JP2009229513A - Variable focal lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable focal lens which is relatively tolerant of disturbance and has a structure to serve as either a convex lens or a concave lens. <P>SOLUTION: A first medium 12 and a second medium 14 are both flowable and have mutually different refractive indexes. The first medium 12 is charged between a substrate 16 and a first thin film 18. The second medium 14 is charged between the first thin film 18 and a second thin film 20. A first electrode 22 is fitted to the substrate 16. A second electrode 24 is fitted to the first thin film. The first thin film 18 is so flexible to change its shape in accordance with a voltage applied between the first electrode 22 and second electrode 24. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a variable focus lens.

  Patent Document 1 listed below describes a variable focus lens using an electrowetting technique. In this technique, two types of liquids having different refractive indexes are stacked on a substrate, and the wettability (contact angle) between the lower liquid and the substrate is electrically controlled. Thereby, the curvature of the interface between two liquids is changed. Since this boundary surface becomes a light refracting surface, a variable focus lens can be realized with this technique.

Such variable focus lenses are generally
・ Because there are no moving parts, it is hard to break. ・ Motors and gears are not required for changing the focus. Therefore, it is suitable for downsizing. ・ Since the structure is simple, there are advantages such as low manufacturing costs.

  For this reason, this type of variable focus lens is expected to be put to practical use as an optical component for small cameras for mobile phones and optical pickups.

  By the way, in the technique of above-mentioned patent document 1, there exists a possibility that the interface shape between two liquids may change due to disturbance. The disturbance is, for example, an external force such as vibration or gravity and a temperature change. In this technique, when the specific gravity of the two liquids is different, the shape of the boundary surface between the two liquids may be deformed by being influenced by external forces such as vibration and gravity. Even when the specific gravity of the two liquids is equal in the initial state, the specific gravity changes due to a temperature change if the thermal expansion coefficients of the two liquids are different. As a result, the boundary surface shape between the two liquids may be deformed due to the influence of external forces such as vibration and gravity.

  As described above, in this technique, even if two liquids having the same specific gravity are used at a certain temperature, a difference in specific gravity occurs between the two liquids due to a temperature change. In addition, since the magnitude of the influence of vibration and gravity is proportional to the volume of the two liquids, it is difficult to increase the lens diameter with this technique, and a diameter of about 5 mm will be the limit.

  Furthermore, in this technique, since the shape of the casing that encloses the liquid greatly affects the shape of the boundary surface between the two liquids, in order to obtain a lens surface without distortion, a casing without distortion is necessary. Therefore, high-precision three-dimensional processing is required for the production of the casing.

  On the other hand, the present inventors have proposed the technique described in Non-Patent Document 1 below. In this technique, a silicone resin is sealed between a film made of a resin called parylene (a general term for paraxylylene resins) and a substrate. Electrodes are attached to the parylene film and the substrate, respectively.

  In the technique of Non-Patent Document 1, the curvature of the parylene film can be changed by applying a voltage between both electrodes. Thereby, a variable focus lens can be provided.

With this technology,
-Even if there is an influence of disturbance (vibration, gravity, and temperature change), the curvature of the parylene film is difficult to change, so a lens that is resistant to disturbance can be provided.
-Even when the diameter is large (for example, 10 mm or more), a lens resistant to disturbance can be provided.
・ Since the shape of the casing that encloses the liquid does not affect the shape of the liquid, high-precision three-dimensional processing is not necessary for manufacturing the casing (this is extremely advantageous in terms of miniaturization and manufacturing cost). ),
There is an advantage.

However, the technique of Non-Patent Document 1 has a problem that it is theoretically difficult to make a concave lens.
JP 2006-178469 A Binh-Khiem Nguyen, et. Al., "Electrically Driven Varifocal Micro Lens Fabricated by Depositing Parylene Directly on Liquid," pp. 305-308, Proceedings of IEEE MEMS 2007, Kobe, Japan, 21-25 January 2007.

  The present invention has been made in view of the above circumstances. An object of the present invention is to provide a variable focus lens that is relatively resistant to disturbance and has a structure in which both a convex lens and a concave lens can be realized.

  The present invention has a configuration described in any of the following items.

(Item 1)
A first medium, a second medium, a substrate, a first thin film, a second thin film, a first electrode, and a second electrode;
Both the first medium and the second medium have fluidity,
And the first medium and the second medium have different refractive indexes,
A first space is formed between the substrate and the first thin film,
A second space is formed between the first thin film and the second thin film,
The first space and the second space are in a superimposed state,
The first medium is filled in the first space;
The second medium is filled in the second space;
The first electrode is attached to the substrate;
The second electrode is attached to the first thin film;
A voltage can be applied between the first electrode and the second electrode,
The variable focus lens, wherein the first thin film has a flexibility capable of being deformed according to a voltage applied between the first electrode and the second electrode.

  In the variable focus lens of Item 1, the first thin film can be deformed according to the voltage applied between the first electrode and the second electrode. The first thin film defines the surface shape of the first medium or the second medium. This surface shape constitutes a refracting surface for light rays passing through these media. Therefore, according to the present invention, a variable focus lens can be realized.

  By appropriately selecting the refractive indexes of the first medium and the second medium, various adjustment ranges of the refractive power in the variable focus lens can be set. A concave lens can also be realized by selecting the radius of curvature obtained by deformation of the first thin film and the refractive indices of the first medium and the second medium.

(Item 2)
2. The variable focus lens according to item 1, wherein the refractive index n1 of the first medium and the refractive index n2 of the second medium are in a relationship of n1 <n2.

  If comprised in this way, it will become possible to comprise a concave lens with a 1st thin film.

(Item 3)
2. The variable focus lens according to item 1, wherein the refractive index n1 of the first medium and the refractive index n2 of the second medium are in a relationship of n1> n2.

  If comprised in this way, it will become possible to comprise a convex lens with a 1st thin film.

(Item 4)
A third medium and a third thin film;
A third space superimposed on the second space is formed between the third thin film and the second thin film,
The variable focus lens according to any one of Items 1 to 3, wherein the third medium is filled in the third space.

  In general, in the present invention, up to nth thin films (n is an integer of 2 or more) can be used. A lens effect can be obtained by filling a medium between thin films and adjusting the refractive index of these mediums. The radius of curvature of the thin film can be adjusted by attaching electrodes to all or part of the thin film and adjusting the potential between the electrodes. In this way, a variable focus lens having a desired focal length can be configured.

(Item 5)
Furthermore, a third electrode, a fourth electrode, and a spacer are provided,
The spacer is disposed between the first thin film and the second thin film;
The third electrode is attached to the spacer;
The fourth electrode is attached to the second thin film;
A voltage can be applied between the third electrode and the fourth electrode,
The variable according to any one of Items 1 to 4, wherein the second thin film has flexibility that can be deformed according to a voltage between the third electrode and the fourth electrode. Focus lens.

  If it is configured so that the radius of curvature of the second thin film can be further adjusted as in the present invention, a so-called zoom lens can be obtained.

(Item 6)
A second substrate and a third medium;
A third space superimposed on the second space is formed between the second thin film and the second substrate,
The variable focus lens according to any one of Items 1 to 3, wherein the third medium is filled in the third space.

(Item 7)
An opening is formed in the substrate,
The first space is opened to an external space by the opening,
The variable focus lens according to any one of Items 1 to 6, wherein the first medium is air.

  According to the present invention, it is possible to provide a variable focus lens that is relatively resistant to disturbance and has a structure in which both a convex lens and a concave lens can be realized.

(First embodiment)
Hereinafter, a variable focus lens according to a first embodiment of the present invention will be described with reference to FIGS.

  The variable focus lens of the present embodiment includes a first medium 12, a second medium 14, a substrate 16, a first thin film 18, a second thin film 20, a first electrode 22, a second electrode 24, and a spacer. 26 as a main configuration.

  Both the first medium 12 and the second medium 14 have fluidity. Specifically, liquid is used as the first medium 12 and the second medium 14. Furthermore, the first medium 12 and the second medium 14 have different refractive indexes. Suitable materials for the first medium 12 or the second medium 14 include, but are not limited to, diffusion pump oil (silicone oil), liquid paraffin, glycerin, and ionic liquid.

  In this embodiment, the substrate 16 is made of a transparent and highly insulating material. An example of such a material is glass. Other usable materials include, but are not limited to, PET (polyethylene terephthalate) resin and acrylic resin.

  A first space 28 is formed between the substrate 16 and the first thin film 18. A second space 30 is formed between the first thin film 18 and the second thin film 20. The first space 28 and the second space 30 are superimposed on each other.

  The first medium 12 is filled in the first space 28. The second medium 14 is filled in the second space 30.

  In the present embodiment, the first electrode 22 is configured in a sheet shape, and is attached to the surface of the substrate 16. In the present embodiment, the second electrode 24 is formed in a sheet shape, and is attached to the surface of the first thin film 18 (see FIG. 2). A specific method for attaching these electrodes will be described later.

  The second electrode 24 is electrically insulated from the first electrode 22. Further, a power supply circuit 32 capable of applying a voltage is connected between the first electrode 22 and the second electrode 24 so that a predetermined voltage (DC voltage in this embodiment) can be supplied thereto. It has become.

  In this embodiment, both the first electrode 22 and the second electrode 24 are made of a material having high transparency and high conductivity. Examples of such a material include ITO (Indium Tin Oxide) and a metal thin film having a thickness of about 5 nm.

  The first thin film 18 has a flexibility that can be deformed according to the voltage applied between the first electrode 22 and the second electrode 24.

  In FIG. 1, reference numeral 18 a indicates a thin film disposed between the first electrode 22 and the first thin film 18. Similarly, reference numeral 20 a indicates a thin film disposed between the spacer 26 and the second thin film 20.

  Next, the operation of the variable focus lens in the present embodiment will be described with reference to FIG.

  First, in this embodiment, it is assumed that the refractive index n1 of the first medium 12 and the refractive index n2 of the second medium 14 satisfy the relationship n2> n1. In this case, as shown in FIG. 3A, it can be expected that the function of a concave lens is basically achieved. The imaginary focus of the concave lens shown in FIG.

  Here, a voltage is applied between the first electrode 22 and the second electrode 24 to generate an attractive force between the two electrodes. This can be realized, for example, by applying a potential difference between both electrodes (see FIG. 3B).

  Then, the 1st thin film 18 to which the 2nd electrode 24 is attached deform | transforms with the attractive force added to the 2nd electrode 24, and the curvature radius becomes small (refer FIG.3 (b)). As a result, the radius of curvature of the upper surface (that is, the lens surface) of the first medium 12 filled between the first thin film 18 and the substrate 16 is also reduced.

  Then, the incident angle of incident light on the surface (lens surface) of the first medium 12 is increased, and the exit angle can be increased. Thereby, as shown in Drawing 3 (b), the position of imaginary focus F can be made to approach. In this example, a variable focus lens can be realized in this way.

  In this description, it is assumed that the refractive index n1 of the first medium 12 is substantially equal to the refractive index of the substrate 16 in order to simplify the description. For this reason, it is assumed that the light refraction at the interface between the first medium 12 and the substrate 16 is small (see FIG. 3A).

  Strictly speaking, depending on the refractive index of the first thin film 18 and the second thin film 20, a lens action in these thin films can be considered. However, if the thickness of these thin films is sufficiently reduced, it is practically used. It is possible to ignore the effect. In addition, if necessary, the refractive index of these thin films is made closer to that of the first medium 12 and the second medium 14, so that the influence of the lens action by these thin films can be further reduced.

  In the lens of this embodiment, since the medium is covered with a thin film, even if there is a disturbance (vibration, gravity, and temperature change), vibration and deformation of the medium surface can be prevented or reduced. There are advantages. For this reason, the precision of the obtained focal distance can be improved.

  In the present embodiment, when the potential difference between the first electrode 22 and the second electrode 24 is set to approximately 0, the upper surface shape of the first medium 12 returns to the initial state due to the elasticity of the first thin film 18. . Thereby, the position of the imaginary focus F can be returned to the initial position. In order to make the potential difference between the first electrode 22 and the second electrode 24 substantially zero, for example, the voltage application to these electrodes may be canceled.

  Here, the driving principle of the lens of this embodiment will be described in more detail. When a voltage is applied between the first electrode 22 and the second electrode 24, an attractive force acts between the two electrodes, and the first thin film 18 is attracted to the substrate 16 (see FIG. 3B). Here, since the distance between both electrodes is short in the peripheral portion of the first medium 12, a large attractive force is generated. On the other hand, in the vicinity of the center of the first medium 12, the inter-electrode distance is long, so that a large attractive force is not generated. For this reason, only the peripheral portion of the first medium 12 is greatly deformed, and the first thin film 18 is attracted to the substrate 16. Here, when attention is paid to the fact that the volume of the liquid sealed by the first thin film 18 and the substrate 16 is constant, the first medium 12 in the peripheral portion in the initial state is in a state where a voltage is applied between the electrodes. Then, it is thought that it moves near the center. As a result, in the state where the voltage is applied, the lens aperture is small and the lens height is large compared to the initial state. That is, the radius of curvature of the lens can be reduced by applying a voltage.

(Adjusting the refractive power of the lens)
Next, the principle when adjusting the refractive power (lens power) of the lens will be described. First, the code is defined as follows.
n0: refractive index of air outside the lens,
n1: refractive index of the first medium,
n2: refractive index of the second medium,
R1: radius of curvature of the first thin film,
R2: radius of curvature of the second thin film.

In this case, the refractive power can be set as follows.
N2-n0> 0: The upper surface of the second medium 14 is a convex lens,
N1-n2> 0: The upper surface of the first medium 12 (the boundary surface between the first medium 12 and the second medium 14) is a convex lens,
N1-n2 <0: the upper surface of the first medium 12 is a concave lens,
(N2-n0) / R2 + (n1-n2) / R1> 0: a convex lens as a whole lens,
(N2-n0) / R2 + (n1-n2) / R1 <0: concave lens as a whole.

  However, the two expressions for the entire lens are strictly approximate expressions when the thickness of the spacer 26 is smaller than R1 and R2. In some embodiments, there is no problem using this approximate expression. Even if the thickness of the spacer 26 is larger than R1 and R2, the refractive power can be set using n0, n1, n2, R1, R2 and the thickness t of the spacer 26.

(Lens manufacturing method)
Next, an example of a method for producing a variable focus lens according to the present embodiment will be described with reference to FIG.

  First, a glass substrate 16 is prepared (FIG. 4A). Next, the first electrode 22 is formed on the upper surface of the substrate 16. In this example, ITO (Indium Tin Oxide), which is a transparent electrode material, is used as the first electrode 22.

  Next, the thin film 18a made of transparent resin is patterned, and the upper surface of the first electrode 22 is opened. As this transparent resin, for example, an amorphous fluororesin (trade name “Cytop”) can be used. In this state, the first medium 12 is disposed on the upper surface of the first electrode 22. In this state, the first medium 12 rises upward due to its own surface tension (see FIG. 4B). In this example, liquid paraffin is used as the first medium 12.

  Next, the first thin film 18 is formed on the upper surface of the first medium 12 (see FIG. 4C). In this example, a parylene resin having a film thickness of about 500 nm is used for the thin film 18. Such a thin film can be formed, for example, by vapor deposition.

  Next, the second electrode 24 is disposed on the upper surface of the first thin film 18 (see FIG. 4D). In this example, the second electrode 24 is made of gold or aluminum having a film thickness of about 5 nm. The second electrode 24 can also be formed by vapor deposition, for example.

  Next, a spacer 26 is disposed above the first thin film 18 (see FIG. 4E). As this spacer 26, in this example, polyvinyl chloride (PolyVinylChloride) is used. Further, the second medium 14 is filled into the space formed inside the spacer 26. As a material of the second medium 14, in this example, silicone oil is used.

  Thereafter, the second thin film 20 is formed on the upper surface of the second medium 14 (see FIG. 4F). In this example, the thin film 20 is made of a parylene resin having a film thickness of about 1000 nm. Such a thin film can also be formed by vapor deposition, for example.

(Experimental example)
Next, an experimental example using the variable focus lens shown in FIG. 4 will be described with reference to FIGS.

  FIG. 5 shows an image obtained by the lens of this embodiment when the voltage between the first electrode 22 and the second electrode 24 is 0V. On the other hand, FIG. 6 shows an image obtained when the voltage between both electrodes is 300 V (direct current). Also from this figure, it can be seen that the focal length can be varied by the lens of this embodiment.

  The experimental conditions in this experimental example are as follows.

(Experimental conditions)
Imaging method: Observe an object with a microscope through the lens of this embodiment,
The diameter of the lens of this embodiment: 4 mm,
Object to be imaged: paper with “MEMS 2008” written on it,
Microscope: Keyence VHX-500,
Microscope magnification: 50 times (constant),
Distance between object and lens: 29mm (constant),
Distance between lens and microscope: 26 mm (constant).

(Second Embodiment)
Next, a variable focus lens according to a second embodiment of the present invention will be described with reference to FIG. In the description of this embodiment, elements that are basically the same as those in the first embodiment described above are denoted by the same reference numerals to simplify the description.

  The lens further includes a third medium 34, a third thin film 36, and a second spacer 38.

  The 3rd thin film 36 is arrange | positioned in the state superimposed on the 2nd thin film 20 (refer FIG. 7). A third space 40 is formed between the second thin film 20 and the third thin film 36, and the third medium 34 is filled therein.

  In the present embodiment, the third electrode 41 is attached to the spacer 26, and the fourth electrode 42 is attached to the second thin film 20. Further, the second power supply circuit 45 can apply a voltage between these electrodes.

  Similarly, the fifth electrode 43 is attached to the second spacer 38, and the sixth electrode 44 is attached to the third thin film 36. The third power supply circuit 46 is also connected to these electrodes so that a desired voltage can be applied independently.

  In FIG. 7, reference numeral 36 a indicates a thin film disposed between the fifth electrode 43 and the third thin film 36.

  According to the lens of the second embodiment, the curvature radii of the upper surfaces of the first to third media can be changed by adjusting the potential difference between the electrodes facing each other. Thereby, a focal distance can be changed.

  In the second embodiment, the third medium is exemplified, but in general, the nth medium can be stacked by using the nth thin film (n is an integer of 2 or more). By changing the radius of curvature of the surface of these media by the voltage, the focal length of the stacked lenses can be changed.

  Other configurations and advantages of the second embodiment are basically the same as those of the first embodiment, and thus further detailed description is omitted.

(Third embodiment)
Next, a variable focus lens according to a third embodiment of the present invention will be described with reference to FIG. In the description of this embodiment, elements that are basically the same as those in the first embodiment described above are denoted by the same reference numerals to simplify the description.

  This lens further includes a third medium 48 and a second substrate 50 in addition to the lens of the first embodiment.

  The second substrate 50 is disposed in parallel with the substrate 16 described in the first embodiment and at a distance.

  A third space 52 is formed between the second substrate 50 and the second thin film 20, and a third medium 48 is filled therein.

  A third electrode 53 and a fourth electrode 54 that are electrically insulated from the first electrode 22 and the second electrode 24 are attached to the second substrate 50 and the second thin film 20, respectively.

  A second power supply circuit 55 similar to the power supply circuit 32 is connected to the third and fourth electrodes 53 and 54, and a desired voltage can be independently applied thereto.

  According to the lens of the third embodiment, the voltage between the first electrode 22 and the second electrode 24 and between the third electrode 53 and the fourth electrode 54 is adjusted to be arranged between the substrates. The radius of curvature of the medium can be changed. Thereby, a focal distance can be changed.

  Other configurations and advantages of the third embodiment are basically the same as those of the first embodiment, and thus further detailed description is omitted.

(Fourth embodiment)
Next, a variable focus lens according to a fourth embodiment of the present invention will be described with reference to FIG. In the description of this embodiment, elements that are basically the same as those in the first embodiment described above are denoted by the same reference numerals to simplify the description.

  In this lens, an opening 161 is formed in the substrate 16, and the first space 28 is exposed to the outside. In this example, the first medium 12 is air supplied from the outside through the opening 161. That is, in this example, the refractive index n1 of the first medium 12 and the refractive index n0 of air are equal. That is, n1 = n0.

  Furthermore, in this example, the refractive index n2 of the second medium 14 is different from the refractive indexes n1 and n0. In this lens, as in the case of the other embodiments, the entire lens can be a convex lens or a concave lens in accordance with the desired refractive power. As in the case of the other embodiments, n2 <n1 or n2> n1 can be set in accordance with the desired refractive power. However, in this embodiment (n1 = n0), it is practically difficult to make the refractive index n2 of the second medium 14 smaller than the refractive index n1 of the first medium 12 (= the refractive index n0 of air).

  Also in the lens of the fourth embodiment, as in the case of the first embodiment, the first medium 12 and the second medium 14 correspond to the voltage applied between the first electrode 22 and the second electrode 24. The curvature radius of the boundary surface (lens surface) can be changed. Thereby, a focal distance can be changed.

  Other configurations and advantages of the fourth embodiment are basically the same as those of the first embodiment, and thus detailed description thereof is omitted.

(Fifth embodiment)
Next, a variable focus lens according to a fifth embodiment of the present invention will be described with reference to FIG. In the description of this embodiment, elements that are basically the same as those in the first embodiment described above are denoted by the same reference numerals to simplify the description.

  In this lens, the third electrode 41 is attached to the spacer 26, the fourth electrode 42 is attached to the second thin film 20, and the second power supply circuit 45 is connected to the third electrode 41 and the fourth electrode 42. Are connected so that a desired voltage can be applied independently.

  Further, in this lens, the second thin film 20 preferably has a flexibility that can be deformed according to the voltage between the third electrode 41 and the fourth electrode 42.

  In the lens of the fifth embodiment, the curvature radii of the upper surfaces of the first medium 12 and the second medium 14 can be independently changed by supplying an appropriate voltage between the opposing electrodes. . For this reason, in the lens of the present embodiment, it is possible to change the magnification and focus. That is, according to this embodiment, it is possible to provide a zoom lens (see FIG. 11).

  Other configurations in the fifth embodiment are basically the same as those in the first embodiment, and thus detailed description thereof is omitted.

(Sixth embodiment)
Next, a variable focus lens according to a sixth embodiment of the present invention will be described with reference to FIGS. In the description of this embodiment, elements that are basically the same as those in the first embodiment described above are denoted by the same reference numerals to simplify the description.

  In this lens, the first mirror 56 is disposed on the upper surface of the first thin film 18. Further, the second mirror 58 is disposed on the upper surface of the second thin film 20.

  A reflective optical system can be formed by attaching each mirror as shown in FIG. These mirrors can be manufactured, for example, by vapor deposition of aluminum. The light passing through the second thin film 20 is first reflected by the lower first mirror 56, then reflected by the upper second mirror 58, and finally passes through the first thin film 18 to be focused. As a result, an imaging surface is obtained at a position (F1) closer to the original focal point (F2) of the light that has passed through the second thin film 20, so that the optical system can be made thinner. Similarly to the other embodiments, the focal length can be finely adjusted by driving the first thin film 18 and the second thin film 20 by electrostatic force.

  Moreover, the lens effect | action shown in FIG. 13 can be obtained by comprising the 1st mirror 56 and the 2nd mirror 58 with a light control mirror. That is, if the lower first mirror 56 is a dimming mirror, the focal length can be greatly changed by selecting whether the light passing through the second thin film 20 is transmitted through or reflected by the first mirror 56. it can. However, the dimming mirror here refers to a dimming material capable of switching between a “mirror state” that reflects light and a “transparent state” that transmits light by the action of voltage or the like. Even when the dimming mirror is used, the focal length can be finely adjusted by driving the first thin film 18 and the second thin film 20 by electrostatic force.

  In addition, since the wavelength transmission property may exist in the reflective transmission characteristic in a light control mirror, it is preferable to use the light control mirror corresponding to the target wavelength.

  Further, in order to control the reflection / transmission characteristics of the dimming mirror, it is preferable to provide a corresponding electrode and power supply circuit.

  Other configurations in the sixth embodiment are basically the same as those in the first embodiment, and thus detailed description thereof is omitted.

  Note that the description of the embodiment and the examples is merely an example, and does not indicate a configuration essential to the present invention. The configuration of each part is not limited to the above as long as the gist of the present invention can be achieved.

It is sectional drawing for showing the fundamental structure of the variable focus lens which concerns on 1st Embodiment of this invention. It is a disassembled perspective view of the variable focus lens shown in FIG. FIGS. 4A and 4B are explanatory diagrams for explaining the operation of the variable focus lens shown in FIG. It is explanatory drawing for demonstrating an example of the manufacturing method of the variable focus lens shown in FIG. It is explanatory drawing which shows the image (in the case of voltage 0V) obtained with the lens of the experiment example. It is explanatory drawing which shows the image (in the case of voltage 300V) obtained with the lens of the experiment example. It is sectional drawing for showing the fundamental structure of the variable focus lens which concerns on 2nd Embodiment. It is sectional drawing for showing the fundamental structure of the variable focus lens which concerns on 3rd Embodiment. It is sectional drawing for showing the fundamental structure of the variable focus lens which concerns on 4th Embodiment. It is sectional drawing for showing the fundamental structure of the variable focus lens which concerns on 5th Embodiment. It is explanatory drawing for demonstrating the zoom effect | action in the variable focus lens of FIG. FIG. 1A shows a state in which only the first thin film is driven. FIG. 2B shows a state where only the second thin film is driven. It is sectional drawing for showing the fundamental structure of the variable focus lens which concerns on 6th Embodiment. It is explanatory drawing for demonstrating the effect | action of the light control lens in the variable focus lens of FIG. FIG. 4A shows the operation when light is transmitted through the light control lens. FIG. 2B shows the operation when light is reflected by the light control lens.

Explanation of symbols

12 First medium 14 Second medium 16 Substrate 161 Opening 18 First thin film 18a Thin film 20 Second thin film 20a Thin film 22 First electrode 24 Second electrode 26 Spacer 28 First space 30 Second space 32 Power supply circuit 34/48 First 3 medium 36 3rd thin film 36a thin film 38 2nd spacer 40 * 52 3rd space 41 * 53 3rd electrode 42 * 54 4th electrode 43 5th electrode 44 6th electrode 45 * 55 2nd power supply circuit 46 3rd power supply circuit 50 Second substrate 56 First mirror 58 Second mirror

Claims (7)

A first medium, a second medium, a substrate, a first thin film, a second thin film, a first electrode, and a second electrode;
Both the first medium and the second medium have fluidity,
And the first medium and the second medium have different refractive indexes,
A first space is formed between the substrate and the first thin film,
A second space is formed between the first thin film and the second thin film,
The first space and the second space are in a superimposed state,
The first medium is filled in the first space;
The second medium is filled in the second space;
The first electrode is attached to the substrate;
The second electrode is attached to the first thin film;
A voltage can be applied between the first electrode and the second electrode,
The variable focus lens, wherein the first thin film has a flexibility capable of being deformed according to a voltage applied between the first electrode and the second electrode.   2. The variable focus lens according to claim 1, wherein the refractive index n <b> 1 of the first medium and the refractive index n <b> 2 of the second medium have a relationship of n <b> 1 <n <b> 2.   2. The variable focus lens according to claim 1, wherein the refractive index n <b> 1 of the first medium and the refractive index n <b> 2 of the second medium are in a relationship of n <b> 1> n <b> 2. A third medium and a third thin film;
A third space superimposed on the second space is formed between the third thin film and the second thin film,
The variable focus lens according to claim 1, wherein the third medium is filled in the third space. Furthermore, a third electrode, a fourth electrode, and a spacer are provided,
The spacer is disposed between the first thin film and the second thin film;
The third electrode is attached to the spacer;
The fourth electrode is attached to the second thin film;
A voltage can be applied between the third electrode and the fourth electrode,
The said 2nd thin film has the softness | flexibility which can deform | transform according to the voltage between the said 3rd electrode and the said 4th electrode. The any one of Claims 1-4 characterized by the above-mentioned. Variable focus lens. A second substrate and a third medium;
A third space superimposed on the second space is formed between the second thin film and the second substrate,
The variable focus lens according to claim 1, wherein the third medium is filled in the third space. An opening is formed in the substrate,
The first space is opened to an external space by the opening,
The variable focus lens according to claim 1, wherein the first medium is air.