CN101349810B - Optical axis positioning device for liquid lens - Google Patents

Abstract

The invention discloses an optical axis positioning device for a liquid lens. The optical axis positioning device comprises a transparent substrate, a symmetrical electrode structure and a transparent insulating layer. The electrode structure is capable of supplying an electric field and defines an electrode center axis. The insulating layer itself provides an optical axis positioning structure that is circumferentially symmetric to the electrode center axis. In particular, an optical axis of the liquid lens is substantially coaxial with the electrode central axis in the absence of the electric field provided by the electrode structure.

Description

Optical axis positioning device for liquid lens

technical field

The present invention relates to an optical axis orientating device, in particular to an optical axis orientating device for a liquid lens.

Background technique

Generally speaking, a liquid lens refers to a lens whose focal length can be adjusted. In the optical system, zoom lenses are roughly divided into two types: mechanical zoom and electronic zoom. The mechanical zoom lens uses the change of the front and rear expansion and contraction of the lens itself to achieve the purpose of zooming. Because the lens of mechanical zoom is too thick and bulky for increasingly thinner and smaller digital cameras or mobile phones with camera functions, many thin and light cameras use electronic zoom lenses.

In the prior art, the electronic zoom technology can use the droplet as a lens, and use mechanisms such as electro-wetting to control the shape and curvature of the droplet, thereby changing the focal length of the droplet. However, if the position of the liquid bead is not fixed, the optical axis of the liquid bead may shift left and right, causing the lens to fail to focus accurately.

One of the existing methods for fixing the liquid beads, as shown in FIG. 1 , is to place the liquid beads 12 in the depression of the bell-shaped three-dimensional structure 14 so that the liquid beads 12 cannot roll. Another method for fixing the liquid beads, as shown in FIG. 2 , is to place the liquid beads 22 in a fluid chamber (fluid chamber) 20 , and then insert another liquid 24 for assisting in fixing the liquid beads 22 . Since the two liquids will not mix with each other, the surface tension balance will reach the arc junction as shown in Figure 2.

The disadvantages of the above-mentioned prior art are that the manufacturing method of the hardware is too complicated and the manufacturing cost is too expensive.

Contents of the invention

The object of the present invention is to provide an optical axis positioning device for a liquid lens to solve the above problems. The liquid lens includes a sealing liquid and a lens liquid. In a preferred embodiment of the present invention, the optical axis positioning device includes a transparent substrate, a symmetrical electrode structure and a transparent insulating layer.

The transparent substrate has an upper surface. The electrode structure is formed on the upper surface of the substrate. The electrode structure is capable of supplying an electric field and itself defines an electrode central axis. The insulating layer is formed on the upper surface of the substrate and covers the electrode structure. Further, the insulating layer itself provides an optical axis positioning structure, and the optical axis positioning structure is circumferentially symmetrical to the central axis of the electrode. Wherein, the lens liquid is placed on the optical axis positioning structure. In addition, the encapsulation fluid fills the liquid lens and coats the lens fluid. Thereby, when the electrode structure does not provide the electric field, an optical axis of the liquid lens is substantially coaxial with the central axis of the electrode.

Another preferred embodiment of the present invention is a liquid lens. The liquid lens includes a chamber, a symmetrical electrode structure, a transparent insulating layer, a lens liquid, and an encapsulation liquid. The cabin includes a transparent base material with an upper surface, and the base material is located in the cabin. The electrode structure is formed on the upper surface of the substrate. The electrode structure is capable of supplying an electric field and itself defines an electrode central axis. The insulating layer is formed on the upper surface of the substrate and covers the electrode structure. Further, the insulating layer itself provides an optical axis positioning structure, and the optical axis positioning structure is circumferentially symmetrical to the central axis of the electrode. The lens liquid is arranged on the optical axis positioning structure. The encapsulating liquid fills the capsule and covers the lens liquid. Thereby, when the electrode structure does not provide the electric field, an optical axis of the liquid lens is substantially coaxial with the central axis of the electrode. In addition, through the electric field provided by the electrode structure, a curvature of the lens fluid can be adjusted.

Compared with the prior art, the optical axis positioning device used in a liquid lens of the present invention can effectively position the optical axis. Since the structure and implementation of the optical axis positioning device and the liquid lens of the present invention are simpler than those of the prior art, the cost of manufacturing hardware can be saved. In addition, from a technical point of view, the optical axis positioning device of the present invention can also be applied to other liquid lenses with different operating principles.

Description of drawings

In order to make the above-mentioned and other purposes, features and advantages of the present invention more obvious and understandable, preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings:

Fig. 1 and Fig. 2 are respectively the method for fixing liquid beads in the prior art;

Fig. 3 is a schematic diagram of a liquid lens in a preferred embodiment of the present invention, and the optical axis positioning structure in the figure is a platform;

4A to 4D are top views of possible optical axis positioning structures;

5 is a schematic diagram of a liquid lens according to another preferred embodiment of the present invention, and the optical axis positioning structure in the figure is a concave region; and

FIG. 6 is a graph obtained by performing an optical axis deviation angle test on a liquid lens and a liquid lens without an optical axis positioning structure according to a preferred embodiment of the present invention.

Detailed ways

Please refer to FIG. 3 . FIG. 3 is a schematic diagram of an optical axis positioning device 302 used in a liquid lens 300 according to a preferred embodiment of the present invention. The liquid lens 300 includes an encapsulation liquid 308 and a lens liquid 306 .

In one embodiment, the encapsulation liquid 308 and the lens liquid 306 can be immiscible and non-conductive, and a density of the lens liquid 306 is substantially equal to a density of the encapsulation liquid 308 to avoid □The impact of heavy □ between the liquid, and successfully achieve the shape of the liquid lens.

The encapsulation fluid 308 can be a first dielectric fluid, and the lens fluid 306 can be a second dielectric fluid. For example, the first dielectric liquid can be an optical oil, and the second dielectric liquid can be a mixture of polyhydric alcohols. Because the refractive index of the encapsulating liquid 308 (ie, optical oil) is relatively large, the combined liquid lens 300 can be used as a concave lens. Alternatively, the first dielectric liquid can be a mixture of polyols, and the second dielectric liquid can be the optical oil. Since the refractive index of the encapsulating liquid 308 (ie, a mixture of several polyols) is small, the combined liquid lens 300 can act as a convex lens.

In another embodiment, one of the encapsulating liquid 308 and the lens liquid 306 may have conductivity. Likewise, the encapsulation liquid 308 and the lens liquid 306 are immiscible, and a density of the lens liquid 306 is approximately equal to a density of the encapsulation liquid 308 .

As shown in FIG. 3 , the optical axis positioning device 302 includes a transparent substrate 3020 , a symmetrical electrode structure 3022 and a transparent insulating layer 3024 . The transparent substrate 3020 has an upper surface. The electrode structure 3022 is formed on the upper surface of the substrate 3020 . The electrode structure 3022 can supply an electric field and itself defines an electrode central axis 302A, and the transparent insulating layer 3024 also takes the electrode central axis 302A as its central axis.

In one embodiment, the electrode structure 3022 may form several concentric circles.

The insulating layer 3024 is formed on the upper surface of the substrate 3020 and covers the electrode structure 3022 . Further, the insulating layer 3024 itself provides an optical axis positioning structure, and the optical axis positioning structure is circumferentially symmetrical to the electrode central axis 302A. In practical applications, the optical axis positioning structure may be a platform or a recessed area, and the morphology of the optical axis positioning structure may be a circle or an ellipse.

4A to 4D are top views of possible optical axis positioning structures. As shown in Figure 4A and Figure 4B, the shape of the platform 40 can be a circle or an ellipse; The shape can also be a circle or an ellipse.

The lens fluid 306 is placed on the optical axis positioning structure. In addition, the encapsulation liquid 308 fills the liquid lens 300 and covers the lens liquid 306 . Thus, when the electrode structure 3022 does not provide the electric field, an optical axis (not shown) of the liquid lens 300 is substantially coaxial with the electrode central axis 302A. In other words, the insulating layer 3024 has a specific pattern (ie optical axis positioning structure), so that an offset angle or a displacement between the optical axis of the liquid lens 300 and the electrode central axis 302A can be ignored.

Please refer to FIG. 3 again. FIG. 3 is a schematic diagram of a liquid lens according to another preferred embodiment of the present invention. The liquid lens 300 includes a transparent substrate 3020 , a symmetrical electrode structure 3022 , a transparent insulating layer 3024 , a capsule 304 , a lens liquid 306 , and an encapsulation liquid 308 . The capsule body 304 includes a transparent substrate 3020 with an upper surface, and the substrate 3020 is located in the capsule body 304 .

In one embodiment, the encapsulation liquid 308 and the lens liquid 306 can be immiscible and non-conductive, and a density of the lens liquid 306 is substantially equal to a density of the encapsulation liquid 308 to avoid □The impact of heavy □ between the liquid, and successfully achieve the shape of the liquid lens.

The encapsulation fluid 308 can be a first dielectric fluid, and the lens fluid 306 can be a second dielectric fluid. For example, the first dielectric liquid can be an optical oil, and the second dielectric liquid can be a mixture of polyhydric alcohols. Because the refractive index of the encapsulating liquid 308 (ie, optical oil) is relatively large, the combined liquid lens 300 can be used as a concave lens. Alternatively, the first dielectric liquid can be a mixture of polyols, and the second dielectric liquid can be the optical oil. Since the refractive index of the encapsulating liquid 308 (ie, a mixture of several polyols) is small, the combined liquid lens 300 can act as a convex lens.

In another embodiment, one of the encapsulating liquid 308 and the lens liquid 306 may have conductivity. Likewise, the encapsulation liquid 308 and the lens liquid 306 are immiscible, and a density of the lens liquid 306 is approximately equal to a density of the encapsulation liquid 308 .

The electrode structure 3022 is formed on the upper surface of the substrate 3020 . The electrode structure 3022 can supply an electric field and itself defines an electrode central axis 302A, and the transparent insulating layer 3024 also takes the electrode central axis 302A as its central axis.

In one embodiment, the electrode structure 3022 may form several concentric circles.

The insulating layer 3024 is formed on the upper surface of the substrate 3020 and covers the electrode structure 3022 . Further, the insulating layer 3024 itself provides an optical axis positioning structure, and the optical axis positioning structure is circumferentially symmetrical to the electrode central axis 302A. In practical applications, the optical axis positioning structure can be a platform or a recessed area and the shape of the optical axis positioning structure can be a circle or an ellipse.

4A to 4D are top views of possible optical axis positioning structures. As shown in Figure 4A and Figure 4B, the shape of the platform 40 can be a circle or an ellipse; The shape can also be a circle or an ellipse.

The lens fluid 306 is placed on the optical axis positioning structure. The encapsulation fluid 308 fills the capsule 304 and covers the lens fluid 306 . Thereby, when the electrode structure 3022 does not provide the electric field, an optical axis of the liquid lens 300 is substantially coaxial with the electrode central axis 302A. Moreover, through the electric field provided by the electrode structure 3022, a curvature of the lens liquid 306 can be adjusted. In other words, a contact angle of the lens liquid 306 is adjustable to achieve the effect of changing the focal length of the liquid lens 300 .

FIG. 5 is a schematic diagram of a liquid lens according to another preferred embodiment of the present invention, which is substantially the same as FIG. 3 , so it will not be repeated here, except that the shape of the optical axis positioning structure here presents a concave region.

Please refer to FIG. 6 . FIG. 6 is a graph obtained by testing an optical axis deviation angle of a liquid lens according to a preferred embodiment of the present invention and a liquid lens without an optical axis positioning structure. The horizontal axis in the figure represents the external voltage applied to the electrode structure, so that the electrode structure can supply an electric field; the vertical axis represents the deviation angle of the optical axis of the liquid lens. The curve of rhombus mark represents the liquid lens without optical axis positioning structure, while the curve of triangular mark and circular mark represents the optical axis positioning structure with a circular platform and the optical axis positioning with a circular concave area of the present invention respectively. Structured liquid lenses. As shown in FIG. 6, within the range of supplied voltage, the liquid lens of the present invention has a small optical axis deviation angle. In particular, in the case where the electrode structure does not provide the electric field, an offset angle or a displacement between an optical axis of the liquid lens of the present invention and the central axis of the electrode can be ignored. In other words, the optical axis of the liquid lens is substantially coaxial with the central axis of the electrode.

Compared with the prior art, the optical axis positioning device used in a liquid lens of the present invention can effectively position the optical axis. Since the structure and implementation of the optical axis positioning device and the liquid lens of the present invention are simpler than those of the prior art, the cost of manufacturing hardware can be saved. In addition, from a technical point of view, the non-optical axis positioning device of the present invention can also be applied to other liquid lenses with different operating principles, such as liquid lenses using electrowetting effect.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the described embodiments, and those skilled in the art can also make various equivalent modifications or replacements without departing from the spirit of the present invention. , these equivalent modifications or replacements are all included within the scope defined by the claims of the present application.

Claims (16)

1. An optical axis positioning device applied to a liquid lens, characterized in that: the liquid lens comprises a packaging liquid and a lens liquid, and the optical axis positioning device comprises: A transparent substrate, the substrate has an upper surface; a symmetrical electrode structure formed on said upper surface of said substrate, said electrode structure capable of supplying an electric field and itself defining an electrode central axis; and a transparent insulating layer formed on the upper surface of the substrate and covering the electrode structure, the insulating layer itself provides an optical axis positioning structure surrounding the Symmetrical to the central axis of the electrode, the lens liquid is placed on the optical axis positioning structure, the encapsulating liquid fills the liquid lens and covers the lens liquid, wherein the optical axis positioning structure is a convex There is a platform or a concave area, the platform or the concave area has an edge, and the edge surrounds a containing range, the lens liquid is contained in the containing range, and the optical axis positioning structure covers the part of the substrate an upper surface, the edge distinguishes the upper surface covered by the optical axis positioning structure and the upper surface not covered by the optical axis positioning structure; Thereby, when the electrode structure does not provide the electric field, an optical axis of the liquid lens is substantially coaxial with the central axis of the electrode. 2. The optical axis positioning device according to claim 1, wherein the shape of the optical axis positioning structure is a circle or an ellipse. 3. The optical axis positioning device according to claim 1, characterized in that: the electrode structure forms a form of several concentric circles. 4. The optical axis positioning device according to claim 1, characterized in that: the encapsulation liquid and the lens liquid are immiscible and non-conductive, and a density of the lens liquid is equal to a density of the encapsulation liquid Roughly equal. 5. The optical axis positioning device as claimed in claim 4, wherein the encapsulation liquid is a first dielectric liquid, and the lens liquid is a second dielectric liquid. 6. The optical axis positioning device as claimed in claim 5, wherein the first dielectric liquid is an optical oil, and the second dielectric liquid is a mixture of several polyols. 7. The optical axis positioning device as claimed in claim 5, wherein the first dielectric liquid is a mixture of several polyols, and the second dielectric liquid is an optical oil. 8. The optical axis positioning device according to claim 1, characterized in that: the encapsulation liquid and the lens liquid are immiscible, and a density of the lens liquid is approximately equal to a density of the encapsulation liquid, so One of the encapsulation liquid and the lens liquid has conductivity. 9. A liquid lens, characterized in that it comprises: a capsule, the capsule comprising a transparent substrate having an upper surface, the substrate positioned within the capsule; a symmetrical electrode structure formed on said upper surface of said substrate, said electrode structure capable of supplying an electric field and itself defining a central axis; a transparent insulating layer formed on the upper surface of the substrate and covering the electrode structure, the insulating layer itself provides an optical axis positioning structure surrounding the symmetrical about said central axis; a lens liquid, the lens liquid is placed on the optical axis positioning structure; and an encapsulation liquid, the encapsulation liquid fills the cabin and covers the lens liquid; Thereby, in the case where the electric field is not provided by the electrode structure, an optical axis of the liquid lens is substantially coaxial with the central axis of the electrode, and through the electric field provided by the electrode structure, the A curvature of the lens fluid can be adjusted, Wherein, the optical axis positioning structure is a raised platform or a depressed area, and the platform or the depressed area has an edge, and the edge surrounds a containing range, the lens liquid is contained in the containing range, and the The optical axis positioning structure covers part of the upper surface of the substrate, and the edge distinguishes the upper surface covered by the optical axis positioning structure and the upper surface not covered by the optical axis positioning structure. 10. The liquid lens according to claim 9, wherein the shape of the optical axis positioning structure is a circle or an ellipse. 11. The liquid lens as claimed in claim 9, wherein the electrode structure forms a form of several concentric circles. 12. The liquid lens according to claim 9, wherein the encapsulation liquid and the lens liquid are immiscible and non-conductive, and a density of the lens liquid is approximately equal to a density of the encapsulation liquid . 13. The liquid lens of claim 12, wherein the encapsulating liquid is a first dielectric liquid, and the lens liquid is a second dielectric liquid. 14. The liquid lens of claim 13, wherein the first dielectric liquid is an optical oil, and the second dielectric liquid is a mixture of polyols. 15. The liquid lens of claim 13, wherein the first dielectric liquid is a mixture of polyols, and the second dielectric liquid is an optical oil. 16. The liquid lens according to claim 9, characterized in that: the encapsulation liquid and the lens liquid are immiscible, and a density of the lens liquid is approximately equal to a density of the encapsulation liquid, and the encapsulation liquid One of the liquid and the lens liquid is conductive.

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