JP2000285459A - Optical disc device and optical disc cartridge device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical disc device and an optical cartridge device which enables writing and/or reading of information onto/from an optical disc in a state without a resin layer and can eliminate the influence of tilt which causes a trouble when the information is write and/or read onto/from the optical disc. SOLUTION: An optical disc device which writes and/or reads information onto/from an optical disc 11 by using an optical pickup has a cartridge 12 in which the optical disc 11 is enclosed and a transparent member provided between the optical disc 11 and the object lens of the optical pickup. Information can be written and/or read directly onto/from the side of the optical disc 11 on which unevenness is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical disk device and an optical disk cartridge device.

[0002]

2. Description of the Related Art Generally, an information storage device using an optical disk includes a compact disk (hereinafter referred to as C) as the optical disk.
D) or a digital video disk (hereinafter referred to as a DVD). JP-A-10-
Japanese Patent Application Publication No. 79135 discloses at least a laser light source, an objective lens, a liquid crystal panel for correcting aberration formed by dividing a transparent electrode into a predetermined shape, and a light receiving element, and a laser emitted from the laser light source. Light is incident on the information recording surface of the optical disk via the aberration correction liquid crystal panel and the objective lens to form a light spot, and the resulting reflected light is received by the light receiving element and recorded on the optical disk. A tilt servo device in an optical disc reproducing apparatus provided with an optical pickup for reading a signal corresponding to information to be read, the signal detecting a signal corresponding to a tilt angle in a radial direction between an information recording surface of the optical disc and an optical axis of the objective lens. A tilt detection unit, and a drive circuit that variably drives the applied voltage of each divided portion of the liquid crystal panel, The driving circuit drives each of the divided portions of the liquid crystal panel so as to have a predetermined applied voltage in accordance with the detection output of the tilt detecting means. The tilt servo device in the optical disc reproducing apparatus is characterized in that aberration correction of the objective lens inclined at the tilt angle is performed on the information recording surface of the optical disc by adjusting the phase difference of the optical disc.

[0003]

The recording density of DVDs and the like is higher than that of CDs, so that the conditions for reading and writing information are strict. For example, in an optical disk device using a DVD or the like, it is ideal that the optical axis of the optical pickup is perpendicular to the recording surface of the optical disk. However, the optical disk is actually made of resin, and therefore has considerable undulation. . Therefore, when the optical disc is rotated, the optical axis of the optical pickup and the recording surface of the optical disc are not always perpendicular. Hereinafter, when the recording surface of the optical disc and the optical axis of the optical pickup are not perpendicular to each other, this is referred to as tilt.

As shown in FIG. 8, a recording layer 1 of an optical disk has resin layers 3, 4 on an objective lens 2 side of an optical pickup.
Is provided, when the recording layer 1 is not perpendicular to the optical axis of the optical pickup, the optical path in the resin layers 3 and 4 is bent from the dashed line to the solid line in the drawing, and the light spot on the optical disk cannot be correctly focused. Coma aberration 5 occurs.
If the coma aberration 5 is larger than the allowable amount, there occurs a problem that reading and writing of information from / to the optical disk cannot be performed properly.

As a means for eliminating the influence of tilt, there is a method of thinning a resin layer between an objective lens and a recording layer of an optical disk. The reason that the resin layer 4 of the DVD as shown in FIG. 8B is actually half of the resin layer 3 of the CD as shown in FIG. However, in the case of this method, when recording at a higher density than DVD, the resin is made thinner to further reduce the influence of tilt, but this time, when dust or scratches are formed on the disc, There is a problem that signals cannot be read and written correctly.

Further, there is a tilt servo device described in Japanese Patent Application Laid-Open No. 10-79135, which corrects coma aberration by controlling the phase of a laser beam using a liquid crystal panel. Since the light passes through the panel, the amount of laser light is attenuated, and it is difficult to obtain the energy required for writing.

According to the present invention, it is possible to write and / or read information on an optical disk without a resin layer, and to generate a tilt when writing and / or reading information on an optical disk. It is an object of the present invention to provide an optical disk device and an optical disk cartridge device that can eliminate the influence of the above.

[0008]

According to a first aspect of the present invention, there is provided an optical disk apparatus for writing and / or reading information on an optical disk using an optical pickup, wherein the optical disk is sealed. The optical disc includes a cartridge, a transparent member provided between the optical disc and the objective lens of the optical pickup, and writes and / or reads information directly from the side of the optical disc where the irregularities are formed.

According to a second aspect of the present invention, in the optical disk device according to the first aspect, a window formed of the transparent member is provided in the cartridge. According to a third aspect of the present invention, in the optical disk device according to the second aspect, guide means for guiding the optical pickup are provided on both sides of the window. According to a fourth aspect of the present invention, in the optical disk device according to the first aspect, the cartridge is filled with a gas that becomes a dry atmosphere.

According to a fifth aspect of the present invention, in the optical disk device according to the first aspect, a desiccant is provided in the cartridge. The invention according to claim 6 is the optical disc device according to claim 5, wherein the desiccant is replaceable. According to a seventh aspect of the present invention, in the optical disk device according to the sixth aspect, the moisture absorption state of the desiccant can be visually recognized.

An eighth aspect of the present invention provides a cartridge which is detachably mounted on a main body of an optical disk device for writing and / or reading information on an optical disk by using an optical pickup, and wherein a cartridge in which the optical disk is sealed, A transparent member provided between the optical pickup and an objective lens of the optical pickup, wherein writing and / or reading of information is directly performed by the optical disc device from the side of the optical disc where the irregularities are formed.

[0012]

FIG. 1 shows a part of a first embodiment of the present invention. In FIG. 1, reference numeral 11 denotes an optical disk for reading and writing information. This optical disk 11 has no resin layer between the recording layer and the objective lens of the optical pickup. Reference numeral 12 denotes a cartridge in which the optical disk 11 is sealed. The cartridge 12 has a transparent window 1 at a portion between the recording surface of the optical disk 11 and the objective lens of the optical pickup.
3 are provided.

The window 13 is formed of a transparent member, and the inside of the cartridge 12 is completely sealed, and a dry atmosphere is formed by sealing a dry gas. The portion of the cartridge 12 where the window 13 is provided (the portion on the left side and lower side of the center portion) is one step lower (on the middle side of the cartridge 12).
The window 1 is formed closer to the optical disk 11 by being formed so that the portion on the left side of the central portion is one step thinner.
3 is provided near the lower side of the optical disk 11.

Reference numeral 14 denotes the optical disk 1 for rotating the optical disk 11 by rotating the rotary shaft 15 of a spindle motor.
1 is a member for transmitting a rotational force to the member 1.
4 is made of a ferromagnetic material such as Fe. Reference numeral 16 denotes a member for rotating the optical disk 11 with a good posture together with the rotational force transmitting member 14, and reference numerals 17 and 18 denote rotary bearings made of radial bearings.

The rotational force transmitting member 14 is provided in the cartridge 1
The optical disk 11 is rotatably supported by a radial bearing 18 at a lower central portion of the optical disk 2, and is fixed to a lower surface of the central portion of the optical disk 11. The member 16 is rotatably supported by a radial bearing 17 at a central upper portion in the cartridge 12, and is fixed to an upper surface of a central portion of the optical disk 11. Therefore, the optical disk 11 is rotatably supported in the cartridge 12.

Reference numeral 19 denotes a positioning member for determining the center of the cartridge 12. The positioning member 19 is fixed to the upper central portion of the cartridge 12, and has a conical concave portion 19a. Optical disk 11, cartridge 12,
Each of the above members 14, 16, 19 and radial bearing 1
Numerals 7 and 18 constitute an optical disk cartridge device, which is removably provided on the main body of the optical disk device (excluding the optical disk cartridge device) and is set on the rotating shaft 15 of the spindle motor. The spherical convex portion 20 a of 20 is fitted into the concave portion 19 a of the positioning member 19, and the positioning of the cartridge 12 is performed.

Although not shown, the cartridge 12 is positioned in the height direction and the rotation direction of the optical disk by positioning members other than the cartridge positioning member 20 in the main body of the optical disk device, and is always determined with respect to the rotation shaft 15 of the spindle motor. It is designed to be installed at a designated location. The rotating shaft 15 of the spindle motor has a permanent magnet (not shown) mounted thereon and is magnetically coupled to the rotating force transmitting member 14, so that the rotating force transmitting member 14 transmits the rotating force by magnetic force without contact. I have. The main body of the optical disk device is well known, and has an optical pickup.

FIG. 2 is an enlarged view of the vicinity of the window 13 of the present embodiment. The read / write objective lens 21 of the optical pickup is moved in a focus direction and a track direction by a focus servo system and a track servo system to perform focusing and tracking, and the optical disc 11 has a recording layer 11a on the lower side. Is provided. When the spindle motor rotates and its rotating shaft 15 rotates, the rotating shaft 1
5, the torque is transmitted to the torque transmitting member 14 by magnetic force in a non-contact manner, and the torque transmitting member 14 and the optical disc 11
And the member 16 rotates. The main body of the optical disk device reads and writes information on the optical disk 11 through the objective lens 21 and the window 13 using an optical pickup.

At this time, the optical disk 11 is displaced to some extent in the vertical and horizontal directions as indicated by the arrows in the figure. Objective lens 2
Numeral 1 moves up, down, left and right following the optical disk 11 by a focus servo system and a track servo system. Here, since the surface of the optical disk 11 is undulating, the recording layer 11a of the optical disk 11 and the optical axis of the objective lens 21 do not always become perpendicular to each other. It is always kept perpendicular to the optical axis. Therefore, even if the objective lens 21 moves, the light incident from the window 13 does not change in the direction of refraction as shown in FIG. In other words, coma due to refraction hardly occurs.

FIG. 3 shows a part of a second embodiment of the present invention. In the second embodiment, in the first embodiment, the optical disc cartridge device is different from the first embodiment in that a member 22 for rotating the optical disc 11 in a good posture and a member for rotating the optical disc 11 are used instead of the rotational force transmitting member 14. The rotational force of the rotating shaft 15 of the spindle motor is
, And a radial bearing 24 of a rotary bearing is used in place of the radial bearing 18.

The rotational force transmitting member 23 is made of a ferromagnetic material such as Fe, and the radial bearing 24 is a shield bearing shielded by rubber or the like. The shield bearing 24 is used to prevent dust and dirt from entering. The member 22 is a cartridge 1
The optical disk 11 is rotatably supported by a radial bearing 24 at a lower central portion of the optical disk 2 and is fixed to the lower surface of the optical disk 11 at the central portion.

The rotational force transmitting member 23 is integrally rotatable with the member 22 at a lower central portion in the cartridge 12 by a radial bearing 24 so as to be rotatable, and is set on the rotating shaft 15 of the spindle motor. When the spindle motor rotates and its rotating shaft 15 rotates, the rotating shaft 15
The optical disk 11 and the members 16 and 22 are rotated by transmitting the rotational force by magnetic force to the rotational force transmitting member 23 in a non-contact manner. In the second embodiment, as in the first embodiment, coma due to refraction hardly occurs.

FIG. 4 shows a part of a third embodiment of the present invention. In the third embodiment, the thickness of the first embodiment is reduced. In the third embodiment, the optical disk cartridge device according to the first embodiment is different from the first embodiment in that
, And radial bearings 17 as rotating bearings,
Thrust bearings 25 and 26 are used in place of 18. The optical disk 11 has thrust bearings 25, 26
Is provided, and is rotatably supported at the center in the cartridge 12 by thrust bearings 25 and 26. Also, instead of the torque transmitting member 14, a torque transmitting member 27 made of a ring-shaped ferromagnetic material is used.
The rotational force transmitting member 27 is used for the optical disc 1.
1 is fixed concentrically to the lower surface. Thereby, the size of the entire device can be reduced.

FIG. 5 shows a part of a fourth embodiment of the present invention. In the fourth embodiment, the third embodiment is a double-sided type capable of reading and writing on both sides of an optical disk. In the fourth embodiment, the optical disc cartridge device according to the third embodiment uses an optical disc 28 having recording layers on both sides instead of the optical disc 11.
The cartridge 12 is provided with a transparent window 29 not only in the lower part but also in the upper part. The window 29 is made of a transparent member.

In the cartridge 12, the portion provided with the window 29 (the upper portion on the left side of the center portion) is formed one step lower (on the middle side of the cartridge 12), and the portion on the left side of the center portion is formed one step thinner. As a result, a window 29 is formed near the optical disk 28, and a window 29 is provided near the upper side of the optical disk 28. The main body of the optical disk device is
A known device capable of reading and writing information on both sides of the optical disk 28 without reversing the cartridge is used, and reading and writing information on both surfaces of the optical disk 28 through an objective lens and windows 13 and 29 using an optical pickup respectively. . The main body of the optical disk device can be used even in a single-sided device by turning the cartridge upside down. In this embodiment, when the optical disk 28 is a ROM or the like, there is a merit that the optical disk 28 can be made at once by a stamper, which is advantageous in terms of cost.

FIG. 6A is a front view showing an optical disk cartridge device according to a fifth embodiment of the present invention, and FIGS. 6B and 6C are cross-sectional views taken along line AA of FIG. -B
It is a line sectional view. The fifth embodiment is different from the first embodiment in that guide rails 30 and 31 are integrally provided on both sides of the window 13 on the outer surface of the cartridge 12 in parallel with the radial direction of the optical disk 11 as guide means. The optical pickup 32 having the lens 21 is integrally provided with a reference roller 33 and a follower roller 34.

The optical pickup 32 is lightly pressed to the left in FIG. 6C, and the rollers 33 and 34 roll on the guide rails 30 and 31 so that the optical disc 1 is rotated.
1 in the radial direction. The optical pickup 32 moves in the radial direction of the optical disk 11 along the guide rails 30 and 31 by being driven by a seek motor (not shown). Since the optical pickup 32 is moved along the side of the cartridge 12 in this manner, the occurrence of tilt is further suppressed, and coma hardly occurs.

In each of the embodiments other than the first embodiment, similarly to the fifth embodiment, the optical pickup 32 is moved in the radial direction of the optical disk 11 along the cartridge 12 by driving by a seek motor. You may make it do.

FIG. 7 shows a part of a sixth embodiment of the present invention. This sixth embodiment is different from the first embodiment in that
A desiccant is provided. In the above embodiment, since the cartridge 12 is not completely sealed, air can enter and exit even if dust and dust can be blocked. Therefore, the sixth
In this embodiment, a moisture absorbent 35 is provided as a desiccant in order to prevent dew condensation due to moisture absorption in the cartridge 12.

The hygroscopic agent 35 comprises a hygroscopic filter 35a and a filter fixing material 35b, and the hygroscopic filter 35a is exchangeably fixed to a part of the cartridge 12 by the filter fixing material 35b. The moisture absorption filter 35a is exposed inside the cartridge 12, and absorbs moisture in the cartridge 12. This moisture absorbent 35 can be replaced as needed. The moisture absorption filter 35a changes its color when moisture is absorbed, so that the moisture absorption state can be known. In each of the embodiments other than the first embodiment, the desiccant 35 is replaceably attached to a part of the cartridge 12 so as to be exposed inside the cartridge 12, similarly to the sixth embodiment. Is also good.

Although the embodiments of the present invention have been described above, it is needless to say that the present invention can be applied without being limited to these embodiments. In each embodiment, nitrogen may be used as the dry gas, and silica gel may be used as the desiccant. In addition, the above bearing is not only a rolling bearing,
A sliding bearing may be used. The transparent member constituting the window is desirably thin glass, but may be polycarbonate resin or acrylic resin. Further, it goes without saying that the transparent member and the guide rail which constitute the cartridge and the window may be integrally formed of resin.

As described above, according to the above embodiment, it is possible to read and write information on the optical disk without the resin layer, and to tilt or cause a trouble when reading and writing information on the optical disk. The influence can be eliminated.

[0033]

As described above, according to the first aspect of the present invention, since the optical disk is sealed in the cartridge,
An optical disk having no resin layer can be used, and the influence of tilt can be avoided. Furthermore, an optical disk without a resin layer can be provided with recording layers on both sides,
In such a case, it is possible to make a double-sided optical disk at a time with a stamper, which is advantageous in cost.

According to the second aspect of the invention, since the cartridge is provided with the window formed of the transparent member, the influence of tilt can be avoided as compared with the optical disk having the resin layer. According to the third aspect of the invention, since the guide means for guiding the optical pickup is provided on both sides of the window, the influence of tilt can be further avoided.

According to the fourth aspect of the present invention, since the inside of the cartridge is filled with the gas which becomes a dry atmosphere, it is possible to write and / or read a signal to and from the optical disk without dew condensation inside the cartridge. According to the fifth aspect of the present invention, since the desiccant is provided in the cartridge, it is possible to write and / or read a signal on the optical disk satisfactorily without dew condensation in the cartridge.

According to the sixth aspect of the present invention, since the desiccant can be exchanged, it is possible to write and / or read the signal on the optical disk satisfactorily without condensation in the cartridge. According to the invention according to claim 7, since the moisture absorption state of the desiccant can be visually recognized, it is possible to write and / or read a signal on the optical disk satisfactorily without dew condensation in the cartridge.

According to the eighth aspect of the present invention, since the optical disk is sealed in the cartridge, an optical disk having no resin layer can be used, and the influence of tilt can be avoided. Furthermore, an optical disk having no resin layer can be provided with recording layers on both surfaces, and in the case of a ROM or the like, a double-sided optical disk can be manufactured at once with a stamper, which is advantageous in cost.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a part of a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view showing the vicinity of a window of the embodiment.

FIG. 3 is a sectional view showing a part of a second embodiment of the present invention.

FIG. 4 is a sectional view showing a part of a third embodiment of the present invention.

FIG. 5 is a sectional view showing a part of a fourth embodiment of the present invention.

FIG. 6 is a front view showing an optical disk cartridge device according to a fifth embodiment of the present invention, and a sectional view taken along line AA of FIG.
It is a B sectional view.

FIG. 7 is a sectional view showing a part of a sixth embodiment of the present invention.

FIG. 8 is a diagram for explaining a conventional device.

[Explanation of symbols]

 11, 28 Optical disk 12 Cartridge 13, 29 Transparent window 30, 31 Guide rail 32 Optical pickup 33, 34 Roller 35 Hygroscopic agent

Claims (8)

[Claims] 1. An optical disk device for writing and / or reading information on an optical disk using an optical pickup, comprising: a cartridge in which the optical disk is sealed;
An optical disc device, comprising: a transparent member provided between the optical disc and an objective lens of the optical pickup, wherein information is written and / or read directly from the side of the optical disc where the irregularities are formed. 2. The optical disk device according to claim 1, wherein
An optical disk device, wherein the cartridge is provided with a window formed of the transparent member. 3. The optical disk device according to claim 2, wherein
An optical disk device, wherein guide means for guiding the optical pickup are provided on both sides of the window. 4. The optical disk device according to claim 1, wherein
An optical disk device, wherein the inside of the cartridge is filled with a gas that forms a dry atmosphere. 5. The optical disk device according to claim 1, wherein
An optical disc device, wherein a desiccant is provided in the cartridge. 6. The optical disk device according to claim 5, wherein
An optical disk device, wherein the desiccant is replaceable. 7. The optical disk device according to claim 6, wherein
An optical disk device, wherein the moisture absorption state of the desiccant can be visually recognized. 8. A cartridge which is detachably mounted on a main body of an optical disk apparatus for writing and / or reading information on and from an optical disk by using an optical pickup and in which the optical disk is sealed, an objective lens of the optical disk and the optical pickup And a transparent member provided between the
An optical disk cartridge device wherein writing and / or reading of information is directly performed by the optical disk device from the side of the optical disk where the unevenness is formed.