WO2018081917A1

WO2018081917A1 - Gas lens

Info

Publication number: WO2018081917A1
Application number: PCT/CN2016/104201
Authority: WO
Inventors: 胡笑平
Original assignee: 博立多媒体控股有限公司; 胡笑平
Priority date: 2016-11-01
Filing date: 2016-11-01
Publication date: 2018-05-11

Abstract

A gas lens, comprising a sealable cavity (110) and light gas (120). The cavity (110) has transparent cavity walls (111, 112) for the incidence and exit of the light (LL), the cavity (110) is filled with the light gas (120) which has a density less than that of air under the same physical conditions. The gas lens uses the light gas (120) filled in the sealed cavity (110) as the lens body, being able to reduce the weight of the lens; moreover, the gas lens achieves the optical design on the basis of the shape of the cavity (110) and the properties of the light gas (120), and thus, benefiting from the flexibility of the gas form, has many advantages compared to the conventional solid lens, for example, the gas lens can achieve continuous variation of the refractive index.

Description

Gas lens technology field

[0001] The present invention relates to the field of optical components, and in particular to an optical lens internally filled with a gas.

BACKGROUND OF THE INVENTION

[0003] Optical lenses are typically made of a solid transparent material. Solid materials have a higher refractive index and are stronger, making it easy to achieve optical designs such as convergence or divergence. However, this also constitutes a limitation. The density of solid materials is generally large, which results in a low weight of the lens. Especially for large optical systems that need to be used in the air or in space, existing heavy solid lenses exist. insufficient. Therefore, optical lenses that are lighter and easier to adjust are worth studying.

[0004] In the PCT application entitled "Fresnel Lens System" previously published by the inventors of the present invention, published on June 2, 2016, International Publication No. WO/2016/082097, An optical lens partially filled with a liquid or gas, but mainly used to improve the optical performance of the tooth surface of the Fresnel lens, and the optical design using the filling portion is not considered.

[0005]

SUMMARY OF THE INVENTION

In accordance with the present invention, a gas lens is provided that includes a closable cavity and a light gas. The cavity has a transparent cavity wall into which light is incident and exiting, and a light gas is filled in the cavity. The so-called light gas has a density under the same physical conditions that is less than the density of the air. Density referred to herein refers to mass density, also known as specific gravity.

[0008] Preferably, the light gas has a refractive index greater than a refractive index of air under the same physical conditions.

Preferably, the lens according to the present invention may further comprise a pressure or temperature control unit for varying the pressure or temperature of the light gas within the chamber.

[0010] The gas lens according to the present invention creatively uses the light gas filled in the closed cavity as the lens body

The optical design can be realized based on the shape of the cavity and the nature of the gas, thanks to the flexibility of the gas form, so that the gas lens according to the present invention has the following significant advantages compared with the conventional solid lens.

[0011] 1. The weight of the lens can be greatly reduced, and the lens can even be suspended in the air. This is in the massive sun It is very advantageous for applications such as focusing, astronomical lenses, and giant ground photography lenses.

[0012] 2. It is possible to easily obtain an arbitrary refractive index within a certain range by mixing different kinds of gases, for example, a continuous change in refractive index can be achieved, which greatly expands the degree of freedom of optical design; A gas mixture having a density lower than that of air and a gas mixture having a refractive index of more than 1 can easily obtain an arbitrary refractive index in a range of more than 1 and less than 1.3, which is difficult to achieve with a solid lens.

[0013] 3. Due to the density of the gas, the temperature and pressure are closely related to each other, and the optical effect of the gas lens can be easily adjusted by changing the temperature and pressure of the light gas, so that a richer and more flexible means can be used to change the lens. The focal length.

[0014] Specific examples in accordance with the present invention will be described in detail below with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

1 is a schematic view of a gas lens of Embodiment 1;

2 is a schematic view of a gas lens of Embodiment 2;

3 is a schematic view of a gas lens of Embodiment 3;

4 is a schematic view of a gas lens of Embodiment 4.

DETAILED DESCRIPTION

Embodiment 1

[0022] One embodiment of a gas lens in accordance with the present invention can refer to FIG. 1, including a closed cavity 110 and a light gas 120.

[0023] The cavity 110 includes a first cavity wall 111 and a second cavity wall 112 that face each other.

[0024] In this embodiment, the cavity 110 is composed of a first cavity wall 111 and a second cavity wall 112. In other embodiments, the cavity may also be comprised of more cavity walls, which may include both cavity walls (e.g., transparent walls or reflective walls) for optical design, as well as non-optical cavity walls that do not participate in optical design. For example, in a conventional lens, if there is a good seal between two adjacent lenses, the two lenses and a barrel between them form a cavity, wherein the two lenses respectively serve as the first cavity wall And the second cavity wall, the lens barrel can be regarded as a non-optical cavity wall. In other embodiments, the tightness of the cavity may also be controllable, for example, the cavity may be smashed or closed by a valve in communication with the cavity.

[0025] In this embodiment, the first cavity wall and the second cavity wall are both transparent cavity walls. For ease of description, the walls of the chamber are ordered in the order of contact with the external ray LL, the light being incident from the first chamber wall and emerging from the second chamber wall. In particular, when a mirror face is provided on the cavity wall or in the optical system, some of the cavity walls may be exposed to light multiple times, and the cavity walls may be ordered in the order in which the light first contacts the cavity wall. In other embodiments, the cavity may also have an opaque cavity wall, such as a portion of the cavity wall being a non-optical cavity wall, or at least a portion of at least one of the first cavity wall and the second cavity wall, depending on the needs of the actual application. The mirror surface is provided as long as the cavity has a transparent cavity wall for the light to enter and exit.

The shape of the first cavity wall and the second cavity wall may be designed as needed, for example, may be selected from one of the following: a concave shape having a non-uniform thickness (which may form the cavity wall as a concave lens), and an uneven thickness Convex shape (which allows the cavity wall to be formed as a convex lens), a flat shape with a uniform thickness, a curved surface with a uniform thickness, a Fresnel lens, and the like. A detailed description of the Fresnel lens can be found in the PCT application of the International Publication No. WO/2016/082097, which is not described here. The first cavity wall and the second cavity wall may be made of any kind of transparent material, for example, a rigid material of a fixed shape or an elastic material whose shape may vary with an external force. Preferably, the cavity wall may be made of a material having a high reflectance in one direction and a high transmittance in the other direction, so that the lens has better optical performance. In other embodiments, the first and second chamber walls may also utilize partially transparent, partially reflective material, or a mirrored surface may be provided at portions of the chamber wall.

[0027] The light gas 120 is filled in the cavity 110 and formed as a main body of the lens. The term "light gas" refers to a gas whose density is less than the density of air under the same physical conditions, which makes it possible to reduce the weight of the lens according to the present invention and even to be suspended in the air. This is very advantageous in some large size applications. Gases that are lighter than air include hydrogen, helium, methane or mixtures of them with other gases. The same physical conditions are referred to as the same temperature and pressure.

[0028] Preferably, the light gas can adopt a gas whose refractive index is greater than the refractive index of air under the same physical condition, so that the light gas itself is also used to realize the optical effect of the lens, for example, to achieve concentrating, astigmatism, or change. Focus and other effects.

[0029] There are many gases having a refractive index greater than the refractive index of air, such as acetone, alcohol, methane, and the like. The gas for filling may be selected from one of these substances or a mixed gas containing at least one of these substances. By selecting the kind of gas and changing the mixing ratio, an arbitrary refractive index between 1 and 1.30 can be easily obtained, thereby realizing a low refractive index lens in which solid materials are difficult to manufacture, and continuous adjustment of the refractive index can be realized, which greatly expands the lens. The degree of freedom in design.

[0030] As a preferred embodiment, the lens according to the present invention may further include pressure or temperature control Unit. Based on these control elements, the gas lens of the present invention can be designed to have a function of autofocus or zoom. For example, the gas lens of the present embodiment preferably further includes a pressure control unit 130.

[0031] The pressure control unit can act on the chamber wall or light gas to change the pressure of the gas in the chamber (for example, to make the pressure of the gas in the chamber different from the air outside the lens), thereby changing the focal length or other optical characteristics of the lens. For example, the pressure control unit may change the curvature of the cavity wall made of the elastic material or the distance between the cavity walls by applying an external force, and the external force may be selected from the group consisting of: electric field force, magnetic field force, deformation force, pressure, tensile force, surface tension. Wait. For another example, the pressure control unit can charge or withdraw gas through a valve communicating with the cavity, and if the cavity wall is made of an elastic material, this will correspondingly change the curvature of the cavity wall or the distance between the cavity walls.

[0032] The pressure control unit 130 of the present embodiment includes an adjustable voltage source 133 that is coupled to the first chamber wall by a mating circuit 134. Accordingly, the first cavity wall 111 can be made of a piezoelectric material such as transparent PVC. The second cavity wall 112 is made of a resilient or rigid transparent material. An adjustable voltage source is used to control the voltage applied to the piezoelectric material formed as the first cavity wall, and the curvature of the first cavity wall is controlled by the inverse piezoelectric effect. By changing the curvature of the first chamber wall, the focal length of the gas lens can be adjusted or changed to achieve automatic focusing or zooming of the gas lens.

[0033] In other embodiments, a temperature control unit may alternatively or be used, for example, the matching circuit in this embodiment is designed as a heating or cooling circuit, and the corresponding cavity wall has a temperature change according to a change of the control voltage. Ability, or good thermal conductivity.

[0034] The temperature control unit can also act on the chamber wall or light gas to change the temperature of the gas in the chamber (for example, to make the temperature of the gas in the chamber different from the air outside the lens). For example, the temperature control unit can heat or cool the chamber wall. For some substances that are not gaseous at normal temperatures, the temperature control unit can be used to keep the light gas formed by these materials in a gaseous state. The temperature change of the gas in the cavity can also change the curvature of the cavity wall made of elastic material or the distance between the cavity walls, and when the temperature of the gas in the cavity is higher than the air enthalpy outside the lens, it can also bring extra to the lens. The lift.

[0035] The gas lens according to the present invention can have various preferred features as described above or alternatively, and thus has a rich function. It is worth mentioning that, as can be seen from the above description, the refractive index, density, pressure, and temperature of the light gas in the cavity are easily adjusted, and can be adjusted even after the gas lens is manufactured, so the lens according to the present invention can be Has good adaptability and parameter correction ability.

Embodiment 2 [0037] Another embodiment of the gas lens according to the present invention can be referred to FIG. 2, including a closed cavity 210, a light gas 220, and a pressure control unit 230.

[0038] The cavity 210 is composed of a first cavity wall 211 and a second cavity wall 212. The light gas 220 may be any gas having a density lower than that of air, such as hydrogen, helium or other inert gas. In the present embodiment, a gas having a refractive index greater than that of air such as methane is preferably used.

[0039] The first chamber wall 211 is made of a transparent elastic material, and the second chamber wall 212 is made of an elastic material having a mirror surface.

(or a rigid material) is formed, and the mirror surface faces the first cavity wall, so that the lens of this embodiment is formed as a reflection type lens. After the light LL is incident from the first cavity wall, it is reflected by the second cavity wall and then emitted by the first cavity wall. Due to the effect of the cavity wall and the light gas, the light is concentrated near the optical axis at the exit pupil. Due to its light weight, the lens of this embodiment can be used, for example, to make a reflective panoramic lens for a large aerial camera.

[0040] The pressure control unit 230 includes a magnetic element 231 and a coil 232. The magnetic element is fixed around the first cavity wall or the second cavity wall, and the coil is disposed below the cavity (may also be placed above or around). When the coil is energized, the electromagnetic field it generates interacts with the magnetic element, thereby changing the curvature of at least a portion of the cavity wall of the cavity or the distance between the walls of the cavity. For example, coil 232 energizes to create a suction force on magnetic element 231, thereby squeezing the cavity and at least changing the curvature of first cavity wall 211.

[0041] In this embodiment, an applied electromagnetic force is used to change the curvature of the cavity wall, and based on this control capability, autofocus or zoom of the gas lens can be achieved. In other embodiments, the curvature of the walls of the chamber or the distance between the walls of the chamber can also be varied by the tension or pressure created by the deformation of other materials. For example, a variable length element that surrounds the periphery of the cavity, such as a memory metal, MEMS, electric ferrule, etc., may be provided, and the focal length of the gas lens is changed by applying pressure or tension to the cavity by changing the length of the element.

The gas lens according to the present invention can be used in conjunction with a conventional lens, such as the solid lens 291 shown in this embodiment, to better achieve the desired optical design. The conventional lens used can be selected from a fixed focus lens, a focusable lens (autofocus lens), or a zoom lens.

Embodiment 3

Another embodiment of the gas lens according to the present invention can be referred to FIG. 3, including a closed cavity 310, a light gas 320, and a temperature control unit 340.

[0045] The cavity 310 is composed of a first cavity wall 311 and a second cavity wall 312. The gas 320 can be any gas having a density lower than that of air. In the present embodiment, a gas having a refractive index greater than that of air is preferably used. [0046] The central region of the first cavity wall 311 around the optical axis is disposed as a mirror surface 31 Γ, and other regions are transparent. The second cavity wall 312 is transparent about a central region of the optical axis, and other regions are disposed as mirror faces 312'. Thus, the lens of this embodiment is formed as a double reflection panoramic lens. After the light LL is incident from the transparent region of the first cavity wall, it is reflected by the second cavity wall. Due to the action of the cavity wall and the light gas, the light is concentrated near the optical axis and then reflected by the central region of the first cavity wall. Finally, it is ejected from the central area of the second cavity wall.

[0047] The temperature control unit 340 includes a controllable power source 341 and a circuit 342 that changes the temperature of the light gas 320 by heating the chamber wall (e.g., the second chamber wall shown in FIG. 3). A change in gas temperature changes the pressure in the chamber, thereby changing the optical parameters of the gas lens, such as the focal length or field of view. In some embodiments, if the cavity wall is made of an elastic material and the temperature change of the gas in the cavity causes a change in the curvature of the cavity wall, it is necessary to consider the optical design based on temperature control.

Example 4

Another embodiment of the gas lens according to the present invention can be referred to FIG. 4, including a closed cavity 410, a light gas 420, a pressure control unit 430, and a built-in lens 450.

[0050] In the above embodiments, the gas lens is used either as a separate lens or in cascade with other lenses. This embodiment shows a case where a gas lens is nested with a built-in lens.

[0051] The cavity 410 is composed of a first cavity wall 411, a second cavity wall 412, and a third cavity wall 413 as a side wall.

The first cavity wall and the second cavity wall are optical lenses made of a rigid transparent material, and the third cavity wall 413 is made of an elastic material, which can be elongated or shortened as the pressure inside the cavity changes.

[0052] The built-in lens 450 in this embodiment is also a gas lens including a closed cavity 410', a light gas 420' and a pressure control unit 430'. The cavity 410' is composed of optical lenses 411' and 412 and side walls 413', and is made of a rigid material. In other embodiments, a plurality of built-in lenses may be provided, or other types of lenses such as solid lenses may be selected.

[0053] The pressure control unit 430 includes a gas delivery device 435, for example, a two-way air compressor may be employed. One end of the gas delivery device is connected to the cavity 410 through a valve 436, and the other end is in communication with the external gas storage tank 434. By extracting gas from the cavity 410 or filling the cavity with gas, the pressure and/or light in the cavity is changed. The type of gas (for example, changing the type of light gas or the mixing ratio). The pressure control unit 430' is similar to the pressure control unit 430 and includes a gas delivery device 435', a valve 436' and a gas storage tank 434', and will not be described again.

[0054] The chambers of the two gas lenses of the embodiment are connected to the external gas storage tank through respective pressure control units. The working pressure: the pressure control unit 430 can adjust the pressure of the gas 420 to make the elastic cavity wall 413 expand and contract, thereby changing the distance between the lenses 411 and 412 serving as the cavity wall, thereby changing the focal length; the pressure control unit 430' is adjusted The pressure of the gas 420' changes the refractive index of the gas 420' (the 410' cavity shape remains unchanged), thereby further adjusting the focal length.

[0055] This embodiment provides another method of implementing a zoom function using a gas lens. On the one hand, a gas lens can be nested with other types of lenses or another gas lens; on the other hand, for gas lenses, in addition to changing the lens focal length by changing the curvature of the cavity wall or the refractive index of the gas, The focal length can be changed by changing the distance between the walls of the cavity on the optical axis.

[0056] The cavity of the two gas lenses in this embodiment is filled with light gas, or the cavity 410' may preferably be filled with a gas having a refractive index greater than that of air. In other embodiments, the gas in any one of the gas lenses can also be selected as air, thereby eliminating a gas storage tank.

[0057]

The present invention has been described with reference to the specific embodiments of the present invention. It is understood that the above embodiments are only used to help the understanding of the present invention and are not to be construed as limiting the invention. Variations to the above-described embodiments may be made by those skilled in the art in light of the teachings herein. technical problem

Problem solution

Advantageous effects of the invention

Claims

Claim

[Claim 1] A gas lens, comprising:

A closable cavity having a transparent cavity wall for the incidence and exit of light, and a light gas filled in the cavity, the light gas having a density under the same physical conditions that is less than the density of the air.

[Claim 2] The lens according to claim 1, wherein

The light gas has a refractive index greater than the refractive index of air under the same physical conditions.

[Claim 3] The lens according to claim 1, wherein

The light gas is selected from one of the following substances, or a mixed gas containing at least one of the following: hydrogen, helium, nitrogen, methane.

[Claim 4] The lens according to any one of claims 1 to 3, further comprising one or more of the following features:

a pressure control unit for changing a pressure of the light gas in the cavity;

a temperature control unit for changing the temperature of the light gas in the chamber.

[Claim 5] The lens according to any one of claims 1 to 4, wherein the cavity includes a first cavity wall and a second cavity wall facing each other, at least part of at least one of which is The shape of the first cavity wall or the second cavity wall is selected from one of the following: concave shape with uneven thickness, convex shape with uneven thickness, flat shape with uniform thickness, curved surface with uniform thickness, Fresnel lens

[Claim 6] The lens according to claim 5, wherein

At least a portion of at least one of the first chamber wall and the second chamber wall is a mirror surface, or at least one of the first chamber wall and the second chamber wall is made of a partially transparent, partially reflective material, or

At least one of the first chamber wall and the second chamber wall is made of a material having a high reflectance in one direction and a high transmittance in the other direction.

[Claim 7] The lens according to claim 6, wherein

The central area of the first cavity wall around the optical axis is arranged as a mirror surface, the other areas are transparent, the second cavity wall is transparent around the central area of the optical axis, and the other areas are arranged as mirror surfaces. The lens according to claim 4, wherein

At least part of the cavity wall of the cavity is made of an elastic material.

The pressure control unit is for changing the curvature of the cavity wall made of the elastic material or the distance between the cavity walls by applying an external force, or for filling or withdrawing the light gas. The lens according to claim 8, wherein

The pressure control unit includes a variable length element surrounding an outer circumference of the cavity, or the pressure control unit includes a magnetic element and a coil, the magnetic element being fixed to at least a portion of the cavity wall of the cavity, The coil is disposed above or below or around the cavity. When the coil is energized, the electromagnetic field generated by the coil interacts with the magnetic element to change the curvature or cavity wall of at least part of the cavity wall of the cavity. the distance between.

The lens according to claim 8, wherein

At least part of the cavity wall of the cavity is made of a piezoelectric material.

The pressure control unit includes an adjustable voltage source for controlling a voltage applied to the piezoelectric material to control a curvature of a chamber wall made of a piezoelectric material or a distance between chamber walls. The lens described, characterized in that

The pressure control unit includes a gas delivery device that connects the cavity to an external gas canister

The type of pressure and/or light gas in the chamber is varied by withdrawing gas from the chamber or by charging a gas into the chamber.

A lens according to any one of claims 1 to 11, wherein

Also included is at least one built-in lens nested within the cavity, the built-in lens being selected from a solid lens and a gas lens.