JPH0447290B2 - - Google Patents

Description

Detailed Description of the Invention Field of Application This invention relates to a structure in which ceramic substrates having an electro-optic effect are laminated with electrode members interposed therebetween to form a large number of light transmitting portions, and a structure in which a large number of substrate convex portions provided on the substrate are laminated via electrode members. The present invention relates to an improvement in a light shutter element having a structure in which a light transmitting part is formed between sandwiched members, and particularly to a light shutter element that prevents light leakage and has a complete light shutter function.

BACKGROUND ART Among optical shutters that utilize electro-optic effects, an optical shutter element whose electric field direction forms an intersection angle of 45° with the polarization direction of incident light is arranged between a pair of polarizing elements whose polarization directions are orthogonal to each other. Optical elements constructed with this structure are considered to have a variety of applications, such as writing devices for optical printers, shutters for optical cameras, stereoscopic glasses, and protective goggles for welding.

As shown in Fig. 5, the optical shutter element is
Ceramic substrate 1 with multiple electro-optic effects such as (PbLa)(ZrTi)O ₃ , LiNbO ₃ , Bi ₁₂ SiO ₂₀
are laminated and fixed in the thickness direction of the substrate 1 via an electrode member 2 made of Ni or the like, and the thickness end face of each laminated substrate 1, that is, the exposed end face is used as a light transmitting surface 3, and each substrate 1 is used as a light transmitting part. This configuration is known.

This laminated board is provided with an insulating layer 4 that insulates every other electrode member 2 exposed on its side end face, and is further provided with an external power supply electrode 5 that connects another electrode member 2 every other layer. .

As another structure of the optical shutter element, as shown in FIG. A known configuration is known in which an electrode member 13 is attached to the peripheral surface, the thickness end face, that is, the exposed end face of each substrate convex portion 12 is used as a light transmitting surface 14, and each substrate convex portion 12 is used as a light transmitting portion.

Further, on both side end faces of the substrate 10, power feeding external electrodes 15 are formed to electrically connect every other electrode member 13 deposited in the groove 11.

Problems with the Prior Art In the configurations of these optical shutter elements, it has been impossible to completely block light when natural light is used.

When the cause of light leakage was investigated, it was discovered that a phenomenon as shown in FIG. 6 occurred.
FIG. 6 is a partially detailed vertical sectional view of the optical shutter element having the structure shown in FIG. 5 described above.

Of the light transmitted through one polarizer (not shown), the light incident perpendicularly to the light transmission surface 3 of the light shutter element, that is, the light incident parallel to the electrode member 2 (α in the figure) is the light The light passes through the substrate 1 of the shutter element, but is completely blocked by the other (rear) polarizer (not shown).

Furthermore, when a half-wavelength voltage is applied to the electrode member 2 of the optical shutter element, the incident light changes in the direction of the electric field due to the action of the electric field formed between the electrode members 2.
Rotate 90° and pass through the rear polarizer.

However, as mentioned above, optical shutters are used for various purposes, and the light used is usually natural light, and the light incident on the optical shutter element is not necessarily parallel light as indicated by α in the figure.

As shown by β in FIG. 6, the light incident on the light transmission surface 3 of the light shutter element at an angle θ with respect to the parallel light α is reflected by the electrode member 2, and
The reflected light reaches the rear polarizer.

Normally, light is thought to consist of P waves (the direction of vibration of the electric field of light is perpendicular to the electrode member) and S waves (the direction of vibration of the electric field of light is parallel to the electrode member). In particular, in reflected light, the reflectance of P waves and S waves is different, and it is generally said that the reflectance of S waves is higher, and the direction of the electric field of light changes slightly before and after reflection.

That is, in FIG. 6, the electric field direction of the light incident on the optical shutter element and the electric field direction of the light reflected by the electrode member 2 are slightly different, and a part of the light reaching the rear polarizer is Even though no voltage is applied to the shutter element, the light passes through the polarizer.

Similarly, in the optical shutter element having the configuration shown in FIG. 7, the electrode member 13 deposited in the groove 11 reflects the incident light at a certain angle, even though no voltage is applied to the optical shutter element. However, the light passes through the polarizer, making it difficult to completely block the light.

Therefore, in fields where a complete optical shutter function is required, such as the shutter of an optical camera, there has been a strong desire to improve these optical shutter elements.

Purpose of the Invention In view of the above-mentioned current state of the optical shutter element, an object of the present invention is to provide an optical shutter element that prevents light leakage due to light tilted with respect to a light transmission surface and has a complete optical shutter function. do.

Summary of the Invention The present invention provides a light shutter element in which a ceramic material having a predetermined shape having an electro-optic effect is sandwiched between electrode members, and the exposed end face is used as a light transmitting surface. A light shutter element characterized in that a light-impermeable film made of an insulating material for preventing reflection and transmission from the member surface is deposited near the exposed portion of the electrode member on the exposed end face serving as the light-transmitting surface. It is.

Further, to describe a specific example of the present invention, ceramic substrates having an electro-optical effect are laminated and fixed in the thickness direction of the substrates via electrode members, and the thickness end face of the laminated substrate, that is, the exposed end face is used as a light transmitting surface. The light shutter element is characterized in that a light-opaque film made of an insulating material is coated near the exposed portion of at least one electrode member on the exposed end face.

Furthermore, a plurality of parallel grooves are provided in a ceramic substrate having an electro-optical effect, and an electrode member is adhered to the inner peripheral surface of the groove, and the thickness end surface of the substrate, that is, the exposed end surface at the tip of the substrate convexity is made into a light transmitting surface. The light shutter element is characterized in that a light-opaque film made of an insulating material is coated near the exposed portion of the electrode member on the exposed end face.

Preferred configuration of the invention In the present invention, the ceramic substrate having an electro-optic effect is (PbLa)(ZrTi)O ₃ ,
Known materials such as LiNbO ₃ and Bi ₁₂ SiO ₂₀ can be used.

Furthermore, a known material such as Ni can be used as the electrode member 2.

The light-opaque film provided at a specific position, which is a feature of this invention, can be placed near the exposed part of the electrode member on the light-transmitting surface depending on the purpose and use of the light shutter element, the required light transmittance, the light shielding rate, or the light source used. They are arranged in a band shape at the required locations with an appropriately selected width.

Additionally, the light-opaque film can be provided on either the incident side, the output side, or both of the light-transmitting surface of the substrate, but it is recommended to provide it at least on the incident side to ensure light blocking. preferable.

The material of the light-opaque film may be a light-reflecting material as long as it literally prevents light from entering and exiting, but a light-absorbing material is more preferable.

Furthermore, since conductive substances may inhibit normal electric field formation between electrode members, an insulating substance is used as the material for the light-opaque film.

Therefore, as the light-opaque film, for example, a black insulating resin or paint can be provided by a known method such as screen printing.

Disclosure of the Invention Based on Drawings FIG. 1 is a perspective view showing an embodiment of an optical shutter element according to the present invention, FIG. 2 is a longitudinal sectional view thereof, and FIG. 3 is a partially detailed view. FIG. 4 is a perspective view showing another embodiment of the optical shutter element according to the present invention.

First, the optical shutter element shown in FIG. 1 includes a ceramic substrate 1 having a plurality of electro-optic effects.
The substrates 1 are laminated and fixed in the thickness direction through electrode members 2 made of Ni or the like, and the thickness end faces of each of the laminated substrates 1, that is, the exposed end faces are used as light transmitting surfaces 3, and each substrate 1 is used as a light transmitting part. It is said that

This laminated board is provided with an insulating layer 4 that insulates every other electrode member 2 exposed on its side end face, and is further provided with an external power supply electrode 5 that connects another electrode member 2 every other layer. .

The light-opaque film 6, which is a feature of the present invention, is formed in a band shape with a width t so as to cover the electrode member 2 exposed between the light-transmitting surfaces 3, as shown in FIGS. 1 to 3. .

Therefore, as is clear from FIG. 3, the light γ incident at an angle θ′ with respect to the perpendicular axis of the film 6 is not reflected by the light-impermeable film 6 onto the electrode member 2. Transmits through the substrate 1.

That is, in the configuration of FIG. 3, all light at an angle smaller than θ', in other words, light at an angle closer to parallel light, is blocked by a polarizer (not shown) located at the rear. Become.

In addition, if the width t of the light-opaque film 6 is increased more than necessary, the area of the light-transmitting surface 3 will be reduced and the transmission efficiency will be reduced. It is desirable to make a selection after fully considering the incident angle of the incident light.

Further, in the example shown in FIG. 1, a configuration is shown in which a light-opaque film 6 is coated only on the light-transmitting surface 3 on the light incident side, but in order to prevent reflected light from passing through the light shutter element, It is preferable to form the electrode near the exposed part of the electrode member on the light emission side (back surface), and furthermore, it is preferable to provide it on both the incident and output sides.

Next, in the optical shutter element shown in FIG. 4, a plurality of parallel grooves 11 are provided on one main surface of a ceramic substrate 10 having an electro-optic effect, and a plurality of substrate protrusions 1 are formed.
2 is formed protrudingly, and an electrode member 13 is formed on the inner peripheral surface of the groove 11.
The thickness end face, that is, the exposed end face of each substrate convex portion 12 is used as a light transmitting surface 14, and each substrate convex portion 12 is used as a light transmitting portion.

Further, on both side end faces of the substrate 10, power feeding external electrodes 15 are formed to electrically connect every other electrode member 13 deposited in the groove 11.

In the above structure as well, as in the light shutter element having the structure shown in FIG. 1, the width t
A light-opaque film 16 is formed in the form of a band.

By selecting the width dimension t of this light-opaque film 16 to be an appropriate dimension, reflections incident on the light-transmitting surface 14 at an angle and reflected by the electrode member 13 can be prevented without reducing the transmission efficiency. Light leakage can be prevented.

Examples Example 1 In order to confirm the effects of this invention, the light shutter elements shown in FIG. 1 (present invention) and FIG. The amount of leaked light was measured using

As a substrate for each element, (PbLa)(ZrTi)O ₃ was used, in which the amount of La substituted for Pb was 9 atomic %, and the Zr/Ti ratio was 65/35.

Additionally, 1 μm thick Ni was deposited as an electrode member.

The dimensions of each part shown in Figures 1 and 5 are as follows: Thickness of optical shutter element d=0.5mm, The distance between each electrode was set to l = 0.5 mm.

In the structure shown in FIG. 1 (invention), a strip-shaped black paint having a width t=0.1 mm was applied as a light-opaque film.

As a result, in the conventional configuration shown in FIG. 5, the amount of leaked light was 5%, whereas in the configuration shown in FIG. 1 according to the present invention, the amount of leaked light could be reduced to only 1%.

Example 2 In order to confirm the effects of the present invention, the light shutter elements shown in FIG. 4 (present invention) and FIG. 7 (conventional example) having the above-described configurations were fabricated, and the same light source (sodium lamp) was used. The amount of leaked light was measured.

As a substrate for each element, (PbLa)(ZrTi)O ₃ was used, in which the amount of La substituted for Pb was 9 atomic %, and the Zr/Ti ratio was 65/35.

Additionally, 1 μm thick Ni was deposited as an electrode member.

The dimensions of each part shown in Figures 4 and 7 are as follows: Thickness of optical shutter element d=0.5mm, Each electrode distance l=0.5mm, The groove depth d' was set to 0.3 mm.

In the structure shown in FIG. 4 (invention), a black paint strip having a width t=0.1 mm was applied as a light-opaque film.

As a result, in the conventional configuration shown in FIG. 7, the amount of leaked light was 3%, whereas in the configuration shown in FIG. 1 according to the present invention, the amount of leaked light could be reduced to only 0.5%.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the optical shutter element according to the present invention, FIG. 2 is a longitudinal sectional view thereof, and FIG. 3 is a partially detailed view thereof. FIG. 4 is a perspective view showing another embodiment of the optical shutter element according to the present invention. FIG. 5 is a perspective explanatory view of a conventional optical shutter element, and FIG. 6 is a partially detailed sectional view thereof. FIG. 7 is a perspective view of another conventional optical shutter element. 1...Ceramics substrate, 2...Electrode member, 3
. . . Light transmitting surface, 4 .
Electrode member, 14...Light-transmitting surface, 15... External electrode for power supply, 16... Light-opaque film.

Claims (1)

[Scope of Claims] 1. In a light shutter element in which a ceramic material having a predetermined shape having an electro-optical effect is sandwiched between electrode members and the exposed end face is a light transmitting surface, incident light that is inclined with respect to the light transmitting surface is transmitted to the electrode. A light shutter element characterized in that a light-impermeable film made of an insulating material for preventing reflection and transmission from the member surface is deposited near the exposed portion of the electrode member on the exposed end face serving as the light-transmitting surface. .