JPH10115809A - Varifocal lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a lens possible to cope with both of nearsightedness and farsightedness, and to easily change a focal distance according to the change of a reading distance and the change of eyesight by filling the inside of the lens with a transparent liquid and adjusting the focal distance by controlling the pressure of the liquid. SOLUTION: When the sealing liquid 6 is force-fitted between the main lens 1 and the auxiliary lens 2, the thickness of the center of a part constituted of the lenses 1 and 2 is increased and the focal distance is shortened. Then, an optimum condition for reading a book and the like is selected. A pressure adjustment mechanism A is a piston type or a diaphragm type and fitted to the supporting arm part of spectacles or the rim frame of the lens. By a cover lens 5, the flexibly deformed lens 2 is airtightly held from the outside and the mechanical damage and the dew-condensation of the tenacious lens 2 are prevented. The outside shape of the lens 2 is formed similar to the lens 1 and the part other than the lens part is made to adhere extending over the whole surface so as to smoothly connect a boundary. Besides, it is also possible that only the focus varying part of the lens 1 is formed to have special curvature and the other part is constituted of a plane surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

TECHNICAL FIELD The present invention relates to an optical lens design technique.

[0001]

2. Description of the Related Art In the field of eyeglasses, there are two types, one for reading and one for living.
Two ranges having different focal lengths are provided in a single lens to provide an object that can be used for both directions. Alternatively, an auxiliary lens for reading is attached so as to be easily retracted.

[0002]

SUMMARY OF THE INVENTION The curvature of a lens can be changed completely or partially so that it can be used for both long and short distances, and can be easily adjusted according to a change in reading distance or a change in visual acuity. To provide a lens with a structure that can change the focal length.

[0003]

[Means for Solving the Problems] Two transparent lens plates made of glass or plastic are hermetically bonded around the periphery thereof,
A transparent liquid is sealed in the space formed between the two plates. A capillary connected to the liquid portion is provided, and liquid is taken in and out through the capillary to increase and decrease the pressure. An increase in pressure results in a reduction in the focal length, and a reduction in pressure increases the focal length.

[0004]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG.
Indicates an auxiliary lens made of plastic, which is hermetically bonded to the main lens at the periphery. Reference numeral 3 denotes a piston for supplying a sealed liquid 6 to a small-diameter pipe leading to a liquid filled in a space between 1 and 2, and 4 denotes a cylinder thereof. Filled liquid 6
Is press-fitted between the main lens 1 and the auxiliary lens 2, the thickness of the central portion of the portion constituted by the lenses 1 and 2 increases, and the focal length decreases. In this way, optimal conditions for reading and other situations can be selected. The pressure adjusting mechanism is a piston type, a diaphragm type, or the like, and is attached to a supporting arm portion of spectacles or an edge frame of a lens. Reference numeral 5 denotes a cover lens, which holds the flexible deformable auxiliary lens 2 from the outside in an airtight manner, and can prevent mechanical damage and dew condensation on the tough auxiliary lens. The outer shape of the auxiliary lens 2 is formed in the same manner as the main lens 1, and is adhered over the entire surface except for the lens portion, so that the boundary line is smoothly connected. It is also possible to provide a special curvature only to the variable focus portion of the main lens and to make the liquid-enclosed portion of the auxiliary lens a flat surface, thereby facilitating the manufacture and adhesion of the auxiliary lens.

FIG. 2 shows a structure in which a main lens is formed of a flat plate and a cover lens has a lens function. This has the effect of facilitating the manufacture of a tough auxiliary lens and facilitating adhesion with the main lens. In this example, the cover lens has a function as the whole lens. In the expression of FIG. 2, the auxiliary lens has a curvature at the focus variable portion, but when there is no pressure of the sealing liquid, the auxiliary lens is manufactured as a simple flat plate, and is deformed into a shape by the pressure of the sealing liquid 6. The manufacture and bonding of the auxiliary lens can be facilitated.

FIG. 3 shows an example in which only the variable focal length portion of the main lens has a lens function. In this case, the initial form of the auxiliary lens can be flat, and
Can be used to form the curvature of the auxiliary lens. This example also aims at facilitating the production of the auxiliary lens and the adhesion with the main lens. Also in this case, the cover lens has the function of the entire lens.

[0007]

FIG. 1 is a sectional view showing a basic configuration.
The auxiliary lens 2 is a cover lens configured to avoid contact with the outside world and contact with the outside air. The tough auxiliary lens 2 is adhered to the main lens over the entire surface other than the enclosed portion of the encapsulated liquid 6 to prevent the generation of a distinct boundary line between the lens portion and the adhered portion.

[0008]

The visual acuity gradually changes, but since the eyeglasses can be adjusted to the optimum conditions at hand without changing the glasses each time, the eyeglasses can always be used in an optimum state. Further, since the diopter of this lens can be adjusted by an auxiliary lens, it is not necessary to manufacture many types of lenses having different powers, and mass production can be performed within a certain range. If the auxiliary lens 2 is air-tightly protected by a cover lens or the like, there is no danger of damage or concern about dew condensation due to temperature change.

[0009]

[Brief description of the drawings]

FIG. 1 Sectional view

FIG. 2 is a sectional view

FIG. 3 is a sectional view

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main lens 2 Auxiliary lens 3 Piston 4 Cylinder 5 Cover lens 6 Filled liquid

Claims (2)

[Claims] 1. A lens whose focal length can be adjusted by forming a part or the whole of a lens formed of a plane or an aspect into a double structure, filling a transparent liquid therein, and adjusting the liquid pressure through a communication hole. , And glasses incorporating the lens. 2. The lens according to claim 1, further comprising a cover lens for protecting the surface from the external environment, and eyeglasses incorporating the lens.