JPH02113224A - Electrooptical stop device - Google Patents

Abstract

PURPOSE:To eliminate leak of light from an electrode take-out part and to simplify the structure of the electrode take-out part by forming segments in a complete ring shape, and increasing the area of the electrode take-out part. CONSTITUTION:A 1st liquid crystal cell 14 has a transparent electrode 16 formed entirely on one internal surface (internal surface of a polarizing plate 12) and transparent electrodes 17a - 17d are formed at alternate equally divided sectorial parts on the other side (front surface of the polarizing plate 12) at positions corresponding to concentric circumference-directional parts. A 2nd liquid crystal cell 15 is so constituted that the sectorial parts where the transparent electrodes 17a - 17d are formed right on the rear surface of the polarizing plate 12 cover the sectorial parts of the 1st liquid crystal cell 14 where the transparent electrodes 17a - 17d are present. Then, the segments are all formed in the complete ring shape and their external electrodes are led out by using the sectorial parts where the transparent electrodes 17a - 17d are present, thereby increasing the area of the part. Consequently, the leak of light from the electrode lead-out part is eliminated and the structure of the electrode lead-out part is simplified.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an electro-optic aperture device such as a liquid crystal aperture.

[Conventional technology]

Recently, it has been proposed to use electro-optic aperture devices such as liquid crystal apertures in optical instruments.

As an example of the electro-optical aperture device, for example,
There is one described in JP-156219.

As shown in FIG. 8, a liquid crystal cell 1 is provided with a plurality of concentric transparent electrode patterns 2a, 2b, 2c, and 2d.

A power supply is connected to the switches 4a, 4b, 4c, and 4d through the switches 4a, 4b, 4c, and 4d, respectively.

Select 1, 2, 3.4 of 4d and turn it on or off
By doing so, the transmission or shielding area was changed, creating a variable aperture.

[Problem to be solved by the invention]

However, in the case of the above-mentioned conventional example, there is a problem in that the pattern does not form a perfect ring shape in the electrode extraction portion A, and light leaks from there even in the shielded state. Furthermore, since the area of the electrode lead-out portion A must be made as small as possible, there is also the problem that the structure becomes *i.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to provide an electro-optical diaphragm device that eliminates light leakage from the electrode extraction portion and also has a simple structure of the electrode extraction portion.

[Means and operations for solving the problems] One of the electro-optic aperture devices according to the present invention includes a transparent cell having a transparent electrode on the inner surface and a substance having an electro-optic effect sealed inside. Turn on the power supply connected to the transparent electrode to the transparent cell.
In an electro-optic diaphragm device comprising a plurality of concentric circular segments whose transmission and shielding states are switched by turning N-OFF, the transparent cell is provided with a transparent electrode formed on the entire surface of one side of the inner surface, and A first cell in which a transparent electrode is formed in a portion corresponding to a part of the plurality of segments in the circumferential direction on the other side, and a transparent electrode is formed on the entire surface of one side of the inner surface, and the plurality of segments on the other side. and a second cell in which a transparent electrode is formed in a part in the circumferential direction of the segment that covers the part on the other side of the first cell that does not have a transparent electrode. It has a complete ring shape, and also allows for a large area for the electrode extraction portion.

Another electro-optical diaphragm device according to the present invention is provided with a transparent cell having a transparent electrode on the inner surface and a substance having an electro-optic effect sealed therein, and the transparent cell has a transparent cell that has a transparent electrode on its inner surface and a substance having an electro-optic effect. In an electro-optic aperture device comprising a plurality of concentric segments whose transmission and shielding states are switched by turning on and off a connected power source, the transparent electrode is connected to one or two of the plurality of segments. ,3. ...
- By stacking a plurality of ring-shaped transparent electrodes corresponding to each individual cell and whose outer periphery coincides with the outer periphery of the transparent cell through an insulating layer, all the segments become completely ring-shaped. Also, all electrodes can be taken out from the outer periphery of the transparent cell.

〔Example〕

Hereinafter, the present invention will be described in detail based on the illustrated embodiments.

FIGS. 1 and 2 are a cross-sectional view of the first embodiment and a diagram showing a transparent electrode pattern of one cell thereof, respectively. 11,1
Reference numeral 2.13 denotes a polarizing plate that also serves as three transparent substrates whose polarization directions are alternately orthogonal, and first and second transparent cells 14 and 15 are formed between them. In the first liquid crystal cell 14, a transparent electrode 16 is formed on the entire surface of one side of the inner surface (the inner surface of the polarizing plate 11), and as shown in FIG. Transparent electrodes 17a, 17b are provided at portions corresponding to portions of the plurality of anniversary circles in the circumferential direction at every other portion of the equally divided fan-shaped portions.

17C and 17d are formed. However, it is better that the sector-shaped part with the transparent electrode is slightly larger than the sector-shaped part without the transparent electrode.
On top of b, 17c, and 17d, there are polarizing plates 11 whose orientation directions are respectively
and 12 polarization directions and alignment films 18 and 19, respectively.
are laminated, and a nematic liquid crystal 20 with positive dielectric anisotropy is sealed inside. That is, liquid crystal cell 1
4 is a twisted nematic liquid crystal cell.

And, as shown in FIG. 2, a transparent electrode 17a.

Externally extracted electrodes 20a, 20b, 20c,
20d is connected, and each external lead-out electrode 20a, 20b, 20c, 20d of all the fan-shaped portions is connected.

The second liquid crystal cell 15 has the same structure as the first liquid crystal cell 14 but with the front and rear directions reversed, and has transparent electrodes 17a, 17b, 17c on the rear surface of the polarizing plate 12,
The fan-shaped portion where 17d is formed covers the fan-shaped portion of the first liquid crystal cell 14 where transparent electrodes 17a, 17b, 17c, and 17d are not provided. Furthermore, as shown in FIG. 1, after the external lead-out electrodes 20a, 20b, 20c, and 20d of the first and second liquid crystal cells 14 and 15 are connected, respectively, switches 21a, 21b, and 21c are connected.
, 21d to the power source 22, and after the external extraction electrodes 16a of the fully transparent electrodes 16 of the first and second liquid crystal cells 14 and 15 are also connected, the power source 2
Connected to 2. In addition, the external extraction electrode 20b comrades,
Connection status of comrades 20C and 20d and switch 21b
, 21c and 21d are not shown for convenience of drawing. Therefore, as is clear from the above description, the transparent electrodes 17a, 17b, 1 of the first and second liquid crystal cells 14 and 15
7c and 17d each constitute a complete ring-shaped segment as a whole, and these segments are concentric circles.

Since this embodiment is configured as described above, when the switches 21a, 21b, 21c, and 21d are all OFF as shown in FIG. 1, the liquid crystal molecules are in a twisted arrangement.
The linearly polarized light that has passed through the polarizing plate 11 and entered the first liquid crystal cell 14 has its plane of polarization rotated by 90 degrees by the liquid crystal cell 14, passes through the polarizing plate 12, and then rotates the plane of polarization by 90 degrees in the liquid crystal cell 15.
The light is rotated by 0° and passes through the polarizing plate 13. Therefore, at this time, the diaphragm is fully open.

Next, when only the switch 21a is ON, the first and second
Only the liquid crystal molecules in the portion corresponding to the transparent type 117a of the liquid crystal cells 14 and 15 are homeotropically aligned, and there is no effect of rotating the plane of polarization of linearly polarized light. The linearly polarized light that has passed through the portion corresponding to the transparent electrode 17a of the first liquid crystal cell 14 cannot pass through the polarizing plate 12, and the linearly polarized light that has passed through the polarizing plate 11 and passed through the portion of the first liquid crystal cell 14 that does not have the transparent electrode 17a. Even if it can pass through the polarizing plate 12, it will pass through the part corresponding to the transparent electrode 17a of the liquid crystal cell 15 of node 2, so it will not be able to pass through the polarizing plate 13.In addition, in other parts, the light Therefore, the transparent electrodes 17a of both product cells 14 and 15
Only the portion of the ring-shaped segment constituted by is in the shielding state, and the aperture diameter at this time becomes the inner diameter of the ring-shaped segment.

Based on the same principle as above, when the switches 21a and 21b are ON, the transparent electrodes 17a of both product cells 14 and 15
The two ring-shaped segments formed by the transparent electrodes 17b and 17b are shielded from light, and the inner diameter of the segment formed by the transparent electrodes 17b becomes the aperture diameter, and the switches 21a and 21
When b and 21c are ON, the three ring-shaped segments formed by the transparent molds 117a, 17b and 17c of both product cells 14 and 15 are shielded from light, and the inner diameter of the segment by the transparent electrode 17c is narrowed. The diameter of the switches 21a, 2lb, and 21c.

21d are all ON, the four ring-shaped segments formed by all the transparent electrodes 17a, 17b, 17c, and 17d of both product cells 14 and 15 are in a light-shielded state, and the segments formed by the transparent electrodes 17d are blocked. The inner diameter becomes the aperture diameter, that is, the aperture becomes the minimum opening degree.

In this way, the aperture opening degree can be changed to five levels, but in this embodiment, all the segments are completely ring-shaped as described above, so no light leaks in the light-shielded state. or,
The external electrode can be taken out using the fan-shaped part without the transparent electrode, and the area of that part can be increased.
The structure of the electrode extraction part becomes simple.

FIG. 3 is a cross-sectional view of the second embodiment, which consists of a twisted nematic ink liquid crystal cell 23 and two polarizing plates 24 and 25 sandwiching the liquid crystal cell 23 and having polarization directions perpendicular to each other. It is configured. The liquid crystal cell 23 includes two transparent substrates 27 and 27', a transparent electrode 26a formed on the entire inner surface of the transparent substrate 27, and an insulating layer 2 on the transparent electrode 26a.
A ring-shaped transparent electrode 26 with a medium inner diameter is laminated via 8.
b, a ring-shaped transparent electrode 26e with a small inner diameter formed on the inner surface of the 1-light substrate 27', and a ring-shaped transparent electrode 26d with a larger inner diameter laminated on the transparent electrode 26C with an insulating layer 29 interposed therebetween. , transparent electrode 26b insulating layer 28 and transparent electrode 26d
, alignment films 30 and 31 which are laminated on the insulating layer 29 and whose alignment directions are twisted by 90' to each other, and both alignment films 30.
. And each transparent electrode 2
6c, 26b, 26d, and 26a correspond to 1, 2, 3, and 4 of the plurality of concentric segments, respectively, and their outer peripheries coincide with the outer periphery of the liquid crystal cell 23. Further, each transparent electrode 26a, 26b, 26c, 25d is connected to a switch 32a, respectively.
, 32b, 32c, and 32d.

Since this embodiment is configured as described above, when the switches 32a, 32b, 32c, and 32d are all OFF as shown in FIG. 3, the diaphragm is fully opened according to the same principle as the first embodiment. Become. Also, turn on switches 32b and 32d.
In this case, only the portion corresponding to the transparent electrode 26d becomes light-shielded, and the aperture diameter at this time becomes the inner diameter of the transparent electrode 126d. Further, when the switches 32b and 32c are turned on, only the portion corresponding to the transparent electrode 26b becomes light-shielded, and the aperture diameter at this time becomes the inner diameter of the transparent electrode 26b.

Further, when the switches 32a and 32c are turned on, only the portion corresponding to the transparent electrode 26C becomes light-shielded, and the aperture diameter at this time becomes the inner diameter of the transparent electrode 26c, that is, the minimum opening degree.

In this way, the aperture opening degree can be switched in four stages, but in this embodiment, all the segments are completely ring-shaped.
Furthermore, since there is no interval between segments, there is no light leakage in the light-shielded state.

Moreover, since all the electrodes can be taken out from the outer peripheral edge of the liquid crystal cell 23, the structure of the electrode extraction part becomes simple.

Note that these embodiments can be applied not only to liquid crystal apertures but also to electrochromic apertures and the like.

FIG. 4 is a cross-sectional view of the third embodiment. In this embodiment, the liquid crystal cell 23 has a convex lens shape, the transparent electrode 26C has a full-face shape (circular shape), and the center portion 25a of the polarizing plate 25 has a polarizing polarizer. This lens is made of a simple piece of glass with no function and is constructed as a lens that also serves as an aperture, and the structure other than these point plates is the same as that of the second embodiment. Therefore, in this embodiment, the polarizing plate 2
Since the central portion 25a of the lens 5 has no polarizing effect, the refractive power changes only in this portion when the aperture is narrowed down to the minimum opening.

FIG. 5 is a schematic diagram of the fourth embodiment, showing the polarizing plates 24 and 2.
The polarization directions of the central portion 31a of the alignment film 31 are aligned with the alignment direction of the alignment film 30, and the alignment directions of the other portions are twisted by 90°. That is, the molecular arrangement of the liquid crystal cell 32 is such that the portion corresponding to the central portion 31a of the alignment film 31 is in a homogeneous arrangement, and the other portions are in a twisted arrangement.

Since the present embodiment is configured as described above, when the applied voltage is OFF, the light incident on the liquid crystal cell 23 through the polarizing plate 24 has a polarization plane in the portion corresponding to the central portion 31a of the alignment film 31. Since the light is not rotated, it passes through the polarizing plate 25, but in other parts, the plane of polarization is rotated by 90° and is blocked by the polarizing plate 25. That is, the aperture is in a closed state.

On the other hand, when the applied voltage is turned on, the molecular arrangement of the liquid crystal 32 becomes homeotropic in all parts, and as a result, the plane of polarization of the light that passes through the polarizing plate 24 and enters the liquid crystal cell 23 is not rotated in the entire area. Therefore, all of the light passes through the polarizing plate 25. That is, the aperture is fully opened.

In this way, the aperture opening degree can be switched in two steps, but in order to create two regions with different orientation directions, the orientation treatment (rubbing treatment, etc.) is performed on the orientation film 31 twice in different directions, and the second Since it is only necessary to partially cover the processing surface using a mask, this method is much simpler than the method of processing transparent electrodes as in the first to third embodiments, and the manufacturing cost is significantly lower. There are advantages.

FIG. 6 is a sectional view of the fifth embodiment, in which a cylindrical transparent member 34 is disposed in the center of the liquid crystal cell 23.

Since this embodiment is configured as described above, when the applied voltage is OFF, the light that passes through the polarizing plate 24 and enters the liquid crystal cell 23 is polarized because the plane of polarization is not rotated in the transparent member 34. It passes through the plate 25, but the plane of polarization is rotated by 90 degrees in the part where the liquid crystal 32 is located, so the polarizing plate 25
is shielded by

That is, the aperture is in a closed state.

On the other hand, when the applied voltage is turned on, the molecular arrangement of the liquid crystal 32 becomes a homeotropic arrangement, and as a result, the light that passes through the polarizing plate 24 and enters the liquid crystal cell 23 cannot be rotated in the polarization plane over the entire area, so all of the light passes through the polarizing plate 24. Pass 25. That is,
The aperture becomes fully open.

In this way, the aperture opening degree can be switched between two stages, but a transparent adhesive mixed with a material for gap control may be used as the transparent member 34, in which case a spacer can be provided in the center of the liquid crystal cell 23. It has the same effect as

FIG. 7 is a schematic diagram of the sixth embodiment, in which the polarization directions of the polarizing plates 24 and 25 are twisted by 90 degrees with respect to each other, and the central portion 25a of the polarizing plate 25 is made of simple glass without a polarizing function. It is.

Since this embodiment is configured as described above, when the applied voltage is OFF, the polarization plane of the light incident on the liquid crystal cell 23 through the polarizing plate 24 is rotated by 90 degrees, so that the polarizing plate 25
pass through the entire area. That is, the aperture is fully open. On the other hand, when the applied voltage is turned off, the molecular arrangement of the liquid crystal 32 becomes a homeotropic arrangement, and as a result, the polarizing plate 2
4 and enters the liquid crystal cell 23, the plane of polarization is not rotated, so the light passes through the central portion 25a of the polarizing plate 25, but is blocked in other portions. That is, the aperture is in a closed state.

〔Effect of the invention〕

As described above, the electro-optical diaphragm device according to the present invention has important practical advantages in that there is no leakage of light from the electrode lead-out part and the structure of the electrode lead-out part is simple.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a first embodiment of an electro-optic aperture device according to the present invention, FIG. 2 is a diagram showing a transparent electrode pattern of one cell of the first embodiment, and FIGS. 3 and 4 are cross-sectional views, respectively. Cross-sectional views of the second embodiment and the third embodiment, FIG. 5 is a schematic diagram of the fourth embodiment,
FIG. 6 is a sectional view of the fifth embodiment, FIG. 7 is a schematic diagram of the sixth embodiment, and FIG. 8 is a diagram showing a transparent electrode pattern of a conventional example. 11.12,13,24.25...polarizing plate, 14.
15.23---One liquid crystal cell, 16.17a, 17b,
17c, 17d, 26a, 26b, 26c. 26d...Transparent electric bridge, 18, 19, 30.31...
...Alignment film, 20.32...1 item, 20a, 2 (l
b. 20 c, 20 d---External extraction electrode, 21
a, 21b, 21c, 21d, 32a, 32b, 32c
32d...Switch, 22.33...Power supply, 2
5a...Central part, 27.27'...Transparent substrate,
28°29...Insulating layer, 34...Transparent member. 1P1 Figure 2 Figure 3 Figure 1-4 lJ Figure 25 O 6m

Claims (2)

[Claims] (1) A transparent cell having a transparent electrode on the inner surface and a substance having an electro-optic effect sealed inside is provided, and transmission and shielding can be performed by turning on and off a power supply connected to the transparent electrode in the transparent cell. In an electro-optical diaphragm device comprising a plurality of concentric segments whose states can be switched, the transparent cell has a transparent electrode formed on the entire surface of one side of the inner surface, and a transparent electrode formed on the entire surface of the plurality of segments on the other side. A first cell in which a transparent electrode is formed in a portion corresponding to a part of the circumferential direction, and a transparent electrode is formed on the entire surface of one side of the inner surface, and a part of the plurality of segments in the circumferential direction on the other side. Yes, the first
an electro-optical diaphragm device comprising: a second cell having a transparent electrode formed in a portion covering the portion without the transparent electrode on the other side of the cell; (2) A transparent cell having a transparent electrode on the inner surface and a substance having an electro-optic effect sealed inside is provided, and the transparent cell can be transmitted through or shielded by turning on and off a power supply connected to the transparent electrode. In an electro-optic diaphragm device comprising a plurality of concentric segments whose states can be switched, the transparent electrode is connected to one, two, or two of the plurality of segments.
An electro-optic diaphragm characterized in that it is constructed by laminating a plurality of ring-shaped transparent electrodes corresponding to each of the transparent cells and whose outer periphery coincides with the outer periphery of the transparent cell through an insulating layer. Device.