JP3058958B2 - Hologram lens manufacturing method and hologram lens manufacturing apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a hologram lens such as a hologram f.theta. Lens used for a scanner unit such as a laser printer or a facsimile machine, and an apparatus for manufacturing a hologram lens used for implementing the method.

[0002]

2. Description of the Related Art FIG. 7 shows a polygon mirror printer as an example of a light beam scanning device. The laser beam emitted from the semiconductor laser 8 is condensed by the condenser lens 9 and then applied to the mirror surface of the polygon mirror 10. The laser beam reflected by the mirror surface is exposed on the photosensitive drum 11 via the reflection mirror 15. The polygon mirror 10 is rotated at a predetermined speed about a vertical axis, whereby scanning in the main scanning direction corresponding to the axial direction of the photosensitive drum 11 is performed, and an image plane (corresponding to the scanning) is formed on the photosensitive drum 11. (Focal plane) 12 is formed.

By the way, as described above, the polygon mirror 1
When the laser beam is scanned at 0, the image plane 12 is limited due to the limitation on the processing accuracy of the mirror surface of the polygon mirror 10.
However, there is a disadvantage in that the curved shape shown in FIG. 7 is generated, and the focus is not accurately formed on the surface of the photosensitive drum 11, so that a large spot diameter is recorded in the peripheral portion of the image surface 12, and high-quality printing cannot be performed. is there.

In order to eliminate such a defect, as shown in FIG. 8, an fθ lens 14 is disposed between the polygon mirror 10 and the reflection mirror 15, and the fθ lens 14 increases the processing accuracy of the polygon mirror 10. It is only necessary to correct the curvature of the image plane 12 due to a manufacturing error due to the restriction of the above. In the drawing, reference numeral 13 denotes a collimator lens.

[0005] However, according to such a correction method,
In order to produce a high-performance scanner unit, a large number of high-precision lenses are required, which complicates the mechanism, requires stricter processing accuracy, and requires a long time for assembly and adjustment. There is a problem that the cost is increased.

In order to solve such a problem, a method using a hologram instead of the fθ lens has recently been proposed. In other words, since holograms use the phenomenon of light diffraction, unlike a lens that uses light refraction, the function performed by a plurality of lenses can be replaced by one optical component, reducing the number of components. This is because significant cost reduction is possible.

[0007] Such a hologram has a 2P (Photo Polymerization) as shown in FIG.
It can be made by a molding process. However, FIG. 9 shows a 2P molding process used for manufacturing an optical disk or the like. Hereinafter, the manufacturing process of the 2P molding process will be described.

First, as shown in FIG. 9A, a transparent substrate 3 and a stamper 2 having stripe information of a hologram, that is, a stamper 2 having an uneven shape corresponding to a hologram, are prepared. 3a is applied.

Subsequently, as shown in FIG. 9B, the transparent substrate 3 is brought into contact with the stamper 2 from above with the surface on which the ultraviolet curing resin 3a is applied facing downward.

Subsequently, as shown in FIG. 9C, a pressing step of pressing the transparent substrate 3 against the stamper 2 at a predetermined pressure is executed. At this time, the extruded ultraviolet curable resin 3 a is uniformly spread between the gap between the transparent substrate 3 and the stamper 2.

Subsequently, as shown in FIG. 9D, ultraviolet rays are irradiated from above the transparent substrate 3 to cure the ultraviolet curing resin 3a. Thereby, the hologram information is transferred to the contact surface of the transparent substrate 3.

Subsequently, as shown in FIG. 9 (e), the transparent substrate 3 is peeled off from the stamper 2, thereby obtaining the transparent substrate 3 on which a hologram is produced.

[0013]

According to the above-described 2P molding process, a hologram fθ lens that can replace the fθ lens 14 can be manufactured.

By the way, when the angle of view of the hologram fθ lens used (mounted) in the scanner unit is increased in order to improve the performance of the scanner, the length in the scanning direction (main scanning direction) is accordingly increased. Because of the necessity, it has an elongated shape different from the shape of a normal fθ lens, that is, a rectangular shape. The hologram fθ lens having such a rectangular shape is different from a circular one such as an optical disk for the following reason.
Fabrication was difficult with the molding process.

That is, when an optical disk or the like is manufactured by the 2P molding process, the irregularities of the stamper 2 may have a groove depth of about 0.1 μm and a groove pitch of about 1.6 μm. In order to use the same as a lens, the diffraction efficiency of light at the hologram must be improved. Therefore, the groove depth needs to be 10 times or more that of an optical disc. Therefore, in the step of FIG. 9B, when the transparent substrate 3 and the stamper 2 are brought into contact with each other, the two are brought into contact by a steep contact method, so that a phenomenon that air bubbles are trapped in the ultraviolet curable resin 3a occurs. It is disadvantageous in that it is easy to perform and many defective products are generated.

According to the conventional 2P molding process, since the transparent substrate 3 and the stamper 2 are finally brought into contact and pressed in a parallel state, when the transparent substrate is rectangular, the width is narrow. Since the flow of the ultraviolet-curable resin 3a is very small, bubbles trapped in the ultraviolet-curable resin 3a at the time of pressurization are not discharged to the outside, and the same drawbacks as described above occur.

Further, in the peeling step shown in FIG. 9 (e), in the case of an optical disk, the substrate is concentric and it is not necessary to form a hologram at the center.
As shown in FIG. 1 and FIG. 11, if the center of the transparent substrate 3 is pushed up by a center pin (ejector pin) 20 having a large diameter, the transparent substrate 3 can be peeled off from the stamper 2. Since a uniform peeling force acts on the transparent substrate 3 as a whole, a problem such as breakage of the transparent substrate 3 does not occur.

On the other hand, the hologram fθ lens 14
When the transparent substrate 3 has a rectangular shape as shown in FIG.
Since it is necessary to form a hologram on the entire surface of the device, the center pin 20 as described above cannot be used as an ejector pin. Therefore, as shown in FIG. 12, it is necessary to take a peeling step in which one end of the transparent substrate 3 is lifted up by an ejector pin and peeled off.

However, according to such a peeling method,
Since the cured ultraviolet curable resin 3a is in close contact with the stamper 2, an excessive load acts on the transparent substrate 3 during peeling due to the adhesive force between the two, and as shown in FIG. There is a drawback that it bends greatly and in some cases breaks (see FIG. 3B).

In order to prevent such substrate destruction, a transparent substrate 3 made of tempered glass may be used. However, when such a tempered glass substrate is used, the hologram fθ
There is a new disadvantage that the lens becomes expensive.

Under such circumstances, it has been urgently desired to establish a 2P molding process capable of manufacturing a large-sized and rectangular hologram lens on an inexpensive transparent substrate such as unreinforced glass or plastic.

SUMMARY OF THE INVENTION The present invention has been made in order to meet such a demand, and a method of manufacturing a hologram lens capable of improving the yield and greatly reducing the cost, and an apparatus for manufacturing a hologram lens used for implementing the method. The purpose is to provide.

[0023]

According to the present invention, there is provided a method of manufacturing a hologram lens, comprising the steps of: applying an ultraviolet curable resin to a surface of one end of a rectangular transparent substrate; and applying the transparent substrate to a stamper having hologram fringe information. Is gradually contacted from one end side to which the ultraviolet-curable resin is applied, and finally, the two are brought into parallel contact with each other, and the ultraviolet-curable resin is irradiated with ultraviolet light to cure the ultraviolet-curable resin and form the transparent substrate. Transferring the hologram fringes to the surface of the transparent substrate, and peeling the transparent substrate from the stamper so that a uniform peeling force acts on the outer peripheral area of the transparent substrate, thereby achieving the above object. Achieved.

The apparatus for manufacturing a hologram lens according to the present invention is characterized in that a transparent substrate having a rectangular shape and having an ultraviolet curable resin applied to the surface at one end is used to transfer hologram fringe information from one end to which the ultraviolet curable resin is applied. A hologram lens manufacturing apparatus for making a hologram lens by gradually bringing the hologram fringe information into contact with the stamper, thereby transferring the hologram fringe information to the transparent substrate, wherein the receiving support portion has a shape corresponding to the outer shape of the transparent substrate. A substrate holder that supports the transparent substrate with the receiving support portion, a stamper base that supports the stamper, and has a plurality of guide holes in a peripheral portion, and the substrate holder is coated with the ultraviolet curable resin. A rotating shaft rotatably connected to the stamper base with one end serving as a fulcrum; After the stripe information is transferred to the transparent substrate and the rotation axis is detached from the transparent substrate and the stamper base, the substrate holder is pressed through the guide holes, and the substrate holder is separated from the stamper base. A plurality of ejector pins, thereby achieving the above object.

[0025]

When the transparent substrate coated with the UV curable resin at one end as described above is gradually brought into contact with the stamper with the coating side as a fulcrum, the UV curable resin is brought into contact with the transparent substrate by capillary action at the time of contact. Since the fluid flows smoothly toward the other end, no bubbles are trapped in the ultraviolet curable resin.

Further, when the transparent substrate is peeled off from the stamper so that a uniform peeling force acts on the outer peripheral area of the transparent substrate as described above, stress concentration does not occur on the transparent substrate at the time of peeling. Therefore, since the transparent substrate is not broken, a hologram lens can be manufactured using a transparent substrate made of unreinforced glass or plastic material.

[0027]

Embodiments of the present invention will be described below.

FIG. 1 shows an apparatus for manufacturing a hologram lens according to the present invention. This apparatus contacts a stamper 2 having hologram information with a transparent substrate 3 coated with an ultraviolet curable resin. 3 is pressed against the stamper 2, and thereafter, the ultraviolet curing resin is cured, whereby the hologram information of the stamper 2 is transferred to the transparent substrate 3.
Thereafter, the transparent substrate 3 is moved by a plurality of ejector pins 7.
And used to produce a hologram lens by peeling off from the stamper 2. The configuration of each unit will be described below.

The transparent substrate 3 is used for producing the above-mentioned hologram fθ lens, and is formed by molding an inexpensive material such as unreinforced glass or plastic into a rectangular shape. The transparent substrate 3 is supported by a substrate holder 4 having a rectangular parallelepiped shape. More specifically, as can be seen particularly from FIG.
Has a recessed receiving support portion 40 corresponding to the outer shape of the transparent substrate 3, and has a structure in which the transparent substrate 3 is supported by the receiving support portion 40. Furthermore, around the receiving support part 40, it became higher by one step,
A glass support 41 is formed, and the glass support 4
The structure 1 supports the pressurized glass 5. Furthermore,
A connection hole 42 is formed at one end of the substrate holder 4 so as to penetrate in the front-rear direction of the drawing.

On the other hand, the stamper 2 has a rectangular shape similar to that of the transparent substrate 3 and is supported by a supporting portion 100 formed on the stamper base 1 having a rectangular plate shape. Stamper base 1
A pair of connecting pieces 101, 101 are integrally connected to one end of the connecting piece in the front-rear direction of the paper surface.
The coupling shaft 7 is fitted into the shaft holes 102, 102 formed in the through hole 01.

When connecting the substrate holder 4 and the stamper base 1, one end of the substrate holder 4 is sandwiched between the connecting pieces 101, 101 so that the connecting holes 42 and the shaft holes 102, 102 are aligned with each other. , 102, 102 with shaft 7
Is performed. FIG. 2 shows a connection state between the substrate holder 4 and the stamper base 1. In the connection state,
The substrate holder 4 is rotatable with respect to the stamper base 1 around the shaft 7 as a fulcrum.

A large number of pin holes 103 are formed through the other end of the stamper base 1 and a portion slightly deviated inward from the connecting pieces 101, 101. When peeling the transparent substrate 3 described later, the pin holes 103, 10
The plurality of ejector pins 6, 6... Push up the transparent substrate 3 through.

Next, a case of manufacturing a hologram fθ lens by a 2P molding process using the hologram lens manufacturing apparatus of the present invention will be described with reference to FIGS.

First, the substrate holder 4 in the connected state is moved to the position shown in FIG.
Then, a predetermined amount of an ultraviolet curable resin is applied to the inner surface at one end of the transparent substrate 3 by separating from the stamper base 1 as shown in FIG. Subsequently, the substrate holder 4 is rotated at a low speed toward the stamper base 1 from this state, and the transparent substrate 3 is gradually brought into contact with the stamper 2 from one end where the ultraviolet curable resin is applied. As shown in FIG. 4, the transparent substrate 3 and the stamper 2 are finally brought into parallel contact.

In the case of the contact step in which the transparent substrate 3 is gradually brought into contact with the stamper 2 from one end side on which the ultraviolet-curable resin is applied, the ultraviolet-curable resin is not covered by the transparent substrate 3 due to the capillary phenomenon at the time of contact. Since the fluid flows smoothly toward the end side, there is no problem that bubbles are trapped in the ultraviolet curable resin.

Subsequently, a pressing step of pressing the pressing glass 5 and thereby pressing the transparent substrate 3 against the stamper 2 is performed. By this pressing step, the hologram information of the stamper 2 is transferred to the transparent substrate 3. Subsequently, a curing step of irradiating ultraviolet rays from above the pressurized glass 5 and thereby curing the ultraviolet curable resin is performed.

Subsequently, the shaft 7 is pulled out of the connecting hole 42 and the shaft holes 102, 102, and then, as shown in FIG. 4, from this state, the plurality of ejector pins 6, 6,. Through which the substrate holder 4 is lifted, thereby separating the substrate holder 4 from the stamper base 1. Thereby, the transparent substrate 3 is peeled off from the stamper 2, and the transparent substrate on which the hologram information is transferred, that is, the hologram fθ lens is manufactured.

In this peeling step, the push-up by the ejector pins 6, 6,... Is performed against the adhesive force between the ultraviolet curable resin and the stamper 2, but in the present invention, it is shown in FIG. 5 and FIG. As described above, since the entire outer peripheral area of the transparent substrate 3 is supported by the receiving support portion 40 of the substrate holder 4, stress concentration does not occur on the transparent substrate 3 during peeling. Therefore, according to the present invention, there is no problem that the transparent substrate 3 is broken.

A square frame-shaped air pipe 30 shown in FIG. 1 is disposed between the substrate holder 4 and the stamper base 1, and air is blown into the air pipe 30 from a nozzle formed in the air pipe 30 during a peeling process. In this case, since the peeling step of the substrate holder 4 is accelerated by the air pressure, there is an advantage that the peeling step can be performed more smoothly.

In the above embodiment, the case where the present invention is applied to the production of the hologram fθ lens has been described.
The same applies to the manufacture of other hologram lenses such as a hologram sin θ lens and a hologram tan θ lens.

[0041]

According to the present invention, no bubbles are trapped in the ultraviolet curable resin in the contact step, and the transparent substrate is not broken in the peeling step. There is an advantage that the cost can be remarkably improved and the cost can be significantly reduced.

Furthermore, since the transparent substrate is not destroyed in the peeling step, a hologram lens can be manufactured using a transparent substrate made of an inexpensive material such as unreinforced glass or plastic. Therefore, in this regard,
There is an advantage that can greatly contribute to cost reduction.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an apparatus for manufacturing a hologram lens of the present invention.

FIG. 2 is an assembly view of the apparatus for manufacturing a hologram lens of the present invention.

FIG. 3 is a perspective view showing a step of bringing a transparent substrate coated with an ultraviolet curable resin into contact with a stamper using the apparatus for manufacturing a hologram lens of the present invention.

FIG. 4 is a perspective view showing a step of peeling a transparent substrate from a stamper using the apparatus for manufacturing a hologram lens of the present invention.

FIG. 5 is a cross-sectional view showing a substrate holder and a transparent substrate held by the substrate holder.

FIG. 6 is a sectional view taken along line AA of FIG. 5;

FIG. 7 is a perspective view showing a polygon mirror printer as an example of a light beam scanning device.

FIG. 8 is a perspective view showing a polygon mirror printer including a field curvature correction unit.

FIG. 9 is a process chart showing a conventional 2P molding process.

FIG. 10 is a sectional view showing a case where a peeling step in a conventional 2P molding process is applied to an optical disc.

FIG. 11 is a perspective view showing the step of FIG. 10;

FIG. 12 is a view showing a defect due to a conventional 2P molding process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stamper base 2 Stamper 3 Transparent substrate 3a Ultraviolet curing resin 4 Substrate holder 40 Receiving support part 5 Pressurized glass 6 Ejector pin 7 Shaft

──────────────────────────────────────────────────続 き Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G02B 5/18, 5/32 G03H 1/00-5/00

Claims (2)

(57) [Claims] 1. A step of applying an ultraviolet curable resin to the surface of one end of a rectangular transparent substrate, and gradually applying the transparent substrate to a stamper having hologram fringe information from one end of the transparent substrate to which the ultraviolet curable resin is applied. Contact,
Finally, a step of bringing the two into parallel contact, a step of irradiating the ultraviolet-curable resin with ultraviolet light, curing the ultraviolet-curable resin and transferring hologram fringes to the surface of the transparent substrate, and an outer peripheral area of the transparent substrate. And peeling the transparent substrate from the stamper such that a uniform peeling force acts on the hologram lens. 2. A transparent substrate having a rectangular shape and having an ultraviolet curable resin applied to the surface at one end thereof is gradually brought into contact with a stamper having hologram fringe information from one end to which the ultraviolet curable resin is applied. A hologram lens manufacturing apparatus for manufacturing a hologram lens by transferring the hologram fringe information to the transparent substrate, comprising a receiving support portion having a shape corresponding to the outer shape of the transparent substrate, A substrate holder that supports a transparent substrate, a stamper base that supports the stamper, and has a plurality of guide holes in a peripheral portion, and the substrate holder is attached to the stamper base with one end where the ultraviolet curable resin is applied as a fulcrum. A rotating shaft rotatably coupled to the ultraviolet curing resin, the ultraviolet curing resin is irradiated with ultraviolet light, the hologram stripe information is transferred to the transparent substrate, and the rotating An apparatus for manufacturing a hologram lens, comprising: a plurality of ejector pins for pressing the substrate holder through the guide holes after the shaft is detached from the transparent substrate and the stamper base, and peeling the substrate holder from the stamper base.