JPS62161118A - Variable focus liquid crystal spectacles - Google Patents

Abstract

PURPOSE:To easily manufacture variable focus lenses meeting the characteristics of the human eyes by providing low-resistance electrodes having the notches provided to the circumferences of liquid crystal lenses. CONSTITUTION:The liquid crystal lenses 2, 3 are respectively constituted by forming the liquid crystal cells of a spheroconcave lens 4 and flat plate glass 5 formed with electrodes 6, 6 of transparent conductive films consisting of SnO2, In2O3, SnO2+In2O3, etc. at the insides thereof, and joining both plates via a spacer 8 consisting of an insulator. The low-resistance electrodes 9, 10 consisting of chromium, nickel, etc. are disposed to cover the peripheral edges of the lenses to the electrodes 6, 7 of such transparent conductive films and are connected from one end to an external driving power source 11 respectively by connecting wires 12, 13. The voltage distribution curve by the voltage impressed by the power source 11 to the right and left liquid crystal lenses 2, 3 is as shown by dotted lines on the lens faces of the liquid crystal lenses to act in such a manner that the apparent refractive indices of the liquid crystals increase in the regions gear the interrupted parts 15, 16 of the electrodes 9, 10 on the nose side of the spectacle lenses 2, 3.

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to eyeglasses using variable focus liquid crystal lenses, and more specifically, to symmetrically align left and right variable focus liquid crystal lenses used in eyeglasses to make it easier to see objects near and far. This invention relates to glasses with a pari-focus function.

[Prior Art] The idea of making a lens with a variable focal length by utilizing the refraction phenomenon of liquid crystals has already been proposed in, for example, Japanese Patent Application Laid-Open No. 52-32348, Japanese Patent Application Laid-Open No. 54-99654, and Japanese Patent Publication No. 1982-
This can be seen in Publication No. 50339, etc. An example of such a conventional lens using a liquid crystal (hereinafter referred to as a liquid crystal lens) will be described with reference to the cross-sectional view and plan view of FIGS. 5 and 6.

The liquid crystal lens 20 is constructed by providing transparent conductive layers 23 and 24 on a spherical concave lens 21 and a flat glass 22, respectively, and filling a liquid crystal 26 in the space formed when these are bonded together via an insulating layer 25. . The transparent conductive layer 2
An alternating current voltage from an alternating current power source 27 is applied between 3 and 24 in a variably adjustable manner. Further, even when this AC voltage is not applied, alignment processing is performed so that the liquid crystal molecules are aligned in a certain specific direction, and in the drawing, the IR1 product molecules are homogeneously aligned.

When a voltage is applied to this liquid crystal lens 20, the liquid crystal lens 20
The molecules of the liquid crystal 26 in 0 rotate so that the long axis direction of the molecules is aligned with the direction of the electric field (in the case of a liquid crystal with positive dielectric anisotropy). Here, a polarizing plate 28 is combined as shown in FIG. 7 with a liquid crystal lens 20 having a director of liquid crystal molecules shown by an arrow n in FIG. When the liquid crystal molecules in the liquid crystal lens 20 are rotated by changing the applied voltage, the refractive index of the liquid crystal 26 changes between the refractive index n of extraordinary rays and the refractive index n of ordinary rays.
It changes with O.

Therefore, the focal length is f, the refractive index is n, and the curvature of both sides of the lens! 11 diameters as rl and r2, the focal length of the lens can be changed by increasing the focal length of the lens.

[Problems to be Solved by the Invention] Incidentally, in order to adjust the variable focal length of such a liquid crystal lens 20, an AC voltage from an external drive power source 27 is applied to the electrodes 23. of the transparent conductive layer via a variable resistor. When applied to one end of 24, these transparent electrodes 23, 24 have sheet resistance 3
Since the resistance is uniformly distributed over the entire surface from one end of the transparent electrode 23 to the other end of the transparent electrode 23, 24, there is a voltage drop depending on the distance from the electrode opening.
The voltage distribution applied to 6 will be different. That is, when a desired voltage is applied, the voltage is the highest at the electrode outlet, and the voltage decreases as it moves away from the outlet. Therefore, the refractive index distribution of the liquid crystal changes uniformly on the lens surface of the liquid crystal lens 20. It ends up being something you don't do.

[Means for Solving the Problems] Therefore, in the present invention, in order to uniformly apply the intended applied voltage to the electrodes 23 and 24 of the transparent conductive film over the entire surface of the liquid crystal lens 20, the periphery of the lens is By arranging low-resistance electrodes along the sides, the voltage distribution applied to the liquid crystal is made almost uniform, and when viewing close objects with the left and right lenses of the glasses, the parts near the nose or the bottom of the left and right lenses By forming discontinuous low-resistance electrodes in some of the parts, it gives the liquid crystal lens an electric field distribution that matches the characteristics of the eye. The eyeglasses are formed with a portion having a high apparent refractive index and use variable focus DK lenses having a parifocus function.

[Example] The present invention will be explained below based on illustrated embodiments.

FIG. 1 is a perspective view of the glasses, in which the left and right lenses 2.3 are composed of liquid crystal lenses. FIG. 2 shows a cross-sectional view of this liquid crystal lens 2.3 along line A-A in FIG. 02
．． ■ Spherical concave lens 4 and flat glass 5 on which transparent conductive film electrodes 6 and 7 such as o203, 5n02 + Io203 are formed
A liquid crystal cell is formed from the two plates, and the two plates are joined together with an insulating spacer 8 interposed therebetween.

As shown in FIG. 3, low resistance electrodes 9 and 10 made of chromium, gold, aluminum, nickel, etc. are arranged on the electrodes 6 and 7 of the transparent conductive film using steam tubes or the like so as to cover the periphery of the lens. The external drive power supply 1 is connected from one end of the
1 by connecting lines 12 and 13, respectively.

Therefore, the external drive power supply 1 is connected to the left and right liquid crystal lenses 2 and 3.
1, the voltage distribution curve due to the voltage applied by the lens surface of the liquid crystal cell becomes as shown by the dotted line in FIG. In the region closer to 16°, the apparent refractive index of the liquid crystal becomes higher. Therefore, when the line of sight of the eyeball moves toward the center of the eye while trying to see from a distant object to a nearby object while wearing glasses configured in this way, the liquid crystal lenses 2 and 3 act as if they are in pari-focus mode that matches the characteristics of the eye. It is possible to create glasses with variable focus liquid crystal lenses that act like lenses and allow more natural viewing of objects near and far.

Figure 4 shows the low resistance electrode 9.1 of the liquid crystal lens in Figure 3 above.
The low resistance electrodes 9' and 10 are provided on the lower part of the liquid crystal lens, whereas the portions 15 and 16 where t71 ends at 0 are provided on the nose side.
15' and 16' are formed, and its function is almost the same as that shown in FIG. 3 above. In this case as well, the apparent refractive index of the liquid crystal in the lower portion of the liquid crystal lens 2.3 becomes high, and glasses with pari-focus lenses for reading and other viewing purposes can be easily manufactured.

In this example, the liquid crystal lens 2.3 is replaced with a spherical concave lens 4.
Although the flat glass 5 has been described to form a liquid crystal cell, this cell may be a liquid crystal lens having a lens shape composed of a pair of spherical concave lenses, one using a convex surface, one using a Fresnel lens surface, etc. Of course, the action and effect are the same. [Effect of the invention] In eyeglasses using variable focal length liquid crystal lenses, by providing a low-resistance electrode with a notch around the liquid crystal lens, it is easy to create pari-focus lenses that match the characteristics of the human eye. can be made to

[Brief explanation of drawings]

FIG. 1 is a perspective view of variable focus liquid crystal glasses of the present invention, FIG. 2 is a sectional view taken along line A-A in FIG. 1, and FIGS. 3 and 4 are similar to FIG. FIG. 5 and FIG. 6 are longitudinal and cross-sectional views of the liquid crystal lens, and FIG. 7 is a perspective view of the combination of the liquid crystal lens and polarizing plate. It is. 2.3...Liquid crystal lens 6.7...Transparent conductive film electrode 9.9',
10.10'...Low resistance electrode 15.15', 16.1
6'...Notch part of low resistance electrode %1 Figure horse 2 Shihoki 3 square 40

Claims (1)

[Scope of Claims] Variable focus liquid crystal glasses using liquid crystal lenses whose refractive index is changed by applying a voltage to a liquid crystal cell in which a liquid crystal is sealed in a hollow space formed by opposing transparent conductive films, comprising: Variable focus liquid crystal glasses characterized in that a low-resistance electrode having a notch in a part of the nose or lower part is provided on the peripheral edge of the transparent conductive film of the cell.