JPS60175001A - Microlens array - Google Patents

Abstract

PURPOSE:To form easily a minute lens by applying a transparent resin, whose degree of polymerization is dissociated with ultraviolet rays, on a transparent base material and exposing it to light with a round mask pattern and developing it. CONSTITUTION:A transparent photodissociative resin layer 11 is coated on one face of a base material formed with a glass or plastic transparent plane plate. This resin layer 11 is exposed with a partially transparent mask 13 and is developed to attain a microlens array. Circular patterns are formed in the mask 13, and the degree of polymerization of the photodissociative resin is changed continuously by irradiation of light because the transmittance is changed successively toward the peripheral parts of circles. Consequently, the transmittance of the mask is so selected that the section of the polymerized photodissociative resin is circular, thereby forming a transparent resist having a spherical section.

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention relates to a method for forming a microlens.

[Background technology and its problems]

When an image of an original document placed at a short distance, for example, a few seconds apart, is to be imaged on a photosensitive functional element, conventionally, optical fibers having a graded index as shown in FIG. 1 have been used as a bundle lens. However, lenses with this type of structure have the disadvantage that the optical path length is long and the optical loss in the optical path is large. On the other hand, forming a large number of microlenses on the same plane as shown in Figs. 1 and 2 is extremely advantageous in reducing the above-mentioned optical loss, but it is extremely difficult to form such small lenses on the car body using technology. Met.

[Purpose of the invention]

The present invention has been developed in view of the wheel shape, and provides a method for forming microlenses that can relatively easily form microlenses. [Summary of the Invention] According to the present invention, Applying a transparent resin whose degree of polymerization dissociates with ultraviolet rays to a transparent substrate, exposing it to light using a 5-circular mask pattern to locally form dissociated portions and non-dissociated portions, and remove the dissociated portions to form irregularities. Well, this white part can now function as a lens.

〔Effect of the invention〕

According to the present invention described above, microlenses can be formed extremely easily on a transparent substrate by using a resin that dissociates with ultraviolet rays, and microlenses that are thin and have low optical loss can be provided. effective.

[Embodiments of the invention]

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIGS. 3(a) to 3(C) are partially cutaway perspective views for explaining the method of forming a microlens according to the present invention.

That is, in FIG. 3(a), reference numeral 10 denotes a base formed of a transparent flat plate of glass or plastic ring, and a transparent photolabile resin layer 1 is provided on one surface of this base 10.
Coat 1. This photo-dissociable resin layer 11 is made of, for example, acrylic that dissociates under ultraviolet light.

There are urethane, epoxy, silicone, etc. A microlens array can be realized by exposing and developing a partially transparent mask 13 on such a resin layer 11 as shown in FIG. 3(b). More specifically, as shown in FIG. 4, the mask 13 is formed with a five-circle pattern, and the transmittance of each circle changes successively toward the periphery.

Therefore, since the degree of polymerization of a photodissociable resin changes continuously when irradiated with light, if the transmittance of the mask is selected so that the cross section of the polymerized photodissociable resin becomes circular, the cross section can be changed. A spherical transparent resist can be formed.

The pattern of the microlens array is a repeating pattern of circular dots as shown in FIG.

The degree of polymerization at the beginning of each day is illustrated in FIG.

When the concentration of the mask is varied continuously, the degree of polymerization of the resist is such that a cylens with a curved cross section is formed as shown in FIG.

Furthermore, in the interval 9 of such a pattern in which the density changes continuously, the dry plate 14 is placed apart as shown in FIG. 6, and a lens similar to that shown in FIG. 4 is formed on the resist 2 by utilizing the diffraction of light. I can do it.

Furthermore, by forming the microlens array not only on one side of the glass plate 1 but also on both sides (11, 11') as shown in FIG. 7, an erect image can be obtained.

Further, as shown in FIG. 8, a color filter 14 is placed on the glass.
-1, 14-2, 14-3, then lenses 2,
3, a color lens array can be formed. .

[Brief explanation of drawings]

1 and 2 are a perspective view and a partially enlarged perspective view showing the basic structure of a microlens array. FIG. 3 is a partially enlarged perspective view showing an embodiment of the method for forming a microlens array according to the present invention. FIG. 4 is an explanatory diagram of a mask for obtaining a microlens array, and FIG. 5 is a plan view showing an example of the mask. FIG. 6 is a sectional view showing another example of the mask, and FIGS. 7 and 8 are sectional views showing modified examples of the present invention. lO...Transparent BA substrate 11...Transparent resin 13...Pattern mask Agent Patent attorney Kensuke Norichika (and one other person) Figure l Figure 3 Figure 4 Figure 5 Figure 6

Claims (5)

[Claims] (1) A transparent substrate such as glass or plastic is coated with a transparent resin whose degree of polymerization is dissociated by ultraviolet rays, and a lens is formed by exposing it to at least one circular mask pattern and developing it. microlens array. (2) The above-mentioned micropattern is an array with continuously changing density. (3) The microlens array according to claim 1, wherein the micropattern is formed at a 4° angle using a diffraction effect. (4) The microlens array according to claim 1, wherein the lenses are formed on both sides of a transparent substrate. (5) The microlens array according to claim 1, characterized in that a color filter is interposed between the transparent substrate and the lens.