JPH02141938A - Optical pickup device - Google Patents

Abstract

PURPOSE:To save the rotation waiting time by dividing a luminous flux radiated from a light source into two, recording information by the 1st light spot and reproducing the information recorded with the 1st spot through the use of the 2nd light spot. CONSTITUTION:A light radiated from a semiconductor laser 1 is divided into P polarized luminous flux Bp an S polarized luminous flux Bs by a Wollaston prism 5, collected on an information recording face of a disk 9 to form light spots SPOTp,SPOTs by an objective lens 8. When the disk 9 is driven, the part on which the information is recorded by the light spot SPOTp reaches the spot SPOTs soon. The polarized direction of the reflected light of the spot SPOTs is bent by the Kerr effect of the recorded magnetic information and the light is transmitted through the lens 8 and separated by a polarized beam splitter 13. The P polarized light component is made incident in a photodetection face 15E and the S polarized light component is made incident into the photodetection face 16B, and the information is reproduced by arithmetic operation. Thus, the recording of the information is implemented by the process of erasure disk rotation recording verify.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an optical information recording medium such as an optical disc, or
The present invention relates to an optical pickup device that is installed in a drive device for a magneto-optical information recording medium such as a magneto-optical disk and is used for recording, reproducing, or erasing information on the recording medium.

(Prior Art) Optical pickup devices that record, reproduce, or erase information by focusing light onto the recording surface of an optical information recording medium such as an optical disk or a magneto-optical information recording medium such as a magneto-optical disk are well known. It is being

In a conventional optical pickup device that records, reproduces, and erases information on a magneto-optical disk, only one beam of light is incident on the magneto-optical disk, and it is focused on the recording surface of the magneto-optical disk. Since the mainstream is the so-called 1-spot method, in which there is only one optical spot, when recording information, the previous information is erased, the disk is rotated once, and then the information is recorded, and then the disk is rotated once more. It was necessary to reproduce and confirm the recorded information (so-called verification). For this reason, in magneto-optical disk drives equipped with conventional optical pickup devices, it is necessary to wait two rotations when recording information, which has the disadvantage of lengthening the access time. I couldn't figure it out.

Furthermore, even in conventional optical pickup devices that record and reproduce information on and from optical discs, only one beam of light enters the optical disc, so when recording information, one disc is A process of reproducing and confirming the information recorded during rotation (so-called verification) is required, and it is necessary to wait for one rotation of the disk.

The disadvantage is that the access time becomes longer.

As expected, it was not possible to increase the speed of the drive device.

Therefore, in order to increase the speed of optical disk drive devices and magneto-optical disk drive devices, two light emitting sources are provided in the optical pickup devices installed in these devices, and two light emitting sources are installed on the disk.
An optical pickup device has been proposed that records and verifies information at the same time using a so-called two-spot method in which two light beams are incident (for example,
9-58638).

(Problem to be Solved by the Invention) However, in the optical pickup device seen in the above-mentioned publications, the first semiconductor laser is a light source for recording information, and the first semiconductor laser is a light source for reading information immediately after recording (verification). Since the configuration includes two laser light sources, the second semiconductor laser serving as the light source, the two semiconductor lasers must be controlled independently, making the control and circuit configuration complicated. When lasers are provided for recording and verifying, two sets of optical systems (for example, collimating optical systems) are required to guide the emitted light from these two semiconductor lasers to the disk, respectively, which increases the size of the optical pickup device. This is a problem because the entire disk drive device becomes larger and the number of parts of the optical pickup device also increases, resulting in a significant increase in manufacturing costs.

The present invention has been made in view of the above circumstances, and aims to shorten access time by using a two-spot method, and
It is an object of the present invention to provide an optical pickup device that realizes the above-mentioned two-spot method using one light source, and can simplify driving control of the light source, downsize the device, and reduce costs.

(Means for Solving the Problems) In order to achieve the above object, in the optical pickup device according to the present invention, a light beam emitted from one light source is divided into two, and the optical axes of the two light beams are divided at a minute angle. and a light splitting means for condensing the two light beams split by the light splitting means onto the recording surface of the optical information recording medium or magneto-optical information recording medium at a minute interval to form two light spots. and a photoelectric conversion means for receiving and photoelectrically converting each of the two light beams reflected from the recording surface of the optical information recording medium or the magneto-optical information recording medium, The first light spot on the side that precedes the movement of the recording surface of the recording medium or magneto-optical information recording medium is for erasing, recording, and reproducing information, and the other second light spot is for reproducing information. , when recording information.

The light source is optically modulated by the information to be recorded, the information is recorded by the first light spot, and the information recorded by the first light spot is immediately reproduced by the second light spot. Features.

(Function) In the optical pickup according to the present invention, the light beam emitted from one light source is divided into two by the light splitting means, and the two divided light beams are condensed by one condensing means to form two light spots. Since the structure forms a two-spot type optical pickup device, it is possible to realize a two-spot type optical pickup device with a relatively simple structure.

(Example) Hereinafter, the present invention will be explained in detail based on the illustrated example.

FIG. 1 is a schematic configuration diagram of an optical pickup device showing one embodiment of the present invention, and first, the configuration of the optical pickup device and the layout of the optical system will be explained with reference to FIG.

In FIG. 1, reference numeral 1 is a semiconductor laser (LD) that is a laser light emission source, reference numeral 2 is a collimating lens, and reference numeral 3 is a collimating lens.
is a beam shaping prism, code 4 is a λ/2 plate, code 5 is a Wollaston prism, code 6 is a half prism, code 7
1 is a light receiving element such as a photodiode (PD), 8 is an objective lens for condensing light, 9 is a disk serving as an information recording medium, 10 is a magnetic head for generating a magnetic field, 11 is a condensing lens, and 12 is a condensing lens. A λ/2 plate, 13 is a polarizing beam splitter (PBS), 14 is a cylindrical lens, 15 and 16 are light-receiving elements whose light-receiving surface is divided into a plurality of parts, and the light emitted from the semiconductor laser 1 is It becomes parallel light by collimating lens 2.

After being shaped into a nearly perfectly circular parallel beam by the beam shaping prism 3, it is adjusted by the λ/2 plate 4 so that the polarization components, that is, the P-polarized light and the S-polarized light, are approximately 4=1. The light beam transmitted through the λ/2 plate 4 is reflected by the Wollaston prism 5.
The luminous flux is divided into two into P-polarized luminous flux BP and S-polarized luminous flux Bs, and the optical axes of the two luminous fluxes are divided by a minute angle, and the luminous flux is further divided into two into P-polarized luminous flux Bp and S-polarized luminous flux Bs. The half prism 6 divides the light into transmitted light and reflected light. Here, the P-polarized light flux BP and the S-polarized light flux Bs, which are about half the amount of light reflected by the half prism 6, are incident on the light receiving element 7, and the P-polarized light flux BP and the S-polarized light flux Bs, which have passed through the half prism 6, are incident on the light receiving element 7.
is focused on the information recording surface of the disk 9 by the objective lens 8, and two optical spots 5POTp, 5 are formed on the information recording surface.
Form each POT. In addition, the above two light spots 5
The light amount ratio between POTp and 5POTs is the same as the light amount ratio adjusted when the light passes through the λ/2 plate 4, that is, approximately 4:1.

Now, one or more is an illumination optical path from the semiconductor laser 1 to the disk 9.

Next, the P-polarized light beam BP and the S-polarized light beam Bs, which form the optical spots 5POTp and 5POTs, respectively, are reflected on the information recording surface of the disk 9, and are each turned into parallel light beams by the objective lens 8, and about half are reflected by the half prism 6. The light is then converged by the condensing lens 11.

By the way, in the case of the embodiment shown in FIG. 1, the disk 9 is a magneto-optical disk, and the P-polarized light beam BP and the S-polarized light beam Bs at the time of information reading are determined according to the magnetic information recorded on the disk 9.
Due to the Kerr effect, the polarization direction of the reflected light is at the Kerr angle θk
(approximately 0.6). For example, as shown in FIG. 2, the reflected light of the S-polarized light beam Bs shown in FIG. Then, the light beam whose direction is bent due to the Kerr effect is further rotated by 45 degrees by the λ/2 plate 12 as shown in FIG. Each P-polarized light component BPP+Bsp is separated from the S-polarized light component, passes through a polarizing beam splitter 13, is subjected to astigmatism by a cylindrical lens 14, and is incident on a light receiving element 15.

Furthermore, the S-polarized light components Bps and Bss of the P-polarized light flux Bp and the S-polarized light flux Bs are reflected by the polarization beam splitter 13 and are incident on the light-receiving element 16. In addition, light receiving element 1
5 has a light receiving surface of 15A and 15B.

It is divided into five parts 15C, 150, and 15E, and the light receiving element 16 is divided into two parts 16A and 16B.

Next, an information recording method using the optical pickup device having the configuration shown in FIG. 1 will be explained.

Now, when recording information, first, the light amount of the light spot 5POTp by the P-polarized light beam BP is made constant.

By applying a magnetic field of constant strength using the magnetic head 10, the direction of magnetization on the information recording surface of the disk 9 becomes uniform. That is, the information previously recorded on the disc 9 is erased.

Next, immediately after erasing the information, the magnetic field applied by the magnetic head 10 is reversed, and the disk 9 is rotated once. The part erased first is the light spot 5POT due to the P-polarized light beam BP.
When it reaches the P position, the amount of light emitted by the semiconductor laser 1 is changed based on the recording information signal.

In step 22, when the semiconductor laser 1 emits light strongly based on the recording information signal, the optical spot 5POTp irradiation part of the disk 9 is heated, and the heating part is heated by the magnetic field applied in the opposite direction to that during erasing by the magnetic head 10. The magnetization direction of is reversed. Furthermore, when the amount of light emitted from the semiconductor laser 1 is weak, the light spot 5poTp irradiation part of the disk 9 does not become very hot and is not affected by the magnetic field applied by the magnetic head 10, so that the magnetization of the light spot 5POTp irradiation part of the disk 9 The direction is maintained in the direction of magnetization during erasing. Therefore, by changing the light intensity of the semiconductor laser 1 in accordance with the recording information signal under a constant magnetic field applied by the magnetic head IO, the magnetic medium of the disk 9 is magnetized in the direction corresponding to the information recording signal, and the magnetic information is recorded as.

Next, if the rotation direction of the disk 9 is the direction of the arrow in FIG. 1, the portion where information is recorded by the light spot 5POTp of the P-polarized light beam BP immediately reaches the position of the light spot 5POTs of the S-polarized light beam Bs. Here, the light spot 5POTs due to the S-polarized light flux Bs is the P-polarized light flux B
The amount of light is smaller than the light spot 5POTp due to P (
(approximately 1/4), the portion of the disk 9 irradiated with the optical spot 5POTs does not become very hot and is not affected by the magnetic field applied by the magnetic head IO.

Now, the polarization direction of the reflected light of the light spot 5POTs due to the S-polarized light beam Bs irradiated on the information recording portion of the disk 9 is bent by the Kerr effect of the recorded magnetic information, and as described above, the light is transmitted through the objective lens 8. After that, it is reflected by the half prism 6 and becomes convergent light by the condensing lens 11, and then separated into a P polarized light component and an S polarized light component by the polarization beam splitter 13, and the P polarized light component (Bsp) is sent to the light receiving element 15. The light is incident on the light receiving surface 15E, and the S polarized light component (
B ss) enters the light-receiving surface 16B of the light-receiving element 16, and the outputs of both light-receiving elements 15°16 are E and G, and the difference (E-
By calculating G), the information recorded on the disk 9 can be reproduced, and the optical spora h of the P-polarized light beam Bp
The information recorded by 5POTp is securely stored on disk 9.
Verification is performed immediately after recording to check whether the data has been recorded. That is, according to the optical pickup device having the configuration shown in FIG. 1, information can be recorded in the steps of (erasing) # (one rotation of the disk) (recording) # (verification), and the information can be recorded in one rotation of the disk. Information can be recorded.

Therefore, according to the optical pickup device according to the present invention having the configuration shown in FIG.
(Rotation) - # (Record #) => (1 rotation of the disk) Access time when recording information compared to a 1-spot optical pickup device in which information could not be recorded without rotating the disk twice. can be significantly shortened.

Next, a method for reproducing information using the optical pickup device shown in FIG. 1 will be described.

For the disc 9 on which information has already been recorded, the amount of light emitted from the semiconductor laser 1 is set to a weaker amount of light than that during information recording, that is, a so-called reproduction power.

Therefore, the light spot 5POTp formed by the P-polarized light beam Bp focused by the objective lens 8 is irradiated onto the information recording surface of the disk 9 with a weaker light intensity than during information recording. The reflected light from the disk 9 is reflected by the disk 9 due to the Kerr effect.
The direction of polarization is bent according to the direction of the magnetic field recorded in the beam, and as described above, this reflected light BP passes through the objective lens 8, is reflected by the half prism 6, and becomes convergent light by the condenser lens 11. Thereafter, it is separated into a P polarized light component and an S polarized light component by a polarizing beam splitter 13, and the P polarized light component (Bpp) is incident on the four-divided light receiving surfaces 15A, 15B, 15C, and 150 of the light receiving element 15, and the S polarized light component is (Bps) is one light receiving surface 16A of the light receiving element 16.
is incident on the Here, the respective photoelectric conversion outputs of the incident light to the four-divided light-receiving surfaces 15A, 15B, 15c, and 150 of the light-receiving element 15 are defined as A, B, C, and D, and the light-receiving element 1
When the photoelectric conversion output of light incident on the light receiving surface 16A of No. 6 is F, an information reproduction signal can be obtained by calculating (A+B+C+D)-F.

Incidentally, during this information reproduction, the optical spot 5POTs by the S-polarized light beam Bs is also irradiated onto the disk 9, but the reflected light of this optical spot 5POTs is not used for reproduction.

By the way, in order to form a light spot 5POTρ by the P-polarized light beam Bp and a light spot 5POTs by the S-polarized light beam Bs on the information recording surface of the disk 9, the focal point of the objective lens 8 must be precisely aligned with the information recording surface of the disk 9. For this reason, so-called focus control, which moves the objective lens 8 in the optical axis direction, is required. Here, as described above, the P-polarized light beam Bp reflected by the disk 9 is reflected by the half prism 6 and becomes convergent light by the condensing lens 11, and then passes through the λ/2 plate 12 and the polarizing beam splitter 13. P polarization component E3pp and S polarization component B
The convergent beam of P-polarized light component 13pp is transmitted to the four-split light receiving surface 15A of the light receiving element 15 as a convergent light having astigmatism by the cylindrical lens 14.

15B, 15C, and 150. The focus detection method will be explained below with reference to FIG.

FIG. 3 shows a four-division light-receiving surface 15A of the light-receiving element 15.

15B, 15G, and 150. During so-called focusing, when the disk 9 is in focus, the light receiving surface 15A divided into four parts of the light receiving element 15, as shown in FIG. 3(n), is shown. The spot shapes on 15B, 15C, and 15D are almost perfect circles, and the amount of light irradiated to each of the four light-receiving surfaces 15A, 15B, 15C, and LSD of the light-receiving element 15 is equal, so that each light-receiving surface 15A,
15B, 15C.

If the photoelectric conversion outputs of the 15D are A, B, C, and D, then (A + C) - (B + D) = 0.

Also, if the disk 9 is not in focus, the third
As shown in Figure (1) or (III).

Four-divided light-receiving surfaces 15A, 15B, 1 of the light-receiving element 15
The spot shape on 5C, 150 is a tilted ellipse, and (A+C)-(B+D)≠0.

That is, in the case of Figure 3 (1), (A + C) - (B + D) > 0, and in the case of Figure 3 (I[), (A + C) - (B + D) < 0. Become. Therefore, by moving the objective lens 8 up and down in the optical axis direction by an actuator (not shown) so that (A+C)-(B+D)=0, it is possible to focus on the information recording surface of the disk 9. . still,
The focus detection method described above is the so-called astigmatism method.

Next, the information recording method using the optical pickup device according to the present invention will be explained in more detail with reference to FIG.

Now, when recording a binary information code as shown in FIG. 4(a) on the disk 9, when the information code changes from "0" to "1" or from "1" to "0", Suppose that the drive signal of the laser 1 is changed as shown in Fig. 4(b).In other words, the laser drive signal (Fig. 4(b)) that changes corresponding to the information code (Fig. 4(a)) is changed as shown in Fig. 4(b). The intensity of the amount of light emitted from the semiconductor laser changes accordingly.

Incidentally, in the optical pickup device having the configuration shown in FIG. 1, half of the light emitted from the semiconductor laser 1 is reflected by the half prism 6 and enters the light receiving element 7. Therefore, the light receiving element 7 can control the amount of light emitted from the semiconductor laser 1. Here, Fig. 4(c)
is the output signal of the light receiving element 7 for controlling the amount of light.

Now, when the laser drive signal changes as shown in FIG. 4(b) due to the information code shown in FIG. The amount of light changes as shown in FIG. 4(d). When the light intensity of this optical spot 5POTp is small, the optical spot 5POTρ position on the disk 9 is not heated, so that the magnetization direction of the magnetic medium in that part is changed to the magnetic head 10.
For example, as shown in FIG. 4(e), the magnetic head 1 during erasing remains unchanged regardless of the direction of the magnetic field applied by
When the applied magnetic field direction of 0 is the direction that magnetizes to the south pole, the magnet remains as the south pole.

Next, when the light intensity of the optical spot 5POTρ becomes large as shown in FIG. The direction of the applied magnetic field of 10 (opposite direction to that during erasing) is reversed, and the magnetic field becomes N-pole, for example, as shown in FIG. 4(e). Therefore, as shown in FIG. 4(e), a magnetic signal corresponding to the information code (FIG. 4(a)) is recorded on the disk 9. The method of converting the information code to 091 at the edge of the information bit in this manner is called an edge recording method.

Now, when light with so-called reproduction power is applied to the information recording surface of the disk 9 on which magnetic signals are written as shown in FIG. 4(e), an information reproduction signal as shown in FIG. 4(f) is obtained. However, the optical spot 5PO of the S-polarized light beam for verification is
Since the optical axis of Ts is shifted downstream in the moving direction (rotation direction) of the disk 9 from the recording optical spot 5POTp, the information reproduction signal with a delay is shown in FIG. 4(g). You can get it like that.

By the way, as described above, the information reproduction signal from the optical pots 5POTs is based on the difference (E -G), but since this is a difference in photoelectric conversion output, it changes depending on changes in the amount of light incident on each light receiving element. That is, due to a change in the output light amount of the semiconductor laser 1 (FIG. 4(b)), the information reproduction signal (E-G) by the optical 5POTs changes.

The information reproduction signal (verify signal) actually obtained during verification is a signal in which signals due to changes in light intensity are superimposed, as shown in Figure 4 (h).In other words, the laser drive signal based on the information code is the verify signal. This results in a gain fluctuation of .

Therefore, in order to eliminate this gain fluctuation, the laser drive signal or the signal of the light receiving element 7 for controlling the light amount described above is inverted to form a gain adjustment signal as shown in FIG. 4(i), and this gain adjustment signal is The information reproduction signal shown in 41M (h) is adjusted by 41M (h) to obtain a verify signal after gain mu (FIG. 4 (j)). Furthermore, Figure 4 (
The verify signal shown in j) is the same as the ideal information reproduction signal by the optical spot 5POTPs shown in FIG. If the delay is removed, this is equivalent to the ideal information reproduction signal shown in FIG. 4(f).

Incidentally, FIG. 5 schematically shows an example of the configuration of a circuit for automatically performing each of the above calculations.

The circuit shown in FIG. 5 is a well-known addition circuit (+).
It is composed of a subtraction circuit (-), a logic circuit, etc., and the signals from each light receiving element 15, 16, and 17 are added to an addition circuit (
+), subtraction circuits (-), logic circuits, etc., verify signals and focus error signals during information recording,
A reproduction signal during information reproduction and a semiconductor laser (LD) control signal can be obtained.

Note that a division circuit or the like is used as the gain variable means for performing the gain rAM of the verify signal described above.

Now, the optical pickup device described above with reference to FIGS. 1 to 5 is an embodiment in which a magneto-optical disk is used as an information recording medium, but the present invention uses an optical disk as an information recording medium. The present invention can also be applied to an optical pickup device in the same manner.

FIG. 6 shows a schematic configuration diagram of an optical pickup device when an optical disk is used as an information recording medium.
Components with the same reference numerals as those in the figures are the same components. still,
In the figure, reference numeral 17 is an optical disk serving as an information recording medium, and reference numeral 18 is
19 is a condensing lens, 19 is a cylindrical lens, and 20 is a plurality of light receiving surfaces 20A, 20B, 2Q.
This is a light receiving element divided into C, 200, and 20E.

In FIG. 6, the illumination optical path from the semiconductor laser 1 to the optical disk 17 is constructed in the same manner as the optical pickup device for the magneto-optical disk shown in FIG. 2. Beam shaping prism 3. A recording/reproducing light spot 5P consisting of a P-polarized light beam Bp passes through an illumination optical path consisting of a λ12 plate 4, a Wollaston prism 5, a half prism 6, and an objective lens 8.
It is divided into a verification light spot 5POTs consisting of the OTP and the S-polarized light beam Bs, and is irradiated onto the information recording surface of the optical disc 17.

Then, the P-polarized light beam Bp and the S-polarized light beam Bs reflected on the information recording surface of the optical disk 17 are reflected by the half prism 6, and then become convergent light by the condenser lens 18, and generate astigmatism by the cylindrical lens 19. and is incident on the light receiving element 20.

Here, the light receiving element 7 for light amount management and the light receiving element 20 for signal detection are connected to an arithmetic circuit having a circuit configuration as schematically shown in FIG. 7, for example, and the light receiving element 20 for signal detection A verify signal at the time of information recording is obtained by detecting a photoelectric conversion output signal from the light receiving surface 20E on which the S-polarized light beam is incident, and performing gain adjustment on the signal using an inverted signal of the light amount signal by the light receiving element 7. . Furthermore, if each photoelectric conversion output signal from the four-divided light-receiving surface 2OA, 20B, 20C, and 20D into which the P-polarized light flux of the light-receiving element 20 for signal detection is incident is denoted as A, B, C, and D, (A+C) -(B+D), the focus error signal is detected, and (A+B+
C+D), a reproduction signal at the time of information reproduction is obtained.

Further, a semiconductor laser control signal is obtained by the light receiving element 7 for controlling the amount of light.

The circuit shown in FIG. 7 is constructed of well-known addition circuits (+), subtraction circuits (-), logic circuits, etc. so that the above-mentioned operations are automatically performed.

The circuit configuration is not limited to what is shown in the drawings, and various modifications are possible.

Now, in the optical pickup device for an optical disk according to the present invention having the configuration shown in FIG. 6, the optical disk 17 is irradiated with two light spots, one for recording/reproducing and one for verifying, so that information cannot be recorded. Verification is performed at the same time, and the waiting time for disk rotation can be shortened.

(Effect of the invention) As described above based on the illustrated embodiment.

According to the present invention, two light spots can be formed on the information recording surface of a magneto-optical disk, optical disk, etc. even though there is only one light emitting source, and information recording and verification can be performed almost simultaneously. As a result, the disk rotation waiting time can be reduced compared to conventional single-spot optical pickup devices, and the access time of magneto-optical disk drives and optical disk drives can be significantly shortened. can.

Furthermore, since the optical pickup device according to the present invention is configured with one light emitting source, the device does not become bulky unlike the conventional two-spot type optical pickup device, and there is also less increase in manufacturing costs. It has the advantage of In addition, the light source can be controlled in the same way as in the 1-spot method.
Since only one light source needs to be controlled, the control does not become complicated.

Furthermore, since the optical pickup device according to the present invention records information using an optical modulation method, it is easy to control the magnetic head that applies a magnetic field when recording information.

[Brief explanation of the drawing]

111i! I is a schematic configuration diagram of an optical pickup device for a magneto-optical disk showing an embodiment of the present invention, FIG. 2 is an explanatory diagram of the bending of the polarization direction due to the Kerr effect, and FIG. 3 is a diagram in which the light-receiving surface is divided into four parts. An explanatory diagram of a focus detection method using a light receiving element, FIG. 4 is an explanatory diagram of a reproduction signal when information is recorded by the optical pickup device configured as shown in FIG. 1, and FIG. 5 is an explanatory diagram of the optical pickup device configured as shown in FIG. 1. A schematic circuit configuration diagram showing an example of an arithmetic circuit for obtaining various signals from each light receiving element,
FIG. 6 is a schematic configuration diagram of an optical pickup device for an optical disk showing another embodiment of the present invention, and FIG. 7 is a diagram for obtaining various signals from each light receiving element of the optical pickup device having the configuration shown in FIG. 6. FIG. 2 is a schematic circuit configuration diagram showing an example of an arithmetic circuit of FIG. 1... Semiconductor laser, 2... Collimating lens, 3... Beam shaping prism, 4... λ/2 plate, 5... Wollaston prism, 6... Half prism, 7.15.16.20... light receiving element,
8...Objective lens, 9...Magneto-optical disk, 1
0... Magnetic head, 11, 18... Condensing lens, 12... λ/2 plate, 13... Polarizing beam splinter, 14.19... Cylindrical lens,
BP...P polarized light flux, Bs...S polarized light flux, 5
POTp...P-polarized light spot, 5POT
s... Light spot of S-polarized light flux. '1154 Kuni Sai Zen 4th figure Chi δ Illusion ('I) (I[[) Form 6 Kuni Shape figure 7 Fig. 2θ

Claims (1)

[Claims] An optical pickup device that records, reproduces, or erases information by condensing light onto the recording surface of an optical information recording medium or magneto-optical information recording medium, and divides the light beam emitted from one light source into two. and a light splitting means for splitting the optical axes of the two light beams at a minute angle, and a light splitting means for splitting the optical axes of the two light beams at a minute angle; one condensing means for condensing light at a certain interval to form two optical spots; and a photoconductor for receiving the two beams reflected from the recording surface of the optical information recording medium or the magneto-optical information recording medium. The first light spot on the side that precedes the movement of the recording surface of the optical information recording medium or magneto-optical information recording medium is for erasing, recording, and reproducing information. , the other second light spot is for reproducing information, and when recording information, the light source is optically modulated by the information to be recorded, and the first light spot records information, and the second light spot An optical pickup device characterized in that the spot immediately reproduces information recorded by the first optical spot.