JPH04298712A - Optical device - Google Patents

Abstract

PURPOSE:To decrease the number of lenses in use and to omit an adjusting mechanism for the gap between the lenses by obtaining different refract on characteristics by one light transmission body. CONSTITUTION:The optical device consists of the light transmission body 1 made of as transparent material which varies in refractive index by being applied with a voltage, a transparent electrode 2 formed on the surface of the light transmission body 1, and a means which applies the voltage. Further, the transparent material which varies in refractive index by the voltage application is made of LiTaO3 or LiNbO3. Therefore, when the voltage is applied to the light transmission body 1 made of LiTaO3, LiNbO3, etc., the light transmission body is strained internally to vary in refractive index. The variation in the refractive index has correlation with the shape of the light transmission body 1, the position of the transparent electrode 2, and the applied voltage, so they are so set as to obtain desired refractive index variation in advance, thereby obtaining plural refraction characteristics by the same light transmission body.

Description

[Detailed description of the invention]

[Object of the invention]

0002

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to optical devices such as lenses and prisms widely used in microscopes, eyeglasses, and the like.

0003

2. Description of the Related Art Conventionally, optically transparent bodies such as lenses and prisms have been known, which are formed by molding a transparent material such as glass with a high refractive index so as to obtain a predetermined refraction effect.

[0004] These optically transparent bodies are manufactured in many types with different refractive properties depending on the use and purpose, and these optically transparent bodies can be used singly or in combination, or in combination as necessary. The interval between the two is adjusted to obtain a predetermined refraction characteristic.

[0005]

SUMMARY OF THE INVENTION As described above, conventional optical devices have had the problem of requiring a large number of lenses and prisms having different refractive properties depending on the application. Furthermore, when combining multiple optically transparent bodies and adjusting their spacing, a spacing adjustment mechanism is required, which increases the length of the device and complicates the structure due to the adjustment mechanism. there were.

The present invention was made to solve these difficulties, and an object of the present invention is to provide an optical device in which a single optically transparent body has a plurality of refraction characteristics.

[Configuration of the invention]

[0008]

[Means for Solving the Problems] An optical device according to the present invention includes (a) a transparent body made of a transparent material whose refractive index changes by applying a voltage; and (b) a surface of the transparent body. A transparent electrode is formed; and (c) means for applying a voltage to the transparent electrode.

[0009] Examples of the transparent material (a) whose refractive index changes upon application of voltage used in the present invention include LiTaO3 and LiNb having an ilmenite structure.
O3, Ba2Na with tungsten bronze structure
Examples include single crystals such as Nb5O15, among which LiTaO3 and LiNbO3 are particularly suitable for the present invention.

[0010] These transparent substances are usually formed into the shape of a well-known lens or prism, but depending on the purpose, a plate-like substance can also be used. In order to form a transparent material from these materials, the crystal axis of the transparent material is made parallel to the optical axis or at a predetermined angle. As the transparent electrode (b), a commonly used vapor-deposited film of tin oxide, indium oxide, or the like can be used, and if necessary, it is formed into a predetermined pattern shape by a known lithography technique.

[0011] As the voltage applied to the transparent electrode (c), a direct current voltage is usually used, and if necessary, the voltage applying means is provided with a voltage adjustment mechanism.

0012

[Operation] When a voltage is applied to a transparent material made of LiTaO3, LiNbO3, etc., stress is generated within the transparent material and the refractive index changes. This change in refractive index has a correlation with the shape of the transparent body, the position of the transparent electrode, and the applied voltage, so if these are set in advance to obtain the desired change in refractive index, it is possible to Multiple refractive properties can be obtained in the body.

Therefore, by adjusting the applied voltage, the focal length of glasses or other optical devices can be changed,
It is possible to omit an interval adjustment mechanism when a plurality of transparent bodies are used in combination.

[0014]

[Example] Next, an example of the present invention will be described.

In FIG. 1, Z of LiNbO3 single crystal
On both sides of the convex lens 1 formed with its axis aligned with the optical axis,
A transparent electrode 2 made of a vapor-deposited film of tin oxide is formed.

Furthermore, the transparent electrode 2 of the lens 1 is connected via an electric wire 3 to a DC power supply device consisting of a voltage converter 4 and a battery 5. 6 is a switch.

In this embodiment, when the switch 6 is opened and no voltage is applied to the transparent electrode film 2, the convex lens 1 functions as a lens having a unique refractive index derived from its shape.

When the switch 6 is closed and a DC voltage is applied to the transparent electrode 2 of the lens 1, the refractive index changes due to the electro-optical effect of the single crystal of LiNbO3, and the lens 1
focal length changes.

FIG. 2 is a perspective view of an embodiment in which the present invention is applied to eyeglasses.

In the figure, the convex lens 1 shown in FIG. 1 is attached to an eyeglass frame 7. Further, the transparent electrode 2 of the convex lens 1 is connected to an electric wire 3 embedded in the eyeglass frame 7.
Voltage converter 4 embedded in eyeglass frame 7 via
and is connected to a DC power supply device consisting of a battery 5 detachably attached to the eyeglass frame 7.

According to this embodiment, the focal length of the glasses can be changed by opening and closing a switch (not shown).

The above is an example in which the present invention is applied to a convex lens, but it can be similarly applied to a concave lens.

When the present invention is used as bifocal glasses, a sensor whose voltage changes depending on the angle of elevation (upward inclination of the optical axis) is used to function as near glasses when the face is facing upward or horizontally. It is also possible to configure the glasses to function as reading glasses when facing downward.

Furthermore, it is possible to change the optical path by forming a transparent electrode on any surface of the optical path of the prism, or to change the refractive characteristics of a part of the optical path by forming a transparent electrode locally on the transparent material. You can also

Furthermore, the device of the present invention is applied to one of the lenses of an optical device that changes the focus of the optical device by changing the spacing between a plurality of lenses on the optical path, thereby omitting the spacing adjustment mechanism between the lenses. It is also possible.

[0026]

[Effects of the Invention] As explained above, the optical device according to the present invention can obtain different refractive characteristics using the same transparent body, so it is possible to reduce the number of lenses used and adjust the distance between the lenses. It is possible to omit the mechanism.

[Brief explanation of drawings]

FIG. 1 is a diagram schematically showing an embodiment of the present invention.

FIG. 2 is a perspective view showing another embodiment of the invention.

[Explanation of symbols]

1... Convex lens, 2... Transparent electrode, 3... Electric wire, 4...
Voltage converter, 5...Battery, 6...Switch, 7...Eyeglass frame

Claims (2)

[Claims] 1. (a) a light transmitting body made of a transparent material whose refractive index changes by applying a voltage; (b) a transparent electrode formed on the surface of the light transmitting body; and (c) the transparent body. 1. An optical device comprising means for applying a voltage to an electrode. 2. The transparent material whose refractive index changes by applying a voltage is LiTaO3 or LiNbO3.
The optical device according to claim 1, characterized in that it consists of the following.