JPH0651107A - Production of liquid lens - Google Patents

Abstract

PURPOSE:To relatively easily form a high-precision liq. lens by ejecting a transparent liq. into a hollow part and heating the weld zone while preventing the heat transmission practically to the part except the weld zone. CONSTITUTION:A transparent liq. 3 is sealed within the members 1 and 2 consisting of a transparent thermoplastic resin and forming a lens. A good heat conductor is arranged at the weld zones 4 and 5, and a cooling mechanism is provided in the other lens element parts. Consequently, the conductor is heated to heat only the weld zones 4 and 5, and the members 1 and 2 are not heated. By this method, the weld zones 4 and 5 are integrated to seal the liq. 3, the members 1 and 2 are not heated, and the design values are maintained. In this case, a transparent optical plastic of a halogen-substituted polycyclic structure such as polycarbonate and acrylic resin is preferably used as the thermoplastic material for the members 1 and 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid lens manufacturing method.

[0002]

2. Description of the Related Art However, such a liquid lens has various problems and is rarely used in practice. The use as an optical element of an optical system that requires particularly high precision is not well known. One of the reasons is that a highly accurate lens cannot be formed due to deformation of the container or the like when the liquid is injected into the transparent container forming the lens and then the liquid is sealed. Therefore, it is not possible to reduce the cost, and it is often easier to manufacture and it is more cost effective to form the entire lens with a transparent synthetic resin.

Specifically, this type of liquid lens is shown in FIG.
The container 11 and 12 is formed in the shape of a lens as shown in FIG. 1, and is formed by injecting the liquid 13 into the container and joining the members 11 and 12 constituting the container at the boundary portion 14 thereof.

[0004]

In the above liquid lens, when the members 11 and 12 are joined together by using an adhesive, a misalignment occurs. In addition, there is a problem of inclination due to the influence of the thickness of the adhesive and the fact that the thickness varies depending on the location.

Further, when the two members are joined by heat welding, heating affects other than the welded portion. Even in this method, avoiding eccentricity is a difficult problem.

It is an object of the present invention to provide a method of forming a liquid lens which is relatively easy to manufacture and has high precision.

[0007]

SUMMARY OF THE INVENTION A method of manufacturing a liquid lens according to the present invention comprises a welded portion integrally formed with a lens made of a transparent thermoplastic resin which constitutes a lens shape. After joining two members and injecting a transparent liquid into the hollow portion, the welded portion is heated so that heat is hardly transferred to portions other than the welded portion to form a lens.

Specifically, in the state where the welded portion is cooled by the good thermal conductor and the others are cooled, the welded portion is heated and welded through the good thermal conductor.

As another method, there is a method in which an electric resistor such as a nichrome wire is molded in the welded portion, and the welded portion is heated and welded by energizing this.

Further, an absorber for electromagnetic waves is inserted into the welded portion, electromagnetic waves are applied thereto, and the welded portion is heated and welded to form a lens.

Further, a far-infrared ray absorber is inserted into the welded portion, and the far-infrared ray is irradiated to heat the welded portion to form a lens.

[0012]

EXAMPLES Examples of the liquid lens forming method of the present invention will be described below.

FIG. 1 is a sectional view of a liquid lens, in which 1 and 2 are members forming a lens made of a transparent thermoplastic resin, and a transparent liquid is sealed inside. Here, 4 and 5 are welded parts.

A first embodiment of a method for welding the welded portion of such a liquid lens will be described. As shown in FIG. 2, the welded parts 4, 5
A good heat conductor is placed on the other lens element and a cooling mechanism is provided on other lens element portions.

As a result, heat is applied to the good heat conductor to heat only the welded portions 4 and 5, and the member forming the lens is prevented from being heated by the cooling mechanism. According to this method, the welded portions 4 and 5 are integrated with each other to bring the liquid 3 into close contact with each other, and the members 1 and 2 forming the lens are not heated at all and maintain the state of the designed value.

In the second embodiment, as shown in FIG. 2, electric resistances such as nichrome wires are provided in the welded portions 4 and 5, respectively, and a current is passed through the lead wires. In this way, the liquid resistance is formed by energizing the electric resistor to generate heat to weld the welded portions 4 and 5, and then cutting the lead wire.

In this embodiment, the electric resistor and the lead wire may be arranged at the most suitable places when molding the members 1 and 2 forming the lens.

Next, in the third embodiment, an electromagnetic wave absorbing material such as ferrite is provided in place of the electric resistor, and the electromagnetic wave is radiated to heat the absorbing material to heat and weld the welded portion to form a liquid lens. Form.

Further, in the fourth embodiment, a far-infrared absorber, such as an electric resistor or an absorber for electromagnetic waves, is used to irradiate far-infrared rays to cause heat generation and welding.

Also in these second to fourth embodiments, it is more preferable to weld the lens portion while cooling it.

If a powdery material is used as the electromagnetic wave absorbing material in the third and fourth embodiments, only the required portion can be heated.

As the thermoplastic material of the member forming the lens of such a liquid lens, a halogen-substituted polycyclic structure, for example, transparent optical plastic such as polycarbonate or acrylic resin is preferable.

As the liquid to be sealed, diethyl butyrate, methyl benzoate, isobutane, diethyl glycol, dimethyl ether, 1 bromonaphthalene, 1 chloronaphthalene, etc. can be considered.

Optical plastic has a refractive index of about 1.50 (polycarbonate 1.54, acrylic 1.49).
Therefore, the refractive index is 1. like 1-bromonaphthalene.
If a liquid having a high level of about 6 is used, the difference between the refractive index of the member forming the lens and the refractive index of the member forming the lens can be utilized. On the contrary, if a liquid having a refractive index of about 1.5, such as diethyl butyrate, is used, it can be treated as one lens if there is almost no difference in the refractive index between the member forming the lens and the liquid.

[0025]

According to the method of the present invention, it is possible to accurately manufacture a joint between members forming a lens as designed.
It is possible to make an accurate liquid lens.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is a sectional view of a conventional liquid lens.

[Explanation of symbols]

 1 member for forming lens 2 member for forming lens 3 liquid 4 welded portion 5 welded portion

Claims (4)

[Claims] 1. A liquid lens, which has a lens-like appearance and is made of a transparent synthetic resin having a hollow portion and which is filled with a liquid in a hollow portion between the two members. Further, an integrally formed welding portion is provided, heating means made of a good heat conductor is provided in the vicinity of the welding portion, and a cooling mechanism is arranged around the two members, and the heating means is heated to weld the welding portion. How to make a liquid lens to form. 2. The method according to claim 1, wherein an electric machine resistor is provided in the welded part instead of the good thermal conductor, and the electric machine resistor is energized to generate heat to weld the welded part. 3. The method according to claim 1, wherein the welded portion is provided with an absorber for electromagnetic waves, and the absorber is heated by radiating the electromagnetic waves to weld the welded portion. 4. The method according to claim 1, wherein a far-infrared absorber is provided on the welded portion, and the welded portion is welded by irradiating with far-infrared rays.