WO2009136667A1

WO2009136667A1 - Variable focus lens, liquid crystal lens, and device using those for giving stimulus to eye

Info

Publication number: WO2009136667A1
Application number: PCT/JP2009/059023
Authority: WO
Inventors: 山本正男; 佐藤進
Original assignee: スカラ株式会社
Priority date: 2008-05-09
Filing date: 2009-05-08
Publication date: 2009-11-12
Also published as: JP5551587B2; JPWO2009136667A1

Abstract

Provided is a liquid crystal lens without requiring a large potential difference to drive it and having an overall shape with low roughness. The liquid crystal lens (100) includes two parallel transparent plates (10), two transparent electrodes (20) along the inner sides of the plates (10), and a liquid crystal layer (30) placed between the plates (10). On at least one of the inner sides of the two transparent electrodes (20), powder of barium titanate which is dielectric is adhered with a concentric distribution of the concentration decreasing from the center of the plates (10) toward the periphery. When a potential difference between the transparent electrodes (20) is produced, the electric field produced in the space where the liquid crystal layer (30) is placed is different in different portions because of the existence of the dielectric. Since, the degree of orientation of the liquid crystal layer (30) varies in the different portions, the liquid crystal lens (100) functions as a lens.

Description

Title of invention

Technical Field of Variable Focus Lens, Liquid Crystal Lens, and Apparatus for Stimulating Eyes Using the Lens

This effort is related to a variable focus lens that is mainly composed of a liquid crystal lens with variable focus. Yarn 1 background technology

Lenses are one of the application fields of liquid crystals that are applied in various fields. The lens, called a liquid crystal lens, utilizes the property of a liquid crystal that its refractive index changes depending on the orientation state. By controlling the liquid crystal layer arranged perpendicular to the light transmission direction so that the alignment state is different for each part in the direction perpendicular to the light transmission direction, for example, a uniform thickness Even liquid crystals can have lens-like properties.

Such a liquid crystal lens has a major feature that it can change the properties of the lens (for example, the focal length) by changing the alignment state of the liquid crystal, and can give or lose the properties of the lens. is there. In other words, the liquid crystal lens functions as a variable focus lens.

This feature is different from the classic lens that is made by giving a glass or resin a transparent or concave shape to a transparent glass, and its properties are fixed. Yes.

A conventional liquid crystal lens is configured as follows, for example.

One type of conventional liquid crystal lens has two transparent plates arranged in parallel, and a voltage between them arranged along the two plates (for example, inside the plate). A transparent electrode for applying a liquid crystal, and a liquid crystal layer filled between two plates. In general, the two plates are both rectangular. Both two transparent electrodes In general, a force that is the same size and shape as the two plates, at least one of them is often provided with a circular opening. When such a transparent electrode is used, if a predetermined potential difference is applied between the two transparent electrodes, the electric field generated at the center of the transparent electrode opening becomes the weakest and the electric field generated at the edge of the transparent electrode opening is the strongest. Therefore, the strength of the electric field is generated from the center of the transparent electrode opening to the outside. Based on the distribution of the electric field, the liquid crystal in the liquid crystal layer filled between the two plates changes the orientation state depending on the site, and thus the above-described liquid crystal lens has a function as a lens. Of the conventional liquid crystal lenses, other types have two transparent plates arranged in ^, and are arranged in layers along the two plates to apply a voltage between them. A transparent electrode, and a liquid crystal layer filled between two plates. In general, both plates are rectangular. One of the two plates is a flat plate, and for example, a layered transparent electrode is provided inside. The other of the two plates has, for example, a dome-shaped convex portion that bulges outward in the center thereof, and the other transparent electrode is disposed along the periphery of the flange portion and the convex portion. (In this case, the transparent electrode along the plate having the convex portion is provided outside the plate including the surface of the convex portion). When such a transparent electrode is used, if a predetermined potential difference is applied between the two transparent electrodes, the distance between the two transparent electrodes increases in the portion closer to the top of the dome-shaped member. The electric field generated between the transparent electrodes increases from the apex of the member toward the base. Based on the distribution of the electric field, the liquid crystal in the liquid crystal layer filled between the two plates changes the alignment state depending on the part, so the above-mentioned liquid crystal lens has a function as a lens. become.

Both of these liquid crystal lenses have been successful for some time, but are not without their improvements. ,

In the former liquid crystal lens, an opening is provided in at least one of the transparent electrodes. However, the liquid crystal layer positioned inside the powerful opening does not have a transparent electrode that gives a potential difference to the liquid crystal layer (liquid crystal The part of the layer that is located inside the opening is not sandwiched between the transparent electrodes from both sides.) When the opening is large, the gradient of the electric field from the edge of the opening to the center of the opening is maintained in the desired state. It is difficult. If the potential difference created between the two transparent electrodes is increased, can the generated electric field gradient be maintained within the preferred range? However, the larger the aperture, the greater the potential difference that must be applied between the two transparent electrodes. Therefore, the former liquid crystal lens tends to be limited in application fields. In addition, increasing the potential difference between the two transparent electrodes requires a power source for generating a high voltage, which is difficult in terms of cost and somewhat difficult in terms of safety. These also tend to lead to restrictions on the application field of liquid crystal lenses.

A liquid crystal lens having a convex portion has a drawback that a potential difference to be applied between the transparent electrodes is large, and the overall thickness tends to increase due to the presence of the convex portion. In other words, the conventional liquid crystal lens has large restrictions on the shape and size, and the ratio of the part that does not function as a lens is large compared to the total area, and the voltage of the liquid crystal lens is low. There is a problem that it is difficult to drive.

In addition to the liquid crystal lens, the liquid crystal of the liquid crystal lens is a predetermined substance that changes its refractive index depending on the site according to the electric field distribution (for example, an electro-optic crystal such as KTN (potassium niobate tantalate, KTal-xNbx03) can be used to obtain a more general varifocal lens, but even such a varifocal lens can be used in the liquid crystal lens described above. The same is true for the existence of such defects.

[Patent Document 1] Japanese Patent Laid-Open No. 2 0 0 5-9 2 0 0 9

[Patent Document 2] Japanese Patent Laid-Open No. 2 0 0 6-3 3 1 3 2 4 8

[Non-Patent Document 1] Liquid crystal molecular alignment effect and its application to new optical devices (Akita University, Department of Electrical and Electronic Engineering Susumu Sato Z 2 0 0 6 Japan Liquid Crystal Society Annual Meeting)

The present invention provides a liquid crystal lens in which the restriction on the shape and size is small, the proportion of the portion that does not function as a lens is small compared to the overall size, and at most, the liquid crystal lens can be driven at a lower voltage than in the past. The main challenge is to provide the first variable focus lens. Summary of the Invention

In order to solve the above-mentioned problems, the present inventor proposes the following liquid crystal lens. The liquid crystal lens includes two transparent plates arranged at a predetermined interval, two transparent electrodes provided in pairs with the two plates along the two plates, and the 2 A liquid crystal layer disposed between two transparent electrodes, and a dielectric constant distribution forming a dielectric constant distribution in a plane direction of the two transparent electrodes provided in a space between the two transparent electrodes. And when the voltage is applied between the two transparent electrodes, a refractive index distribution is generated in the liquid crystal layer by the electric field distribution generated according to the dielectric constant distribution forming means. It is a liquid crystal lens.

In this liquid crystal lens, dielectric constant distribution forming means for providing a dielectric constant distribution in the plane direction of the two transparent electrodes is provided in a space between the two transparent electrodes. Then, depending on the distribution of the electric field formed between the transparent electrodes when a potential difference is applied between the transparent electrodes in accordance with the change in the dielectric constant formed by the dielectric constant distribution forming means, The refractive index distributions in are different. That is, in the liquid crystal lens according to the present invention, even if there is no opening in either of the two transparent electrodes, or the two transparent electrodes are parallel, and the distance between the transparent electrodes is any part of the two transparent electrodes. Even if it is constant, when a potential difference is formed between the two transparent electrodes, the electric field generated between the two transparent plates can be changed depending on the location of the plate due to the change in the dielectric constant described above. Depending on the location of the liquid crystal layer, the alignment state of the liquid crystal can be changed. In such a liquid crystal lens according to the present invention, it is not necessary to make a hole in the transparent electrode or provide a convex part on the plate as in the prior art. Therefore, the potential difference between the transparent electrodes can be reduced.

That is, the liquid crystal lens of the present invention has less restrictions on the shape and size, and the ratio of the portion that does not function as a lens is smaller than the overall size, and can be driven at least at a lower voltage than in the past. It will be a thing.

The above-described invention can be more generalized by replacing the liquid crystal lens of the invention with a variable focus lens. In other words, in the above-described invention, a refractive index distribution is generated between two transparent electrodes when a voltage is applied between the two liquid crystal layers of the liquid crystal layer that they have. It is possible to replace it with a layer of a predetermined material.

In such a case, the above-described invention includes two transparent plates arranged at a predetermined interval, and two transparent electrodes provided in pairs with each of the plates along the two plates. A dielectric constant in a plane direction of the two transparent electrodes, provided in a space between the electrode, a layer made of a predetermined material disposed between the two transparent electrodes, and the two transparent electrodes A dielectric constant distribution forming means for providing a distribution, and when the voltage is applied between the two transparent electrodes, the electric field distribution generated according to the dielectric constant distribution forming means It can be a varifocal lens with a refractive index profile in the layer.

The present invention described above can have the following variations.

In the following description, the description will be made on the assumption that the variable focus lens is a liquid crystal lens in order to make the description concrete, but the liquid crystal of the liquid crystal lens is replaced with the “predetermined substance” as described above. It is possible for a person skilled in the art to disclose an invention having a variable focus lens having such a “predetermined substance” in place of a liquid crystal lens. Will understand. In other words, in the following description, “liquid crystal layer” can be read as “layer”, and “liquid crystal lens” can be read as “variable focus lens”. The plate used in the liquid crystal lens of the present invention may be a flat plate, but is not necessarily a flat plate. For example, the plate may be curved. Further, at least one surface of the plate used in the liquid crystal lens of the present invention may be uneven. The two plates are arranged almost in parallel, but they do not have to be completely TO. If the two plates are both flat, have no irregularities, and are completely corrugated, the liquid crystal lens can be made thinner.

The dielectric constant distribution formed by the dielectric constant distribution forming means in the present invention may be appropriately selected according to the purpose that the liquid crystal lens should have. The dielectric constant variation can be designed, for example, by considering the shape of the plate (the plate itself can function as a lens depending on the shape) and other optical systems combined with the liquid crystal lens. .

For example, the dielectric constant distribution given by the dielectric constant distribution forming means in the present invention is, for example, the refraction of light when vertically incident on the two plates when a voltage is applied to the two transparent electrodes. The rate may increase or decrease gradually around the optical axis. In this way, the liquid crystal lens can easily function as a lens. In this case, the dielectric constant distribution given by the dielectric constant distribution forming means may be a concentric distribution. In this way, the liquid crystal lens functions as a lens. It becomes easy to let.

The dielectric constant distribution forming means in the present invention is not particularly limited as long as it can form a dielectric constant distribution. For example, the dielectric constant distribution forming means may be formed by a concentration distribution of a dielectric powder whose particle size does not affect the transparency of the liquid crystal lens.

The dielectric may be any material, for example, barium titanate.

The particle size of the dielectric may be a level that does not affect the transparency of the liquid crystal lens (in many cases, the transparency to visible light). For example, the diameter may be on the order of m or less. It is done.

The dielectric constant distribution forming means may be layered. In this case, the term “layered” includes not only a continuous layer as a whole but also a discontinuous layer as a whole. A discontinuous layer as a whole is, for example, a case where a part of the layer is missing or a layer that is scattered.

In the present invention, the dielectric constant distribution forming means described above may be provided in the space between the two transparent electrodes, as already described. In the present application, the phrase “inside the space between two transparent electrodes” includes the surface of the two transparent electrodes facing the space between the two transparent electrodes.

In the present invention, the two transparent electrodes are paired with each of the two plates. That is, in the present invention, there are two pairs of plates and transparent electrodes. The pair of these two pairs of plates and transparent electrodes may be in a positional relationship in which the inner transparent electrode is on the outer side of the plate or vice versa (in this application, “outer” The term “means the side far from the center of the thickness of the liquid crystal layer). There is no need for the positional relationship between the transparent electrode and the plate (internal / external positional relationship) to be the same between the two pairs of plates and transparent electrodes.

The transparent electrode does not necessarily have to be in close contact with a force plate provided along the plate. Other members may exist between the transparent electrode and the plate.

The force depending on the positional relationship between the pair of plates and the transparent electrode The change in the dielectric constant in the present invention can be provided at the locations exemplified below.

The plate on the outside of the plate included in a pair of the two pairs of the plate and the transparent electrode When the paired transparent electrodes are provided, the dielectric constant distribution forming means may be provided on the inner surface of the transparent electrode.

When the transparent electrode paired with the plate is provided outside the plate included in a pair of the two pairs of the plate and the transparent electrode, the dielectric constant distribution forming means includes the transparent electrode It may be provided on the plate paired with. In this case, the dielectric constant distribution forming means may be provided in any part (for example, the inside) of the plate included in a pair of the two pairs of the plate and the transparent electrode. And may be provided on at least one surface of the plate included in a pair of the transparent electrodes.

When the transparent electrode paired with the plate is provided outside the plate included in a pair of the two pairs of the plate and the transparent electrode, the dielectric constant distribution forming means includes the transparent electrode (For example, between the transparent electrode and the plate paired with the transparent electrode, or the inside of the plate paired with the transparent electrode). Also good. When there is a transparent layer, the dielectric constant distribution forming means may be provided in any part of the transparent layer (for example, the inside thereof), but the dielectric constant distribution forming means is provided on at least one surface of the transparent layer. You can be done.

When the transparent electrode paired with the plate is provided inside the plate included in a pair of the two pairs of the plate and the transparent electrode, the dielectric constant distribution forming means It may be provided on the inner surface of the electrode.

When the transparent electrode paired with the plate is provided inside the plate included in a pair of the two pairs of the plate and the transparent electrode, the dielectric constant distribution forming means It may be provided in a transparent transparent layer provided inside the electrode. In the case where there is a transparent layer, the change in dielectric constant may be provided in any part of the transparent layer (for example, inside thereof), but the dielectric constant distribution forming means is provided on at least one surface of the transparent layer. May be.

The change in the dielectric constant may be provided in both a pair of two plates and a transparent electrode (and in some cases, a transparent layer).

When the dielectric constant distribution forming means is provided on the inner surface of the transparent electrode, the dielectric constant distribution forming means is arranged on the inner surface of the transparent electrode such that the particle size does not affect the transparency of the liquid crystal lens. By providing a concentration distribution of the dielectric powder A dielectric constant distribution can be formed.

When the dielectric constant distribution forming means is provided on the surface of the plate, the dielectric constant distribution forming means has such a degree that the particle size does not affect the transparency of the liquid crystal lens on at least one surface of the plate. By providing a distribution of the concentration of the dielectric powder thus formed, an dielectric distribution can be formed.

When the dielectric constant distribution forming means is provided on the surface of the transparent layer, the dielectric constant distribution forming means has such a degree that the particle size does not affect the transparency of the liquid crystal lens on at least one surface of the transparent layer. By providing a distribution of the concentration of the dielectric powder thus formed, a dielectric constant distribution can be formed.

When distributing dielectric powder on the surface of a predetermined object such as a plate, transparent electrode, transparent layer, etc., printing is performed by using an ink-like one in which dielectric powder is mixed into some kind of binder. A distribution of the concentration of the dielectric powder can be created on the surface of a given object. Since the printing technology is highly complete, there is no great difficulty in creating a dielectric powder concentration distribution on the surface of a plate, transparent electrode, or transparent layer.

The liquid crystal lens of the present application is expected to be applied in various fields. For example, it can be applied to the following devices for stimulating the eyes (hereinafter sometimes simply referred to as “stimulators”). Be expected.

The device for stimulating the eye includes two transparent plates arranged at a predetermined interval, and two transparent electrodes provided in pairs with the plates along the two plates. A liquid crystal layer disposed between the two transparent electrodes, and a dielectric distribution that provides a dielectric constant distribution in a plane direction of the two transparent electrodes provided in a space between the two transparent electrodes. Forming means, a voltage applying means for applying a desired voltage between the two transparent electrodes, and when the voltage is applied between the two transparent electrodes, the dielectric constant distribution forming means Accordingly, a refractive index distribution is generated in the liquid crystal layer due to the electric field distribution generated, and a fixing means for fixing the plate of the liquid crystal lens in front of the user's eyes. ing.

The voltage applying means in this apparatus automatically changes the voltage applied between the transparent electrodes as time passes.

In this stimulator, the voltage application means changes the voltage applied between the transparent electrodes. This makes it possible to automatically change the focus of the liquid crystal lens. As a result, users who wear this eye stimulator and see the outside through the liquid crystal lens in front of their eyes are forced to change their focus by automatically changing the focus of the liquid crystal lens. You will be tempted. This is considered useful for preventing hyperopia and myopia.

Note that this apparatus may include two liquid crystal lenses for both eyes or only one for one eye.

The liquid crystal lens of the above-described device for stimulating the eye can also be replaced by a more general variable focus lens.

In this case, the device for stimulating the eye includes two transparent plates arranged at a predetermined interval, and two devices provided in pairs with each of the front f along the two plates. A transparent electrode, a layer made of a predetermined substance disposed between the two transparent electrodes, and a dielectric constant in a plane direction of the two transparent electrodes provided in a space between the two transparent electrodes. A dielectric constant distribution forming means for providing a distribution; a voltage applying means for applying a desired voltage between the two transparent electrodes; and when the voltage is applied between the two transparent electrodes, the dielectric constant A variable-focus lens in which a refractive index distribution is generated in the layer by an electric field distribution generated according to the distribution forming means, and a fixing means for fixing the plate of the variable-focus lens in front of the user's eye , And the voltage application hand The stage is a device for stimulating the eye that automatically changes the voltage applied between the transparent electrodes as time passes. Brief Description of Drawings

FIG. 1 is a perspective view showing the configuration of the liquid crystal lens according to the first embodiment.

FIG. 2 is a plan view conceptually showing one surface of the transparent electrode of the liquid crystal lens shown in FIG.

FIG. 3 is a perspective view showing a configuration of a liquid crystal lens according to the first modification.

FIG. 4 is a perspective view showing a configuration of a liquid crystal lens according to the second modification.

FIG. 5 is a perspective view showing a configuration of a liquid crystal lens according to Modification 3.

FIG. 6 is a perspective view showing a configuration of a liquid crystal lens according to Modification 4. FIG. 7 is a perspective view showing a configuration of a device for applying stimulation to the eye according to the second embodiment. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, preferred first and second embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that items common to both embodiments are denoted by common reference numerals, and common description is omitted.

First embodiment

FIG. 1 shows a liquid crystal lens 100 A in the first embodiment.

The liquid crystal lens 10 O A has two transparent plates 10. The transparent plate 10 of this embodiment is not necessarily limited to this, but is a flat plate having a uniform thickness. In this embodiment, these plates 10 are made of glass, but can be made of a resin such as acrylic. In this embodiment, the two transparent plates 10 have the same shape and are parallel to each other.

A transparent electrode 20 is provided inside each of the two transparent plates 10. The transparent electrode 20 may be a well-known one, and is made of ITO (tin oxide / tin oxide), zinc oxide, tin oxide or the like. The transparent electrode 20 is a known method such as a sputtering method, a vacuum deposition method, a sol-gel method, a cluster beam deposition method, or a PLD method. In this embodiment, the transparent electrode 20 is in close contact with the inner surface of the plate 10. Is provided.

A liquid crystal layer 30 is provided between the two plates 10. In this embodiment, a liquid crystal layer 30 is provided between two plates 10 via a transparent electrode 20. Although not necessarily limited to this, in this embodiment, the liquid crystal layer 30 has a higher degree of liquid crystal orientation in the portion where the liquid crystal layer 30 is located, and the refractive index becomes higher. Is supposed to be small. Note that the liquid crystal used in this embodiment is a thermotop pick liquid crystal, and more specifically, a nematic liquid crystal with positive dielectric anisotropy.

However, in spite of its name, the liquid crystal layer 30 does not necessarily have to be composed of liquid crystals. When a voltage is applied between the two transparent electrodes 20, it corresponds to the electric field. 2009/059023

1 1

What is necessary is just to be comprised with the predetermined | prescribed substance with the property which produces refractive index distribution. An example of a layer made of such a material is a liquid crystal layer made of liquid crystal, and another example is made of electro-optic crystals, for example KTN (potassium niobate tantalate, KTal-x bx03) Electrical engineering crystal layer.

The transparent electrode 20 is connected to an external power circuit 40 and a cable 41. The power supply circuit 40 can apply a desired potential difference between the two transparent electrodes 20.

In this embodiment, since it is inside the two transparent electrodes 20 force plates 10, a device for changing the dielectric constant is devised on the inner surface of the transparent electrode 20.

The ideas are as follows.

In this embodiment, the inner surface of one of the two transparent electrodes 20 has a concentration distribution in a concentric circle centered on the center of the transparent electrode 20 in plan view. Of powder is attached.

As the dielectric, for example, a known material such as Roche 1 1 e salt (abbreviation: R salt), dihydrogen dihydrogen power (abbreviation: KD P), or arsenic potassium arsenate, a similar substance of KD P, should be used. However, in this embodiment, barium titanate (abbreviation: BT), which is more widely used, is used.

The particle size of the dielectric powder need only be small enough not to affect the transparency of the liquid crystal lens 10 OA (in this embodiment, the transparency to visible light), but in this embodiment, it is less than the μm order. The size, more specifically, in the order of nm. That is, the dielectric powder in this embodiment is so-called nanoparticles.

To adhere the dielectric to the transparent electrode 20, a dispersion containing a binder such as polybulal alcohol and a dielectric powder is printed on the inner surface of the transparent electrode 20 using an ink jet printing device. This can be done.

FIG. 2 conceptually shows the state of the surface of the transparent electrode 20 on which the dielectric is printed. Dielectric material is printed in the circled area marked with ¾fe ^ in Fig.2. The center of the circle coincides with the center of the transparent electrode 20 as described above. In this embodiment, the concentration of the dielectric at the center of the circle is substantially zero. The density of the transparent electrode 20 at the edge of the circle is determined according to the size of the refractive index to be generated in this portion. Dielectric In this embodiment, the density gradually increases gradually from the center of the circle as viewed in the radial direction of the circle.

The binder containing the dielectric powder is not necessarily limited to this, but in this embodiment, it is layered. The binder containing the dielectric powder may be a continuous layer or a discontinuous layer. In this embodiment, the binder is formed into a discontinuous layer by ink jet printing.

In this embodiment, the concentration distribution of the dielectric provided on the inner surface of one of the two transparent electrodes 20 is such that the concentration gradually increases from the inside toward the outside around a predetermined point. On the contrary, it is also possible to make a concentric distribution in which the concentration gradually decreases from the inside to the outside with a predetermined point as the center.

In this embodiment, the concentration distribution of the dielectric powder as described above is formed on the inner surface of one of the two transparent electrodes 20. It is possible to form a concentration distribution by the dielectric powder as described above on both inner surfaces. Of course, when the concentration distribution due to the dielectric powder as described above is formed on the inner surface of the two transparent electrodes 20, the concentration due to the dielectric powder formed on the inner surface of the transparent electrode 20. The distribution pattern is not necessarily the same.

The liquid crystal lens 10 O A of this embodiment operates as follows.

First, when there is no potential difference between the two transparent electrodes 20 included in the liquid crystal lens 10 OA (when the power supply circuit 40 does not give a potential difference between the two transparent electrodes 20), The liquid crystal lens 10 0 OA of the embodiment does not function as a lens and basically has a focal length of infinity. However, the liquid crystal lens 10 OA has a different dielectric constant depending on its width direction due to the above-described concentration distribution of the dielectric powder, and therefore the refractive index may differ depending on the width direction based on that. . In this case, the liquid crystal lens 10 OA functions as a lens due to the refractive index distribution corresponding to the concentration distribution of the dielectric powder, but the focal length is considerably long even if this is taken into consideration. It will be a thing.

When the power supply circuit 40 described above gives a potential difference between the two transparent electrodes 20, the liquid crystal lens 10 OA functions as a lens. Power supply circuit 40 has two transparent When a potential difference is applied between the bright electrodes 20, an electric field is generated between the two transparent electrodes 20. This electric field is the center of the above-described circle (transparent The closer to the center of the circle (the center of the transparent electrode 20), the weaker the closer to the center of the circle (the center of the transparent electrode 20), the stronger the distance from the center of the circle. However, the electric field outside the circle is uniform. Therefore, the degree of orientation of the liquid crystal layer 30 when a potential difference is applied between the two transparent electrodes 20 becomes stronger as it is farther from the center of the transparent electrode 20, and the closer to the center of the transparent electrode 20, the stronger the liquid crystal layer 30 becomes. The refractive index increases. This means that the liquid crystal lens 10 OA (more precisely, the portion corresponding to the above circle in the liquid crystal lens 10 OA) functions in the same way as a convex lens having a positive power. If the potential difference that the original circuit 40 gives between the two transparent electrodes 20 becomes large, the overall degree of alignment of the liquid crystal in the liquid crystal layer 30 becomes large, so until the potential difference reaches a certain threshold value. As the potential difference provided between the two transparent electrodes 20 increases, the power of the liquid crystal lens 10 OA increases.

When the concentration distribution of the dielectric is increased as it is closer to the center, the refractive index distribution when a potential difference is applied between the two transparent electrodes 20 becomes smaller as the position is closer to the center of the transparent electrode 20. . This means that such a liquid crystal lens 100 A functions in the same way as a concave lens with negative power. In this case, when the potential difference given by the power supply circuit 40 between the two transparent electrodes 20 is increased, the size of the liquid crystal lens 10 OA is reduced accordingly.

A liquid crystal lens 10 0 B according to Modification 1 will be described.

The liquid crystal lens 100 B according to Modification 1 basically has the same configuration as the liquid crystal lens 10 O A according to the first embodiment.

As shown in FIG. 3, the liquid crystal lens 1 0 0 B according to the modified example 1 has two plates 10 0 and 2 transparent plates from the outside as in the case of the liquid crystal lens 1 0 OA according to the first embodiment. It has an electrode 20, a liquid crystal layer 30, and a power circuit 40 connected to the two transparent electrodes 20. The functions of the plate 10 of the liquid crystal lens 100 B, the transparent electrode 20, and the liquid crystal layer 30 of the modification 1 are the same as those of the first embodiment. The liquid crystal lens of modification 1 is different from the liquid crystal lens according to the first embodiment in that the liquid crystal lens of modification 1 is the liquid crystal lens according to the first embodiment.

This is that two transparent layers 50 that were not included in the 100 A are provided between the transparent electrode 20 and the liquid crystal layer 30. The transparent layer 50 is a transparent layer. In the first modification, the transparent layer 50 is made of a resin formed into a thin film. The type of resin constituting the transparent layer 50 is not particularly limited. In this embodiment, at least one of the two transparent layers 50 is provided with a concentration distribution as shown in FIG. Such a concentration distribution is not necessarily limited to this, but in Modification 1, it is provided on at least one side of at least one of the two transparent layers 50. The method for forming the concentration distribution by the dielectric on the transparent layer 50 may be the same printing as in the first embodiment.

If the dielectric concentration distribution is not formed on both of the two transparent layers 50, the transparent layer 50 may be a single layer. <Modification 2>

A liquid crystal lens 100C according to Modification 2 will be described.

The liquid crystal lens 100 C according to Modification 2 basically has the same configuration as the liquid crystal lens 100 A according to the first embodiment.

As shown in FIG. 4, the liquid crystal lens 100 according to the modified example 2 has two plates 10 and two transparent electrodes 2 similar to those provided in the liquid crystal lens 10 OA according to the first embodiment. 0, a liquid crystal layer 30, and a power supply circuit 40 connected to two transparent electrodes 20.

The liquid crystal lens 1 0 0 C of modification 2 is different from the liquid crystal lens 1 0 0 A according to the first embodiment. The liquid crystal lens 1 0 0 C of modification 2 is opposite to the case of the first embodiment. The two transparent electrodes 20 are both provided outside the plate 10.

In the second modification, the powder power of the dielectric is arranged on at least one surface of the two plates 10 by the same method and concentration distribution as in the first embodiment.

In the liquid crystal lens 100 C of Modification 2, dielectric powder is arranged on the surface of the plate 10. At the same time, or instead, the dielectric powder may be arranged on the inner surface of the transparent electrode 20 by the same method and concentration distribution as in the first embodiment. <Modification 3>

A liquid crystal lens 10 O D according to Modification 3 will be described.

The liquid crystal lens 1 0 0 D according to Modification 3 basically has the same configuration as the liquid crystal lens 1 0 0 B according to Modification 1.

As shown in FIG. 5, the liquid crystal lens 1 0 0 D according to the modified example 3 includes two plates 10 0, two transparent electrodes 2 0, a liquid crystal layer similar to the liquid crystal lens B according to the modified example 1 A power supply circuit 40 connected to 30, two transparent layers 50, and two transparent electrodes 20 is provided.

Liquid crystal lens of modification 3 1 0 0 D force Liquid crystal lens 1 0 0 B of modification 1 differs from liquid crystal lens 1 0 0 D of modification 3 in that both two transparent electrodes 2 0 are deformed. Contrary to the case of Example 1, it is provided on the outside of the plate 10 and two transparent layers 50 are provided between the paired plate 10 and the transparent electrode 20, respectively. That is the point.

In this modified example 3, the dielectric powder is disposed on any one of the transparent layers 50 (for example, any surface of the transparent layer 50) in the same manner and concentration distribution as in the modified example 1. . The transparent layer 50 provided with the concentration distribution by the dielectric powder as described above is provided inside the two plates 10 (for example, in close contact with the inner surface of the two plates 10). May be.

However, if no force or dielectric concentration distribution is formed on one of the two transparent layers 50, one transparent layer 50 may be used. Variation 4>

A liquid crystal lens 1000E according to Modification 4 will be described.

The liquid crystal lens 100 0 E according to the modification 4 basically has the same configuration as the liquid crystal lens 100 0 D according to the modification 3.

The liquid crystal lens 1 0 0 E according to modification 4 is based on modification 3 as shown in FIG. It is connected to two plates 10, two transparent electrodes 20, a liquid crystal layer 30, two transparent layers 50, and two transparent electrodes 20, similar to the liquid crystal lens 100 B. A power supply circuit 40 is provided.

Liquid crystal lens of modification 4 1 0 0 E force The difference from liquid crystal lens 1 0 0 D of modification 3 is that the liquid crystal lens 1 0 0 D of modification 4 is paired in the case of modification 3 The two transparent layers 50 provided respectively between the plate 10 and the transparent electrode 20 are provided inside the plate 10 together.

In this modified example 4, the dielectric powder is arranged on any one of the transparent layers 50 (for example, any surface of the transparent layer 50) in the same manner and concentration distribution as in the modified example 3. . In addition, in the case where it is necessary to form a dielectric concentration distribution in both of the two transparent layers 50, the transparent layer 50 that does not form the dielectric concentration distribution is unnecessary. In that case, the transparent layer 50 is a single layer.

<< Second Embodiment >>

In the second embodiment, a description will be given of an apparatus for applying stimulation to the eye, to which the above-described liquid crystal lens 100 (from 1 00 to 100 0) is applied.

This device 200 is configured in the shape of glasses as shown in FIG.

This device 2 0 0 includes two frames 2 1 0, a bridge 2 2 0 connecting the two frames 2 1 0, and a temple 2 3 0 attached to the outside of the two frames 2 1 0. ing. The frame 2 10, the bridge 2 2 0, and the temple 2 3 0 can be made of metal, for example, but in this embodiment, they are made of resin. The temple 2 3 0 may be foldable with respect to the frame 2 1 0. A known nose pad may be provided on the inner side of the bridge 2 20 or the frame 2 10.

In this embodiment, the frame 2 10 is not necessarily limited to this, but has a circular donut shape. A liquid crystal lens 100 similar to that described in the first embodiment is fitted in the space inside both frames 2 10. As in the case of the first embodiment, the liquid crystal lens 100 includes two transparent plates 10, two layered transparent electrodes 20, a liquid crystal layer 30, and in some cases two transparent layers 50. I have. However, These two transparent plates 10, which were rectangular in the first embodiment, two layered transparent electrodes 20, a liquid crystal layer 30, and optionally two transparent layers 50 are the second embodiment. In all cases, the shape is a circle corresponding to the shape of the space inside the frame 2 10. More specifically, the plate 10 included in the liquid crystal lens 100 of the second embodiment corresponds to the inner part of the broken line shown in FIG. In other words, the liquid crystal lens 100 of the second embodiment is the same as the liquid crystal lens of the first embodiment, the portion of the plate 10 surrounded by the broken line 10, and the corresponding transparent electrode 20 and liquid crystal layer 30. In some cases, the transparent layer 50 is cut out.

The temple 2 3 0 is provided with a control mute 1 1 0. In this embodiment, the control unit 110 is configured such that the power source circuit 40 described in the first embodiment is housed in a resin case formed in a rectangular parallelepiped shape. The control unit 1 1 0 also houses a control circuit that controls the power supply circuit 40. In FIG. 7, both the power supply circuit and the control circuit are not shown. Since the control circuit is a known technology, the control circuit is configured to include a CPU and a memory (not shown), and the CPU executes a program recorded in the memory, thereby generating a potential difference applied to the two transparent electrodes. The power supply circuit 40 is controlled to change automatically at a predetermined timing.

One end of the power supply circuit 40 is connected to the other end of the cable 41 connected to the transparent electrode 20 inside the frame 21, and between the two transparent electrodes 20 via the cable 41. The potential difference can be controlled.

The user uses this device 2 0 0 with two temples 2 3 0 on both ears in the same way as normal glasses. In this state, the two liquid crystal lenses 100 are positioned in front of the right and left eyes of the user, respectively. The user sees the outside world through the liquid crystal lens 100 when using the device 200.

At this time, the power supply circuit 40 is controlled by the control circuit to automatically change the potential difference between the two transparent electrodes 20 of the liquid crystal lens 100 at a predetermined timing. Thereby, the liquid crystal lens 100 changes the focal length as in the case of the first embodiment. A user wearing this device 200 is forced to change the focus of the eye when looking at the outside world. The potential difference between the transparent electrodes 20 by the power supply circuit 40 may be synchronized between the right-eye liquid crystal lens 100 and the left-eye liquid crystal lens 100, or the user's The synchronization may not be performed according to the state of the right eye and the left eye.

Further, in the second embodiment, the liquid crystal lens 100 and the control unit 110 can be provided for only one of the two existing forces for the right eye and the left eye. .

Claims

The scope of the claims

1. Two transparent plates arranged at a predetermined interval;

Two transparent electrodes provided in pairs with each of the plates along the two plates;

A liquid crystal layer disposed between the two transparent electrodes;

A dielectric constant distribution forming means for providing a dielectric constant distribution in a plane direction of the two transparent electrodes, provided in a space between the two transparent electrodes;

With

When a voltage is applied between the ^two transparent electrodes, said by the thus generated electric field distribution permittivity distribution forming means, so that the refractive index distribution in the liquid crystal layer occurs,

Liquid crystal lens.

2.2 The transparent electrode paired with the plate is provided on the outside of the plate included in a pair of the two pairs of the plate and the transparent electrode, and the dielectric constant distribution forming means includes the transparent electrode Provided on the inner surface of the electrode,

The liquid crystal lens according to claim 1.

3.2 The transparent electrode paired with the plate is provided outside the plate included in a pair of the two pairs of the plate and the transparent electrode, and the dielectric constant distribution forming means includes the transparent Provided on the plate paired with an electrode,

The liquid crystal lens according to claim 1.

4. The dielectric constant distribution forming means is provided on at least one surface of the plate.

4. A liquid crystal lens according to claim 3.

5. The transparent electrode paired with the plate is provided inside the plate included in a pair of the two pairs of the plate and the transparent electrode, and the dielectric constant distribution forming unit includes the transparent electrode Provided on the inner surface of the electrode,

The liquid crystal lens according to claim 1.

6. Inside the plate included in a pair of the two pairs of plates and the transparent electrode The transparent electrode paired with a plate is provided, and the dielectric constant distribution forming means is provided in a transparent transparent layer provided inside the transparent electrode.

The liquid crystal lens according to claim 1.

7. The transparent electrode paired with the plate is provided outside the plate included in a pair of the two pairs of the plate and the transparent electrode, and the dielectric constant distribution forming unit includes the transparent electrode It is provided in a transparent transparent layer provided inside the electrode.

The liquid crystal lens according to claim 1.

8. The dielectric constant distribution forming means is provided on at least one surface of the transparent layer,

The liquid crystal lens according to claim 6 or 7.

9. The dielectric constant distribution forming means is layered,

The liquid crystal lens according to any one of claims 1 to 8.

1 0. The two plates are arranged in parallel to each other,

The liquid crystal lens according to claim 1.

11. The liquid crystal lens according to claim 1, wherein the two plates are both flat plates and are arranged in parallel to each other.

1 2. The dielectric constant distribution given by the dielectric constant distribution forming means is

The refractive index of light when vertically incident on the two plates is such that it gradually increases or decreases with the optical axis as the center,

The liquid crystal lens according to claim 1.

1 3. The dielectric constant distribution given by the dielectric constant distribution forming means is:

It has a concentric distribution,

The liquid crystal lens according to claim 12.

1 4. The dielectric constant distribution forming means forms the dielectric constant distribution by the distribution of the concentration of the dielectric powder whose particle size does not affect the transparency of the liquid crystal lens. ,

The liquid crystal lens according to claim 1.

15. The dielectric constant distribution forming means forms the dielectric constant distribution based on the distribution of the concentration of the dielectric powder, the particle size of which does not affect the transparency of the liquid crystal lens. The distribution of the concentration of the dielectric powder is formed on the inner surface of the transparent electrode,

6. A liquid crystal lens according to claim 2 or claim 5.

16. The dielectric constant distribution forming means forms the dielectric constant distribution by the distribution of the concentration of the dielectric powder whose particle size does not affect the transparency of the liquid crystal lens. The distribution of the concentration of the dielectric powder is formed on at least one surface of the plate,

5. A liquid crystal lens according to claim 4.

17. The dielectric constant distribution forming means forms the dielectric constant distribution by the distribution of the concentration of the dielectric powder whose particle size does not affect the transparency of the liquid crystal lens. The concentration distribution of the dielectric powder is formed on at least one surface of the transparent layer.

+ Liquid crystal lens according to claim 7.

1 8. The dielectric is barium titanate,

The liquid crystal lens according to any one of claims 14 to 17.

1 9. Two transparent plates, spaced at a predetermined interval,

Two transparent electrodes provided in pairs with each of the plates along the two plates, a liquid crystal layer disposed between the two transparent electrodes,

Voltage applying means for applying a desired voltage between the two transparent electrodes;

Have

When a voltage is applied between the two transparent electrodes, a refractive index distribution is generated in the liquid crystal layer by an electric field distribution generated according to the dielectric constant distribution forming means.

A liquid crystal lens,

A fixing means for fixing the plate of the liquid crystal lens in front of the user's eyes; and

The voltage applying means automatically marks between the transparent electrodes as time passes. To change the applied voltage,

A device for stimulating the eyes.

2 0. Two transparent plates arranged at a predetermined interval;

A layer of a predetermined material disposed between the two transparent electrodes;

With

A variable focus lens, wherein when a voltage is applied between the two transparent electrodes, a refractive index distribution is generated in the layer by an electric field distribution generated by the dielectric constant distribution forming means.

2 1. Two transparent plates arranged at a predetermined interval,

Two transparent electrodes provided in pairs with each of the two plates along the two plates, a layer made of a predetermined substance disposed between the two transparent electrodes,

Have

When a voltage is applied between the two transparent electrodes, a refractive index distribution is generated in the layer by an electric field distribution generated according to the dielectric constant distribution forming means, a variable focus lens,

Fixing means for fixing the plate of the variable focus lens in front of the user's eye;

With

The voltage applying means automatically changes the voltage applied between the transparent electrodes as time passes.

A device for stimulating the eyes.