JP3529047B2 - Optical pickup - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup used in a disc player such as a DVD, and is particularly inexpensive, has a small number of parts, and can be easily attached / detached with a semiconductor laser, has high performance and does not cause a reading error. It is the one.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. 200
1-14712 and the like. An example thereof will be described with reference to FIG. 6, in which a photodiode PD is arranged at one end opening 3a of the light passing hole 3 with the half mirror 2 of the pickup body 1. In addition, the collimator lens QWP and the objective lens OL are arranged in the other end opening 3b, the semiconductor laser LD is housed in the branch hole 4 formed on the side surface of the pickup body 1, and the photodiode PD and the semiconductor laser LD are compatible with each other. A printed circuit board 6 connected via a flexible cable 5 is fixed to the outer peripheral surface of the pickup body 1 with screws 7. Reference numeral 8 is a support substrate for the semiconductor laser LD, and 9 is a connector fixed to the printed circuit board 6. By connecting a plug 10 to the connector 9, the photodiode PD and the semiconductor laser LD control a microcomputer or the like. Connected to the department.

As shown in FIGS. 7 and 8, the pickup main body 1 includes a base frame portion 1a having a substantially rectangular shape in plan view, and a pair of brackets 1b and a rack 1c integrally projecting from side surfaces of the base frame portion 1a. And a through hole 12 of both brackets 1b is movably fitted to a guide rod 13, and a pinion (not shown) meshing with the rack 1c is rotated in the forward and reverse directions to move the pickup body 1 into the guide rod. It can be moved in the directions of arrows a and b along 13.

Further, a photodiode PD is arranged at the upper end of a main cylinder 1d integrally provided on the base frame 1a, and a semiconductor laser LD is provided on a branch cylinder 1e projecting on a side surface of the main cylinder 1d. And the support substrate 8 of the semiconductor laser LD is fixed to the branch cylinder 1e by a plurality of screws (fasteners) 15.

The board body 6a of the printed board 6 has a substantially rectangular shape, and an engaging hole 16 penetrating the lower part thereof is engaged with a substantially L-shaped protruding portion 17 protruding from the base frame portion 1a. At the same time, the screw 7 is screwed into the screw hole of the base frame portion 1a penetrating through the lower portion of the base frame portion 1a so that it is fixed to the outer peripheral surface of the pickup body 1.

In the above configuration, in the inspection before shipment, the laser light from the semiconductor laser LD is projected onto the disk D through the half mirror 2, the collimator lens QWP and the objective lens OL, and the reflected light is projected through the half mirror 2. It is inspected whether or not a predetermined output is obtained from the semiconductor laser LD by reading the information recorded on the disc D by receiving the light by the photodiode PD,
If a predetermined output cannot be obtained, the screw 7 is unscrewed to remove the substrate body 6a from the pickup body 1, and then the screw 15 is unscrewed to remove the support substrate 8 from the pickup body 1. The semiconductor laser LD is pulled out from the branch hole 4 and replaced with a new one.

[0007]

According to the above construction, since a plurality of screws 15 are required to fix the support substrate 8 to the pickup body 1, the number of parts is increased and the manufacturing cost is high. It takes a lot of time to attach and detach the screws 15. Further, when the support substrate 8 is removed from the pickup body 1 and the semiconductor laser LD is replaced, the substrate body 6a in front of the support substrate 8 is an obstacle, so the substrate body 6a is removed from the pickup body 1. It is necessary to remove it, which is troublesome and troublesome, and the work efficiency is low.

Moreover, the problem here is that the semiconductor laser LD is heated by the projection of the laser beam and its performance is lowered. Therefore, conventionally, the pickup body 1 is molded by aluminum die casting to promote heat dissipation.
Is expensive.

Therefore, the pickup body 1 is molded from inexpensive hard synthetic resin, and the supporting substrate 8 of the semiconductor laser LD is formed.
It is considered that the metal plate is used as a metal plate to promote heat dissipation, but if the support substrate 8 is enlarged to increase the heat dissipation effect, it becomes bulky and contacts peripheral devices.
There is a limit to how large it can be, and when a high-performance semiconductor laser LD is used, the heat generated is large, and the pickup body 1 is thermally expanded and deformed (see the phantom line in FIG. 6). The optical axis O connecting the diode PD and the objective lens OL may be bent to cause a reading error. Therefore, as the semiconductor laser LD, there is no choice but to select one that generates less heat, and the selection range is narrowed.

In view of the above-mentioned conventional drawbacks, it is an object of the present invention to provide an optical pickup which is inexpensive, has a small number of parts, is easy to attach and detach a semiconductor laser, has high performance, and is free from reading errors. .

[0011]

In order to achieve the above object, the invention according to claim 1 is such that a photodiode is arranged at one end opening of a light passage hole with a half mirror of a synthetic resin pickup body, and A collimator lens and an objective lens are arranged in the end openings, a semiconductor laser is arranged in a position in the light passage hole facing the half mirror, and a supporting substrate of the semiconductor laser is fixed to the outer peripheral surface of the pickup body. In an optical pickup in which a printed circuit board connected to the photodiode and the semiconductor laser via a cable is provided on an outer peripheral surface of a pickup body, the support substrate is fixed to the outer peripheral surface of the pickup body by a fastener. An end portion of a substantially L-shaped lever integrally projecting on the supporting substrate is detachably engaged with a through hole penetrating the substrate body. Is provided in a position that the fastening device has been visually the supporting substrate from the front spaced from the substrate main body, the supporting substrate and the substrate main body is characterized in that it consists of a metal plate.

According to the above construction, the tip of the lever provided on the supporting substrate of the semiconductor laser is simply engaged with the through hole penetrating the substrate body of the printed circuit board to prevent the supporting substrate from unintentionally rotating. It is possible to reduce the number of fasteners for fixing the support substrate to the pickup body by the amount of rotation by the lever, which is economical.

When the semiconductor laser is replaced with a new one as a result of the inspection before shipment, the semiconductor laser is picked up by simply removing the tip of the lever from the through hole of the substrate body and removing the fastener. In this case, since the fastening member is provided at a position spaced from the substrate body when the supporting substrate is viewed from the front, the fastening device for the supporting substrate is not disturbed by the substrate body. It is possible to quickly and easily carry out the mounting and demounting work, and at that time there is no need to remove the substrate body from the pickup body, so that the semiconductor laser can be replaced quickly.

Further, since the metal substrate body of the printed circuit board and the metal support substrate of the semiconductor laser are directly connected via the lever, the heat dissipation area can be expanded without enlarging the support substrate. As a result, the heat transmitted to the synthetic resin pickup body can be positively dissipated to the atmosphere. Therefore, there is no risk that the pickup body will be thermally expanded and deformed by the heat generated by the semiconductor laser, and the optical axis connecting the photodiode and the objective lens will be maintained in a straight line shape as in the case of the conventional metal pickup body. It is possible to prevent the occurrence of reading errors, and it is possible to use even high-performance semiconductor lasers that generate a lot of heat, and the selection range of the semiconductor lasers can be widened, which makes it possible to manufacture inexpensive and highly accurate optical pickups. You can

According to a second aspect of the present invention, the photodiode is arranged at one end opening of the light passage hole with the half mirror of the synthetic resin pickup body, and the collimator lens and the objective lens are arranged at the other end opening. A semiconductor laser is arranged in a position facing the half mirror in the light passage hole, and a supporting substrate of the semiconductor laser is fixed to the outer peripheral surface of the pickup body and connected to the photodiode and the semiconductor laser via a cable. In the optical pickup in which the printed circuit board is provided on the outer peripheral surface of the pickup body, the support substrate is fixed to the outer peripheral surface of the pickup body by a fastener, and the printed circuit board is attached to the support substrate.
The tip of a substantially L-shaped lever projecting from the body penetrates the substrate body.
It is characterized in that it is engageably and disengageably engaged with the provided through hole .

According to the above construction, the tip of the substantially L-shaped lever provided on the support substrate of the semiconductor laser is connected to the base of the printed circuit board.
Since the support substrate is prevented from rotating by engaging with the through hole formed in the plate body, the number of fasteners for fixing the support substrate to the pickup body is reduced by the amount corresponding to the rotation stopper. Can and is economical.

As a result of the inspection before shipment, the semiconductor laser
When replacing the
Just remove it from the through hole of the main body and remove the fastener,
You can easily remove the laser diode from the pickup body.
At that time, the board body from the pickup body at that time
Since there is no need to remove it, it is easy to replace the laser diode.
It can be done quickly.

According to a third aspect of the invention, in the invention of the second aspect, the supporting substrate and the substrate body are made of a metal plate.
It is characterized in that it comprises.

According to the above structure, since the metal substrate body of the printed circuit board and the metal support substrate of the semiconductor laser are directly connected via the lever, the heat dissipation area can be increased without enlarging the support substrate. The heat transmitted to the synthetic resin pickup body can be positively dissipated to the atmosphere. Therefore, there is no risk that the pickup body will be thermally expanded and deformed by the heat generated by the semiconductor laser, and the optical axis connecting the photodiode and the objective lens will be maintained in a straight line shape as in the case of the conventional metal pickup body. It is possible to prevent the occurrence of reading errors, and it is possible to use even high-performance semiconductor lasers that generate a lot of heat, and the selection range of the semiconductor lasers can be widened, which makes it possible to manufacture inexpensive and highly accurate optical pickups. You can

[0020]

1 to 5 show an optical pickup according to an embodiment of the present invention, in which a support substrate 8 is made of a hard synthetic resin pickup body 1 by a single fastener 15. While being fixed to the end surface of the branch cylinder 1e,
A substantially L-shaped lever 19 integrally provided on the support substrate 8 is removably engaged with a through hole 20 formed through the substrate body 6a of the printed circuit board 6. Since the configuration other than the above is almost the same as the configuration shown in FIGS. 6 to 8, the same reference numerals are given to the same portions and the description thereof will be omitted.

As shown in FIGS. 2 to 4, the substrate body 6a of the printed circuit board 6 is made of a metal plate such as a substantially rectangular aluminum plate, and integrally protrudes from the upper edge of the metal plate to the support substrate 8 side. The through hole 20 is provided through the protrusion 6b.

Metal supporting substrate 8 of the semiconductor laser LD
Is a metal plate such as an aluminum plate. In this embodiment, the support substrate 8 is visually observed from the front (see FIG. 4), and a fastener is provided at a position separated from the substrate body 6a at the left end of the support substrate 8. A fitting insertion hole 21 for inserting 15 is provided through,
The lever 19 is integrally provided at the right end of the support substrate 8.

In the above structure, when assembling the optical pickup, the fastener 15 is fitted into the fitting hole 21 of the support substrate 8.
The semiconductor laser LD is housed in the branch hole 4 by screwing the support substrate 8 into the screw hole 22 on the end surface of the branch tube portion 1e and fixing the support substrate 8 to the end surface of the branch tube portion 1e. The substrate body 6a of the substrate 6 may be fixed to the base frame portion 1a of the pickup body 1 by the protrusion 17 and the screw 7, and the tip end portion 19a of the lever 19 may be engaged with the through hole 20 of the protrusion 6b.

When the semiconductor laser LD is replaced with a new one as a result of the inspection before shipment, the tip portion 1 of the lever 19 is
9a may be removed from the through hole 20 of the substrate body 6a, the fastener 15 may be removed, and the semiconductor laser LD may be extracted from the branch hole 4.

According to the above construction, by simply engaging the tip end portion 19a of the lever 19 provided on the support substrate 8 of the semiconductor laser LD with the through hole 20 of the protrusion 6b of the printed circuit board 6,
The support substrate 8 can be prevented from rotating unexpectedly, and the number of fasteners 15 for fixing the support substrate 8 to the pickup body 1 can be reduced by the amount of the rotation stop by the lever 19, which is economical. Target.

When the semiconductor laser LD is replaced with a new one as a result of the inspection before shipment, the tip portion 1 of the lever 19 is replaced.
The semiconductor laser LD can be separated from the branch cylinder portion 1 by simply removing 9a from the through hole 20 of the substrate body 6a and removing the fastener 15.
It can be easily removed from the end face of e, and in this case, the fastener 15 allows the support substrate 8 to be viewed from the front and the substrate body 6
Since it is provided at a position separated from a, the substrate body 6
The fastener 15 for the support substrate 8 without being disturbed by a.
It is possible to quickly and easily carry out the mounting and demounting work of the semiconductor laser LD, and at that time, it is not necessary to remove the substrate body 6a from the pickup body 1, so that the semiconductor laser LD can be replaced quickly.

Furthermore, since the metal substrate body 6a of the printed circuit board 6 and the metal support substrate 8 of the semiconductor laser LD are directly connected via the lever 19, the support substrate 8 does not have to be large. The heat radiation area can be expanded, and thus the heat transmitted to the synthetic resin pickup body 1 can be actively dissipated to the atmosphere. Therefore, there is no possibility that the pickup body 1 is thermally expanded and deformed due to the heat generated by the semiconductor laser LD, and the optical axis O connecting the photodiode PD and the objective lens OL is linear as a predetermined line like the conventional metal pickup body. It is possible to prevent the occurrence of a reading error by maintaining the same shape, and it is also possible to use a high-performance semiconductor laser LD that generates a lot of heat
The selection range of the semiconductor laser LD can be expanded,
This makes it possible to manufacture an inexpensive and highly accurate optical pickup.

In the above embodiment, the lever 19 is integrally extended to the support substrate 8 of the semiconductor laser LD, and the through hole 20 is provided to the substrate body 6a of the printed circuit board 6, but the semiconductor laser LD is reversed. The through hole 20 may be provided through the supporting substrate 8 and the lever 19 may be integrally extended to the substrate body 6a of the printed substrate 6.

[0028]

According to the first aspect of the present invention, the support substrate is formed by simply engaging the tip of the lever provided on the support substrate of the semiconductor laser with the through hole penetrating the substrate body of the printed circuit board. It is possible to prevent unintended rotation, and the number of fasteners for fastening the support substrate to the pickup main body can be reduced by the amount of rotation by the lever, which is economical.

When the semiconductor laser is replaced with a new one as a result of the inspection before shipment, the tip of the lever is removed from the through hole of the substrate body, and the fastener is removed to pick up the semiconductor laser. In this case, since the fastening member is provided at a position spaced from the substrate body when the supporting substrate is viewed from the front, the fastening device for the supporting substrate is not disturbed by the substrate body. It is possible to quickly and easily carry out the mounting and demounting work, and at that time there is no need to remove the substrate body from the pickup body, so that the semiconductor laser replacement work can be carried out quickly.

Furthermore, since the metal substrate body of the printed circuit board and the metal support substrate of the semiconductor laser are directly connected via the lever, the heat dissipation area can be expanded without enlarging the support substrate. As a result, the heat transmitted to the synthetic resin pickup body can be positively dissipated to the atmosphere. Therefore, there is no risk that the pickup body will be thermally expanded and deformed by the heat generated by the semiconductor laser, and the optical axis connecting the photodiode and the objective lens will be maintained in a straight line shape as in the case of the conventional metal pickup body. It is possible to prevent the occurrence of reading errors, and it is possible to use even high-performance semiconductor lasers that generate a lot of heat, and the selection range of the semiconductor lasers can be widened, which makes it possible to manufacture inexpensive and highly accurate optical pickups. You can

According to the second aspect of the present invention, the tip portion of the substantially L-shaped lever provided on the support substrate of the semiconductor laser is attached to the printing plate.
Since the support substrate is prevented from rotating by engaging the through hole formed in the substrate body of the substrate , the number of fasteners for fixing the support substrate to the pickup body by the amount corresponding to the rotation stopper. Can be reduced and it is economical.

As a result of the inspection before shipment, the semiconductor laser
When replacing the
Just remove it from the through hole of the main body and remove the fastener,
You can easily remove the laser diode from the pickup body.
At that time, the board body from the pickup body at that time
Since there is no need to remove it, it is easy to replace the laser diode.
It can be done quickly.

According to the third aspect of the invention, since the metal substrate body of the printed circuit board and the metal support substrate of the semiconductor laser are directly connected via the lever, the size of the support substrate should be increased. Therefore, the heat radiation area can be expanded, and the heat transmitted to the synthetic resin pickup body can be positively dissipated to the atmosphere. Therefore, there is no risk that the pickup body will be thermally expanded and deformed by the heat generated by the semiconductor laser, and the optical axis connecting the photodiode and the objective lens will be maintained in a straight line shape as in the case of the conventional metal pickup body. It is possible to prevent the occurrence of reading errors, and it is possible to use even high-performance semiconductor lasers that generate a lot of heat, and the selection range of the semiconductor lasers can be widened, which makes it possible to manufacture inexpensive and highly accurate optical pickups. You can

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view showing the principle of an optical pickup according to an embodiment of the present invention.

FIG. 2 is a perspective view of the same.

FIG. 3 is an exploded perspective view of the same.

FIG. 4 is a front view of the same.

FIG. 5 is a plan view of the same.

FIG. 6 is a schematic vertical sectional view showing a conventional example.

FIG. 7 is a front view of the same.

FIG. 8 is a plan view of the same.

[Explanation of symbols]

1 Pickup body 2 half mirror 3 Light passage hole 6 printed circuit boards 6a Printed circuit board body 8 Semiconductor laser support substrate 15 screws (fastener) 19 Lever (engagement part) 19a Lever tip 20 Through hole (engaged part) PD photodiode QWP collimator lens OL objective lens LD semiconductor laser D disk

Claims (3)

(57) [Claims] 1. A photodiode is arranged at one end of a light passage hole with a half mirror of a synthetic resin pickup main body, and a collimator lens and an objective lens are arranged at the other end opening, and A semiconductor laser is arranged at a position facing the half mirror, a support substrate of the semiconductor laser is fixed to an outer peripheral surface of the pickup body, and a printed circuit board connected to the photodiode and the semiconductor laser via a cable is a pickup body. In the optical pickup provided on the outer peripheral surface of the substrate, the support substrate is fixed to the outer peripheral surface of the pickup body by a fastener, and the tip of a substantially L-shaped lever integrally projecting on the support substrate is printed on the print substrate. The through hole formed in the substrate body of the substrate is removably engaged, and the fastening member visually checks the supporting substrate from the front. The optical pickup is provided at a position separated from the substrate body, and the support substrate and the substrate body are made of a metal plate. 2. A photodiode is arranged at one end opening of a light passage hole with a half mirror of a synthetic resin pickup body, and a collimator lens and an objective lens are arranged at the other end opening portion of the light passage hole. A semiconductor laser is arranged at a position facing the half mirror, a support substrate of the semiconductor laser is fixed to an outer peripheral surface of the pickup body, and a printed circuit board connected to the photodiode and the semiconductor laser via a cable is a pickup body. In the optical pickup provided on the outer peripheral surface of the optical pickup, the supporting substrate is fixed to the outer peripheral surface of the pickup main body by a fastener, and a substantially L-shaped lens integrally projected on the supporting substrate.
The tip of the bar penetrates the board body of the printed board.
An optical pickup characterized by being removably engaged with a through hole . 3. The support substrate and the substrate body are made of a metal plate.
The optical pickup according to claim 2, characterized in that.