JPH039540B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a beam shutter for optical pickup, and more particularly, a stopper contact portion, a blocking portion, a passage portion having a smaller diameter than the blocking portion, a housing portion, and a protruding portion are connected in the axial direction. The formed cylindrical shutter rod is arranged so that its axial direction is perpendicular to the optical axis of the semiconductor laser, and the passing portion does not block the light beam of the semiconductor laser, near the emission surface of the semiconductor laser. The stopper contact portion is inserted into a coil spring that is in contact with the tip end surface of an adjustment screw installed in a through hole drilled in an outer wall of the optical pickup housing, and the stopper contact portion is inserted into one end of the coil spring so that the cutoff the end surfaces of the parts are in contact with each other, the housing part is housed in a borehole provided in the optical pickup housing, and the through hole bored between the wall surface of the borehole and the outer wall of the optical pickup housing is inserted through the housing part. and the protruding part protrudes from the outer wall of the optical pickup housing, the blocking part and the passing part are positioned near the emission surface of the semiconductor laser, and the beam is attached to the player so as to be movable in the direction of the optical pickup housing. A shutter operating plate is disposed with a gap from the end face of the protruding portion, and the shutter rod is slid in the axial direction by the operation of the beam shutter operating plate, and the semiconductor laser is passed through the passage portion. This invention relates to a beam shutter for optical pickup that allows a light beam to pass through.

The beam shutter of a conventional optical pickup is
As shown in FIG. 1, it is placed between an objective lens A and a 90° deflection mirror B. The beam shutter, as shown in FIG. A roughly V-shaped shutter frame 5 is disposed inside the pick-up housing 2, to which the blocking plate 1 is fixed, the other end is disposed outside the optical pick-up housing 2, and a roller is pivotally connected; is inserted into the pin 3, one end is fixed to one end of the shutter frame 5,
The other end consists of a torsion coil spring 7 fixed within the optical pickup housing 2. The roller 4 then comes into contact with a plate 7 provided on a player (not shown), and the optical pickup housing 2 moves along the plate 7.

When the player is operated, the plate 7 is pushed toward the optical pickup housing 2, and accordingly, the shutter frame 5 is pushed toward the optical pickup housing 2 via the roller 4 and rotates counterclockwise about the pin 3 as a fulcrum. Therefore, the blocking plate 1 also rotates and the beam shutter opens.
Even if the optical pickup housing 2 moves, the roller 4 rolls along the plate 7, so the beam shutter remains open.

When the player is inactive, the plate 7 returns to its original state, so the pressure contact between the plate 7 and the roller 4 is released, and the shutter frame 5 is rotated clockwise by the restoring force of the torsion coil spring 6. Therefore, the blocking plate 1 also rotates and the beam shutter is closed.

In FIG. 1, C is a semiconductor laser, D is a deflection beam splitter, E is a collimator lens,
F indicates a quarter-wave plate, and G indicates a disk.

In this prior art, the beam shutter is operated with the diameter of the light beam increasing as shown in FIG. 1, so the operating stroke is large and space loss is therefore large.
Although this is not a particular problem in large-sized optical pickups, it becomes a serious problem in small-sized optical pickups.

The present invention has been made by focusing on the problems of the prior art, and includes continuous formation of a stopper contact portion, a blocking portion, a passage portion having a smaller diameter than the blocking portion, a housing portion, and a protruding portion in the axial direction. A cylindrical shutter rod is disposed near the emission surface of the semiconductor laser, and the shutter rod is slid in a direction perpendicular to the optical axis of the semiconductor laser by the operation of a beam shutter operation plate outside the optical pickup housing. In particular, it is aimed at solving the above-mentioned problems.

The present invention will be explained below based on the drawings.

FIG. 3 to FIG. 6 are diagrams showing one embodiment of the present invention.

First, to explain the structure, reference numeral 10 is a cylindrical shutter rod, which has a stopper contact part, a blocking part, a passage part smaller in diameter than the blocking part, a storage part, and a protruding part continuously formed in the axial direction. . That is, the shutter rod 10 is connected to the stopper contact portion 10E and the stopper contact portion 10E, and blocks the light beam of the semiconductor laser 11. Hole 12A
A blocking portion 10A that slides on the inner surface of the blocking portion 10A.
A passage section 10B is connected to the optical pickup housing 12 and is connected to the passage section 10B and allows the light beam of the semiconductor laser 11 to pass therethrough. The storage section 10C is connected to the storage section 10C, and is inserted into a through hole 12D bored between the wall surface of the bored hole 12B and the outer wall 12C of the optical pickup housing 12, and its tip end is inserted into the outer wall 12C.
A protrusion 10D protrudes from C. The shutter rod 10 has an axial direction that is perpendicular to the optical axis 11a of the semiconductor laser 11, and a central axis 10a that corresponds to the optical axis 11a of the semiconductor laser 11.
so that it deviates downward (or upward) from a,
That is, the passage section 10B is arranged near the emission surface of the semiconductor laser 11 so as not to block the light beam of the semiconductor laser 11.

The outer diameter of the passage part 10B is determined so as not to block the light beam by taking into account the deviation of the central axis 10a of the shutter rod 10 from the optical axis 11a of the semiconductor laser 11, and the outer diameter of the passage part 10B is determined by taking into consideration the diffusion angle of the light beam. The length of the passage section 10B is determined so as not to block the flow.

The outer diameter of the blocking portion 10A is naturally larger than the outer diameter of the passage portion 10B, and the outer diameter of the storage portion 10c is naturally larger than the outer diameter of the protruding portion 10D.

Reference numeral 13 denotes an adjustment screw, which is screwed into a screw hole 14 provided at one end of the through hole 12A, and is adjusted from the outside of the optical pickup housing 12. A stopper 13A having a diameter smaller than the outer diameter of the adjusting screw 13 is protruded from the center of the tip of the adjusting screw 13. Stopper 13A is shutter rod 10
It faces a stopper contact portion 10E protruding from the end face of the blocking portion 10A.

15 is a coil spring, and stopper 13
A and the stopper contact portion 10E, and both ends thereof are in contact with the distal end surface of the adjusting screw 13 and the end surface of the blocking portion 10A. The strength of the coil spring 15 and the stroke of the shutter rod 10 are adjusted by an adjusting screw 13. Then, with the coil spring 15 expanded, the blocking portion 10A of the shutter rod 10 blocks the light beam of the semiconductor laser 11, and with the coil spring 15 being compressed, the passing portion 10B blocks the light beam of the semiconductor laser. The passage section 10 allows the passage to pass through.
The position of B is determined.

Reference numeral 16 denotes a beam shutter operating plate, one end of which is attached to a player (not shown) so as to be movable in the direction of the optical pickup housing 12, and its middle portion is disposed with a gap from the end surface of the protrusion 10D of the shutter rod 10. There is.

When the optical pickup housing 12 is linearly fed, the protrusion 10D and the beam shutter operation plate 16 come into contact, and the end surface of the protrusion 10D slides on the beam shutter operation plate 16, but this sliding resistance is reduced. Therefore, the end surface of the protrusion 10D is made spherical. Further, in order to further reduce the sliding resistance, one end of the lever 17 is attached to the outer wall 12C of the optical pickup housing 12 as shown in FIG. Roller 1 on the other end
8 may be attached, and the roller 18 may be brought into contact with the beam shutter operation plate 16.

In FIG. 6, 19 is a deflection beam splitter, 20 is a collimator lens, 21 is a quarter wavelength plate, 22 is a 90° deflection mirror, and 23 is a light sensor.

Next, the action will be explained.

When the player is inactive, the shutter rod 1
Since the beam shutter operating plate 16 is not in operation and is not pushed by the beam shutter operating plate 16, the shutter rod 10 is moved toward the beam shutter operating plate 16 side by the force of the coil spring 15. is being pushed. Therefore, the blocking portion 10A of the shutter rod 10 is located at a location that blocks the light beam of the semiconductor laser 11, and the beam shutter is in a closed state.

Next, when the player is operated, the beam shutter operating plate 16 operates and moves toward the optical pickup housing 12, so the protrusion 10D of the shutter rod 10 is pushed from the beam shutter operating plate 16, and the shutter rod 10 is moved toward the coil spring 15. It moves toward the adjusting screw 13 against the force and stops when the stopper 13A of the adjusting screw 13 and the stopper contact portion 10E of the shutter rod 10 come into contact. Therefore, the passage section 10B of the shutter rod 10 is
The beam shutter is located at a place where the light beam of No. 1 passes through, and the beam shutter is in an open state.

Next, to change the beam shutter from the open state to the closed state, the beam shutter operating plate 16 is returned to its original state. Then, coil spring 15
The force causes the shutter rod 10 to move toward the beam shutter operating plate 16, and the beam shutter becomes closed.

Since the shutter rod 10 is disposed near the emission surface of the semiconductor laser 11, the diameter of the light beam at the position of the shutter rod 10 is extremely small, so that its operating stroke can be extremely small. Therefore, space loss is small,
Suitable for small optical pickups.

As explained above, the present invention provides a cylindrical shutter rod which continuously forms a stopper contact portion, a blocking portion, a passage portion having a smaller diameter than the blocking portion, a housing portion, and a protruding portion in the axial direction. The axial direction is perpendicular to the optical axis of the semiconductor laser, and the passage part is arranged near the exit surface of the semiconductor laser so as not to block the light beam of the semiconductor laser,
The stopper contact portion is inserted into the inside of the coil spring that is in contact with the tip end surface of an adjustment screw installed in a through hole bored in the outer wall of the optical pickup housing, and the stopper contact portion is inserted into one end of the coil spring. the end faces of the optical pick-up housing are in contact with each other, the storage section is housed in a borehole provided in the optical pickup housing, and a through-hole bored between the wall surface of the borehole and an outer wall of the optical pickup housing is inserted through the housing part. the protruding portion protrudes from the outer wall of the optical pickup housing, the blocking portion and the passing portion are located near the emission surface of the semiconductor laser, and the beam is attached to the player so as to be movable in the direction of the optical pickup housing. The shutter operating plate is disposed with a gap from the end face of the protrusion, and the action of the beam shutter operating plate causes the shutter rod to slide in the axial direction, so that the operating stroke of the shutter rod is extremely large. Since it is smaller, space loss can be extremely reduced, and it can be applied to small optical pickups.

Furthermore, since the shutter rod is formed in the shape of a shutter rod, even if the shutter rod rotates, the shutter function will not be affected.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the arrangement of a conventional beam shutter, Fig. 2 is an exploded perspective view of the conventional beam shutter, Fig. 3 is an exploded perspective view showing an embodiment of the present invention, and Fig. 4 is an exploded perspective view of the conventional beam shutter. FIG. 5 is a sectional view taken along the line A-A in FIG. 4, and FIG. 6 is a plan view of the beam shutter in a closed state, showing an embodiment of the invention. , FIG. 7 is a plan view showing another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...Shutoff plate, 2...Optical pick-up housing, 3...Pin, 4...Roller, 5...Shutter frame, 6...Torsion coil spring, 7
...Plate, 10...Shutter rod, 11
... Semiconductor laser, 13 ... Adjustment screw, 15 ...
Coil spring, 16...beam shutter operation plate.

Claims (1)

[Claims] 1. A cylindrical shutter rod having a stopper contact portion, a blocking portion, a passage portion having a smaller diameter than the blocking portion, a housing portion, and a protrusion continuously formed in the axial direction, the axial direction of which is perpendicular to the optical axis of the semiconductor laser. In order to prevent the passage part from blocking the light beam of the semiconductor laser, an adjustment screw is disposed near the emission surface of the semiconductor laser and is installed in a through hole bored in the outer wall of the optical pickup housing. The stopper contact portion is inserted into the inside of the coil spring that is in contact with the tip end surface, and the end surface of the blocking portion is brought into contact with one end of the coil spring, and the stopper contact portion is inserted into the bored hole provided in the optical pickup housing. The projecting portion is inserted through a through hole formed between the wall surface of the bored hole and the outer wall of the optical pickup housing, and the protruding portion is protruded from the outer wall of the optical pickup housing. The blocking portion and the passing portion are located near the player, and a beam shutter operating plate, which is attached to the player so as to be movable in the direction of the optical pickup housing, is placed with a gap from the end face of the protrusion, and the player When the player is not in operation, the force of the coil spring causes the blocking portion to be positioned on the emission surface of the semiconductor laser to block the light beam, and when the player is in operation, the beam shutter operating plate moves to close the blocking portion to the protruding portion. A beam shutter for an optical pickup, which contacts an end face of the shutter rod, slides the shutter rod in the axial direction against the force of the coil spring, positions the passage portion at the exit surface of the semiconductor laser, and allows the light beam to pass through.