part of the light spot covers the information pit. A part of the light spot also covers the tracking track.

The MPU keeps moving the light spot with the AT offset applied, and when the track number section 6-2 is detected in a part of the light spot, the objective lens further moves in the same direction. As described above, the amount of light applied to each track of the light spot is adjusted by the tracking track 4-3.
The AT offset is applied until the track number section 6-2 becomes larger than the track number.

At this point, the MPU stops giving an offset to the AT control circuit and returns to the normal AT control. As a result, A in the information pit of the track number section
T will be redrawn. Thereafter, one-beam PP / AT control is performed in the information pit. After reproducing all the information, the light spot S0 is shifted from the information track 2-2 to the tracking track 4-2 by giving the same AT offset as described above.

As described above, it is possible to reproduce information while performing one-beam PP / AT control on the optical card even if the information detection by the light spot is used at the transition timing of the light spot. .

(Sixth Embodiment) Hereinafter, a sixth embodiment of the present invention will be described.
Will be described with reference to FIG. 18 and FIG. The configuration of the optical head section for reproducing information from the optical card is the same as that of the first embodiment except for the position detector section of the objective lens, and the description is omitted here. The same applies to the positional relationship between the signal processing system or the optical card and the light spot.

FIG. 18 shows a position detection system of the objective lens 16. The objective lens 16 is held by a lens barrel 31,
About the center 35 of. The rotation direction is a substantially linear direction as shown by y 'in the figure in a minute range, and is the y' direction shown in Fig. 19, that is, the tracking track direction. Here, reference numeral 32 denotes a two-division position sensor,
34 is a light source.

The position of the objective lens in the y 'direction is detected as follows. Center 3 of optical axis of light source 34 and center 3 of light shield 33
The divergent light from the light source 34 arranged so that 5 substantially coincides with 2
The light enters the division position sensor 32. At this time, the position sensor 3
In the case where the difference between the outputs from the two light receiving surfaces is 0, it indicates that the objective lens is at the neutral position in the y 'direction movement range, and when the difference is not 0, the difference is from the neutral position of the objective lens. In the y 'direction, and the polarity indicates whether it is in the + or-direction.

FIG. 19 is a diagram showing the difference between the outputs of the two light receiving surfaces of the position sensor and the amount of movement of the objective lens from the neutral position. As shown in FIG. 19, the relationship between the amount of movement of the objective lens and the difference between the outputs of the two light receiving surfaces of the position sensor is linear. For example, the difference between the two light receiving surface outputs of the position sensor is Q
In this case, the objective lens is located at the position R, and the position of the objective lens is constantly detected based on the output of the position sensor.

The predetermined amount of movement of the objective lens by the light spot shifting means of the present invention in this embodiment is as follows.
This corresponds to a distance of 6 μm between the center of the tracking track and the center of the information area. When the objective lens is moved by 6 μm, the output of the position sensor is set in advance based on the graph of FIG. 19 showing the relationship between the output value of the objective lens position sensor and the position of the objective lens. Based on the output of the position sensor at the time of the light spot transfer command from the MPU, the objective lens starts to move in a predetermined direction from there. When the output of the position sensor reaches an output corresponding to a preset 6 μm, the objective The lens transfer ends. Transition direction is MPU
Made with more instructions.

The movement of the objective lens is controlled by switching the AT control from the closed control to the open control in accordance with the MPU shift command, and performing the AT control until the output of the position sensor reaches the set value. A current into the coil of the actuator. After confirming that the objective lens has moved by a predetermined amount, the injection of current is stopped and the AT
The control is again switched to the closed control, and the AT control is performed on the tracking track or the information track at the transition destination.

(Seventh Embodiment) Hereinafter, a seventh embodiment of the present invention will be described.
Will be described with reference to FIGS. The configuration of the optical head for reproducing information from the optical card is as follows.
Except for the position detector of the objective lens, the configuration is the same as that of the first embodiment, and the description is omitted here. Also, the signal processing system is the same as in the first embodiment, and a description thereof will be omitted.

As described in the first embodiment, there are various light spot transition timings. In each case, the light spot transition method of the present invention can be applied. The effect of can be obtained.

Hereinafter, the state of the shift of the light spot will be described. As described above, the present embodiment can be applied to various transition timings. As an example, an example in which the transition timing is an information reproduction zone is shown. In addition, since the light spot shifting means is the same as that shown in the first embodiment, the description is omitted.

FIGS. 20 to 23 are views showing the transition between the reproduction zone signal, the tracking track of the light spot S0, and the information track. FIG. 20 shows a case where the light spot S0 moves relatively on the optical card in the direction of arrow L from the tracking track 4-4 to the information track 2-.
3 shows that before the transition, one-beam PP / AT control is performed by the tracking track 4-4, and the MPU
Is shifted to the information track 2-3 by the shift command in response to the playback zone opening command from the
1 in the track number section 6-3 and the information pit string 5-3
It moves while performing beam PP / AT control. In addition,
The reproduction zone signal is a binary signal of 1 and 0. Incidentally, when the reproduction zone signal is 0, it indicates a closed state, and when it is 1, it indicates an open state.

FIG. 21 shows a light spot S0 after information reproduction.
FIG. Here, the information pit row 5-3
After the end of the reproduction, the information track 2-3 is changed to the track number section 6-3 in response to the reproduction zone closing command from the MPU.
From the tracking track 4-3. After the transition,
It moves to the stop / reverse position while performing one beam PP / AT on the tracking track 4-3. As is clear here, the tracking track for performing one-beam PP / AT control of the light spot S0 in FIGS. 20 and 21 is different. This is, as understood from FIGS. 22 and 23, one beam PP · A on the tracking track 4-3.
The light spot S0 inverted at the stop position by performing the T control
Is one beam PP • AT in the tracking track 4-3.
This is because the robot moves in the direction of arrow F while performing control.

In FIG. 22, the light spot S0 has the MP
Information track 2 in response to a playback zone closing command from U
Move to -2. After the transition, information is reproduced while performing one-beam PP / AT control in the track number section 5-2 and the information sequence 6-2. FIG. 23 is a diagram showing the transition to the light spot S0 after the end of information reproduction. Information pit row 5-
After the reproduction of the track No. 2 and the track number section 6-2 is completed,
The light spot is shifted from the information track 2-2 to the tracking track 4-2 in accordance with the reproduction zone closing command from the PU. After the shift, the beam moves to the stop / reverse position while performing one beam PP / AT on the tracking track 4-2. As is clear here, the tracking track for performing one-beam PP / AT control of the light spot S0 in FIGS. 22 and 23 is different.

The same transition is performed when the reproducing operation is performed continuously. At the time of transition, the AT control is switched from the closed control to the open control, and after the transition, the AT control is switched again to the closed control to perform the AT control on the tracking track or the information track.

(Eighth Embodiment) The eighth embodiment according to the present invention further shows another means and a method for shifting a light spot during relative movement. That is, FIG. 24 is a diagram showing a transition state of the light spot when the information track of the optical card includes a sector having no information pit.

In FIG. 24, assuming that the optical card 1 starts moving in the L direction, near the track number section 6-2,
The light spot S0 that has shifted from the tracking track 4-3 to the center of the information track has one beam P at the information pit.
While performing the PAT control, the track number section 6-2 and the sector 5-2-1 in which the information pit is present continue.
To play. Further, based on the management information of the sector read from the optical card 1 in advance, in the sector portion 5-2-2 where no information pit exists, the tracking track 4-3 is used.
In order to perform the AT control, the light spot S0 moves a predetermined amount from the information track area to the tracking track 4-3 after detecting the information indicating the end of the sector 5-2-1. One beam PP ・ A
Continue moving while performing T control.

Next, the light spot S0 is shifted from the tracking track 4-3 to the center of the information track 2-2 in order to reproduce the sector 5-2-3 in which the information pit exists based on the management information. After shifting, one beam P at the information pit
Reproduction of information is performed while performing P-AT control. In addition,
The timing of transition from the tracking track 4-3 to the information track 2-2 in order to reproduce the information of the sector 5-2-3 is based on the optical card of the sector width obtained from the speed V of the optical card 1 and the sector width D. At the moving time T (= D / V). The moving time of the optical card is determined by the MPU in sector 5-
2-1 The time after the reproduction is measured, and when the measured time reaches T, the MPU issues a light spot shift command. After the reproduction of all information is completed, one-beam PP / AT control is performed on the tracking track 4-2 at the transition point b shown in the above-described example.

When a predetermined amount of transition is made between the tracking track and the information track, A
The T control is switched from the close control to the open control, and a current is injected into the coil of the AT actuator so as to shift by a predetermined amount. When the objective lens position detector detects that the shift has been performed by the predetermined amount, the current injection is stopped. After stopping and shifting to a predetermined amount, the control is switched again to the closed control, and A
T control is performed.

By changing the tracking track irradiated by the light spot at the transition point a and the transition point b, the same transition method as described above can be performed without performing another operation when reproducing the next information track. Can be done at Note that the predetermined shift amount at the time of shifting between the tracking track and the information track is the same as in the first embodiment.

[0105]

As described above, a light beam from a light source is applied to an objective lens by an information recording medium comprising a plurality of tracking tracks and a plurality of information areas interposed between the tracking tracks. By irradiating the information recording medium and the light spot relative to each other in the tracking track direction while performing auto tracking control while irradiating the information recording medium as one light spot on the surface of the information recording medium. An optical information reproducing apparatus that scans an information track composed of information pits in the information area with the light spot and reproduces recorded information, wherein during the relative reciprocating movement,
The apparatus further comprises a transition unit that transitions the light spot between the tracking track and the information track.

Therefore, in an optical card having a different tracking track width and information track width, it is possible to reproduce information while performing AT control on each track, thereby achieving a reduction in the number of parts and a reduction in cost. Can be.

Further, according to the present invention, a light beam emitted from a light source is applied to an information recording medium comprising a plurality of tracking tracks and a plurality of information areas arranged so as to be sandwiched between the tracking tracks. While irradiating as a light spot, the information recording medium and the light spot are relatively reciprocated in the tracking track direction while performing auto tracking control,
During the relative reciprocating movement, the light spot is scanned and recorded by the light spot shifted by the shifting means for shifting the light spot between the tracking track and the information track formed of information pits in the information area. In an optical information reproducing apparatus for reproducing information, the light spot is divided into the information track and the tracking track in the information track according to management information for managing an information pit group (hereinafter, referred to as a sector) in the information track area. By switching between the two, the AT control can be performed more stably even in the information area where no information exists, and one track can be used for each optical card having different tracking track widths and information track widths. Information can be reproduced while performing PP / AT control Next, the reduction of the result the number of parts,
Cost reduction can be achieved.

Further, according to the present invention, an information recording medium comprising a plurality of tracking tracks and a plurality of information areas interposed between the tracking tracks is provided.
A light beam from a light source is converged by an objective lens and irradiated as a single light spot on the surface of the information recording medium, and the information recording medium and the light spot are moved in the tracking track direction while performing auto tracking control. The light spot is shifted by a shift unit that shifts the light spot between the tracking track and an information track including information pits in the information area during the relative reciprocation. In the optical information reproducing apparatus that reproduces recorded information by scanning an information track composed of information pits in the information area with the shifted light spot, the light spot shifting means detects the position of the objective lens. The objective lens in the tracking track direction based on the output of the position detector A predetermined amount in a direction substantially perpendicular Te, and wherein the shifting.

Therefore, in an optical card having a different track width, it is possible to reproduce information while performing one-beam PP / AT control on each track, to increase the speed of continuous reciprocating reproduction, to reduce the number of parts, and to reduce the number of parts. Cost reduction can be achieved.

Further, according to the present invention, a light beam from a light source is applied to an information recording medium comprising a plurality of tracking tracks and a plurality of information areas interposed between the tracking tracks. And irradiates the information recording medium with the light spot as a single light spot on the surface of the information recording medium, and performs the auto tracking control while relatively reciprocatingly moving the information recording medium and the light spot in the tracking track direction. During the reciprocating movement, the light spot is transferred by a transfer means for transferring the light spot between the tracking track and an information track composed of information pits in the information area. The optical information reproduction for reproducing the recorded information by scanning the information track composed of the information pits in the area. In the device, a tracking track when the light spot is shifted from the tracking track to the information track and a tracking track when the light spot is shifted from the information track to the tracking track are different tracking tracks. It is characterized by the following.

Therefore, it is possible to reproduce information while performing AT control on each track, thereby achieving a reduction in the number of parts and a reduction in cost.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an optical arrangement of an optical head according to a first embodiment of the present invention.

FIG. 2 is also a photodetector and a processing circuit diagram.

FIG. 3 is a diagram showing a linear encoder.

FIG. 4 is also an optical card speed detection system.

FIG. 5 is a diagram showing a positional relationship between a transition point and each area and each signal.

FIG. 6 is a diagram showing a relationship between an optical card and a light spot.

FIG. 7 is also a diagram showing a shift of a light spot.

FIG. 8 is a diagram showing a shift of a light spot.

FIG. 9 is also a view showing an optical card moving mechanism.

FIG. 10 is a diagram showing a rotary encoder and a detection system.

FIG. 11 is a diagram illustrating a relationship among an encoder pulse signal, a speed, and a transition point according to the second embodiment of the present invention.

FIG. 12 is a diagram illustrating a relationship between a clock signal, a movement time, and a transition point according to the third embodiment of the present invention.

FIG. 13 is a diagram illustrating a relationship among an encoder pulse signal, a moving distance, and a transition point according to the fourth embodiment of the present invention.

FIG. 14 is a diagram showing a relationship between an optical card and a light spot.

FIG. 15 is a diagram showing a relationship between an optical card and a light spot in another modification of the present invention.

FIG. 16 is also a view showing a shift of a light spot.

FIG. 17 is a diagram showing the relationship between the output of the AT control signal and the position of the objective lens.

FIG. 18 is a diagram illustrating an objective lens position detection system according to a sixth embodiment of the present invention.

FIG. 19 is a view showing the positional relationship between the position sensor output and the objective lens.

FIG. 20 is a diagram illustrating a shift of a light spot according to a seventh embodiment of the present invention.

FIG. 21 is a diagram showing a shift of a light spot.

FIG. 22 is also a diagram showing transition of a light spot.

FIG. 23 is a view similarly showing a shift of a light spot.

FIG. 24 is a diagram illustrating a transition state of a light spot when a sector including no information pit is included in the eighth embodiment of the present invention.

FIG. 25 is a schematic configuration diagram of the optical card.

FIG. 26 is a diagram showing a relationship between an optical card and a light spot in a conventional example.

FIG. 27 is a schematic configuration diagram of an optical arrangement of an optical head in a conventional example.

FIG. 28 is a diagram showing a photodetector and a processing circuit in a conventional example.

FIG. 29 is a diagram showing a relationship between respective areas when the optical card is relatively moved in the conventional example.

FIG. 30 is a diagram showing a relationship between a light spot and an optical disc in a conventional example.

FIG. 31 is a sectional view taken along line E in FIG. 30 of a conventional example.

FIG. 32 is a diagram showing a relationship between an optical card and a light spot.

[Explanation of symbols]

 Reference Signs List 1 optical card 2 information track 3 sector with information pit 4 tracking track 5 information pit row 5-2-1 sector with information pit 5-2-2 sector without information pit 6 track number section 10 semiconductor laser 16 objective lens 17 Photodetector 31 Lens barrel 32 Position sensor 33 Light shield 34 Light source 35 Center of axis 70 Linear encoder 71 Speed detector 90 Rotary encoder 91 Pulse motor 92 Connection part 93 Optical card mounting table 94 Light source 95 Sensor 96 Light transmission window 114-118 Addition Circuits 123 to 124 Subtraction circuits S0 and S0 'Light spots D1 and D2 Target travel distances T1 and T2 Target time a Transition point between acceleration and constant speed b Transition point between constant speed and deceleration

Claims (26)

[Claims] 1. An information recording medium comprising a plurality of tracking tracks and a plurality of information areas interposed between the tracking tracks, a light beam from a light source being focused by an objective lens, and By irradiating the surface of the recording medium as one light spot, and while performing auto tracking control, by relatively reciprocating the information recording medium and the light spot in the tracking track direction, by the light spot, An optical information reproducing apparatus that scans an information track composed of information pits in the information area and reproduces recorded information, wherein the light spot is moved between the tracking track and the information track during the relative reciprocating movement. An optical information reproducing apparatus comprising a transition unit for transitioning between optical information reproduction apparatuses. 2. The optical information reproducing apparatus according to claim 1, wherein the shift of the light spot is performed based on opening and closing of a reproduction zone signal indicating a reproduction area of information. 3. The transition of the light spot is controlled such that the light spot is irradiated on the tracking track when the reproduction zone signal is in a closed state, and is irradiated on the information track when the reproduction zone signal is in an open state. The optical information reproducing apparatus according to claim 2. 4. When the reproduction zone signal is closed, the auto tracking control is performed based on the tracking track. When the reproduction zone signal is closed, the auto tracking control is performed based on the information track. 4. The optical information reproducing apparatus according to claim 3, wherein: 5. The optical information reproducing apparatus according to claim 1, wherein the transition of the light spot is controlled based on a relative moving speed in the relative reciprocating movement. 6. The optical information reproducing apparatus according to claim 1, wherein the transition of the light spot is controlled at a boundary between an acceleration / deceleration region and a constant speed region in the relative reciprocating movement. 7. The method according to claim 7, wherein in the transition of the light spot, the light spot is controlled so as to irradiate the tracking track in the acceleration / deceleration area and irradiate the information area in the constant speed area. Item 2. The optical information reproducing device according to item 1. 8. The auto-tracking control is performed based on the tracking track in the acceleration / deceleration area, and the auto-tracking control is performed based on the information track in the constant speed area. An optical information reproducing apparatus according to claim 1. 9. The optical information reproducing apparatus according to claim 1, wherein the shift of the light spot is performed based on a relative movement time in the reciprocating movement. 10. The optical information reproducing apparatus according to claim 9, wherein the movement time is measured by counting a clock signal generated by the MPU simultaneously with the start of movement. 11. The optical information reproducing apparatus according to claim 1, wherein the shift of the light spot is performed based on a relative moving distance in the reciprocating movement. 12. The optical information reproducing apparatus according to claim 11, wherein the moving distance is obtained from a pulse number of an encoder pulse signal. 13. The optical information reproducing apparatus according to claim 1, wherein the shift of the light spot is performed by detecting the information pit at the light spot. 14. The light spot transition irradiates the tracking spot with the light spot in a non-data area without information pits, and irradiates the information spot with the light spot in a data area with information pits. 2. The optical information reproducing apparatus according to claim 1, wherein the operation is performed in the following manner. 15. The non-data area, wherein the auto tracking control is performed on the tracking track,
15. The optical information reproducing apparatus according to claim 14, wherein in the data area, the auto tracking control is performed using information pits. 16. The auto-tracking control is switched from closed control to open control at the time of the light spot transition, and is switched again to closed control after the transition. 14. The optical information reproducing apparatus according to any one of 11 and 13. 17. The optical information reproducing apparatus according to claim 1, wherein said shifting means adds an electric offset in auto tracking control. 18. The optical information reproducing apparatus according to claim 1, wherein the transition means moves the information recording medium with respect to the light spot. 19. A light beam from a light source is focused by an objective lens on an information recording medium including a plurality of tracking tracks and a plurality of information areas interposed between the tracking tracks, and The information recording medium and the light spot are relatively reciprocated in the tracking track direction while irradiating the surface of the recording medium as one light spot and performing auto-tracking control. The light spot is shifted by a shift means for shifting the light spot between the tracking track and the information track composed of the information pits in the information area. In an optical information reproducing apparatus for reproducing recorded information by scanning an information track, The light spot shifting means shifts the objective lens by a predetermined amount in a direction substantially perpendicular to the tracking track direction based on an output of a position detector for detecting a position of the objective lens. Optical information reproducing device. 20. The movement of the objective lens is controlled such that an output of the position detector immediately before the shift of the light spot is used as a reference value, and an output value of the position detector becomes a predetermined value from the reference value. 20. The optical information reproducing apparatus according to claim 19, wherein: 21. The optical information according to claim 19, wherein the movement of the objective lens is performed by applying a current to an auto tracking coil during the open control of the auto tracking control. Playback device. 22. A light beam from a light source is focused by an objective lens on an information recording medium including a plurality of tracking tracks and a plurality of information areas disposed between the tracking tracks, and The information recording medium and the light spot are relatively reciprocated in the tracking track direction while irradiating the surface of the recording medium as one light spot and performing auto-tracking control. The light spot is shifted by a shift means for shifting the light spot between the tracking track and the information track composed of the information pits in the information area. In an optical information reproducing apparatus for reproducing recorded information by scanning an information track, And tracking track when migrating the light spot from the tracking tracks to the information track,
An optical information reproducing apparatus, wherein a tracking track when the light spot is shifted from the information track to the tracking track is a different tracking track. 23. An information recording medium comprising a plurality of tracking tracks and a plurality of information areas interposed between the tracking tracks, wherein a light beam from a light source is focused by an objective lens, and By irradiating the surface of the recording medium as one light spot, and while performing auto tracking control, by relatively reciprocating the information recording medium and the light spot in the tracking track direction, by the light spot, An optical information reproducing apparatus that scans an information track composed of information pits in the information area and reproduces recorded information, comprising management information for managing an information pit group (referred to as a sector) in the information track area. According to the management information, the light spot is located in front of the information track in the information track. Optical information reproducing apparatus characterized by shifting between the tracking tracks. 24. The method according to claim 24, wherein the shift of the light spot from the information track to the tracking track is performed when a predetermined information pit indicating the end of the sector is detected based on the management information. 24. The optical information reproducing device according to 23. 25. The method according to claim 25, wherein the shift of the light spot from the tracking track to the information track is performed by measuring a relative position of the light spot with respect to an information recording medium based on the management information. Item 24. The optical information reproducing device according to item 23. 26. The optical information reproducing apparatus according to claim 25, wherein the measurement of the relative position is performed on a value obtained based on the speed at the time of the relative reciprocating movement and the width of the sector.