JP2819688B2 - Fabrication method of lens on optical fiber end - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a lens on the end of an optical fiber, and more particularly, to a method for manufacturing a lens on the end of a linearly arranged optical fiber array.

[Conventional technology]

2. Description of the Related Art Conventionally, as a configuration of an exposure unit for forming an electrostatic latent image pattern on a photoconductor, there is a system shown by a laser beam printer.

Such a laser beam printer is configured to include, for example, an optical scanning device 100, as shown in FIG.
This device 100 includes a cylindrical rotating head 102 and an optical fiber array that extends radially from the cylindrical shape and has a final end in a line.
It has 105.

A light source 103 is attached to one end of a peripheral edge of the rotary head 102, and a motor is connected to a rear end of the rotary head 102, and the rotary head 102 is rotated by driving the motor. As a result, the light emitted from the light source 103 sequentially enters the incident end 105b of the optical fiber array 105, and is emitted from the exit end 105a.

As shown in FIG. 8, predetermined dots are exposed on the photosensitive drum 30 by the light emitted from the emission end 105a.

In this case, since the light emitted from the emission end 105a is diffused at the flat emission end 105a, which is the end of the optical fiber, for example, an intensity distribution in which the two lights overlap as shown in FIG. Are not formed on the photosensitive drum 30.

In order to deal with such a problem, it is sufficient to reduce the distance between the emitting end 105a and the photosensitive drum 30, but there is a limit due to problems such as mechanical accuracy. Is polished to a convex shape, and a lens is formed at the tip of the optical fiber to cope with the problem.

[Problems to be solved by the invention]

However, since the optical fiber usually has a diameter of only about 100 μm, there is a problem that very fine precision is required for the polishing machine, and it takes a long time for polishing. Further, in a case where a lens is formed at the tip of each optical fiber in an optical fiber array in which optical fibers are linearly arranged, if the polishing is performed after arranging the optical fibers, the space between the optical fibers is very narrow and difficult. is there. Conversely, if the optical fibers are arranged after polishing each optical fiber, the method for producing the optical fiber array is limited, and the optical fiber array cannot be produced efficiently at low cost. There is.

In view of such circumstances, the present invention provides an optical fiber array that is inexpensive, has high productivity, and can form a clear image by manufacturing a lens at the tip of an optical fiber using a photocurable resin. It is an object.

[Means for solving the problem]

In order to achieve such an object, the present invention provides an optical fiber by immersing one end of the optical fiber in an uncured photocurable resin, and then irradiating light from the other end of the optical fiber. The photocurable resin in the vicinity of one end of the optical fiber is cured according to the intensity distribution of light emitted from one end to form a lens at one end of the optical fiber.

In addition, a plurality of optical fibers are arranged in a predetermined form, and one end of these optical fibers is collectively immersed in an uncured photocurable resin at the same time to form a lens in the same manner as described above. .

[Action]

According to the present invention having the above configuration, the light emitted from the light source is incident on one end of the optical fiber, and the incident light is guided to the optical fiber, reaches the other end, and is emitted therefrom. At this time, the other end of the outgoing optical fiber is immersed in the uncured photocurable resin, so that the photocurable resin is cured according to the light intensity distribution of the emitted light, and a lens is formed at the tip of the optical fiber. .

〔Example〕

Hereinafter, a method for producing a lens at the end of an optical fiber according to the present invention will be described with reference to FIGS. 1 to 7.

FIG. 1 shows an example of an apparatus directly used for carrying out the method for producing a lens of the present invention.

In this figure, the apparatus is provided below, a container 7 for storing uncured photocurable resin 6, a plate-like scattering plate 3 provided above the container 7, It becomes the light source of the scattered light of the plate 3 and one end of the optical fiber
A lamp L for projecting light to the incident end 51b),
A reflector 2 for condensing the light emitted from the lamp L and a shielding plate 4 located on a side surface of the optical fiber array 5 for shielding unnecessary light are provided.

The object on which the lens is formed by the method of the present invention is an optical fiber. In FIG. 1, the optical fiber array 5 in which a plurality of the optical fibers 51 are bundled is arranged in a predetermined form. Have been. Such an optical fiber
The other end of 51 is immersed in an uncured photocurable resin 6 (hereinafter referred to as an emission end 51a).

As the photocurable resin stored in the container 7,
For example, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, trimethyl propane triacrylate, trimethylol propane triacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate and the like, polymerized into ethylenically unsaturated acid esters of polyhydric alcohols. As an initiator, a mixture of a diaryl ketone derivative such as benzophenone, miheras ketone, benzoyl methyl ether, isopropylxanthone, isopropylthioxanthone, a benzoylalkyl ether, a ketocoumarin compound, or the like is used.

Next, a method for producing a lens on the end of an optical fiber according to the present invention will be described with reference to FIGS.

First, the lamp L shown in FIG. 1 is turned off, and one end of the optical fiber array 5 bundled in a predetermined shape is immersed in the photocurable resin 6.

Thereafter, the lamp L is turned on for a certain time. When the lamp L is turned on, the light exiting the lamp L is once collected by the reflector 2 and then irregularly reflected by the scattering plate 3, and the scattered light is applied to one end of the optical fiber 5 (incident of each optical fiber). Incident on the end 51b).

This incident light passes through each optical fiber 51,
The light is emitted from the emission end 51a of the optical fiber (immersed in the photocurable resin).

Focusing on the individual optical fibers 51 of the optical fiber array 5 (FIG. 4), the light incident from the incident end 51b is radiated from the output end 51a. As shown in the figure, the intensity increases near the center of the diameter of the optical fiber 51, and gradually decreases toward the periphery.

Therefore, the photocurable resin 6 starts to cure according to the light intensity distribution, and finally cures into a single-sided convex lens shape as shown by a dotted line in FIG.

The optical fiber array 5 thus cured is drawn out of the photo-curable resin 6 in the container 7 as shown in FIG. 3, and thereafter, using an organic solvent such as xylene,
Wash off the uncured photocurable resin sufficiently.

Thereafter, sufficient light is applied to the cured resin portion (lens portion 52) to completely cure the lens portion 52.

With such a method, when optical recording is performed using an optical fiber having a hardened lens portion 52 as shown in FIG. 6, light that has exited the emission end 51a of the optical fiber is collected by the lens portion 52. Therefore, the light intensity distribution on the photosensitive drum 30 becomes extremely sharp as shown in FIG.
Therefore, the output image has an extremely excellent effect of being extremely sharp.

The photosensitive drum 30 is charged by a charger (not shown) in advance, and can form a latent image by being exposed.

Although a lens can be formed at the end of the optical fiber by the method described above, the present invention is not limited to the above-described embodiment, and various changes can be made without departing from the gist of the present invention. . For example, the lens shape can be variously changed using laser light or the like instead of scattered light.

Further, it is needless to say that the lens shape can be arbitrarily changed by appropriately setting the intensity distribution of the light emitted from the optical fiber.

〔The invention's effect〕

As is clear from the above, according to the present invention, a lens can be efficiently formed at the tip of an optical fiber.

That is, compared with the conventional polishing method, the lens can be formed very easily and quickly, and the lens can be easily formed even after arranging the optical fibers in a predetermined form (after forming the optical fiber array). An extremely excellent effect that the formation of is performed.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of an apparatus for directly performing the method of the present invention, FIG. 2 is an enlarged view of a light emitting end of an optical fiber immersed in a photocurable resin, and FIG. FIG. 4 is an enlarged view of a light curable resin lens formed at the tip of the optical fiber, FIG. 4 is a conceptual diagram showing a state in which light is emitted from the tip of the optical fiber immersed in the light curable resin, and FIG. FIG. 6 is a view showing a light intensity distribution when light is emitted from the tip of the optical fiber, FIG. 6 is a view showing how a photosensitive drum is exposed using an optical fiber having a lens formed according to the present invention, and FIG.
FIG. 6 is a diagram showing the distribution of light intensity when the optical fiber in FIG. 6 is used, FIG. 8 is a diagram showing a state in which a photosensitive drum is exposed using an optical fiber without a lens, and FIG. FIG. 8 is a distribution diagram of light intensity when the optical fiber is used, and FIG. 10 is a plan view of an optical scanning device. 3 ... scattering plate, 5 ... optical fiber array, 51 ... optical fiber, 51a ... exit end, 51b ... entrance end, 6 ... photocurable resin, 7 ... container, L ... lamp.

Claims (2)

(57) [Claims] An optical fiber is immersed in an uncured photo-curable resin, and then irradiated with light from the other end of the optical fiber to form a photo-curable resin near one end of the optical fiber. A method for producing a lens at an end of an optical fiber, wherein a resin is cured according to the intensity distribution of light emitted from one end to form a lens at one end of the optical fiber. 2. The optical fiber end according to claim 1, wherein a plurality of optical fibers are arranged in a predetermined form, and one end of each of the optical fibers is collectively immersed in an uncured photocurable resin. How to make lenses.