JPH03167519A - Production of liquid crystal lens - Google Patents

Abstract

PURPOSE:To obtain the liquid crystal lens which has high surface hardness, is resistant to flawing and has a good surface condition by tightly adhering the laminates, which are formed by laminating transparent polycarbonate sheets via an adhesive agent on both surfaces of the variable focus liquid crystal lens, to the projecting or recessed mating surfaces of molds by slightly tacky adhesive agents then pressing the same. CONSTITUTION:Two sheets of the transparent polycarbonate sheets are placed on the mating surface 31 and the molds 3, 4 are pressed to tightly adhere the polycarbonate sheets to the slightly tacky adhesive agent layers 32, 42, then the mold 4 is pulled upward. A photosetting adhesive agent is applied on both surfaces of the flat plate variable focus liquid crystal lens to form the adhesive agent layer on both surfaces of the variable focus liquid crystal lens. This lens is placed on the polycarbonate sheet on the recessed mating surface 31 of the mold 3. The mold 4 is moved downward and after the molds 3 and 4 are pressed, the sheets are exposed with a high-voltage mercury lamp. The pressure is released after exposing and the liquid crystal lens 1 is obtd. The surfaces are hard, are resistant to flawing and have the good surface condition; therefore, this lens is adequately used as the variable focus liquid crystal lens.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a method for manufacturing a liquid crystal lens.

(Prior art) When the crystalline lens of the eyeball is removed due to an eye disease such as cataract, instead of using conventional lenses with a fixed focal length as glasses, it is necessary to use several types of glasses with different focal lengths depending on the distance at which they will be used. It is necessary to make it easy and then use it depending on the situation, which is very inconvenient in real life. For this reason, various liquid crystal lenses whose focal lengths can be electrically varied have recently been proposed. (For example, JP-A-61-13892
(No. 2, Japanese Patent Application Laid-open No. 62-47026) Furthermore, manufacturing liquid crystal lenses from glass is difficult and heavy, and as a countermeasure to this problem, a conductive film made of synthetic resin has been proposed. For example, JP-A-61-2467
No. 19 discloses that a polyether sulfone film (hereinafter referred to as PES) or boris sulfone film is adhered to both sides of a polarizing film, and a transparent conductive film is laminated on one side and a photocurable resin coating layer is laminated on the other side. A transparent conductive film integrated with a polarizing film is described, and by laminating this film and a liquid crystal layer, a lightweight liquid crystal lens can be obtained.

However, the surface of this liquid crystal lens is a photocurable resin coating layer, which has the disadvantage that the surface condition is poor, the surface hardness is low, and it is difficult to shape into a lens shape.

(Problems to be Solved by the Invention) In view of the above drawbacks, an object of the present invention is to provide a method for easily manufacturing a liquid crystal lens that has a high surface hardness, is hard to be damaged, and has a good surface condition.

(Means for Solving the Invention) The variable focus liquid crystal lens used in the present invention can be any conventional variable focus liquid crystal lens as long as it has a liquid crystal layer and a conductive layer for applying a voltage to the liquid crystal layer. It can be used, for example, in a variable focus system, in which a conductive IT○ vapor-deposited layer is layered on both sides of the liquid crystal layer, and a polarizing film with a PES film adhered to both sides is laminated on both sides of the vapor-deposited layer. Liquid crystal lenses are available.

The polycarbonate sheet used in the present invention only needs to be transparent, but the thicker it becomes, the more difficult it is to shape.
A thickness of m to 1 mm is preferred.

In the present invention, since the variable focus liquid crystal lens and the transparent polycarbonate sheet are bonded together with an adhesive, it is preferable that the adhesive is transparent and of a photocurable type.
For example, adhesives mainly composed of acrylate oligomers such as epoxy acrylate, urethane acrylate, and polyester acrylate, to which (meth)acrylate monomers, sensitizers, etc. are added are preferably used. In addition, it is preferable that the adhesive becomes uniform when pressed and that excess adhesive flows out from the edges, so the viscosity should be 200 to 2000 c.
ps is preferred.

The molds used in the present invention include a mold having a lens-shaped concave mating surface and a mold having a convex mating surface.

This mold can be made of any material, but when a photocurable adhesive is used as the adhesive, it is preferably made of a highly transparent material such as polycarbonate, polymethyl methacrylate, or glass.

In addition, the size of the mold is such that the length and width of the mold are smaller than the laminate so that the adhesive extruded when pressed can be wiped off, that is, the end of the laminate can be pushed out of the mold. It is preferable that the width is narrower by about 1 to 2.

The slight adhesive used in the present invention can be used to temporarily attach a laminate or a polycarbonate sheet to a mold, in which polycarbonate sheets are laminated on both sides of the variable focus liquid crystal lens via an adhesive, and after shaping, the Any adhesive that can be used to peel off liquid crystal lenses manufactured from a liquid crystal lens may be used, and adhesives commonly used for adhesive tapes can be used. For example, JP-A-54-41
A microspherical adhesive as described in Japanese Patent No. 988 is preferably used.

In the present invention, a laminate in which transparent polycarbonate sheets are laminated on both sides of the variable focus liquid crystal lens via an adhesive is adhered to the convex or concave mating surface of the mold with a slight adhesive, and then both Either by pressing with a mold and bonding the laminate with adhesive and shaping it into a lens shape, or by adhering at least one of the polycarbonate sheets to the convex or concave mating surface with a slight adhesive, or two sheets. One polycarbonate sheet was closely attached to each of the convex and concave mating surfaces, and then a variable focus liquid crystal lens was placed between the polycarbonate sheets via an adhesive layer. Press with both molds, adhere the laminate with adhesive, and shape it into a lens shape.

In this case, the adhesive layer may be formed on a polycarbonate sheet or may be formed on a variable focus crystal lens.

The thickness of the adhesive layer is preferably 4 to 100 μm since excess adhesive is extruded from the edges by pressing. or,
At this time, it is preferable that the lower mold has a concave mating surface so that air is not trapped in the adhesive layer.

Incidentally, the slightly adhesive layer may be formed on the mating surfaces of the molds, or may be formed on the surface of the laminate or the polycarbonate sheet.

The pressure of the mold may be as long as the above-mentioned laminate is bonded and shaped, but generally the pressure is 0.1 to 1. 1 at 0kg/ci
It is preferable to press for up to 3 minutes, and heating may be performed within a range that does not adversely affect the liquid crystal lens.

After the adhesive hardens, the mold is loosened and the laminate is taken out to obtain a shaped liquid crystal lens.

(Example) Next, an example of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing an example of an apparatus for manufacturing a liquid crystal lens. 2 in the figure is a substantially U-shaped frame, a mold 3 with a concave mating surface 3l facing upward is installed at the bottom of the frame 1, and a mold with a convex mating surface 41 facing downward. 4 is installed on the top of frame 1. The mold 4 is installed in the frame 1 so as to be slidable up and down, and can be pressurized from above to below. Moreover, on the surfaces of the mating surfaces 31 and 4l,
Slightly adhesive layers 32 and 42 are laminated.

Place two transparent polycarbonate sheets with a thickness of 0.5 mm+ on the mating surface 31, press molds 3 and 4 to bring the polycarbonate sheet into close contact with the slightly adhesive layers 32 and 42, and mold 4.
was pulled upwards.

General formula H-(OCJa00CCaHtCO), 1-OC
zH. OOCNH-CbH4NIICO- (OC2}
1400CC4HllGO) - -OCzLO}1
26 parts by weight of the compound represented by (Mw=160001Mn・9000), 70 parts by weight of 2-hydroxy 3-phenoxypropylacrylate, 2 parts by weight of 2,4-diethylthioxanthone, and ethyl p-N,N-dimethylaminobenzoate. A photocurable adhesive consisting of a double-layered area is applied to both sides of a flat variable focus liquid crystal lens using a doctor knife, and a 20 μm thick adhesive layer is formed on both sides of the variable focus liquid crystal lens. It was placed on a polycarbonate sheet on the concave mating surface 31 of. The variable focus liquid crystal lens is made by laminating conductive ITO vapor deposited layers on both sides of the liquid crystal layer, and further, polarizing films with PES films adhered to both sides of the vapor deposited layers. It was .5 yen.

Next, move mold 4 downward, and molds 3 and 4 weigh 0.5 kg/
Pressed with a pressure of C+a. After pressing for 1 minute and wiping off the adhesive extruded from the edge with a tissue, apply 1000 m J/c+ with a 3k-high pressure mercury lamp! exposed. After exposure, the pressure is released, the laminate is taken out, and the thickness is 1. 6
A lenticular liquid crystal lens of ms+ was obtained. FIG. 2 is a partially enlarged sectional view of the obtained liquid crystal lens 1, in which 1l is a variable fish point liquid crystal lens, and 12, 12 is a photo-cured adhesive layered on both sides of the variable focus liquid crystal lens 11. 13 is a transparent polycarbonate sheet adhered to the variable focus liquid crystal lens 11 by an adhesive layer 12.

(Effects of the Invention) Since the method for manufacturing a liquid crystal lens of the present invention is as described above, it can be easily manufactured without the adhesive entering between the polycarbonate sheet and the mold, and the resulting liquid crystal lens can be easily manufactured. The surface is highly hard and scratch-resistant, and the surface condition is good, so it is suitable for use as a variable focus liquid crystal lens.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an example of an apparatus for manufacturing a liquid crystal lens, and FIG. 2 is a partially enlarged sectional view showing an example of a liquid crystal lens manufactured by the present invention. - Laminated body, 11, 12, one adhesive layer, 13 sheet, 2, one frame, concave mating surface, 41 42 one slight adhesive layer, one variable focus liquid crystal lens, - transparent polycarbonate 3 , 4--type 1, 31-- convex mating surface, 32,

Claims (1)

[Claims] 1. A laminate in which transparent polycarbonate sheets are laminated on both sides of a varifocal liquid crystal lens having a liquid crystal layer and a conductive layer for applying a voltage to the liquid crystal layer via an adhesive, and a convex plate having a convex mating surface is used. After adhering with a slight adhesive to the mating surface of a shaped mold or the mating surface of a concave mold having a concave mating surface, or attaching at least one of the two transparent polycarbonate sheets to a convex mold having a convex mating surface. After adhering to the mating surface of the mold or the mating surface of a concave mold having a concave mating surface with a slight adhesive, and placing the variable focus liquid crystal lens between the polycarbonate sheets via an adhesive layer, A method for manufacturing a liquid crystal lens, which comprises bonding a transparent polycarbonate sheet and a variable focus liquid crystal lens to a variable focus liquid crystal lens by pressing with a mold and a convex mold, and shaping the lens into a lens shape.