JPH0581697A - Light pickup device - Google Patents

Abstract

PURPOSE:To provide a device which reads, erases and writes continuous or any information by a high speed search with a short access time from two optical disks and reduces the number of parts and price. CONSTITUTION:A pickup 10 is provided which has two objective lens sections 11 and 12 corresponding to the information surfaces of two optical disks 6 and 7 located on turn tables 4 and 5 which are placed side by side. The light pickup 10 is placed by a guide shaft 8 so that the two objective lens sections 11 and 12 linearly move in the radial directions of the two optical disks 6 and 7. An operation such as information reading is accomplished by switching optical paths of a laser light source 13 located on the pickup 10 by a rotating prism 16 so that the laser light is converged on the information surface of either the required optical disks 6 or 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup device used for reading and erasing information recorded on a magneto-optical disk and writing new information.

[0002]

2. Description of the Related Art In conventional information recording / reproducing devices, some optical pickup devices have been proposed which selectively read information from two optical disks.

First of all, one example is 2 arranged side by side on the same plane.
A single optical disc is mounted on the mounting portion of the spindle, and an optical pickup is installed so that it can be guided and moved between the two optical discs by a guide shaft disposed between the two spindles. Is an optical pickup device that focuses the light on the information surface of the optical disc and guides the reflected light reflected by the information surface of the optical disc to the photodetector to read the information.

In another example, the information (recording) surfaces of the optical discs are opposed to each other on the spindle so that the optical pickups can be guided and moved between the two optical discs. Laser light is reflected in two directions and focused on the information surfaces of both optical disks at the same time, and is reflected by the information surfaces of the respective optical disks.
This is an optical pickup device that switches two reflected lights and appropriately guides them to two photodetectors to read information.

[0005]

In the above-mentioned conventional optical pickup device, the former has a drawback that it takes a long access time because one optical pickup linearly reciprocates between two optical disks during operation.

In the latter case, since the laser light is focused on the two optical disks at the same time, the number of parts of the device is increased and there is a problem in cost.

[0007]

SUMMARY OF THE INVENTION The optical pickup device of the present invention solves the above problems of the conventional device.
An optical disk mounting section disposed on each of two spindles whose rotation axes are parallel to each other at a constant interval, and two objective lens sections corresponding to the information surfaces of the two optical disks mounted on the mounting section. Is provided so that the two objective lens units can linearly move in the radial direction of the two optical disks, and the objective lens unit of any one of the two objective lens units is provided. A rotary prism for switching the optical path of the laser light is provided in the pickup so that the laser light passes therethrough, and the optical path is switched by the rotary prism to focus the laser light on the information surface of the desired optical disk and read the information. , Erasing or writing is performed.

[0008]

In the optical pickup device according to the present invention, reading, erasing or writing of an optical disk is performed by switching the optical path from one optical disk to the other optical disk by a prism, so that high speed search can be performed.

[0009]

FIG. 1 shows an embodiment of an optical pickup device according to the present invention.
The following is a description with reference to FIG.

As shown in FIG. 1, spindle motors 2 and 3 are fixed to a substrate 1 of the information recording / reproducing apparatus main body so that the rotation axes thereof are parallel to each other with a required space, and the spindle motors 2 and 3 are attached to the respective spindle motors 2 and 3. Turntables 4 and 5 on which optical disks (optical recording media) 6 and 7 are mounted are provided on the provided spindles 2'and 3 '.

A guide shaft 8 provided on the substrate 1
Then, the objective lens units 11 and 12 are connected via the linear motor 9.
The optical pickup 10 on which is mounted is guided and pivotally mounted. The objective lens units 11 and 12 include a focus coil, a tracking coil, and the like. The guide shaft 8 is arranged between the spindles 2'and 3'in the radial direction of the optical discs 6 and 7 or in the direction parallel to the radial directions of the optical discs 6 and 7, and accordingly, the optical pickup 10 is provided.
Is linearly moved by the linear motor 9, and the objective lens units 11 and 12 are linearly moved in the radial direction facing the information surfaces of the disks 6 and 7, respectively.

Further, the optical pickup 10 shown in FIG.
As shown in, a semiconductor laser (light source) 13 is provided,
Laser light from the semiconductor laser 13 is collimated by a collimator lens 14
Passing through the optical discs 6 and 7 to become parallel light which is perpendicular to the information surfaces of the optical discs 6 and 7, and the beam splitter 1 is placed on the optical path of the parallel light.
5 are provided.

The transmitted light of the beam splitter 15 is provided on the optical path of this transmitted light, and the rotating prism 16 capable of changing the direction changes the optical path by approximately 90 degrees and goes straight to a fixed prism 17 which is fixed. It is incident. Fixed prism 1
The light reflected by 7 becomes substantially parallel to the light transmitted through the collimator lens 14, and this reflected light passes through the objective lens portion 11 and is condensed at a predetermined position on the optical disk 6 to write or erase information. Be done. Further, when the information is read, the reflected light from the information surface of the optical disk 6 traces the above optical path in the opposite direction and is branched by the beam splitter 15, and the branched light is passed through the spot lens 18 and the photodetector. The recording information and various servo signals contained in the collected light are collected at 19 and are detected.

As described above, when the writing, erasing or reading operation of the information on the optical disk 6 is completed and the writing, erasing or reading operation of the information on the other optical disk is performed, the rotating prism 16 is set to the position shown in FIG. As shown, the rotary shaft 20 'of the rotary motor 20 is mounted, and as shown in FIG. 4, when the disk switching signal is input to the control means 21, the rotary motor 20 is instructed and the rotary prism 16 is rotated. As shown by the broken line in FIG. 2, the light transmitted through the beam splitter 15 is rotated about the rotation axis 20 ′, its optical path is changed by about 90 degrees by the rotation prism 16, and goes straight in the direction opposite to the fixed prism 17. And is incident on another fixed prism 21 that is fixed.

The light reflected by the fixed prism 21 is
The transmitted light of the collimator lens 14 becomes substantially parallel, and this reflected light passes through the objective lens 12 on the optical pickup 10 moved to a required position by the linear motor 9 and is condensed at a predetermined position of the optical disc 7, Are written and erased. If more information is to be read,
In the same process as in the case of the optical disc 6, the photodetector 19 detects the recording information of the optical disc 7 and various servo signals.

The relationship between the linear motor 9, the rotary motor 20 and the control means 21 for controlling them is shown in the block circuit diagram of FIG. 4 is a conventional circuit of the information recording / reproducing apparatus, 27 is a signal processing circuit for digitally processing the signal of the optical pickup 10, 22 is a servo error signal for outputting a signal to the servo phase compensation circuit 24. The generation circuit 23 is a laser light control circuit 23 for controlling the laser light of the optical pickup 10.

Since the optical pickup device of the present invention has the above-described structure, if the operation of the pickup 10 is switched from the optical disk (first optical disk) 6 to the optical disk (second optical disk) 7, the operation is performed. Is as shown in the flowchart of FIG.

[0018]

According to the present invention, since the prism of the optical pickup can be rotated by the rotary motor to switch the traveling direction of the laser light quickly, continuous or arbitrary information from two optical disks can be accessed at high speed with a short access time. Reading (playback) and erasing can be performed by searching, and writing (recording) can be performed. Further, the number of parts is small and the cost can be reduced as compared with the conventional case.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a mounted state of an optical pickup device of the present invention.

FIG. 2 is a schematic configuration diagram of an optical pickup device of the present invention.

3 is a schematic configuration diagram of the optical pickup device of the present invention, which is taken along the substantially central section of FIG.

FIG. 4 is a block circuit diagram showing a relationship between a linear motor, a rotation motor, and control means for controlling them in the optical pickup device of the present invention.

FIG. 5 is a flowchart of the operation of the optical pickup device of the present invention.

[Explanation of symbols]

 6, 7 Optical disk 8 Guide shaft 9 Linear motor 10 Optical pickup 11, 12 Objective lens part 13 Semiconductor laser 16 Rotating prism 17, 21 Fixed prism

Claims (1)

[Claims] 1. An optical disk mounting portion disposed on each of two spindles whose rotation axes are parallel to each other at a constant interval, and 2 corresponding to information surfaces of two optical disks mounted on the mounting portion. A pickup having one objective lens section is provided, and the pickup is provided so that the two objective lens sections can move linearly in the radial direction of the two optical disks.
A rotary prism for switching the optical path of the laser light is provided in the pickup so that the laser light passes through any one of the two objective lens sections, and the optical path is switched by the rotary prism to obtain a desired optical disc. An optical pickup device characterized in that laser light is focused on an information surface to read, erase or write information.