JPH0831006A - Optical pickup, disk and semiconductor package - Google Patents

Abstract

PURPOSE:To increase processing speed of data by converging plural diffracted rays generated by passing a radiated parallel beams through a diffraction grating on data parts of plural tracks on a disk. CONSTITUTION:Three beams are taken out by using the diffracted rays up to a 1st order generated by radiated parallel beams from the semiconductor 1 through the diffraction grating 2, and are converged on the data parts of three tracks on the disk by an objective lens 6 at a time. The change in a light quantity reflected by a pit on the disk is read out by a PIN diode used as a photodetector 9. Thus, since the data on three tracks are read out at a time, the read speed of the data becomes threefold. If the number of the diffracted rays diffracted by the diffraction grating 2 are increased, to be converged on the data parts of respective tracks, and read out, the number of tracks to be read out are increased by the number of pieces of the diffracted rays, and the read speed of the data is increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup using a laser beam such as a CD-ROM or a magneto-optical disc, a disc and a semiconductor package.

[0002]

2. Description of the Related Art In the prior art, even if the diffraction grating 2 is used in the optical pickup, the first-order diffracted light is used only for correcting the track, so that the data of one track at a time is used. I was only reading it. In a disc having spiral tracks, one track is formed continuously like a groove of a record.
Only one laser diode 19 was put in one semiconductor package. The reading speed of a CD-ROM is slower than that of a hard disk. Erase and read / write speed of magneto-optical disk was slow. In a magneto-optical disk, a plurality of optical pickups and a plurality of semiconductor packages are used to increase the erasing / reading / writing speed.
In a magneto-optical disk, if the disk rotation speed is increased in order to increase the erasing / reading / writing speed, the laser light irradiation time during writing becomes shorter, so the laser light output must be increased. A plurality of data such as audio, video, and program were mixed in the data portion of one track on the disc.

[0003]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a method for erasing and reading data of a plurality of tracks on a disk at one time, thereby It is an object of the present invention to provide an optical pickup that increases the erasing / reading speed.

According to a second aspect of the present invention, data on a plurality of tracks are erased and read at once. Alternatively, it is an object of the present invention to provide a spiral disk used in an optical pickup that performs erasing, reading and writing, and in which the optical pickup does not have to be moved even when the disk makes one round.

A third object of the present invention is to provide a semiconductor package which increases the speed of erasing and reading / writing data by radiating a plurality of laser beams at one time.

[0006]

This optical pickup is an optical pickup that uses laser light.
It is characterized in that a plurality of diffracted lights generated by passing the emitted parallel beam through the diffraction grating 2 are focused on the data portions of a plurality of tracks on the disk.

A disc used in an optical pickup is characterized by having a plurality of spiral tracks on the disc.

In this semiconductor package, a plurality of laser diodes 19 are put in one semiconductor package to emit a plurality of laser beams. Alternatively, one laser diode 19 emits a plurality of laser beams.

[0009]

In the optical pickup of the present invention, a plurality of diffracted lights generated by passing a parallel beam through the diffraction grating 2 are focused on the data portions of a plurality of tracks on the disk.
By erasing the data of a plurality of tracks at once or reading the change of the reflected light by the photodetector 9, the data of a plurality of tracks is read at once. This speeds up data erasing and reading.

Since the disc of the present invention is formed with a plurality of spiral tracks, when using an optical pickup that focuses laser light on the data portion of a plurality of tracks on the disc at a time, Since the optical pickup does not have to be moved even when the disk makes one round, the load on the optical pickup is reduced.

In the optical pickup using the semiconductor package of the present invention, a plurality of laser beams are radiated at one time, and the laser beams are focused on the data portion on the disk to erase a plurality of data at a time. Since the reading and writing can be done, the speed of erasing and reading and writing data is increased. Then, compared with the method of using a plurality of semiconductor packages for erasing, reading and writing a plurality of data at a time, and the method of using a plurality of optical pickups, the structure is simpler, and thus the manufacturing cost is low and the manufacturing is easy. . Data can be written on a magneto-optical disk at the same rotation speed as the number of laser beams, so that data can be written quickly without increasing the laser beam output.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 of the accompanying drawings shows the configuration of a first embodiment of an optical pickup for a CD-ROM. FIG. 2 shows FIG.
From the figure, a part of the disk surface, the diffraction grating 2, the polarization beam splitter 3, the PIN photodiode 12, and the part of the movement of the laser light are extracted. First, three beams are extracted by using the first-order diffracted light generated by passing the parallel beam emitted from the semiconductor laser 1 through the diffraction grating 2, and the three beams of three tracks on the disk are simultaneously extracted. The change in the amount of light focused on the data portion by the objective lens 6 and hitting the pit 13 of this track and reflected is
The PIN photodiode 12 used as the photodetector 9 reads out. With this mechanism, the data of three tracks can be read at a time, so the data read speed is tripled. If the number of diffracted lights diffracted by the diffraction grating 2 is increased and the data is focused and read out on the data part of each track, the number of tracks read out is increased by the number of diffracted diffracted lights, and the data reading speed is increased. . The beam spots 14 are shifted back and forth in order to prevent the detection signal from leaking and to avoid crosstalk from adjacent tracks.

3 and 4 show an example of a magneto-optical disk, in which fixed mirrors 15 are arranged at the lower left and upper right, movable mirrors 16 are arranged at the upper left and lower right, and a diffraction grating 2 is provided between the upper left and lower left mirrors. Put in. Then, when writing, as shown in FIG.
The laser beam is reflected without moving the movable mirror 16 and focused on the data portion of one track on the disk for writing. When erasing or reading, as shown in FIG. 4, the movable mirror 16 is moved so that the laser light can pass through the diffraction grating 2, and the diffracted light up to the first order generated by passing the laser light through the diffraction grating 2 is used. Then, the three beams are extracted and focused on the data portions of the three tracks on the disk at a time, thereby erasing and reading the data of the three tracks at a time. When the diffracted light up to the second order is used by the diffraction grating 2, five beams are formed. If these beams are focused on the data part of the track on the disk, 1
Since it is possible to erase and read data on five tracks at a time, the conventional writing procedure: data erasing 5 times, writing 5 times, reading 5 times for checking, data erasing 1 time, writing 5 times, One read is performed for checking, and the data writing speed is increased. In addition to this, the data read speed is increased five times.

FIG. 5 shows an example of a magneto-optical disk in which three spiral tracks are formed, and the first track 1
8, second track 18a, third track 18
b, and three spiral tracks are formed,
When used in an optical pickup that focuses three laser beams onto the data portion of a track on the disc at a time, the optical pickup does not have to move even when the disc makes one round. If an optical pickup is used to manufacture a disk that forms spiral tracks for the number of laser beams on a track that is focused at one time, it is not necessary to move the optical pickup even when the disk makes one round. Also, C
It is also preferable to form a plurality of spiral tracks on a disk having spiral tracks such as a D-ROM and a mini disk.

FIG. 6 shows an example in which one laser diode 19 emits three laser beams. 7 is 2
An example in which two laser diodes 19 are arranged side by side. FIG.
Is an example in which two laser diodes 19 are vertically arranged.
The laser diode 19 shown in FIGS. 6, 7, and 8 is put in one semiconductor package to manufacture a semiconductor package that emits a plurality of laser beams at one time. FIG. 9 shows another example of the magneto-optical disk, in which three laser diodes 19 are arranged side by side in one semiconductor package to emit three laser beams from one semiconductor package. This semiconductor package is used for an optical pickup of a magneto-optical disc, and these three laser beams are focused on the data portions of three tracks on the disc to erase and read data on three tracks at a time. , Do either of the writing to increase the data erasing and reading / writing speed. FIG. 10 shows another example of a magneto-optical disk, in which two laser diodes 19 are vertically arranged in one semiconductor package to emit two laser beams from one semiconductor package. This semiconductor package is used for an optical pickup of a magneto-optical disk, and these two laser beams are focused on the data portion of the same track on the disk, so that reading and writing of data can be performed at the same time. Speed up.

The present invention can take the following embodiments. (1) When it is not necessary to consider the noise of light returning to the semiconductor laser 1 of FIG. 1, the quarter-wave plate 5 can be removed and the polarization beam splitter 3 can be replaced with a half mirror. (2) The PIN photodiode 12 used as the photodetector 9 in FIG. 2 may be another light receiving element.

[0017]

The reading speed of 300 kilobytes of the double speed CD-ROM can be improved up to, for example, the first order generated by passing through the diffraction grating 2 when an optical pickup for converging a plurality of diffracted lights by the diffraction grating 2 is used. By using the diffracted light of, the three beams are extracted, focused on the data portions of the three tracks on the disk, and the change in the reflected light is read by the photodetector 9, so that the reading can be performed in 900 kilobytes Therefore, the data can be read at a speed three times faster than the conventional one.
An optical pickup that collects multiple laser beams.
The use of the disk forming the plurality of spiral tracks reduces the load on the optical pickup because the optical pickup does not have to be moved even when the disk makes one round. In an optical pickup of a magneto-optical disk using a semiconductor package that emits a plurality of laser beams, for example, three laser diodes 19 are put in one semiconductor package and three laser beams are emitted to emit a laser beam on the disc. The erasing and reading / writing speeds when the light is focused on the data portions of the three tracks are three times faster than the conventional one. In addition,
As the disk rotation speed increases, data erasing, reading, and reading / writing speeds also increase. With an optical pickup that can read multiple tracks at once,
Book as audio data, other number as video data,
It is also possible to divide the tracks by application and read out the plurality of tracks at the same time.

[Brief description of drawings]

FIG. 1 is a side view of an optical pickup showing a configuration of a first embodiment of a CD-ROM.

FIG. 2 is a schematic diagram showing an enlarged surface view of a disk 1 portion from FIG. 1, a structure of a diffraction grating, a polarization beam splitter, a PIN photodiode, and movement of laser light.

FIG. 3 is an enlarged perspective view of a part of the disk at the time of writing in the first example of the magneto-optical disk, a configuration of the mirror, and a diagram showing the movement of laser light

FIG. 4 is an enlarged perspective view of a part of the disk at the time of erasing and reading of the first example of the magneto-optical disk, a configuration of a mirror, and a diagram showing the movement of laser light

FIG. 5 is an enlarged perspective view of a disk 1 portion of a magneto-optical disk in which three spiral tracks are formed.

FIG. 6 is a perspective view of an example of emitting a plurality of laser lights from one laser diode.

FIG. 7 is a perspective view of an example in which two laser diodes are arranged side by side.

FIG. 8 is a perspective view of an example in which two laser diodes are vertically arranged.

FIG. 9 is an enlarged perspective view of a disc 1 part of another example of a magneto-optical disc, a perspective view in which three laser diodes are arranged side by side, and a schematic diagram showing laser light.

FIG. 10 is an enlarged perspective view of a disk 1 portion of another example of a magneto-optical disk, a perspective view in which two laser diodes are vertically arranged, and a diagram showing a laser beam.

[Explanation of symbols]

1 ... Semiconductor laser 2 ... Diffraction grating 3 ... Polarization beam splitter 4 ... Collimator lens 5 ... Quarter wavelength version 6 ... Objective lens 7 ... Concave lens 8 ... Cylindrical lens 9 ... Photodetector 10 ...... Disk 11 ...... Laser light 12 ...... PIN photodiode 13 ...... Pit 14 ...... Beam spot 15 ...... Fixed mirror 16 ...... Movable mirror 17 ...... Magneto-optical disk 18, 18a, 1
8b ... Track 19 ... Laser diode

Claims (3)

[Claims] 1. An optical pickup using a laser beam, wherein a plurality of diffracted light beams produced by passing a radiated parallel beam through a diffraction grating (2) are focused on data portions of a plurality of tracks on a disk. An optical pickup characterized by. 2. A disk used in an optical pickup, wherein the disk has a plurality of spiral tracks. 3. A plurality of laser diodes (19) are placed in one semiconductor package to emit a plurality of laser lights. Alternatively, a semiconductor package is characterized in that a plurality of laser beams are emitted from one laser diode (19).