JP4056637B2 - Optical element bonding device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an adhesive device for attaching an optical element to a base or the like of an optical disk device.
[0002]
[Prior art]
FIG. 5 shows an example of a conventional optical element bonding apparatus. Here, it is assumed that the optical element 520 is bonded to a seating surface 510 provided on the base 500 of the optical disc apparatus. The conventional bonding apparatus includes a gantry 550 on which the base 500 is placed and a holder 560 that holds the optical element 520. Then, the holder 560 is moved toward the mount 550 (in the direction of the arrow in the figure) by an elevating mechanism (not shown), and the optical element 520 held by the holder 560 is pressed against the seat surface 510.
[0003]
An ultraviolet curable adhesive is applied to the seating surface 510 in advance. When the elevating mechanism is driven to press the optical element 520 against the seat surface 510, the adhesive is pressurized between the adhesive surface (lower surface) of the optical element 520 and the seat surface 510. When the adhesive is irradiated with ultraviolet rays by the ultraviolet irradiation device 530, the adhesive is cured and the optical element 520 is bonded to the seating surface 510.
[0004]
[Problems to be solved by the invention]
Here, if the adhesive layer between the optical element 520 and the seating surface 510 is thick, the optical element 520 is displaced due to the expansion and contraction of the adhesive layer due to temperature change. It is known to be desirable. However, when the viscosity of the adhesive is high, even if the adhesive is pressed between the optical element 520 and the seating surface 510, unevenness in the thickness of the adhesive is likely to occur, and the adhesive layer is made thin and uniform. There was a problem that it was difficult.
[0005]
In view of the circumstances as described above, an object of the present invention is to make an adhesive layer for bonding an optical element to a seating surface thin and uniform.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problems, an optical element bonding apparatus according to claim 1 is an apparatus for (1) pressing an optical element against a seating surface of a component and pressurizing an adhesive between the optical element and the seating surface. Pressure means, (2) viscosity reducing means for reducing the viscosity of the adhesive between the optical element and the seating surface, and (3) curing means for curing the adhesive between the optical element and the seating surface. It is configured. Then, the adhesive is pressurized while reducing the viscosity, and then cured.
[0007]
In this way, if pressure is applied while reducing the viscosity of the adhesive, even a high-viscosity adhesive tends to flow and easily spreads uniformly between the optical element and the seating surface. If the adhesive is cured in this state, the adhesive layer between the optical element and the seating surface can be made thin and uniform. The viscosity reducing means is a heating means (for example, a heating coil), and the curing means is an ultraviolet irradiation means.
[0008]
Further, the method for adhering an optical element according to claim 5 is as follows: (1) an adhesive is applied to a seating surface of a certain component, and (2) the optical element is pressed against the seating surface to adhere between the optical element and the seating surface. Pressurize the agent, (3) heat the adhesive between the optical element and the seating surface to reduce its viscosity, and (4) cure the adhesive between the optical element and the seating surface by irradiating with ultraviolet rays. It is characterized by.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a plan view showing a schematic configuration of an optical disc apparatus according to an embodiment, and FIG. 2 is a schematic view showing an optical system of the optical disc apparatus. As shown in FIGS. 1 and 2, the optical disc apparatus is fixed to a movable portion 3 equipped with an objective lens 10 for converging a laser beam onto the recording surface of the optical disc 2 and a main body (not shown) of the optical disc apparatus. The optical unit 6 is used.
[0010]
As shown in FIG. 1, the movable part 3 is held so as to be movable along a pair of center yokes 41 and 42 fixed to an optical disc apparatus main body (not shown). The center yoke 41 is connected to a U-shaped side yoke 43 at both ends in the longitudinal direction, and the center yoke 41 and the side yoke 43 form four rectangular sides. A magnet 45 is disposed in a space surrounded by the center yoke 41 and the side yoke 43, and a magnetic circuit is formed by the center yoke 41, the side yoke 43, and the magnet 45. Similarly, another magnetic circuit is formed by the center yoke 42, the U-shaped side yoke 44, and the magnet 46 disposed in a space surrounded by the center yoke 42.
[0011]
The movable portion 3 is provided with a pair of drive coils 47 and 48 that go around the center yokes 41 and 42. That is, the drive coils 47 and 48 are positioned in the pair of magnetic circuits, respectively. When a current is passed through the drive coils 47 and 48, the movable part 3 moves in the direction crossing the track of the optical disc 2 (FIG. 2) (the left-right direction in the figure) due to the action of the magnetic field formed by the magnets 45 and 46. Go straight to.
[0012]
As shown in FIG. 2, the fixed optical unit 6 includes a semiconductor laser 18 that emits a laser beam, a collimator lens 20 that converts divergent light (from the semiconductor laser 18) into parallel light, a composite prism assay 21, an imaging lens 23, A data detection / focus / tracking detection sensor 24 and an APC sensor 25 are provided.
[0013]
The cross-sectional shape of the parallel light beam emitted from the collimating lens 20 is oval due to the characteristics of the semiconductor laser 18, and it is inconvenient to narrow the laser light beam finely on the optical disk 2, so it is necessary to convert it into a substantially circular cross-section. is there. Therefore, the incident surface 21a of the composite prism assay 21 has a predetermined inclination with respect to the incident optical axis, and the cross-sectional shape of the parallel light beam is shaped from an oval shape to a substantially circular shape by refracting the incident light. .
[0014]
The laser beam emitted from the fixed optical unit 6 travels straight through the space and enters the movable part 3, is reflected upward by the deflection mirror 31 provided in the movable part 3, and enters the objective lens 10. The traveling direction of the laser beam from the fixed optical unit 6 coincides with the linear movement direction of the movable unit 3, and the laser beam from the fixed optical unit 6 is directed to the objective lens 10 regardless of the moving position of the movable unit 3. Incident.
[0015]
FIG. 3 shows the relationship between the objective lens 10 and the optical disc 2. The laser beam incident on the objective lens 10 passes through the protective layer 2B of the optical disc 2 and converges on the recording surface 2A. Note that the objective lens 10 mounted on the movable part 3 is controlled to move up and down so as to follow the surface shake of the optical disk 2 in order to keep the distance between the movable part 3 and the recording surface 2A of the optical disk 2 constant. Description of the movement control method of the objective lens 10 called focus servo will be omitted.
[0016]
The return laser beam reflected and returned from the optical disk 2 travels in the opposite direction to the forward path, returns to the fixed optical unit 6, and enters the composite prism assay 21. The half mirror surface 21b of the composite prism assay 21 generates transmitted light and reflected light toward the data detection / focus / tracking detection sensor 24, and separates the laser beam on the return path. The data detection / focus / tracking detection sensor 24 is a composite sensor that reads data information recorded on the optical disc 2 and outputs a data signal, and outputs a focus / tracking error signal. More precisely, the focus / tracking error signal and the data signal are generated by a head amplifier circuit (not shown) and sent to a control circuit or an information processing circuit.
[0017]
Next, an apparatus for bonding the optical element 200 to the unit base of the fixed optical unit 6 will be described. Here, the optical element 200 may be any of the composite prism assay 21 and the collimating lens 20 (FIG. 2) described above.
[0018]
FIG. 4 is a side view of the bonding apparatus 100. The bonding apparatus 100 has a gantry 111 arranged horizontally. The gantry 111 is provided with a plurality of support seats 112 for mounting a unit base (hereinafter simply referred to as a unit base 300) of the fixed optical unit 6 (FIG. 2). The unit base 300 is placed on the seat 112 of the gantry 111 so that the seat surface 301 is horizontal, and is fixed by a clamp mechanism (not shown).
[0019]
The holder 121 that holds the optical element 200 such as a prism is configured to suck and hold the optical element 200 using vacuum suction. The holder 121 is attached to the lower end of the slide shaft 123 extending in the vertical direction. The slide shaft 123 is moved in a direction approaching and separating from the seating surface 301 by an elevating mechanism 120 (indicated by a block).
[0020]
The gantry 111 is provided with a contact pin 114 that penetrates the gantry 111 up and down. A heating coil 115 is incorporated in the outer periphery of the contact pin 114. Further, a heat insulating collar 113 for preventing the heat of the heating coil 115 from being transmitted to the gantry 111 is provided around the insertion hole (of the gantry 111) where the contact pins 114 are arranged.
[0021]
Further, the contact pin 114 is slidably held in the heat insulating collar 113 so that the contact pin 114 comes into contact with the unit base 300, and is attached to the unit base 300 (upward in the drawing) by the coil spring 116. It is energized. The coil spring 116 is held by a cover 117 fixed to the bottom surface of the gantry 111 with screws 118. With this configuration, when a current from a power source (not shown) is supplied to the heating coil 115, the heating coil 115 generates heat, and the heat reaches the seat surface 301 via the contact pins 114 and the unit base 300.
[0022]
In addition, the adhesive device 100 is provided with an ultraviolet irradiation device 130 for irradiating an adhesive (described later) between the optical element 200 and the seat surface 301 with ultraviolet rays.
[0023]
Next, a bonding operation using the bonding apparatus 100 will be described. First, the unit base 300 is placed on the mount 111 and fixed with a clamp (not shown). Then, the optical element 200 is vacuum-sucked on the holder 121. Further, the operator applies the ultraviolet curable adhesive A to the seating surface 301 of the unit base 300 using a dropper, a syringe or the like.
[0024]
Next, the lifting mechanism 120 is driven to move the slide shaft 123 and the holder 121 downward, and press the optical element 200 held by the holder 121 against the seating surface 301 of the unit base 300. Thereby, the adhesive A between the optical element 200 and the seating surface 301 is pressurized with a predetermined pressure.
[0025]
Here, current is passed through the heating coil 115 to heat the adhesive A between the optical element 200 and the seating surface 301. As the adhesive A warms up, its viscosity decreases and it becomes easier to flow. Since the pressure is applied in a state where it easily flows, the adhesive A spreads between the optical element 200 and the seat surface 301 with a uniform thickness. After heating for a predetermined time by the heating coil 115, the ultraviolet ray irradiation device 130 irradiates the adhesive A between the optical element 200 and the seating surface 301 with ultraviolet rays to cure the adhesive.
[0026]
Thus, by applying pressure while reducing the viscosity of the adhesive A and curing the adhesive in that state, the adhesive A between the optical element 200 and the seating surface 301 can be made thin and uniform. Therefore, even a highly viscous adhesive can be made thin and uniform.
[0027]
In the above embodiment, the heating coil 115 is provided on the contact pin 114 attached to the gantry 111. However, if the adhesive A between the optical element 200 and the seat surface 301 can be heated, the holder 121, You may attach to the slide axis | shaft 123 grade | etc.,.
[0028]
【The invention's effect】
As described above, according to the optical element bonding apparatus of the present invention, the adhesive between the optical element and the seating surface is obtained by applying pressure while reducing the viscosity of the adhesive and curing the adhesive in that state. Thin and uniform.
[Brief description of the drawings]
FIG. 1 is a diagram showing a basic configuration of a magneto-optical disk apparatus according to an embodiment.
2 is a schematic view showing an optical system of the optical disc apparatus of FIG. 1. FIG.
FIG. 3 is an enlarged view showing an objective lens and an optical disc.
FIG. 4 is a side view showing the bonding apparatus according to the embodiment.
FIG. 5 is a diagram showing a conventional bonding method.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 100 Bonding device 111 Base 114 Contact pin 115 Heating coil 121 Holder 130 Ultraviolet irradiation device 200 Optical element 300 Unit base 301 Seat surface

Claims (6)

A support part;
A pressing means for pressing an optical element against a seating surface of a component supported by the support unit and pressurizing an adhesive applied between the optical element and the seating surface;
A heating means for reducing the viscosity of the adhesive by heating the adhesive through the component,
A collar provided on the inner periphery of the through hole formed in the support portion, and holding the heating means slidably in the axial direction of the through hole;
Biasing means for pressing the heating means against the component;
Curing means for curing the adhesive;
With
An adhesive device for an optical element, wherein the adhesive is pressurized while being reduced in viscosity by heating and then cured. The optical element bonding apparatus according to claim 1, wherein the biasing unit presses the heating unit against the component from the back side of the seating surface. The optical element bonding apparatus according to claim 1, wherein the collar is a heat insulating collar. The adhesive is an ultraviolet curing adhesive, bonding apparatus of the optical element according to any one of claims 1 to 3, characterized in, that said curing means is a UV irradiation apparatus. The optical device further includes a holding unit that holds the optical element, and the pressing unit moves the optical element to the seating surface by moving one of the holding unit and the support unit in a direction close to the other. bonding apparatus of the optical element according to any one of claims 1 to 4, it is configured such that pressing, characterized by. Bonding apparatus of the optical element according to claim 4 or 5 wherein the heating means have a heating coil, characterized by.

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