JPH0618825A - Optical device - Google Patents

Abstract

PURPOSE:To provide the optical device which makes it possible to obtain a change of plural refraction characteristics and continuous refraction characteristics with one piece of optical transparent body. CONSTITUTION:The light transparent body 1 consisting of a single crystalline body which is changed in refarctive index by impressing a voltage thereto, for example, a single crystalline body, such as LITaO3 or LiNbO3, is provided with a pair of electrode 2, 3 facing each other. A pair of these electrodes 2, 3 are so provided as to impress a voltage in the direction orthogonal with the Z-axis of the crystal axis of the single crystalline body. The electrodes 2, 3 are connected to a means for impressing a DC voltage, for example, a DC power source device 7.

Description

Detailed Description of the Invention

[0001]

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, glasses and the like.

[0002]

2. Description of the Related Art Conventionally, there has been known an optical translucent body such as a lens or a prism formed by molding a transparent material having a high refractive index such as glass so as to obtain a predetermined refraction effect. Many types of these optical translucent bodies having different refraction characteristics are manufactured depending on the use and purpose, and these are used alone or in combination. If necessary, the distance between the combined optical translucent bodies is adjusted so that a predetermined refraction characteristic can be obtained.

[0003]

As described above, the conventional optical device has a problem that a large number of optical transmissive bodies such as lenses and prisms having different refraction characteristics are required according to the use. In addition, when a plurality of optical transmissive bodies are combined and the distance between them is adjusted, an interval adjustment mechanism is required, which increases the length of the device and complicates the structure due to the adjustment mechanism. was there.

The present invention has been made to address the above-mentioned problems of the prior art, and makes it possible to obtain a plurality of refraction characteristics or a continuous change in refraction characteristics with one optical transmissive body. It is an object of the present invention to provide such an optical device.

[0005]

In the optical device of the present invention, a light-transmitting body made of a single crystal whose refractive index is changed by applying a voltage is orthogonal to the Z axis of the crystal axis of the single crystal. It is characterized by comprising a pair of electrodes provided so as to face each other so as to apply a voltage in a direction, and a means for applying a voltage to the translucent body via the electrodes.

The transparent body used in the present invention is, for example, a single crystal body such as LiTaO ₃ or LiNbO ₃ having an ilmenite structure, or Ba ₂ having a tungsten-bronze structure.
It is composed of a single crystal such as NaNb ₅ O ₁₅ . Of these single crystals, LiTaO ₃ and LiNbO ₃ are particularly suitable for the present invention.

[0007]

[Function] A single crystal body such as LiTaO ₃ or LiNbO ₃ changes its refractive index by applying stress to the single crystal body when a voltage is applied. This change in the refractive index has a correlation with the shape of the translucent body, the position of the electrode, and the applied voltage. Therefore, if these are set in advance so that the desired change in the refractive index is obtained, the same translucent The body can obtain multiple refractive properties. Also, LiT
In a single crystal such as aO ₃ or LiNbO ₃ , a larger change in the refractive index can be obtained by applying a voltage in the crystal axis of the crystal in a direction orthogonal to the Z axis. Therefore, by adjusting the applied voltage, it is possible to change the focal length of the spectacles and other optical devices with one light-transmitting body, and it is possible to set a large change rate of the focal length.

[0008]

EXAMPLES Next, examples of the present invention will be described.

FIG. 1 is a diagram schematically showing the structure of an optical device according to an embodiment of the present invention. In the figure, 1 is L
This is a convex lens made of a single crystal such as iTaO ₃ or LiNbO ₃ , and this convex lens 1 is formed such that the Z axis of the crystal axis of the single crystal coincides with the optical axis. On the side surface of the convex lens 1, a pair of electrodes 2, 3 made of a vapor deposition film of Au / Cr, Al or the like is provided.
Are formed to face each other. The electrodes 2 and 3 are provided so that an electric field is applied in a direction orthogonal to the Z axis of the crystal axis of the convex lens 1 made of a single crystal body.

The electrodes 2 and 3 provided on the side surface of the convex lens 1 are connected via a wire 4 to a DC power supply device 7 including a voltage conversion device 5 and a battery 6. The ON / OFF of the voltage from the DC power supply device 7 to the convex lens 1 is performed by the switch 8.

In the optical device of this embodiment, when the switch 8 is opened and no voltage is applied to the electrodes 2 and 3, the convex lens 1 functions as a lens having an inherent refractive index due to its shape. When the switch 8 is closed and a DC voltage is applied to the electrodes 2 and 3 provided on the convex lens 1,
ITaO ₃ is the refractive index changes due to the electro-optic effect of the single crystal and LiNbO ₃ single crystal, the focal length of the convex lens 1 is changed.
Also, the focal length of the convex lens 1 can be continuously changed by adjusting the applied voltage with the voltage conversion device 5 in a state where the switch 8 is closed and a DC voltage is applied to the convex lens 1.

FIG. 2 is a diagram schematically showing the construction of an optical device according to another embodiment of the present invention. In the figure, reference numeral 1 denotes a convex lens 1 made of a single crystal body similar to that of the above-described embodiment, and this convex lens 1 is formed so that the Y axis of the crystal axis of the single crystal body coincides with the optical axis. Transparent electrodes 9 and 10 made of vapor-deposited films of tin oxide, indium oxide, etc. are formed opposite to each other on both main surfaces of the convex lens 1. That is, the transparent electrodes 9 and 10 are provided so as to apply an electric field in a direction orthogonal to the Z axis of the crystal axis of the convex lens 1 made of a single crystal. The voltage application to the convex lens 1 is performed by the DC power supply device 7 as in the above-described embodiment. Further, the transparent electrodes 9 and 10 can be formed into a desired pattern shape by a known lithography technique if necessary.

Also in the optical device of this embodiment, the focal length of the convex lens 1 is changed by turning ON / OFF the switch 8 or by changing the voltage value applied by the voltage converting device 5 as in the optical device of the above-mentioned embodiment. Changes.

In any of the optical devices of the above-mentioned embodiments, Z is one of the crystal axes of the single crystal body constituting the convex lens 1.
The electrodes 2, 3, so that a voltage is applied in a direction orthogonal to the axis,
Alternatively, since the transparent electrodes 9 and 10 are provided, a larger change in the refractive index can be obtained, and the degree of change in the focal length can be set larger. The optical device shown in FIG. 2 requires a transparent electrode, but the change in the refractive index can be set more uniformly.

Next, an embodiment in which the present invention is applied to eyeglasses will be described with reference to FIG. The glasses 11 shown in FIG.
The convex lens 1 shown in FIG. 1 is mounted on a spectacle frame 12 and configured. Further, the electrodes 2 and 3 provided on the convex lens 1 are connected to the voltage conversion device 5 embedded in the eyeglass frame 12 through the electric wire 4 embedded in the eyeglass frame 12.
Is connected to the battery 6 detachably attached to the eyeglass frame 12. According to this embodiment, the focal length of the spectacles can be changed by turning on / off the switch (not shown). The same applies when the convex lens 1 shown in FIG. 2 is used.

When the spectacles of the above-mentioned embodiment are used as bifocal spectacles, a sensor whose voltage changes depending on the elevation angle (upward inclination of the optical axis) is used to function as near glasses when the face is upward or horizontal, It can also be configured to function as reading glasses when facing down.

In each of the above-described embodiments, the optical device of the present invention is applied to a convex lens, but it can be applied to a concave lens as well. be able to. Further, the optical device of the present invention can be applied to a prism, and in such a case, a transparent electrode is formed on an arbitrary surface of the optical path of the prism to change the optical path or the transparent electrode is transparent. It may be locally formed on the optical body to change the refraction characteristics of a part of the optical path. Furthermore, by changing the distance between the lenses on the optical path to change the focus of the optical device,
It is also possible to apply the device of the present invention to one sheet and omit the interval adjusting mechanism between the lenses.

The translucent body used in the present invention is usually used by molding it into a known shape such as a lens or prism.
Depending on the application, it is also possible to use a flat plate.

[0019]

As described above, according to the optical device of the present invention, it is possible to obtain different refraction characteristics with one light-transmitting body, and it is possible to set a large degree of change. Therefore, it is possible to reduce the number of lenses to be used and to omit the interval adjustment mechanism between the lenses.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a configuration of an optical device according to an embodiment of the present invention.

FIG. 2 is a diagram schematically showing a configuration of an optical device according to another embodiment of the present invention.

FIG. 3 is a perspective view showing an embodiment in which the optical device of the present invention is applied to eyeglasses.

[Explanation of symbols]

 1 ... Convex lens 2, 3 ... Electrode 5 ... Voltage conversion device 6 ... Battery 7 ... DC power supply device 8 ... Switch

Claims (2)

[Claims] 1. A translucent body made of a single crystal whose refractive index changes by applying a voltage, and a transparent body facing each other so as to apply a voltage in a direction orthogonal to the Z axis of the crystal axis of the single crystal. An optical device comprising: a pair of electrodes provided and means for applying a voltage to the light-transmitting body via the electrodes. 2. The optical device according to claim 1, wherein the translucent body is made of a LiTaO ₃ single crystal body or a LiNbO ₃ single crystal body.