JPH11191221A - Optical recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a biaxial lens holder in which two objective lenses are integrated from rotation due to the external force. SOLUTION: A CD lens 1 and a DVD lens 2 are installed on a biaxial lens holder 3, which is fixed to a skew plate 4 by biaxis fixing screws 21a and 21b. A notch is formed in a part of the skew plate 4 and the notch is made to be a notch part 24. The skew plate 4 is mounted on a base through skew screws 22a-22c. A pin 23 is formed on the base. The pin 23 is made to be engaged with the notch part 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording / reproducing apparatus, and more particularly, to a biaxial lens holder on which an objective lens for CD and an objective lens for DVD are installed, for preventing displacement of these objective lenses. Optical recording / reproducing apparatus.

[0002]

2. Description of the Related Art It is difficult to use the same optical pickup of a player for reproducing DVDs and CDs due to the difference in the thickness of the disk substrates. Therefore, it is conceivable to provide two optical pickups in order to reproduce both a DVD and a CD in one player. However, the provision of two optical pickups is not actually performed due to the problem of high cost, etc., and it is possible to perform compatible playback between DVD and CD with one optical pickup by the following method. I have.

[0003] The first system is a bifocal lens system, which enables compatible reproduction by forming a hologram on a lens. The liquid crystal shutter system, which is the second system, enables compatible reproduction by switching the diameter of a light beam incident on a lens by the liquid crystal shutter. Further, in the lens switching method which is the third method, two objective lenses for DVD and CD are provided, and by switching between these, compatible reproduction is enabled.
The tilt of the objective lens used in these methods is adjusted and provided so that the laser beam is irradiated perpendicularly to the disk.

[0004]

However, in the above-described lens switching method, if the inclination is adjusted in accordance with one of the objective lenses, the other lens has a degree of freedom in the rotation direction of the disk, so that an external When force is applied, it can cause misalignment. In order to prevent this displacement, it was necessary to inspect the displacement during the final process, and to immediately adhere and fix the position after the position adjustment.

The present invention has been made in view of such a situation. A lens for adjusting the inclination is provided with a notch and a protrusion, and the notch and the protrusion are engaged with each other. Is to be prevented from shifting.

[0006]

According to a first aspect of the present invention, there is provided an optical recording / reproducing apparatus, comprising: a holding member for movably holding an objective lens for irradiating a recording medium with light for recording or reproducing information; and a holding member. A mounting member having a spherical shaft portion on the lower surface, a base member provided with a spherical bearing portion engaged with the spherical shaft portion, and connecting the mounting member so as to adjust the inclination angle, the mounting member and the base member Is characterized in that one and the other are provided with a notch and a projection which engage with each other.

In the optical recording / reproducing apparatus according to the first aspect, a holding member for movably holding an objective lens for irradiating a recording medium with light for recording or reproducing information,
A mounting member to which a holding member is attached and which has a spherical shaft portion on a lower surface, and a base member to which a spherical bearing portion with which the spherical shaft portion is engaged is provided, and the mounting member is connected to be capable of adjusting a tilt angle; One and the other of the member and the base member are provided with engagement portions that are engaged with each other.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below. In order to clarify the correspondence between each means of the invention described in the claims and the following embodiments, each means is described. When the features of the present invention are described by adding the corresponding embodiment (however, an example) in parentheses after the parentheses, the result is as follows. However, of course, this description does not mean that each means is limited to those described.

An optical recording / reproducing apparatus according to the present invention enables an objective lens (for example, a CD lens 1 and a DVD lens 2 in FIG. 2) for irradiating a recording medium with light for recording or reproducing information. A holding member for holding (for example, 2 in FIG. 2)
An axial lens holder 3), a mounting member (for example, the skew plate 4 in FIG. 2) to which the holding member is mounted, and which has a spherical shaft portion (for example, the spherical shaft portion 35 in FIG. 3) on the lower surface.
A spherical bearing portion (for example, the spherical bearing portion 36 in FIG. 3) with which the spherical shaft portion engages is provided, and a base member (for example, the base 5 in FIG. 3) for connecting the mounting member so as to adjust the inclination angle is provided. One of the mounting member and the base member has an engaging portion (for example, the notch portion 24 in FIG.
It is characterized by having the pin 23) of FIG.

FIG. 1 shows the structure of an optical pickup according to the present invention. FIG. 1 (A) is a plan view and FIG. 1 (B) is a side view. In this configuration, a CD lens 1 as an objective lens used when reproducing or recording a CD, and a DV
A DVD lens 2 as an objective lens used when reproducing or recording D is mounted on a biaxial lens holder 3 so as to be movable in a focusing direction and a tracking direction, respectively, and has an integrated structure. The biaxial lens holder 3 is fixed on the skew plate 4. The skew plate 4 is mounted on a base 5 so that the skew can be adjusted. The base 5 is attached by a guide 6 so as to be movable in the radial direction (left and right direction in FIG. 1) of the disk 11 (DVD or CD).

When a focus control signal is supplied to a focus control coil (not shown), the CD lens 1 or DVD lens 2 is moved in the optical axis direction in accordance with the signal, and the tracking control signal is not shown. When supplied to the tracking control coil, it is moved in a direction orthogonal to the optical axis in accordance with the signal.

FIGS. 2 and 3 are views for explaining in detail the skew adjusting mechanism of the biaxial lens holder 3. FIG.
Is a plan view and FIG. 3 is a side view. Biaxial lens holder 3
After the position is adjusted so that the skew plate 4 and the objective lens are parallel, the skew plate 4 is fixed to the skew plate 4 by two-axis fixing screws 21a and 21b. The skew plate 4 is attached to the base 5 via three skew screws 22a to 22c, and a spherical shaft portion 35 is provided on a lower surface side of the skew plate 4. On the upper surface side of the base 5, the spherical bearing portion 3 slidably in contact with the spherical shaft portion 35.
The skew plate 4 is superimposed on the base 5 in a state where the spherical shaft 35 is slidably engaged with the spherical bearing 36.

The above three skew screws 22a to 22c
The skew screw 22 a is screwed into the base 5 from the upper surface of the skew plate 4. The diameter of the hole for inserting the skew screw 22a provided in the skew plate 4 is formed slightly larger than the diameter of the skew screw 22a. In other words, there is a gap between the skew screw 22a and the skew plate 4. Therefore, the contact does not hinder the skew adjustment described later. A skew adjusting screw 31 is mounted between the head of the skew screw 22a and the upper surface of the skew plate 4, so that the skew plate 4 is pressed toward the base 5 via the skew screw 22a. ing.

The other two skew screws 22b and 22c
Are screwed into the skew plate 4 from the lower surface of the base 5. The diameter of the holes for the skew screws 22 b and 22 c provided on the base 5
b, 22c are formed slightly larger than the diameter,
In other words, since there is a gap between the skew screw 22b or 22c and the base 5, by making contact,
There is nothing to prevent skew adjustment.

The skew adjustment is performed on the DVD lens 2 or the CD.
The laser beam emitted from the lens 1 is applied to a disk 11 (FIG. 1).
(B) The skew of the biaxial lens holder 3 is adjusted so as to be irradiated perpendicularly to (B). This skew adjustment is performed by screwing or unscrewing the two skew screws 22b and 22c into the skew plate 4. As a result, the skew plate 4 is
6, the biaxial lens holder 3 fixed on the skew plate 4, and the tilt angles of the DVD lens 2 and the CD lens 1 installed integrally on the biaxial lens holder 3 It is adjusted (skew adjustment).

As described above, the skew adjustment is performed for one of the objective lenses of the CD lens 1 and the DVD lens 2 and is not performed for the other objective lens. Normally, the skew adjustment is performed on the DVD lens 2 because the inclination adjustment accuracy on the DVD side where information is recorded at higher density must be stricter than on the CD side. For this reason, the DVD lens 2 is arranged such that its center is located at the center of the spherical shaft portion 35 (spherical bearing portion 36). Therefore, the skew plate 4 may rotate on the horizontal plane, with the center of the spherical shaft portion 35 (the center of the DVD lens 2) serving as the center of rotation. In other words, the CD lens 1 installed at a position deviated from its center may rotate in a horizontal plane when a strong external force acts thereon, as shown in FIG. This rotation is performed by the skew screw 22a, the skew plate 4, and the skew screw 22 described above.
It occurs only within the range of the gaps that exist between b, 22c and the base 5, but it is necessary to regulate as much as possible.

In order to regulate such rotation, first, a part of the skew plate 4 is cut out,
To form Then, a pin 23 is implanted in the base 5 and engaged with the notch 24. The conditions for determining the shape of the pin 23 and the size of the notch 24 will be described below. (1) When adjusting the skew, a gap is ensured so that the pin 23 and the notch 24 do not interfere with each other. This is because when adjusting the skew, the skew plate 4 is
However, it is necessary to provide a gap between the pin 23 and the notch 24 so as not to hinder the movement. (2) When the skew plate 4 is moved by an external force, the skew plate 4 is kept within a maximum gap determined from an allowable movement amount. That is, as described in (1), a gap is required between the pin 23 and the notch 24 for skew adjustment. However, if the gap is made larger than necessary, it is caused by an external force which is the original purpose. Since the problem of preventing rotation cannot be solved, it is preferable to make the gap as small as possible.

As for the position of the notch 24, it is cheaper to secure the accuracy if it is away from the center of rotation of the skew plate 4, that is, from the DVD lens 2. Therefore, in the case of this example, as shown in FIG. 2, the notch 24 is formed on the opposite side of the DVD lens 2 with the CD lens 1 interposed therebetween.

The pins 23 may be fixed to the base 5 by crimping, or may be formed as projections when the base 5 is formed in advance. Also, recesses (notches) formed in the skew plate 4 and the base 5
The positions of and the projections (pins) may be reversed.

As described above, rotation of the skew plate 4 can be prevented by using the engaging portions (the pin 23 and the cutout portion 24) which engage with each other.
By preventing the skew plate 4 from rotating as described above, the displacement of the objective lens can be eliminated, so that the inspection process and the like in the manufacturing process can be omitted, the diameter of the skew screws 22a to 22c, the mounting of the skew screws 22a to 22c, and the like. Even if the accuracy of the position is roughened, no problem occurs, so that the manufacturing cost can be reduced accordingly.

[0021]

According to the optical recording / reproducing apparatus according to the first aspect, since the engaging portions for mutually engaging are formed on one and the other of the mounting member and the base member, the rotation of the mounting member is prevented. It is possible to prevent the position of the objective lens from shifting.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an optical pickup of the present invention.

FIG. 2 is a plan view for explaining details of an optical pickup.

FIG. 3 is a side view of the optical pickup of FIG. 2 when viewed from the side.

[Explanation of symbols]

1 CD lens, 2 DVD lens, 3 Biaxial lens holder, 4 Skew plate, 5 Base, 2
1a, 21b Biaxial fixing screw, 22a to 22c
Skew screw, 23 pin, 24 notch,
31 Screw for skew adjustment, 35 Spherical shaft, 36
Spherical bearing

Claims (2)

[Claims] 1. A holding member movably holding an objective lens for irradiating light for recording or reproducing information on a recording medium; an attachment member to which the holding member is attached, the attachment member having a spherical shaft portion on a lower surface; An optical recording / reproducing apparatus provided with a spherical bearing portion with which the spherical shaft portion engages, and a base member for connecting the mounting member so that the inclination angle can be adjusted, wherein one of the mounting member and the base member is Is
An optical recording / reproducing apparatus, comprising: an engaging portion that engages with each other. 2. The holding member comprises: a first objective lens arranged at a position corresponding to the spherical shaft portion; and a second objective lens arranged at a predetermined distance from the first objective lens. The engaging portion is provided between the first objective and the second objective lens.
The optical recording / reproducing apparatus according to claim 1, wherein the optical recording / reproducing apparatus is arranged on the opposite side of the objective lens.