JP4674861B2 - Fluid prism - Google Patents

Description

  The present invention relates to a fluid prism in which a fluid capable of transmitting light is disposed between a pair of facing transparent plates, and more particularly to a fluid prism in which the angle formed by both transparent plates is variable.

  As a prism used in an optical apparatus such as a camera, a liquid prism is known in which a transparent liquid is disposed between a pair of facing transparent plates, and an angle formed by both transparent plates is variable (for example, And Patent Document 1).

  In this liquid prism, a pair of transparent plates are sealed with a bellows-like transparent film at the outer periphery, and a sealed space formed by both the transparent plates and the transparent film is filled with a transparent liquid having a high refractive index. The two transparent plates are fixed to the first and second holding frames, respectively. The first holding frame can be rotated around the first support shaft by the first electromagnetic motor, and the second holding frame is the second holding frame. Two electromagnetic motors are rotatable around a second support shaft that is orthogonal to the first support shaft.

Thus, in this liquid prism, the first holding frame rotates around the first support shaft by driving the first electromagnetic motor, so that one of the transparent plates tilts together with the first holding frame, for example, in the vertical direction, or When the second holding frame is rotated around the second support shaft by driving the two electromagnetic motors, the other transparent plate is inclined together with the second holding frame, for example, in the left-right direction. As a result, the angle formed by both transparent plates changes, and the refraction angle of the light beam transmitted through the liquid prism changes.
JP-A-6-337454 (page 2-3)

  By the way, in recent years, in-vehicle cameras or the like are sometimes equipped with in-vehicle cameras for the purpose of grasping road conditions, external environments, other vehicles, and the like. In addition, cameras are often mounted on mobile devices such as mobile phones. In these automobiles and portable devices, since various devices other than cameras are incorporated, it is desirable that the size of the devices to be incorporated including optical devices such as cameras is as small as possible.

  However, in the conventional liquid prism, an electromagnetic motor for generating an electromagnetic driving force for applying a rotational torque to the holding frame that holds the transparent plate is provided as a completely separate body from the transparent plate and the holding frame. For this reason, the whole physique of a liquid prism will become large, and further size reduction is desired. Also, if the electromagnetic motor and the holding frame are completely separate, the efficiency may be reduced or the responsiveness may be reduced when the electromagnetic force generated by the electromagnetic motor is converted into rotational torque for rotating the holding frame. There is a problem of doing.

  The present invention has been made in view of the above circumstances, and it is a technical problem to be solved to provide a fluid prism that is small in size and has high efficiency and responsiveness when changing the angle.

A fluid prism according to the present invention that solves the above-described problems is a light-transmitting light disposed between a pair of transparent plates that are arranged to face each other and one of which is swingable, and between the transparent plates. A fluid prism having a fluid capable of being swung and a variable mechanism for swinging the swingable transparent plate to change an angle formed by the two transparent plates, the other of the pair of transparent plates being the transparent The transparent plate comprising a container having a bottom part constituted by a plate and a cylindrical part formed integrally with the bottom part, wherein the fluid is accommodated in the container and swingable on the surface of the fluid Is disposed in the container and is disposed on the surface of the fluid on the side opposite to the fluid of the swingable transparent plate and refracted with the fluid. different rates and comprises a permeable second fluid light, the variable mechanism is swung Allowed A first electrode integrally provided on the transparent plate, at least one second electrode provided in proximity to the first electrode and paired with the first electrode, the first electrode and the first electrode Voltage applying means for applying a voltage between the two electrodes, and the electrostatic force generated by applying a voltage between the first electrode and the second electrode swings the transparent plate that can swing. The rotation torque is applied to the transparent plate.

  Here, the transparent plate has a light transmission part capable of transmitting light at least in part.

  The fluid has a refractive index different from that of the external atmosphere of the transparent plates.

  In this fluid prism, an electrostatic force is generated by applying a voltage from the voltage applying means between the first electrode and the second electrode paired with the first electrode, and the transparent plate on which the electrostatic force can swing is swung. It is given to the transparent plate as a rotational torque for the purpose. For this reason, the swingable transparent plate swings, and the angle formed by both transparent plates changes. At this time, the fluid disposed between the transparent plates also follows the swinging of the transparent plates. For this reason, the angle formed by the two transparent plates can be arbitrarily changed by controlling the magnitude of the applied voltage from the voltage applying means. Therefore, the refraction angle of the light beam passing through the fluid having a refractive index different from that of the external atmosphere can be changed according to the change of the angle formed by both transparent plates, and a prism having an arbitrary angle can be obtained. Further, if the number of second electrodes paired with the first electrode is increased or the arrangement of the first electrode and the second electrode is changed, the direction of the electrostatic force can be changed. The direction in which the light flux passing through the fluid prism is refracted can be changed by changing the swinging direction.

  In this fluid prism, the first electrode constituting the electrostatic actuator together with the second electrode paired with the first electrode is integrally provided on the oscillating transparent plate itself. That is, some of the components of the variable mechanism are integrally provided on the swinging transparent plate. For this reason, the physique of a fluid prism can be made small compared with the case where all the components of a variable mechanism are provided separately from a transparent plate. In addition, since the rotational torque can be applied to the transparent plate itself integrally provided with the first electrode as the electrostatic actuator, the efficiency and responsiveness when changing the angle of the transparent plate are improved.

  In a preferred aspect of the fluid prism of the present invention, the first electrode and the second electrode have a comb-shaped structure that meshes with each other.

Fluid prism of the present invention comprises a container having a bottom constituted by the other of the front Symbol transparent plate of the pair of the transparent plate, and a cylindrical portion formed integrally with the bottom portion, the said container The transparent plate is disposed on the surface of the fluid while accommodating the fluid.

  In this fluid prism, since the fluid is accommodated in the container, the fluid can be prevented from being scattered. In the fluid prism, a gas that has a refractive index different from that of the external atmosphere and can transmit light can be used as the fluid. In addition, when gas is employ | adopted as a fluid, the sealing property of the gas by which the transparent plate which is accommodated in the container and which can be rock | fluctuated is arrange | positioned is ensured with a film.

Fluid prism of the present invention, while being accommodated before Symbol vessel disposed on a surface opposite to the fluid can oscillate the transparent plate disposed on the surface of the fluid, and the fluid The second fluid has a different refractive index and can transmit light.

  In this fluid prism, the angle formed by the two transparent plates changes when the transparent plate arranged between two kinds of fluids having different refractive indexes and different refractive indexes in the external atmosphere is oscillated. become. For this reason, the freedom degree which changes the refraction angle of the light beam which permeate | transmits this fluid prism increases.

  In a preferred aspect of the fluid prism of the present invention, the container has a transparent lid portion that seals the opening of the cylindrical portion to form a sealed space therein.

  In this fluid prism, since the container in which the fluid is stored is sealed with the transparent lid portion, it is possible to reliably prevent the fluid from scattering. The sealed space of the container may be filled with air in addition to the fluid, but may be filled with the second fluid. In particular, when liquid is used as the fluid and the second fluid and these are filled in the sealed space of the container, the swing of the transparent plate disposed between the fluid and the second fluid is stabilized. Can do.

  The fluid in the fluid prism of the present invention may be liquid or gas. However, when a gas is employed as the fluid, it is desirable to employ a liquid as the fluid in view of the need to provide a sealing means for sealing the gas between the transparent plates.

  In the fluid prism of the present invention, the first electrode as an electrostatic actuator, which is a part of a variable mechanism that changes the angle formed by both transparent plates, is integrally provided on the transparent plate itself. Can be made small, and the efficiency and responsiveness of the variable mechanism can be improved.

  Therefore, when the fluid prism of the present invention is applied to an optical device such as a camera, panning and tilting can be performed with high responsiveness. If panning and tilting can be performed at high speed, application to camera shake correction and the like can be expected.

Hereinafter, specific embodiments and reference embodiments of the fluid prism of the present invention will be described with reference to the drawings.

( Reference form 1 )
In this reference embodiment shown in FIGS. 1 to 3, the fluid prism of the present invention is applied to an optical apparatus having a zoom mechanism. This optical apparatus has a pan / tilt mechanism.

  As shown in FIG. 1, the optical apparatus includes a multifocal lens 1, a first mirror 2, a second mirror (second mirror reflecting surface) 3, an image sensor 4, and second mirror moving means (not shown). A zoom mechanism and a fluid prism (liquid prism) 70 are included.

  The multifocal lens 1 is formed by concentrically combining lens regions having different focal lengths so that the focal length becomes longer in multiple steps toward the outer peripheral direction. Specifically, the multifocal lens 1 includes two lens regions 15 and 16 having different focal lengths, and the lens region 15 has a shorter focal length than the lens region 16.

  The first and second mirrors 2 and 3 are ordinary opaque mirrors. The first mirror 2 has a first mirror reflection surface portion facing the multifocal lens 1 on the image forming side of the multifocal lens 1. The second mirror 3 has a second mirror reflecting surface portion between the first mirror 2 and the multifocal lens 1 and facing the reflecting surface side of the first mirror 2.

  The imaging element 4 is disposed at a position (imaging plane) where an image is formed by shielding or transmitting one or more of the light beams that have passed through the lens regions 15 and 16 of the multifocal lens 1. Specifically, it is located at the center of the first mirror 2.

  The second mirror 3 is parallel to the optical axis of the multifocal lens 1 and does not block the light beam that has passed through the lens region 15 (FIG. 1A), and is perpendicular to the optical axis of the multifocal lens 1. In addition, the position can be switched between the position (FIG. 1B) inserted so as to shield the light beam that has passed through the lens region 15. The second mirror moving means is means for switching the second mirror 3 between both positions. As a method for switching between them, the second mirror 3 is formed of a ferromagnetic material or a ferroelectric material, and a means for changing the direction of applying a magnetic field or an electric field, an electrostatic force or a Lorentz force is used. Means can be exemplified.

  A method for switching the focal length will be described below. When the focal length is increased, the second mirror 3 is inserted by the second mirror moving means (FIG. 1B) in order to use the light bundle transmitted through the lens region 16 of the multifocal lens 1. Moving. As a result, since the light beam that has passed through the lens region 15 is shielded by the second mirror 3, only the light beam that has passed through the lens region 16 reflects from the first mirror 2 and the second mirror 3 and is on the imaging plane. An image is formed on the image sensor 4. On the other hand, when the focal length is shortened, the second mirror moving means moves to the state in which the second mirror 3 is removed (FIG. 1A) in order to use the light bundle transmitted through the lens region 15. As a result, the light beam that has passed through the lens region 15 is imaged as it is on the image sensor 4 on the imaging surface without being shielded by the second mirror 3, whereas the light beam that has passed through the lens region 16. Since there is no second mirror 3 only, the first mirror 2 is reflected from the lens region 16 and then passes through the lens region 15 as it is toward the object side of the multifocal lens 1.

  Accordingly, the light beam transmitted through the lens region 15 is moved as it is, and the light beam transmitted through the lens region 16 is advanced between the first mirror 2 and the second mirror 3 by a distance (one reciprocal half) considering the difference in focal length. Thus, the image planes from the lens regions 15 and 16 coincide.

  In this optical apparatus, a fluid prism 70 capable of bending a light bundle is disposed in the vicinity of the multifocal lens 1 on the opposite side to the imaging side. The fluid prism 70 can also be disposed near the multifocal lens 1 side of the imaging surface.

  As shown in FIGS. 2 and 3, the fluid prism 70 includes a first transparent plate 71 as a bottom portion, a container 73 including a cylindrical portion 72 formed integrally with the first transparent plate 71, and a cylindrical portion 72. And a transparent lid 75 that forms a sealed space 74 therein. In addition, the shape of the cylindrical part 72 is not specifically limited, A cylinder or a prism may be sufficient.

  The first transparent plate 71 has a light transmission part 71a capable of transmitting light in the most central region. Similarly, the transparent lid portion 75 has a light transmission portion 75a capable of transmitting light in most of the central region. These light transmitting portions 71a and 75a are formed by embedding a transparent resin in a portion where silicon is hollowed out by MEMS fabrication.

  A transparent liquid 76 capable of transmitting light is accommodated in a part of the sealed space 74 in the container 73, and an oscillating plate 77 is disposed on the surface of the transparent liquid 76. The type of the transparent liquid 76 is not particularly limited as long as it has a refractive index different from that of the external atmosphere, but it is desirable to use a material having a higher refractive index, for example, matching oil.

  The swing plate 77 is manufactured by MEMS from a conductive silicon plate doped with impurities. The swing plate 77 is formed by thinning a central portion other than both ends of the silicon plate to make a thin plate portion, and embedding a transparent resin in a portion where a central region other than the peripheral portion of the thin plate portion is hollowed out. A rectangular-shaped second transparent plate 78, a frame-shaped conductive portion 77a formed integrally with the outer peripheral edge of the second transparent plate 78, and made of a peripheral portion of the thin plate portion, and both ends of the conductive portion 77a, respectively. And a pair of comb-shaped first electrodes 81a and 81b made of both ends of the silicon plate. Both the comb-shaped first electrodes 81a and 81b are configured to allow electricity to flow through the frame-shaped conductive portion 77a. The swing plate 77 floats on the transparent liquid 76.

  The liquid prism 70 is paired with each of the comb-shaped first electrodes 81a and 81b, and is disposed adjacent to the upper side of one of the comb-shaped first electrodes 81a (the left side in FIG. 2, the same applies hereinafter). And a pair of comb-shaped second electrodes 82a and 82b (hereinafter referred to as the upper comb-shaped second electrode) disposed adjacent to the lower side of the first electrode 81b of the other (right side in FIG. 2; hereinafter the same). Electrode 82a, 82b) and a pair of comb-shaped first electrodes 81a, 81b, respectively, which are arranged close to the lower side of the one comb-shaped first electrode 81a, and the other A pair of comb-shaped second electrodes 83a and 83b (hereinafter referred to as lower comb-shaped second electrodes 82a and 82b) disposed close to the upper side of the comb-shaped first electrode 81b. . The upper comb-shaped second electrodes 82 a and 82 b and the lower comb-shaped second electrodes 83 a and 83 b are disposed and fixed on the inner peripheral surface of the cylindrical portion 72 of the container 73.

  The comb-shaped first electrodes 81a and 81b, the upper comb-shaped second electrodes 82a and 82b, and the lower comb-shaped second electrodes 83a and 83b have a comb-shaped structure that meshes with each other.

  Further, the liquid prism 70 applies a voltage between the comb-shaped first electrodes 81a and 81b and the upper comb-shaped second electrodes 82a and 82b paired with the comb-shaped first electrodes 81a and 81b. First voltage applying means (power source) 84, comb-shaped first electrodes 81a and 81b, and lower comb-shaped second electrodes 83a and 83b paired with the first comb-shaped electrodes 81a and 81b. And a second voltage applying means (power source) 85 for applying a voltage between them.

  Note that the comb-shaped first electrodes 81a and 81b, the upper comb-shaped second electrodes 82a and 82b, the lower comb-shaped second electrodes 83a and 83b, the first voltage applying means (power source) 84, and the second voltage A variable mechanism 80 is configured by the application means (power source) 85. The remaining part of the sealed space 74 in the container 73 is filled with air.

  Further, in the state where no voltage is applied from the first voltage application means 84 and the second voltage application means 85, the comb-shaped first electrodes 81a and 81b, the upper comb-shaped second electrodes 82a and 82b, and the lower side A predetermined gap is formed between the second electrodes 83a and 83b (see FIG. 2B).

  In the fluid prism 70, for example, the first interdigital first electrodes 81a and 81b and the upper interdigital second electrodes 82a and 82b that are paired with the first interdigital first electrodes 81a and 81b, By applying a voltage from the voltage application means 84, between the one comb-shaped first electrode 81a and the upper comb-shaped second electrode 82a, and between the other comb-shaped first electrode 81b and the upper comb-shaped first electrode 81b. An electrostatic force is generated between the second electrode 82 b and the comb-shaped second electrode 82 b, and the swinging plate is used as a rotational torque for swinging the swinging plate 77 that floats on the surface of the transparent liquid 76 and can swing. 77. As a result, between the one comb-shaped first electrode 81a and the upper comb-shaped second electrode 82a, and between the other comb-shaped first electrode 81b and the upper comb-shaped second electrode 82b. The swing plate 77 swings in the direction in which the gap between them is narrowed (see FIG. 3). For this reason, the second transparent plate 78 swings, and the angle formed by the first transparent plate 71 and the second transparent plate 78 changes. At this time, the transparent liquid 76 disposed between the first transparent plate 71 and the second transparent plate 78 also follows the swing of the swing plate 77. For this reason, the angle formed by the first transparent plate 71 and the second transparent plate 78 can be arbitrarily changed by controlling the magnitude of the applied voltage from the first voltage applying means 84. Therefore, the refraction angle of the light beam passing through the transparent liquid 76 having a refractive index different from that of the external atmosphere can be changed according to the change in the angle formed by the first transparent plate 71 and the second transparent plate 78 (FIG. 3 ( It becomes possible to use a prism having an arbitrary angle (see arrow B in a).

  Further, the second voltage applying means 85 is connected between the comb-shaped first electrodes 81a and 81b and the lower comb-shaped second electrodes 83a and 83b that are paired with the comb-shaped first electrodes 81a and 81b. When a voltage is applied, the light flux can be refracted in the opposite direction by turning the second transparent plate 78 in the opposite direction.

  In the fluid prism 70, the comb-shaped first electrodes 81a and 81b constituting the electrostatic actuator are integrally provided on the swinging second transparent plate 78 itself. That is, some of the components of the variable mechanism are integrally provided on the second transparent plate 78. For this reason, the physique of the fluid prism 70 can be made small. In addition, since the rotational torque can be applied to the second transparent plate 78 itself integrally provided with the comb-shaped first electrodes 81a and 81b as electrostatic actuators, the angle of the second transparent plate 78 can be changed. Efficiency and responsiveness are improved.

Further, according to the optical apparatus of this reference embodiment , the pan / tilt mechanism can be realized by the fluid prism 70 as follows. When the second transparent plate 78 is parallel to the surface of the multifocal lens 1 on the incident light side (upper side in FIG. 1), the incident light enters the multifocal lens 1 as it is without bending. When the second transparent plate 78 is swung, the region filled with the transparent liquid 76 becomes a prism and the incident light is bent. Since the refractive index of the transparent liquid 76 is larger than the refractive index of the air that is the external atmosphere of the first and second transparent plates 71 and 78, the incident light is the second light as shown in FIG. It bends in a direction opposite to the direction in which the transparent plate 78 is swung. The degree of bending of the incident light can be controlled by controlling the degree of swing of the second transparent plate 78. That is, the angle of view can be changed in a desired direction by swinging the second transparent plate 78 in the opposite direction to the direction of changing the angle of view.

  The pan / tilt mechanism provided in this optical apparatus is particularly effective on the long focal side of the zoom mechanism. That is, as shown in FIG. 1B, when the long focal point side of the multifocal lens 1 is used, the angle of view becomes small, so the pan / tilt mechanism using the fluid prism 70 is useful.

( Embodiment 1 )
This embodiment shown in FIG. 4 shows a modification of the fluid prism 70. In the fluid prism 70 of the reference embodiment 1 , the remainder of the sealed space 74 in the container 73 (disposed on the surface of the transparent liquid 76). The second transparent liquid 79 having a refractive index different from that of the transparent liquid 76 and capable of transmitting light is accommodated and disposed on the surface of the swing plate 77 opposite to the transparent liquid 76.

  The types and combinations of the transparent liquid 76 and the second transparent liquid 79 are not particularly limited, but it is desirable to employ liquids that do not mix with each other so that they do not mix and diffuse with each other. For example, matching oil having a large refractive index can be used as the transparent liquid 76, and water having a refractive index smaller than that of the matching oil can be used as the second transparent liquid 79. The transparent liquid 76 and the second transparent liquid 79 are filled in the sealed space 74 of the container 73.

  For this reason, in this fluid prism 70, the swing of the second transparent plate 78 disposed between the transparent liquid 76 and the second transparent liquid 79 can be stabilized. In addition, the degree of freedom of changing the refraction angle of the light beam transmitted through the fluid prism 70 can be increased.

  Further, by filling the second transparent liquid 79 with a liquid having a specific gravity similar to that of the transparent liquid 76, it is possible to reduce the influence of gravity, inertia force, and the like.

Other configurations and the operational effects thereof are the same as in the first embodiment .

In the first embodiment and the first embodiment , the direction of the electrostatic force can be increased by increasing the number of second electrodes paired with the first electrode or changing the arrangement of the first electrode and the second electrode. Since the direction in which the transparent plate swings can be changed variously, the direction in which the light beam passing through the fluid prism is refracted can be changed variously.

In the first embodiment and the first reference embodiment , the first transparent plate 71 is fixedly held on the optical device, and the transparent liquid 76 is disposed on the first transparent plate 71 by surface tension. The rocking plate 77 may be disposed on the surface of 76. At this time, the upper comb-shaped second electrodes 82a and 82b and the lower comb-shaped second electrodes 83a and 83b are fixedly held by the optical apparatus. By doing so, the container 73 and the transparent lid 75 are unnecessary, and thus the structure can be simplified.

Furthermore, in the first embodiment and the first reference embodiment , the example in which the liquid is used as the fluid has been described. However, if the sealing property is secured between the first transparent plate 71 and the second transparent plate 78, what is the external atmosphere? Gases having different refractive indexes can be used in place of the fluid. At this time, it is necessary to hold the second transparent plate 78 in a swingable manner by some means.

In addition, in the first embodiment and the first reference embodiment , an example in which the second transparent plate 78 on the side on which the light flux enters among the first transparent plate 71 and the second transparent plate 78 can be swung is described. However, the first transparent plate 71 on the side from which the light beam exits can be made swingable, or both the first transparent plate 71 and the second transparent plate 78 can be made swingable.

1 shows the overall configuration of an optical apparatus according to Reference Embodiment 1 , wherein (a) is a schematic cross-sectional view of a state in which the zoom mechanism is on the short focus side, and (b) is a fluid prism in which the zoom mechanism is on the long focus side. It is the cross-sectional schematic which shows the state in which the light beam is refracting by. The fluid prism in a state where no voltage is applied according to the reference form 1 is shown, (a) is a schematic cross-sectional view showing the overall configuration of the fluid prism, and (b) is a comb-shaped first shape constituting the electrostatic actuator. It is an A direction arrow directional view of Drawing 2 (a) showing only composition of an electrode and a comb-like 2nd electrode. The fluid prism in the state to which the voltage was applied concerning the reference form 1 is shown, (a) is the cross-sectional schematic diagram which shows the whole structure of a fluid prism, (b) is the comb-tooth shaped 1st electrode which comprises an electrostatic actuator. FIG. 4 is a view in the direction of arrow A in FIG. 3A showing only the configuration of the comb-shaped second electrode. 1 is a schematic cross-sectional view illustrating an overall configuration of a fluid prism in a state where no voltage is applied according to Embodiment 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 70 ... Fluid prism 71 ... 1st transparent plate 72 ... Cylindrical part 73 ... Container 74 ... Sealed space 75 ... Transparent cover part 76 ... Transparent liquid (fluid) 77 ... Swing plate 78 ... 2nd transparent plate 79 ... 2nd transparent Liquid (second fluid)
DESCRIPTION OF SYMBOLS 80 ... Variable mechanism 81a, 81b ... Comb-shaped first electrode 82a, 82b, 83a, 83b ... Comb-shaped second electrode 84 ... First voltage application means 85 ... Second voltage application means

Claims (3)

A pair of transparent plates arranged facing each other at an interval and swingable on one side;
A fluid disposed between the transparent plates and capable of transmitting light;
A fluid prism having a variable mechanism that swings the swingable transparent plate to change an angle formed by both the transparent plates;
A container having a bottom formed by the other transparent plate of the pair of transparent plates and a cylindrical portion formed integrally with the bottom, the fluid being contained in the container, The transparent plate that can swing on the surface of the fluid is disposed,
It is housed in the container and disposed on the surface of the swingable transparent plate disposed on the surface of the fluid opposite to the fluid and has a refractive index different from that of the fluid and transmits light. A possible second fluid,
The variable mechanism includes a first electrode provided integrally with the swingable transparent plate, and at least one second electrode provided in proximity to the first electrode and paired with the first electrode. A voltage applying means for applying a voltage between the first electrode and the second electrode, and an electrostatic force generated by applying a voltage between the first electrode and the second electrode can be swung. A fluid prism which is applied to the transparent plate as a rotational torque for swinging the transparent plate.   The fluid prism according to claim 1, wherein the first electrode and the second electrode have a comb-shaped structure that meshes with each other.   The fluid prism according to claim 1, wherein the container has a transparent lid portion that seals the opening of the cylindrical portion to form a sealed space therein.

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