JPS63153501A - Lens array plate and its production - Google Patents

Abstract

PURPOSE:To form a sure light shielding layer prevented from being peeled off by forming many lens parts mutually with intervals on a transmissive base and forming a rough face consisting of fine rugged face on a base face other than the lens parts. CONSTITUTION:A lens array plate 1 is manufactured by working the surface of the glass base 2 so as to form a rough face 4 consisting of fine rugged face, applying paste obtained by mixing glass powder having a sufficiently low meting point as compared to that of the glass plate in a solvent to a position to form lens parts 3 on the base face by screen printing, heating the surface at a temp. range suppressing the disappearance of the rugged face on the rough face 4 to melt the applied glass powder and to mold the surface like lens by the surface tension of the melted solution, and then the whole is cooled and solidified. Namely, the light shielding layer is formed by forming a rugged face on the base glass itself. Thereby, the light shielding layer can be prevented from being peeled off.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a lens array plate in which a large number of small lens portions are arranged and formed on one substrate.

[Prior Art] Lens arrays, which are integrated by arranging a large number of small lenses in a plane with their optical axes parallel and spaced apart, are rapidly in demand in the field of image processing, such as copying machines, facsimile machines, and optical printers. It's increasing.

This type of lens array can be roughly divided into two types: the surface is qt
By embedding a small lens portion with a refractive index distribution in which the refractive index changes in the radial direction from the surface toward the depths in a flat transparent substrate using ion exchange, etc., the above-mentioned results can be achieved while keeping the surface flat. There are two types that provide a lens effect using a refractive index distribution (hereinafter referred to as embedded type), and one that forms a protrusion with a semicircular cross section on the surface of a transparent substrate, and uses the refractive power of the curved surface to provide a lens effect. (hereinafter referred to as F)
There is a protruding type).

Regarding the embedded type lens array, for example, JP-A-57-53702, and regarding the protruding-type lens array, JP-A-60-264334, JP-A-81-1121.
The structure and manufacturing method are disclosed in JP-A No. 61-153Ei02 and the like.

[Problems to be Solved by the Invention] In both the above-mentioned embedded type and protruding type lens array plates, the substrate portion between the lenses is transparent;
There is a problem in that external light passing through this portion has a negative effect on the contrast of the image formed by the lens portion.

In order to solve this problem, a structure was proposed in which the surface of the substrate other than the lens part of the lens array plate was covered with a light-shielding film, but in this structure, the adhesion of the light-shielding film material to the smooth surface of the glass substrate was poor. There was a problem that the film was weak and easily peeled off due to slight temperature differences or handling.

In addition, in the case of a protruding type lens array, the surface is not flat and has many curved protruding parts of the lenses, so it is possible to selectively apply a light-shielding coating only to the surrounding substrate surface, avoiding the lens part. The problem was extremely difficult.

One object of the present invention is to provide a structure in which a lens array plate can block light that passes through parts of the substrate other than the lens portion, and can form a reliable light shielding layer that does not cause peeling.

Another object of the present invention is to provide a method for easily providing a light-shielding layer with high precision only on the substrate surface other than the lens portion of a protruding lens array plate.

[Means for Solving the Problems] The lens array plate of the present invention that achieves the object described in item 1 has a plurality of lens portions formed at mutually spaced intervals on a transparent substrate, and the surface of the substrate other than the lens portions is The rough surface has fine irregularities, so that the transmitted light is diffusely reflected on this rough surface.

Furthermore, in order to further ensure the light-shielding function described in item 1, in the improved structure of the present invention, a light-shielding coating made of a non-transparent material is provided on the rough surface.

In order to create a lens array plate that has a rough substrate surface other than the lens portion, first process the surface of the glass substrate into a rough surface with fine irregularities, and then apply the substrate glass to the area on the surface where the lens portion is to be formed. A paste made by mixing glass powder with a solvent with a sufficiently low melting point is applied by screen printing, and the coated glass powder is melted by heating within a range that does not eliminate the rough surface unevenness, and the lens is formed by the surface tension of the melt. It can be manufactured by molding into a shape and then cooling and solidifying it.

[Operations and Effects] According to the structure of the present invention, light that attempts to pass through the substrate portion between the lens portions is scattered and reflected by the rough surface, so that almost no light reaches the image plane where the image is formed by the lens portion. , good image contrast can be obtained.

Moreover, since the light-shielding layer is formed by adding irregularities to the substrate glass itself instead of using a coated film as in the conventional case, peeling does not occur.

Furthermore, according to the above-mentioned manufacturing method, since the lens part is melted and shaped by surface tension, its surface has a fire-polished mirror surface, and the substrate surface other than the lens part remains as a rough surface. Lens size, shape,
Regardless of the arrangement pattern, it is possible to reliably selectively roughen only areas other than the lens portion.

In addition, when forming the lens part, a paste made by mixing low-melting point glass powder with a solvent is applied onto a flat substrate using a screen printing method, so large-area, highly integrated lens array plates can be manufactured easily and at low cost. Can be mass produced.

[Example] The present invention will be described in detail below based on an example shown in the drawings.

FIG. 1 is an enlarged sectional view showing a lens array plate according to the present invention, and FIG. 2 is a perspective view thereof.

The lens array plate 1 is constructed by forming a large number of hemispherical lens portions 3 at intervals from each other on one side 2A of a transparent substrate 2 made of glass, synthetic resin, etc. There is. The surface 3A of the lens portion 3 is a smooth surface, and the substrate surface other than the lens portion 3 is a rough surface 4 with fine irregularities. Further, the side 2B of the substrate 2 on which the lens portion is not formed is a smooth surface.

In the lens array plate having the structure shown in FIG. Most of the light 5B is scattered and reflected by the rough surface 4, and the partially transmitted light is also scattered in all directions by the uneven surface, so the stray light 5B has almost no effect on the focusing or imaging surface of the lens portion 3. do not have. In other words, the rough surface 4 functions as a light shielding layer. FIG. 3 shows an improved structure of the present invention that further improves light shielding performance.

In this example, a coating 6 of a light-absorbing substance such as a coating of resin containing carbon particles is provided on the rough surface 4 provided around the lens portion 3.

By further providing the light-absorbing coating 6 on the rough surface light-shielding layer 4 in this way, the light that passes through the rough surface 4 is also absorbed by the coating 6, so that light-shielding becomes more complete.

In the illustrated example described above, the lens portion 3 has a hemispherical shape, but as shown in FIG. It can also be used as a lens.

Further, as in the example shown in FIG. 5, lens portions 3 may be provided on both sides of the substrate. Furthermore, the lens portion 3 may be of an embedded type as shown in FIG. 6, in addition to the above-mentioned protruding type. The lens array plate shown in Fig. 6 is created by using a method such as ion exchange diffusion in a limited area within a transparent substrate 2 with a flat surface, so that the refractive index changes in the radial direction from one point on the surface toward the deep part. The refractive index distribution is formed to form a refractive index distribution, and this refractive index changing region is used as the lens portion 3. In this case as well, by making the substrate surface excluding the surface 3A of the lens portion 3 on the substrate surface a rough surface 4, The same effect as described above can be obtained.

Next, a preferred method of roughening the substrate surface other than the lens portion using a protruding lens array plate will be described with reference to FIG.

First, as shown in FIG. 7(a), the lens forming side 10A of the glass substrate 10, which has a flat surface, is roughened by known etching means such as blasting, chemical etching, and abrasive polishing.

- For example, grinding is performed using glass beads with a diameter of 10 μm or more.

Next, a glaze paste 11 in which fine particles of a low melting point glass such as lead borosilicate glass having a melting point sufficiently lower than that of the substrate glass is mixed in a solvent is applied to a portion of the roughened substrate surface 10A where lenses are to be formed. The application of the paste 11 is carried out in the same manner as in the general screen printing method using a screen provided with apertures at a predetermined lens arrangement pitch.

- As an example, screen printing is applied in a circle with a diameter of 200 μm at a thickness of 40 μM and an interval of 300 μl.

Next, the substrate is heated at, for example, about 150° C. for about 1 hour. After drying the paste 11, the glaze glass is melted, but the temperature range is not so high that the unevenness on the substrate surface softens and disappears. For example, it is held at about 430°C for about 20 minutes. The glaze glass particles are melted by this heat treatment, and the melt becomes approximately hemispherical due to surface tension, and by cooling and solidifying, a large number of curved protruding lens portions 3 arranged in a predetermined pattern are formed on the substrate. and surface 3A of lens portion 3
is a fire-polished smooth surface, and the other substrate surfaces remain the original rough surface 10A.

According to the above-mentioned method, there is no need for alignment operations such as the method of first molding the lens part and then providing a light-shielding layer on the peripheral substrate surface. The light-shielding layer can be accurately provided even on a highly integrated and large-area lens array plate without causing problems such as smearing. Next, a preferred method for providing a light-absorbing film only on the rough surface 10A will be described.

A coating 12 of a light-absorbing substance is applied over the entire surface of the lens array plate in which the lens portions 3 are formed to protrude as described above and the surfaces other than the lens portions are roughened, as shown in FIG. 7(d). Attach. - For example, a lens array plate is immersed in an acrylonitrile solution in which carbon powder is dispersed, taken out, and then heated and dried.

Next, the lens array plate 1 with the light-absorbing coating 12 attached thereto is placed in an ultrasonic bath, and only the coating 12 attached to the surface of the lens portion 3 is selectively peeled off.

In other words, since the surface of the lens portion 3 and the back surface of the lens array plate are smooth surfaces, the adhesion force of the substrate 1u12 is relatively weak.On the other hand, on the rough surface portions, the coating material digs into the unevenness of the substrate surface, resulting in an anchoring effect. Therefore, when moderate ultrasonic vibration is applied to the coating or substrate in liquid, the coating 12 will peel off from the surface of the lens portion and the back surface of the lens array plate, where the adhesive force is weak, and it will not adhere to the rough surface. The coating 12 remains, and a predetermined light-absorbing coating 6 can be formed.

According to the above method, even when the lens diameter is extremely small, such as several hundred μm, or when an extremely large number of lens parts are provided, it is possible to apply a limited light-shielding coating accurately in a short time and with simple operations. can.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part showing one embodiment of the present invention, FIG. 2 is a perspective view of the same, FIG. 3 is a sectional view of a main part showing another embodiment of the invention, and FIGS. 4 to 6 are perspective views showing various structural examples of lens portions in the lens array plate of the present invention;
7(a) to 7(e) are cross-sectional views showing an example of a method for manufacturing the lens array plate of the present invention. 1... Lens array plate 2... Substrate 3... Lens part 4... Rough surface 5A
, 5B...Light ray 6.Old...Light absorption coating 1st
Figure 2 Figure 3 Figure 4 Figure 4, /1 104. “ , 3 2 Figure 5

Claims (4)

[Claims] (1) A lens array plate characterized in that a large number of lens portions are formed on a transparent substrate at intervals, and the surface of the substrate other than the lens portions is a rough surface with fine irregularities. (2) A large number of lens parts are formed on a transparent substrate at intervals from each other, the surface of the substrate other than the lens parts is made into a rough surface, and a coating made of a light-absorbing substance is provided on the rough surface. A lens array plate characterized by: (3) Processing the surface of the glass substrate into a rough surface with fine irregularities, and screening a paste containing glass particles whose melting point is sufficiently lower than that of the substrate glass at the location on the surface where the lens portion is to be formed. A lens array plate comprising a step of coating by printing, and a step of melting the coated glass by heating within a range that does not eliminate the rough surface unevenness, forming it into a lens shape by the surface tension of the melt, and then cooling and solidifying it. Production method. (4) Processing the surface of the glass substrate into a rough surface with fine irregularities, and screening a paste containing glass particles whose melting point is sufficiently lower than that of the substrate glass at the location on the surface where the lens portion is to be formed. A process of coating by printing, a process of melting the coated glass by heating within a range that does not eliminate the rough surface unevenness, forming it into a lens shape using the surface tension of the melt, and then cooling and solidifying it, and a process of coating the lens portion and the rough surface. A process of attaching a film of a light-absorbing substance to the entire surface of the substrate, including both sides, and a process of applying vibration to the film or the substrate to selectively peel off the film on the smooth surface of the lens portion, where the adhesion force is relatively low. A method for manufacturing a lens array plate comprising: