JPH0229574Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a non-contact type or contact type pick-up installed in a digital audio disc (DAD) player, and in particular, to a pick-up for moving a slider along a guide shaft connected to a motor. This invention relates to a slider driving device.

[Outline of optical pickup] Recently, various DAD players have been developed.
Furthermore, there are two types of pickups provided in this DAD player: non-contact type and contact type. FIG. 1 schematically shows an example of the structure of an optical pick-up, which is a non-contact type of this type of pick-up, and FIG. 2 shows a conventional slider driving device. A disk 1 loaded into a DAD player or the like has a reflective recording surface 1b formed inside a transparent layer 1a, and pits P for digitally recording information on the tracks of this recording surface 1b. is formed. On the other hand, various detection members constituting the optical pickup are installed on a slider 14, as shown in a plan view in FIG. It is adapted to move along another guide axis 16a parallel to the guide axis 16a. The slider 14 is then roughly fed in the left-right direction in FIG. 2 in accordance with the rotation of the guide shaft 16 having the spiral groove 17.

During this rough movement of the slider 14, in FIG. 1, the beam emitted from the laser diode 2, which is the light source of the optical pickup, passes through the beam splitter 3, the collimating lens 4, and the quarter-wave plate 6. The light is reflected by the prism 7 and reaches the objective lens 8. A beam spot is formed on the recording surface 1b within the disk 1 by the objective lens 8. The beam reflected by the recording surface 1b or the pit p is transmitted through the objective lens 8,
The reflected beam returns to the beam splitter 3 after passing through the prism 7, the quarter-wave plate 6, etc. At this time, the plane of polarization of the reflected beam has been changed by 90 degrees, so it is reflected in the 90-degree direction within the beam splitter 3. , the light is received by a photodiode 10, which is a light receiving element, through a cylindrical lens 9. The presence or absence of the pit p can be detected by the intensity modulation when the beat spot hits the pit p.

In addition, this type of optical pickup includes a focusing servo mechanism 11 for accurately focusing the beam on the recording surface 1b when the slider 14 is being roughly fed, and a focusing servo mechanism 11 for accurately focusing the beam on the recording surface 1b.
A tracking support mechanism 12 is provided for accurately following the track on b. The focusing servo mechanism 11 is constituted by a magnetic circuit consisting of a voice coil 11a integrated with the objective lens 8, a magnet 11b for driving this, and a yoke 11c. The tracking support mechanism 12 also includes a voice coil 12a attached to the entire optical system driven member (indicated by reference numeral 13 in FIG. 1) consisting of the objective lens 8, the focusing servo mechanism 11, etc. , a magnet 12 for driving this
yoke 12c and a yoke 12c. In the focusing servo mechanism 11, the objective lens 8 moves slightly in the vertical direction in the figure within the member 13 by changing the current applied to the voice coil 11a. By changing the current, the objective lens 8 and the like (the entire member 13) can be slightly moved in the left-right direction in the figure. These fine movements correct errors caused by distortion of the disk 1 or eccentricity during clamping when the slider 14 is being roughly fed, and ensure that the beam spot is accurately focused on the recording surface 1b. With this, it is now possible to accurately follow the track.

[Problems with conventional technology]

In the optical pickup described above, in order to move the slider 14 along the guide shaft 16, it is necessary to provide a contact on the slider 14. FIG. 3 shows a half-split nut 18 as one of the conventional examples of this contactor. The female thread of this half-split nut 18 is the spiral groove 1 of the guide shaft 16.
7, the rotation of the guide shaft 16 causes the slider 14 to
It can be converted into the mobility of

However, this halved nut 18 requires machining, which not only increases the number of machining steps, but also
There is a drawback that processing work is complicated.

In addition, a pin is used as another contact, and this is brought into contact with the spiral groove 17 of the guide shaft 16, and the spiral groove 1
It is also conceivable that the slider 14 supporting the pin moves in accordance with the feed of the pin 7, but in this case, the structure supporting both ends of the pin would be complicated;
Another disadvantage is that the mechanism for pressing the pin against the spiral groove 17 with a constant force is complicated.

[Purpose of this invention]

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a pick-up slider drive device that is not only simple in structure but also easy to process and install.

[Structure of the present invention]

In the pick-up slider drive device according to the present invention, a spiral groove is carved on a guide shaft connected to a motor, and a plate-like member is mounted on the slider that is equipped with a detection mechanism and moves along this guide shaft. A protrusion is provided which is formed by folding the protrusion in a close contact state, and a curved surface portion of the outer surface of the folded part of the protrusion is engaged with the spiral groove, and a pressing member that presses the protrusion against the spiral groove is provided. It is made up of.

[Example of the present invention]

Next, one embodiment of the present invention will be explained with reference to FIG. 4 and the following drawings.

FIG. 4 is a plan view showing a portion of an optical pickup in a DAD player, FIG. 5 is a right side view of FIG. 4, and FIG. 6 is a front view showing the features of the present invention.

Reference numeral 14 in the figure is a slider. This slider 14 is inserted through two parallel guide shafts 16, 16a via a steel bearing 19.
The guide shafts 16, 16a are arranged so that the slider 14 can move outward from the turntable 20 side (toward the right in FIG. 4) along the disk 1. Further, a spiral groove 17 is cut into the guide shaft 16, and a motor 15 is connected to one end of the guide shaft 16. The tip 21a of the protrusion 21 is engaged with the spiral groove 17 as a contact (see FIG. 6). This protrusion 21 is formed from a plate-like member that is sheared to a predetermined size. That is, the tip 21a is folded back from this plate-like member to form a rising portion 21b, and the lower end 21b is formed by folding back the tip 21a.
1c is bent on both sides to form a T-shape. Therefore, the tip 21a of this protrusion 21 is formed into an R shape by folding back. Incidentally, the rising portion 21b corresponds to the spiral groove 17 in the drawing view of FIG.
It is tilted and fixed in a direction with a thread slope equal to . Further, the lower end portion 21c is connected to the slider 1.
4 by screws 22. Also,
The tip of an adjuster screw 23 screwed into the slider 14 from below is in contact with the raised portion 21b of the protrusion 21. This adjusting screw 23 is for bringing the tip 21a of the protrusion 21 into contact with the spiral groove 17 with an appropriate pressure (the state shown in FIG. 6). Note that this protrusion 21 is chrome-plated, or the tip 2
The surface of the tip 21a is hardened by hardening the tip 1a.

In addition, in FIG. 4, the turntable 2
0 is for clamping the center portion of the disk 1 and rotationally driving the disk 1 by motor power. Also, the recording surface 1b (first
The optical pick-up 30 for reading the above pit information (see figure) has a detection mechanism consisting of an actuator 31 for servo driving the objective lens 8 and an optical detection section 32, which are connected to the slider 14. It is mounted on and configured. This optical detection unit 32 includes a laser diode 2, a beam splitter 3, a collimating lens 4, a 1/4
It consists of various components of the light emitting-light receiving system, such as a wavelength plate 6, a cylindrical lens 9, and a photodiode 10 (all of which are the same as those shown in FIG. 1).

Next, the operation and effects of the present invention with the above configuration will be explained.

First, in the assembly operation, the slider 14 is inserted through the steel bearing 19 through the guide shafts 16, 16a. Further, the lower end portion 21c of the protrusion 21 is brought into contact with the slider 14 and is attached by screwing the screw 22.
At this time, the tip 21a of the protrusion 21 is engaged with the spiral groove 17 formed in the guide shaft 16. Next, screw the adjusting screw 23 into the slider 14 from below, press its tip directly below the rising portion 21b of the protrusion 21, and apply appropriate pressure to the tip 21a against the spiral groove 17. Apply pressure.

Next, driving of the slider 14 will be explained.

When the turntable 20 rotates, the motor 15 is driven in synchronization with the rotation, and the guide shaft 16 connected to the motor 15 rotates. Then, the tip 21a of the protrusion 21 that engages with the helical groove 17 formed in the guide shaft 16 receives the feeding force from the helical groove 17, and transmits the feeding force to the slider 14. As a result, the slider 14 moves outward from its initial position (toward the right in FIG. 4) in the case of a reading operation.
The recording surface 1b of the disk 1 is moved in a so-called rough feed direction across the track. During this time, the focusing servo mechanism 11 for focusing the beam spot on the recording surface 1b in the disk 1 (see Fig. 1) and the tracking servo mechanism 12 for accurately following the track of the disk 1 are operated. Then, the information on disk 1 is read.

In the illustrated embodiment, a single protrusion 21 is used, but the protrusion 21 may have a plurality of protrusions that match the groove pitch of the spiral groove 17. In addition, this protrusion 21
may be bent into an L-shape, and only the tip 21a may be folded back.

[Effects of this invention]

As described above, according to the present invention, the following effects can be achieved.

(1) The protrusion whose tip engages with the spiral groove carved into the guide shaft is formed by folding a plate-like member into a nearly intimate state, making it easy to process and reducing manufacturing costs. , material costs can be reduced.

(2) Also, since this protrusion is formed by sheet metal processing, it can be bent into a T-shape or L-shape and its base can be used as the mounting part for the slider, making the mounting structure simple. become.

(3) Since the tip of this protrusion is formed into an R shape by folding, it is possible to achieve an optimal contact state with the spiral groove, and moreover, it does not damage the spiral groove.

(4) Furthermore, since the protrusion is pressed against the helical groove by the pressing member, the contact between the protrusion and the helical groove is stable, and the protrusion can be brought into contact with the helical groove with an appropriate force. become.

[Brief explanation of drawings]

Fig. 1 is a component arrangement diagram showing the principle of an optical pickup, Fig. 2 is a plan view showing a conventional slider drive device, Fig. 3 is a partially enlarged perspective view of Fig. 2, and Figs. Fig. 4 is a plan view thereof, and Fig. 5 is a slider driving device according to
The right side view of the figure and FIG. 6 are front views showing the characteristic parts thereof. 1...disk, 14...slider, 15...
Motor, 16... Guide shaft, 17... Spiral groove, 2
1... Projection, 21a... Tip (folded part), 30
...Pickup, 31, 32...Detection mechanism.

Claims (1)

[Scope of utility model registration request] A spiral groove is carved into the guide shaft connected to the motor, while a slider that is equipped with a detection mechanism and moves along this guide shaft has a protrusion formed by folding a plate-like member into almost a tight contact state. A slider drive device for a pick-up, wherein a curved surface of an outer surface of a folded portion of the protrusion is engaged with the spiral groove, and a pressing member for pressing the protrusion against the helical groove.