JPH045055Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Technical Field of the Invention> The invention records information by irradiating a light beam output from a laser element onto a predetermined position on the information recording surface of a disk to form a light spot with a constant diameter. The present invention relates to an optical information reading device that optically reads information from a recording surface.

<Background Art> In a conventional optical information reading device of this type, a lens holding tube holding an objective lens is supported on a fulcrum shaft protruding from a base body so as to be rotatable and vertically movable, and the base body Laser element on the bottom surface of
An optical unit consisting of a beam splitter, a collimator lens, and a light receiving element is provided, and the light beam output from the laser element is irradiated onto the information recording surface of the disk via the beam splitter, collimator lens, and objective lens to read information. ,
The reflected beam on which this information has been read is supplied to the light receiving element via the objective lens, collimator lens, and beam splitter, and is converted into an electrical signal.

Therefore, this conventional device has the disadvantage that when attaching the optical unit to the base body, it is difficult to align the optical axis of the light beam from the collimator lens with the center of the objective lens, making assembly difficult. .

<Purpose of the present invention> The present invention was devised in view of the drawbacks of the conventional device described above, and the support shaft supporting the lens holding cylinder is mounted on the upper surface of the unit holder of the optical unit attached to the lower surface of the base body. The present invention attempts to solve the drawbacks of the conventional device by providing a base member and protruding from the base body.

<Embodiment of the present invention> Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In the figure, 1 is a base body made of a rectangular plate material that constitutes a part of the magnetic circuit, and an oval-shaped beam opening 5 is provided in the center of the base body. The yokes 4, 4 of 1 are provided integrally, respectively. Reference numerals 6 and 6 designate magnets that are fixed to both left and right ends of the base body 1 outside the first yokes 4, 4, and second yokes 7, 7 are fixed to the upper surface thereof.

Reference numeral 8 designates a lens holding cylinder formed by integrally providing a shaft portion 9 with a fulcrum hole 10 having the same axis as the cylinder on the back surface of the center of the top plate of a cylinder whose bottom surface is open;
The top plate 8a has a lens holding port 11, an insertion port 12, and a board mounting port 13, and a focus operation coil 14 is directly wound on the outer circumferential surface of the coil 14, and four tracking devices are provided on the outer circumferential surface of the coil 14. The operating coil 15 is fixed.

Reference numeral 16 denotes a bobbin board made of a printed circuit board having the same diameter as the top plate of the lens holding cylinder 8, and a shaft hole 17 corresponding to the fulcrum hole 10 of the top plate and each opening 11, 12, 13, and lens holding holes are provided on the board surface. Port 18, insertion port 19,
and a mounting opening 20, and is placed on the top plate so that these holes and openings match the holes and openings of the top plate 8a, and fasteners 2 such as screws or rivets are attached.
1 is press-fitted into the board mounting hole 13 through the mounting hole 20, thereby being fixed onto the top plate.
Further, this bobbin board 16 fixes the focusing operation coil 14, the tracking operation coil 15, and a relay wire 25 for electrically connecting each of these coils to a relay board 31, which will be described later, as well as a wiring pattern provided on the board surface. The coils and relay wires are electrically connected. Furthermore, this bobbin board 16
has a convergence hole 22 at one point on its peripheral edge through which the relay wires 25, . . . A slit 24 continuous to the convergence hole 22 is provided in the convex portion 23.

Reference numeral 26 designates a neutral holder made of an elastic material such as rubber, and has a press-in port 27 in the center for press-fitting and supporting the shaft portion 9 of the lens holding cylinder 8, and also has a press-in port 27 at both ends for press-fitting and supporting the shaft portion 9 of the lens holding cylinder 8. Small holes 28, 28 are opened for screws 29, 29 to be fastened to the screw holes 3a, 3a of the support protrusions 3, 3.

The lens holding cylinder 8 fixes the bobbin board 16 on the top plate and attaches the neutral holder 26 to the shaft 9 at the press opening 2.
7, the fulcrum shaft 2 is inserted through the fulcrum hole 10, and both ends of the neutral holder 26 are placed on the support protrusions 3, 3, and the screws 29, 2 are inserted.
9, it is supported and floated on the base body 1 so that it can rotate and move up and down relative to the fulcrum shaft 2 within the range allowed by the neutral holder 26.

In addition, when the lens holding tube 8 is supported on the base body 1, each coil 1 of the lens holding tube 8 is
The peripheral edges fixing the coils 4 and 15 are interposed between the first yoke 4 and the magnet 6, and the second yoke 7, and each coil 14 and 15, the magnet 6, and the first and second
A magnetic circuit having the direction of magnetic flux as shown by arrow A in FIG. 3 is formed in the yokes 4 and 7 of FIG.

To screw the neutral holder 26 onto the support protrusion 3, first insert the lens holding tube 8 into the fulcrum shaft 2 through the fulcrum hole 10, and then insert the screw 29 into the insertion hole 19 of the bobbin board 16 and into the top plate. This can be carried out by inserting it into the lens holding cylinder 18 through the opening 12, and then screwing it into the screw hole 3a of the support projections 3, 3 through the small hole 28 of the neutral holder 26.

Reference numeral 30 denotes an objective lens, and the bobbin substrate 16
It is fitted into the lens holding port 11 of the lens holding tube 8 through the lens holding port 18 of the lens holding tube 8 .

Reference numeral 31 designates the relay board, which is screwed 32 to the center of the front edge of the upper surface of the base body 1. By connecting one end of the relay wire 25 to a wiring pattern formed on the board surface, the relay wire 25 can be connected to the wiring pattern formed on the board surface. It is connected to a control circuit (not shown) of the player via the wiring pattern.

As is clear from the figure, the fulcrum shaft 2 is erected at the center of the upper surface of the unit holder 38 fitted into the fitting opening 34a of the housing 34 fixed to the lower surface of the base body 1 with screws 33. It projects onto the base body 1 through the beam port 5 of the base body 1.

The unit holder 38 is fixed in the fitting opening 34a with a screw 39 inserted into a screw hole 34b provided in the housing 34, and includes a laser element 35, a diffraction grating 40, a beam splitter 41, etc.
Optical units such as a collimator lens 42 and the like are built in above and below, and an optical path 38a is provided to guide the reflected beam from the beam splitter 41 laterally.

Further, the housing 34 includes the optical path 38a.
It has an optical path 34c extending laterally from the side surface of the fitting opening 34a so as to lead to the optical path 34c.
A focusing lens 44 and a cylindrical lens 4 are in c.
5 and the light receiving element 36 to the beam splitter 4.
They are arranged in order from number 1 outward.

The light receiving element 36 is fixed within the light passage 34c with a screw 43 inserted into a screw hole 34d provided in the housing 34.

Since the present invention is constructed as described above, the light beam O output from the laser element 35 is
is irradiated onto the information recording surface of the disk through the diffraction grating 40, beam splitter 41, collimator lens 42, beam aperture 5 and objective lens 30, reads the information, and is reflected.

This reflected reflected beam is returned to the objective lens 3.
0, passes through the collimator lens 42, reaches the beam splitter 41, is direction-changed here, and proceeds within the optical paths 38a, 34c, focusing lens 44,
Light receiving element 36 via cylindrical lens 45
The light is received and converted into an electrical signal.

This electric signal is applied to a control circuit (not shown) to detect focus and tracking errors, and a control signal based on these focus and tracking errors is used to connect the relay wire 25 and relay board 31 to the focus and tracking operation coils 14 and 15. At the same time, the lens holding cylinder 8 moves up and down and rotates around the fulcrum shaft 2 against the holding force of the neutral holder 26, and the light beam O irradiated from the objective lens 30 is focused on a predetermined position on the information recording surface of the disk with a spot of a predetermined diameter.

By the way, in the present invention, since the lens holding cylinder 8 is supported on the fulcrum shaft 2 which is erected at the center of the top plate of the unit holder 38 and protrudes above the base body 1, the light beam O output from the collimator lens 42 is As long as the objective lens 30 is held in the lens holding tube 8 so that the optical axis of Even when attached, the optical axis of the light beam and the center of the objective lens 30 always match, and the light beam can be accurately irradiated onto the information recording surface of the disk.

<Effects of the present invention> As mentioned above, the present invention has a unit holder which is installed upright on the upper surface of the unit holder which houses an optical unit consisting of a laser element, a beam splitter, a collimator lens, etc., and a lens is attached to the fulcrum shaft protruding from the base body. Since the holding tube is supported, even if the mounting position of the unit holder relative to the base body is slightly shifted, the optical axis of the light beam emitted from the optical unit and the center of the objective lens will always remain constant, allowing the light beam to be directed to the disk under optimal conditions. This is an excellent idea that can irradiate the information recording surface of the computer.

[Brief explanation of the drawing]

1 to 4 show an exploded perspective view, a front sectional view, and a plan view of an assembled perspective view of an optical information reproducing apparatus according to the present invention. DESCRIPTION OF SYMBOLS 1... Base body, 2... Fulcrum shaft, 4... First yoke, 5... Beam port, 6... Magnet,
7...Second yoke, 8...Lens holding tube, 14
...Focusing operation coil, 15...Tracking operation coil, 30...Objective lens, 38...
unit holder.

Claims (1)

[Scope of utility model registration request] A lens holding cylinder having an objective lens on the top plate and a coil for focusing and tracking operation on the circumferential surface is provided on the base body so as to be able to move up and down and rotate within a predetermined range, and a yoke is provided on the base body. A magnetic circuit is formed by the magnet and the focusing and tracking operation coils, and a laser element, a beam splitter, a collimator lens, a light receiving element, etc. are provided on the lower surface of the base body, and a light beam output from the laser element is formed. is applied to the objective lens through the beam splitter, the collimator lens, and the beam port on the plate surface of the base body, and from this, the information recording surface of the disk is irradiated to read the information, and the reflected beam that has read this information is to the light receiving element through the objective lens beam port, collimator lens, and beam splitter, at least the laser element,
Beam splitter and collimator lens 1
The lens holding tube is built into one unit holder and provided on the lower surface of the base body, and the lens holding tube is vertically movable and rotated around a fulcrum shaft that is erected on the upper surface of the unit holder and protrudes from the base body. An optical information reading device characterized by supporting.