KR101588316B1 - High speed optical shutter and method of operating the same and apparatus comprising the same - Google Patents

Abstract

An apparatus including a high-speed optical shutter and an operation method thereof and a high-speed optical shutter is disclosed. The optical shutter includes a solid state transparent electro-optic medium having a total reflection surface whose total reflection angle is changed by an external action. The electro-optical medium may be a prism or a prism array whose total reflection angle is changed by the external action. The electro-optical medium may further include an incident light path changing unit. The optical path changing unit may further include a light path changing unit that causes the light to be vertically incident on an object to which light having passed through the electro-optical medium is incident.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a high-speed optical shutter and a method of operating the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical element, and more particularly, to an optical device including a high-speed optical shutter, an operating method thereof, and a high-speed optical shutter.

An optical shutter having a function of transmitting or blocking a light image according to a control signal is a core optical module widely used in imaging devices such as cameras and display devices such as LCDs.

Recently, a 3D camera or LADAR (Laser Radar) technique is being studied to obtain distance information of an object, and a time-of-flight (TOF) To measure the distance between them.

Among various TOF methods, the SLP (Shuttered Light Pulse) method is a method of projecting light of a specific wavelength onto a subject, shuttering a light image of the same wavelength reflected from the subject, obtaining an image through an image pickup device, How to get distance information. In this method, a fast shutter drive is required to have an on / off switching time of several nanoseconds (ns) in order to identify the travel time according to the distance of the light. An image intensifier or semiconductor based optical shutter technology has been proposed as a high speed optical image shutter for this purpose.

However, the image intensifier is expensive and requires expensive high voltage and vacuum packaging. Semiconductor-based optical shutters can overcome the difficulties in operation and structure of the image intensifier, but they are fabricated from semiconductor fabrication process on GaAs substrates and have a more complex structure than conventional photo-diodes and LED devices. And relatively difficult to commercialize in process difficulty.

On the other hand, a conventional optical modulation device using an electro-optical effect includes a Kerr cell or a Pockel cell. Optical modulation devices using electro-optical materials have a reaction rate of several tens of GHz. Therefore, it has been used for a wave guide of a high-speed optical communication.

These devices use the property that the polarization property of a nonlinear crystal made of LiNbO ₃ or the like changes according to a given electric field as a core principle. That is, it has a shutter function for controlling the angle of polarization by using an external electric field to transmit or block polarized incident light.

An embodiment of the present invention provides an optical shutter capable of high-speed shuttering.

Another embodiment of the present invention provides a method of operating such an optical shutter.

Still another embodiment of the present invention provides an optical device including such an optical shutter.

An embodiment of the present invention provides an optical shutter comprising a solid state transparent electro-optic medium having a total reflection surface whose total reflection angle is changed by external action.

Optical path changing means for allowing the light to be vertically incident on an object to which the light having passed through the electro-optical medium is incident.

And an incident light path changing means may be further provided in front of the electro-optical medium.

The electro-optic medium and the optical path changing means may comprise a prism or a prism array.

The prism of the electro-optic medium and the optical path changing means may be arranged so as to have the same shape but to have symmetry with each other.

Wherein the prism array of the electro-optical medium and the optical path changing means includes a plurality of micro-prisms, and the cross-section of the micro-prisms of the electro-optical medium and the micro- The prism array of the electro-optic medium and the optical path changing means may be arranged.

There may be a gap of uniform thickness between the electro-optic medium and the optical path changing means on the light propagation path. At this time, the gap may be filled with air or an optical medium having a refractive index lower than that of the prism or the prism array.

A light absorbing film is attached to one surface of the prism of the electro-optical medium or one surface of the micro-prism, and the one surface may be a surface on which the totally-reflected light is incident.

The electro-optical medium may further include an incident light path changing unit.

The incident light path changing means may be a lens unit for changing the traveling path of the incident light so that the incident light incident on the light path changing means is incident on the electro-optic medium as parallel light.

The electro-optical medium may be a prism or a prism array in which incident light is totally reflected or transmitted according to the external action.

The light incident surface of the prism or the light incident surface of the microprism included in the prism array may be inclined with incident light.

The prism array may be a plurality of micro prisms or annular micro prisms in the form of a strip.

The external action may be an electric field generated according to a voltage application.

A light absorbing film may be attached to the surface of the prism or prism array of the light path changing means which is not on the light path.

The electro-optic medium itself may be tilted with respect to an object to which the light emitted from the electro-optic medium is incident.

According to another embodiment of the present invention, there is provided an operation method of an optical shutter for applying a voltage to the electro-optic medium to change the total reflection angle of the electro-optic medium.

In this method of operation, the voltage can be continuously applied to continuously change the total reflection angle of the electro-optic medium.

The waveform of the voltage may be a square wave or a sinusoidal wave and the waveform is not limited to a square wave or sinusoidal wave.

The electro-optic medium may be a prism or a prism array.

The incidence angle of the incident light incident on the electro-optic medium may be smaller than the fixed total reflection angle of the electro-optic medium, and may be greater than the minimum total reflection angle due to the voltage application.

The incident angle of the incident light incident on the electro-optic medium may be greater than the fixed total square of the electro-optic medium and less than the maximum total square of the applied voltage.

The total reflection angle of the electro-optic medium may be reduced by applying the voltage.

The total reflection angle of the electro-optic medium may be increased according to the application of the voltage.

Yet another embodiment of the present invention provides an optical device including the optical shutter according to the above-described embodiment of the present invention. The optical device may be a distance measuring camera such as a 3D camera or a liquid crystal display device.

When the optical shutter according to the embodiment of the present invention is used, the electro-optical effect of the solid electro-optical material is utilized, so that the durability of the optical shutter can be further strengthened.

In addition, since the optical shutter can be operated at a fast shutter speed of 1 ns, the image can be processed at high speed.

Further, since the optical shutter can be manufactured in a thin plate shape, it can be downsized. After the crystal growth by the thin plate, it is possible to reduce the raw material price and the process cost because it is a structure that can be finely processed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an apparatus including an optical shutter and operation method using a total square control medium according to an embodiment of the present invention and an optical shutter will be described in detail with reference to the accompanying drawings. In this process, the thicknesses of the layers or regions shown in the figures are exaggerated for clarity of the description.

Referring to FIG. 1, an optical shutter according to an exemplary embodiment of the present invention may include an active solid state medium 30 for controlling a total reflection angle. The active solid state medium 30 (hereinafter, referred to as a total square modulation medium) for controlling the total reflection angle may be a medium having a total reflection surface whose internal total reflection angle is changed by external action. The total reflection medium 30 may be various types of electro-optical media. The total square modulation medium 30 may be an electro-optic effect material such as LiNbO ₃ , KTN (KTa _x Ln _1-x O ₃ ), or the like. The shape of the total reflection angle control medium 30 shown in FIG. 1 is a symbolic representation. The external action may be a change in the crystal characteristics of the total reflection medium 30. An example of the crystal characteristic may be a refractive index characteristic of the total reflection medium 30. The internal total reflection angle of the total reflection angle adjustment medium 30 can be made smaller than the fixed total reflection angle by the external action. The fixed total reflection angle refers to a unique total reflection angle of the total reflection angle control medium 30 at the total reflection plane S1 of the total reflection angle control medium 30 when there is no external action. Therefore, depending on the material of the total reflection angle controlling medium 30, the total reflection angle of the total reflection controlling medium 30 may be different. The external action may be, for example, an electric field. The electric field is generated between two electrodes having a potential difference. Therefore, by placing the total reflection angle adjustment medium 30 between two electrodes having a potential difference, an electric field can be applied to the total reflection angle adjustment medium 30. One of the two electrodes may be provided on the incident side of the total reflection angle control medium 30, and the other electrode may be provided on the emission side. As far as the crystal characteristics of the total square modulation medium 30 can be changed, other factors outside the electric field may be used as the external action. The external action can be adjusted over time. Therefore, the external action may be changed continuously, and thus the total reflection angle of the total reflection medium 30 may also be continuously changed. The light emitted from the optical shutter including the total reflection medium 30 is incident on the image sensor 35. The image sensor 35 may be a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) sensor. The image sensor 35 may be any optical sensor capable of converting an optical image given from the full- Sensor.

In FIG. 1, reference numeral L denotes an incident light incident on the total reflection angle controlling medium 30. The incident angle of the incident light L incident on the total reflection plane S1 can be fixed at a given angle. When the total reflection angle of the total reflection medium 30 is smaller than the fixed reflection angle according to the magnitude of the external action, the incident angle of the incident light L is smaller than the fixed total reflection angle of the total reflection medium 30, May be larger than the minimum total reflection angle that the total reflection angle controlling medium 30 can have by the external action. In contrast, when the total reflection angle of the total reflection medium 30 is greater than the fixed reflection angle according to the size of the external action, the incident angle of the incident light L is larger than the fixed reflection angle of the total reflection adjustment medium 30, May be smaller than the maximum total reflection angle that the total reflection angle control medium 30 can have. In FIG. 1, reference numeral Lt denotes an incident angle of the incident light L, which is not affected by the external action, when the total reflection angle control medium 30 is in the shutter-on state, And represents light refracted without total reflection at the total reflection plane S1. The refracted light Lt is incident on the image sensor 35. Therefore, the refracted light Lt becomes light having information to be actually measured or to be obtained. Reference numeral Lr denotes an angle formed by the external totalizing angle of the total reflection angle of the total reflection angle of the total reflection angle of the total reflection angle When the total reflection angle is smaller than the total reflection angle, the light totally reflected by the total internal reflection plane S1 of the total reflection angle control medium 30 is symbolically displayed.

FIG. 2 shows the optical shutter configuration when the total reflection prism 40 of FIG. 1 is the total reflection prism 40. FIG.

Referring to FIG. 2, the total reflection prism 40 may be a right angle prism. The inclined plane 40S2 of the total reflection prism 40 becomes a total reflection plane. Incident light 40L is incident perpendicularly to the incident surface 40S1 of the total reflection prism 40. [ The image sensor 42 may be provided at a position facing the inclined surface 40S2 which is a total reflection surface. The image sensor 42 may be provided at a position where the incident light 40L can be refracted at the inclined plane 40S2. For example, the image sensor 42 may be provided at a position where the refracted light 40T can be incident on the image sensor 42 in a direction perpendicular thereto. The image sensor 42 may be provided at a position where the refracted light 40T is obliquely incident on the image sensor 42. The refracted light 40T may be provided between the prism 40 and the image sensor 42, . The refracted light 40T path changing means will be described later.

2, the incident light 40L passes through the incident surface 40S1 of the total reflection prism 40 and is incident on the inclined surface 40S2, which is a total reflection surface, at an angle 40A given to the incidence surface 40L. The incident light 40L is totally reflected in the prism 40 from the inclined surface 40S2 so that the incident light 40L is reflected by the image sensor 42 Is not reached. Reference numeral 40R denotes light totally reflected on the inclined surface 40S2. The light absorbing means 44 may be provided on the surface of the prism 40 on which the totally-reflected light 40R is emitted. The light absorbing means 44 may be a light absorbing film.

If the given incident angle 40A is smaller than the fixed total square of the prism 40, the incident light 40L does not satisfy the total reflection condition and is refracted at the inclined plane 40S2. The refracted light 40T reaches the image sensor 42. [

When the electric field 40E due to the external application is applied to the prism 40, the total internal angle of the prism 40 may vary. First, as the intensity of the electric field 40E increases, Is smaller than the fixed total square. Second, the total reflection angle of the prism 40 increases as the intensity of the electric field 40E increases.

In the first case, the incident angle 40A of the incident light 40L is smaller than the fixed total square of the prism 40 and larger than the minimum total square angle that the prism 40 can have according to the electric field 40E.

In the second case, the incident angle 40A of the incident light 40L is larger than the fixed reflection angle of the prism 40 and smaller than the maximum total reflection angle that the prism 40 can have according to the application of the electric field 40E. The image sensor 42 includes a plurality of pixels 42P, which may include only one pixel. The image sensor 42 may be the entire image sensor of the optical shutter, or it may be part of the overall image sensor, including at least one pixel. In other words, the prism 40 shown in Fig. 2 may be a total reflection medium corresponding to the entire image sensor of the optical shutter. Further, the prism 40 may be a total reflection medium corresponding to a part of the entire image sensor, including at least one pixel. That is, the optical shutter may include only one prism 40 as a total reflection angle adjusting medium, or may include a prism array formed by using a plurality of prisms 40 shown in FIG. In the latter case, the prism 40 shown in Fig. 2 becomes a unit prism constituting the prism array.

FIG. 3 shows an optical shutter using another type of prism (hereinafter referred to as a second prism) instead of the right angle prism 40 of FIG.

Referring to FIG. 3, the second prism 46 is provided such that the incident surface 46S1 is inclined with respect to the incident light 46L. The second prism 46 is provided so that the total reflection plane 46S2 is parallel to the image sensor 42. [ The incident surface 46S1 and the total reflection surface 46S2 form a given angle, which is less than 90 degrees. A light absorbing means 44 is provided on the surface of the light guiding surface 46S2 of the second prism 46 on which the light totally reflected 46R is emitted. The light absorbing means 44 may be a light absorbing film coated on the surface from which the totally-reflected light 46R is emitted. The image sensor 42 may be provided at a position where the light 46T refracted at the total reflection plane 46S2 of the second prism 46 is incident vertically or obliquely. When the image sensor 42 is arranged such that the refracted light 46T is inclined to the image sensor 42, the refracted light 46T is provided between the image sensor 42 and the total reflection surface 46S2 of the second prism 46, (Not shown) capable of changing the optical path of the light beam. The light 46T refracted by the above means is incident on the image sensor 42 in a direction perpendicular thereto. The above means will be described later. The material of the second prism 46 may be the same as or different from that of the prism 40 of FIG.

3, the path of the incident light 46L will be described. First, the path of the incident light 46L when there is no external action will be examined. The incident light 46L is incident at an incident angle 46A given to the incident surface 46S1. The incident angle 46A is smaller than 90 degrees. The incident light 46L is first refracted at an angle given by the incident surface 46S1. At this time, the first refraction angle of the incident light 46L is determined according to Snell's law. Incident light 46L that is refracted first in the incident surface 46S1 is secondarily refracted by the total reflection surface 46S2 and is incident on the image sensor 42 or totally reflected and absorbed by the light absorbing means 44. [ Incident light 46L is totally refracted or totally reflected from the total reflection plane 46S2 along the incidence angle 46A of the incident light 46L.

Next, the path of the incident light 46L when an external action is present, for example, when the electric field 46E is applied to the second prism 46 is examined. The refractive index of the second prism 46 varies depending on the intensity of the external action. For example, when the second prism 46 is a KTN (KTaLnO ₃ ) prism, the refractive index of the second prism 46 can be adjusted within a range of 2.3 to 2.4 by controlling the intensity of the external action.

The total reflection angle at the total reflection plane 46S2 of the second prism 46 decreases as the intensity of the electric field 46E increases. The incident angle 46A of the incident light 46L can be fixed at a given angle. The incidence angle 46B at which the light incident on the total reflection plane 46S2, that is, the light 46LR that is first refracted at the incidence plane 46S1 is incident on the total reflection plane 46S2, Lt; / RTI > The incident light 46L is an incident angle 46A that can be incident on the total reflection plane 46S2 at an incidence angle 46B at which the first refracted light 46LR is smaller than the fixed total square of the second prism 46, 46S1. When the electric field 46E is applied in this state, the total reflection angle at the total reflection plane 46S2 of the second prism 46 becomes smaller than its fixed total reflection angle. At this time, the intensity of the applied electric field 46E may be about 0V to 150V expressed by the voltage. Assuming that the total reflection angle of the second prism 46 when the intensity of the electric field 46E is the maximum is the minimum total reflection angle, the incidence angle 46B of the first refracted light 46LR with respect to the total reflection plane 46S2 is the minimum It may be larger than the total square. The incident angle 46B of the first refracted light 46LR may have a value between the fixed total reflection angle of the second prism 46 and the minimum total reflection angle. Therefore, when the total reflection angle at the total reflection plane 46S2 becomes smaller than the incidence angle 46B of the first refraction light 46LR depending on the intensity of the applied electric field 46E, the first refracted light 46LR becomes the total reflection plane 46S2 and absorbed by the light absorbing means 44. When the intensity of the electric field 46E is weakened and the total reflection angle of the second prism 46 becomes larger than the incidence angle 46B of the first refracted light 46LR, It passes through the total reflection surface 46S2 and is refracted toward the image sensor 42. [ By controlling the intensity of the electric field 46E applied to the second prism 46 as described above, the total reflection angle of the second prism 46 can be adjusted, and the first-order refracted light incident on the total reflection plane 46S2 It is possible to control the total reflection and the refraction of the light source 46LR.

On the other hand, when the total reflection angle on the total reflection plane 46S2 of the second prism 46 increases with the intensity of the electric field 46E, the incidence angle 46B of the first refracted light 46LR with respect to the total reflection plane 46S2, Is larger than the fixed total square of the second prism (46). Assuming that the total reflection angle of the second prism 46 when the intensity of the electric field 46E is the maximum in the voltage range is the maximum total reflection angle, the incidence angle 46B of the first refracted light 46LR is larger than the maximum total reflection angle small. The incidence angle 46B of the first refracted light 46LR may be greater than the fixed total reflection angle of the second prism 46 and less than the maximum total reflection angle. Therefore, when the total reflection angle of the second prism 46 increases with the intensity of the electric field 46E, the first refracted light 46LR satisfies the first total reflection condition and then deviates from the total reflection condition according to the application of the electric field 46E Passes through the total reflection surface 46S2 so that the optical shutter starts in the initial shutter-off state and becomes shutter-on as the intensity of the electric field 46E increases. In contrast, when the above-described total reflection angle of the second prism 46 decreases with the intensity of the electric field 46E, the total reflection angle is reversed. Soon, the optical shutter starts in the first shutter-on state and becomes shutter-off state as the intensity of the electric field 46E increases.

Next, an embodiment of the optical shutter including the total reflection medium 30 and the optical path changing means will be described. The light path changing means causes the light refracted from the total reflection medium (30) to be incident on the image sensor (35) vertically. In the following description, the same reference numerals are used for the above-mentioned members.

FIG. 4 shows a case where the optical path changing means is provided in the optical shutter shown in FIG.

Referring to FIG. 4, a third prism 48 is provided between the total reflection prism 40 and the image sensor 42 as an optical path changing means. A solid state electro-optical medium having a total reflection surface in which the total reflection angle is changed by an external action by binding the total reflection prism 40 and the third prism 48, may be referred to as an optical shutter. In this case, the total reflection prism 40 is a first medium in which the total reflection angle is changed according to an external action, and the third prism 48 is a second medium in which light incident from the first medium to the image sensor 42 is always vertical, . This expression can be applied to all optical shutters described below, including two prisms or two prism arrays, including a prism or prism array that allows the light incident on the image sensor 44 to be incident perpendicularly to the image sensor 44 have.

Subsequently, the third prism 48 is a right angle prism. The third prism 48 may be the same as the total reflection prism 40. Although the total reflection prism 40 and the third prism 48 may have different materials, the refractive indices of both prisms are larger than the refractive index of air. The total reflection prism 40 and the third prism 48 face the inclined surfaces. The inclined surfaces of the two prisms 40 and 48 are close but not in contact with each other. As a result, a gap 50 having a uniform thickness is formed between the inclined surfaces of the two prisms 40 and 48. The thickness of the gap 50 may be, for example, about 1 to 2 占 퐉. But it may be thinner. Although air is present in the gap 50, other material may be present in the gap 50. At this time, the material existing in the gap 50 is transparent and its refractive index is smaller than the refractive index of the two prisms 40 and 48. As long as this condition is satisfied, the material that may be present in the gap 50 may not be limited to a specific one. Since the thickness of the gap 50 is uniform, the gap 50 serves as an optical medium for moving the traveling direction of light passing through the total reflection surface 40S2 of the total reflection prism 40 by a given distance in a direction perpendicular to the traveling direction do. At this time, the distance of parallel movement is proportional to the thickness of the gap 50. The inclined surface of the third prism 48 is an incident surface through which the light having passed through the gap 50 is incident and faces the inclined surface of the total reflection prism 40, that is, the total reflection surface 40S2. The light emitting surface 48T of the third prism 48 is parallel to the incident surface 40S1 of the total reflection prism 40 and the image sensor 42. [ The light incident on the third prism 48 passing through the gap 50 passes through the total reflection prism 40 in the same direction as the light incident on the total reflection prism 40 passes through the total reflection prism 40 in the reverse direction on the total reflection plane 40S2 And passes through the third prism 48. The light perpendicular to the incident surface 40S1 of the total reflection prism 40 is emitted perpendicular to the light emission surface 48T when passing through the light emission surface 48T of the third prism 48. [ The refraction angle at the light emitting surface 48T becomes 0 DEG. Since the image sensor 42 is parallel to the light emitting surface 48T of the third prism 48, the light that has passed through the light emitting surface 48T of the third prism 48 enters the image sensor 42 vertically do. The path of the light refracted by the total reflection surface 40S2 of the total reflection prism 40 can be changed to be vertically incident on the image sensor 42 by providing the third prism 48. [ By providing the third prism 48 as described above, since the image sensor 42 can be disposed directly under the total reflection prism 40, the horizontal size of the optical shutter can be reduced. 2 and 3, the image sensor 42 may be disposed so that the incident light 40T or 46T is perpendicular to the image sensor 42. [ The optical medium present between the third prism 48 and the image sensor 42 may be the same as the optical medium present in the gap 50.

FIG. 5 shows a case where the optical path changing means is provided in the optical shutter of FIG.

Referring to FIG. 5, a fourth prism 52 is provided between the second prism 46 and the image sensor 42 as optical path changing means. The fourth prism 52 changes the light path emitted from the total reflection surface 46S2 of the second prism 46 to be incident on the image sensor 42 perpendicularly. The incident light 46L incident on the incident surface 46S1 of the second prism 46 is perpendicular to the image sensor 42. [

The fourth prism 52 may be the same prism as the second prism 46 in terms of shape and function. The material of the fourth prism 52 may be the same as or different from that of the second prism 46. The refractive indices of the second and fourth prisms 46 and 52 are higher than the air and may be greater than the refractive index of the optical medium filled in the gap 54 formed between the two prisms 46 and 52. [

The light incidence surface 52S1 of the fourth prism 52 corresponds to the total reflection surface 46S2 of the second prism 46. The two surfaces 52S1 and 46S2 It is very close. However, the two faces 52S1 and 46S2 are not in contact with each other. A gap 54 is formed between the light incident surface 52S1 of the fourth prism 52 and the total reflection surface 46S2 of the second prism 46. [ The two faces 52S1 and 46S2 face each other in parallel, and the gap 54 has a uniform thickness. Thus, the gap 54 may function in the same manner as the gap 50 in FIG. The light emitting surface 52S2 of the fourth prism 52 corresponds to the light incident surface 46S1 of the second prism 46. [ Light incident on the fourth prism 52 through the gap 50 in accordance with the arrangement of the fourth prism 52 is reflected by the light incident on the total reflection surface 46S2 of the second prism 46 in a reverse direction Follow the same path. The traveling direction of the light refracted by the light emitting surface 52S2 of the fourth prism 52 becomes parallel to the incident light 46L incident on the incident surface 46S1 of the second prism 46. [ The incident light 46L incident on the incident surface 46S1 of the second prism 46 is perpendicular to the image sensor 42. [ The light 52T emitted from the light emitting surface 52S2 of the fourth prism 52 is incident on the image sensor 42 in a direction perpendicular thereto. In FIG. 5, the second and fourth prisms 46 and 52 may correspond to the entire image sensor 42, but may correspond to some pixels of the image sensor. For example, the second and fourth prisms 46 and 52 may correspond to at least one pixel included in the image sensor 42 or may correspond to at least two or more pixels. The optical shutter may include a prism array including a plurality of second prisms 46 shown in FIG. 3, and may include a prism array including a plurality of second and fourth prisms 46 and 52 shown in FIG. 5 .

6 shows an embodiment of an optical shutter including means for changing the optical path of incident light (hereinafter referred to as incident light path changing means) such that the light incident on the incident surface of the total reflection medium is parallel light. The incident light path changing means may be a lens unit.

Referring to FIG. 6, collimating means 58 is provided on the light incident surface 40S1 of the total reflection prism 40. FIG. The collimating unit 58 may reflect the spherical wave divergent light 40DL to the plane wave incident perpendicularly to the incident plane 40S1 of the total reflection prism 40 when the light incident on the total reflection prism 40 is the spherical wave divergent light 40DL. And changes to the incident light 40L. The collimating means 58 may be, for example, a lens. The light emitting surface 58S2 of the collimating means 58 is in parallel with the light incident surface 40S1 of the total reflection prism 40 and is in contact with each other. The light incident surface 58S1 of the collimating means 58 is a convex curved surface.

Fig. 7 shows an embodiment of the optical shutter including the incident light path changing means in the case of Fig.

Referring to FIG. 7, a collimating unit 58 is provided on the light incident surface 40S1 of the total reflection prism 40. FIG. The collimating means 58 may be as described in FIG.

Fig. 8 shows an example in which the optical shutter shown in Fig. 3 is further provided with an incident light path changing means 58. Fig. The light 46L incident on the second prism 46 becomes parallel light that is a plane wave even if the spherical wave divergent light 40DL is incident on the optical shutter due to the provision of the incident light path changing means 58. [

Fig. 9 shows an example in which the optical shutters shown in Fig. 5 are further provided with an incident light path changing means 58. Fig. In Fig. 9, the role of the incident light path changing means 58 may be the same as that in Fig.

Next, an optical shutter including an array of a plurality of full-height adjustment media 30 will be described. The unit total square control medium 30 constituting the array in the optical shutter including the array may be the same as or similar to that shown in Figs. 1 to 5.

FIG. 10 shows an embodiment of an optical shutter including an array using the total reflection prism 40 of FIG. 2 as a unit total square control medium. For the members described above, use the same reference number as used.

Referring to FIG. 10, the optical shutter includes a first substrate 62 and a first prism array 60. The first prism array 60 is attached to the light emitting surface of the first substrate 62. The first substrate 62 may be an electro-optic substrate which is transparent to incident light and whose refractive index varies with external action. The first substrate 62 may be made of the same material as the micro prisms 60A constituting the first prism array 60. Also, the first substrate 62 may be a material having a refractive index close to the refractive index of the microprism 60A. As the first substrate 62, for example, glass or sapphire may be used. The incident light incident on the first substrate 62 may be a parallel light. The micro prism 60A may have the same shape, material, and function as the total reflection prism 40 shown in Fig. A light absorbing means 44 is attached to the surface of the micro prism 60A on which the totally reflected light is emitted. The first prism array 60 is composed of a plurality of micro prisms 60A.

The first prism array 60 is formed by depositing an electro-optic substrate to be used as a micro prism 60A on the back surface of the first substrate 62, that is, the light emitting surface, at a thickness t1 or more of the first prism array 60 Or the like, and then cutting and etching the electro-optic substrate. At this time, the thickness of the electro-optic substrate deposited or grown by the cutting can be adjusted, and the cut electro-optic substrate can be shaped like the first prism array 60 by the etching. Another method of forming the first prism array 60 includes forming the first substrate 62 and the electro-optic substrate separately, bonding the electro-optic substrate separately made to the first substrate 62, And the bonded electro-optic substrate is cut and etched as described above. On the other hand, after the electro-optic substrate is patterned in the same shape as the first prism array 60 by the cutting and etching, the light reflected from the total reflection surface 60S2 of each microprism 60A using the directional deposition process The light absorbing means 44 can be formed on the surface to be emitted. 10 (B) is a plan view of the first prism array 60. FIG. (B), a plurality of microprisms 60A are arranged in a strip form. 10A and 10B are cross-sectional views taken along line 10A-10A '.

10, the light 40T refracted at the total reflection plane 60S2 of the first prism array 60 is shown incident at an incidence angle of more than 0 which is inclined to the image sensor 42. However, 40T may be vertically incident on the image sensor 42. [ One of the methods for realizing this is to arrange the image sensor 42 to be inclined with respect to the first substrate 62 as indicated by a dotted line so that the refracted light 40T is incident on the image sensor 42 vertically.

Another method is to provide a second prism array 64 between the image sensor 42 and the first prism array 60, as shown in Fig. The second prism array 64 changes the path of the refracted light 40T so that the light 40T refracted at the total reflection surface 60S2 of the first prism array 60 is incident perpendicularly to the image sensor 42 It is means. In other words, the second prism array 64 is a means for changing the traveling direction of the refracted light 40T so as to be equal to the traveling direction of the incident light incident on the first substrate 62. The first and second prism arrays 60 and 64 are arranged such that the micro prisms 60A and 64A are arranged as in the case of the total reflection prism 40 and the third prism 48 of FIG. Gaps (72 in Fig. 13). An example of such an arrangement can be seen in FIG. However, in FIG. 11, the vertical distance between the first and second prism arrays 60 and 64 is larger than the actual distance for convenience in order to clearly show the first and second prism arrays 60 and 64. A second substrate 66 is provided between the second prism array 64 and the image sensor 42. The second prism array 64 is provided on the light incident surface of the second substrate 66. The second prism array 64 includes a plurality of microprisms 64A. The micro prism 64A may be the same in shape, material, and function as the third prism 48 of FIG. The second substrate 66 may be the same as the material of the microprism 64A of the second prism array 64. [ The material of the second substrate 66 may be a material having a refractive index close to that of the microprism 64A. The material of the second substrate 66 may be the same as that of the first substrate 62. The arrangement of the micro prisms 64A of the second prism array 64 with respect to the micro prisms 60A of the first prism array 60 is the same as that of the third prisms 48 with respect to the total reflection prism 40 shown in FIG. Can be the same as the layout.

On the other hand, when the incident light incident on the first substrate 62 in the optical shutter shown in Fig. 10 is a spherical surface file, and is not parallel light, as shown in Fig. 12, on the light incident surface of the first substrate 62 An incident light path changing means 68 may be further provided. The incident light path changing means 68 changes the path of the incident light 68L incident on the incident light path changing means 68 so that the parallel light enters the light incident surface of the first substrate 62. In other words, the incident light path changing means 68 changes the path of the incident light 68L so that the traveling direction of the incident light 68L incident on the same is the same. Accordingly, the light incident on the first prism array 60 becomes parallel light and the incident surface of each microprism 60a is incident vertically. The incident light path changing means 68 may be, for example, a Fresnel lens sheet.

13, when the incident light incident on the first substrate 62 in the optical shutter shown in Fig. 11 is a spherical file, the incident light path changing means 70 ) May be further provided. The incident light path changing means 70 may be the same as the incident light path changing means 68 of FIG.

14 shows another embodiment of an optical shutter including a prism array composed of a plurality of microprisms.

Referring to Fig. 14 (A), the optical shutter includes a third prism array 74 and an image sensor 42. The third prism array 74 may include a third substrate 74A and a plurality of microprisms 74B. The micro prism 74B is an example of a total reflection angle control medium. Therefore, instead of the micro prism 74B, another type of total reflection medium may be provided. The third substrate 74A is tilted at an angle relative to the image sensor 42. [ As a result, the light incident surface 74AS of the third substrate 74A also tilts at the same angle with respect to the image sensor 42. [ A plurality of microprisms 74B are arranged on the light incident surface 74AS of the third substrate 74A. The plurality of microprisms 74B are arranged in a stepped manner. The plurality of micro prisms 74B are attached to the light incident surface 74AS of the third substrate 74A.

In order to facilitate the understanding of the explanation, FIG. 14B shows the third substrate 74A and the microprism 74B as being separated from each other. The micro prism 74B may be a rectangular prism and may be the same as the micro prism 60A of FIG. The inclined surface, that is, the total reflection surface 74S2, is brought into contact with the light incident surface 74AS of the third substrate 74A. At this time, the surface 74S1 on which the incident light 40L of the micro prism 74B is incident may be parallel to the image sensor 42. [ The internal angle 76 between the image sensor 42 and the third substrate 74A is equal to the internal angle between the light incident surface 74S1 of the micro prism 74B and the total reflection surface 74S2. However, when the image sensor 42 is disposed perpendicularly to the light 74T incident from the third prism array 74, the internal angle 76 between the image sensor 42 and the third substrate 74A is smaller than the internal angle 76 between the image sensor 42 and the third substrate 74A, May be different from the internal angle between the light incidence surface 74S1 of the light exit surface 74B and the total reflection surface 74S2. The third substrate 74A may be a substrate that is transparent to light that has passed through the microprism 74B. The refractive index of the third substrate 74A is larger than the refractive index of air and may be smaller than the minimum refractive index of the microprism 74B due to external action. The incident light 40L incident on the optical shutter is totally reflected or refracted by the total reflection surface 74S2 of the micro prism 74B according to the condition of external action. Therefore, the light incident surface 74AS of the third substrate 74A is a surface to which light refracted by the total reflection surface 74S2 of the micro prism 74B is incident. The light 74R reflected from the total reflection surface 74S2 of the micro prism 74B by the external action such as the electric field 40E passes through the surface perpendicular to the incident surface of the micro prism 74B . Incidentally, the right angle surface is covered with the light absorbing means (44). Therefore, the total reflected light 74R is absorbed by the light absorbing means 44, so that the totally reflected light 74R is not incident on the neighboring micro prism 74B.

The micro prisms 74B are sequentially arranged in order from the highest part to the lowest part of the light incident surface 74AS of the third substrate 74A, as shown in the figure. Thus, if the light 74R that is totally reflected by the total reflection surface 74S2 under the external action proceeds parallel to the light incident surface 74AS, the total reflected light 74R may not affect other neighboring microprisms Therefore, the light absorbing means 44 may not be provided in Fig.

Fig. 14C is a plan view of the third prism array 74. Fig. The third prism array 74 shown in Fig. 14 (A) is a cross-sectional view taken along line 14A-14A in Fig. 14 (C). In Fig. 14, the pixels of the microprism 74B and the image sensor 42 correspond in a one-to-one correspondence. However, one microprism 74B may correspond to two or more pixels. This fact can be applied to the optical shutters including the prism arrays described in Figs. 10 to 13, and also to the optical shutters described later. When one prism array corresponds to a plurality of pixels as described above, the process margin for forming the prism array can be increased, and the prism array can be formed more easily.

On the other hand, when the incident light 40L in the optical shutter of Fig. 14 is a non-parallel light, that is, when the wave surface of the incident light 40L is not plane, (80) for changing the path of the incident light (40L) in front of the light source (74). The incident light path changing means 80 may be the same as the incident light path changing means described above.

On the other hand, a fourth prism array 84 may be further provided between the third prism array 74 and the image sensor 42 as shown in FIG. The fourth prism array 84 is a light path changing means. The light (74T in FIG. 14) refracted by the fourth prism array 84 from the third prism array 74 to the image sensor 42 is incident on the image sensor 42 in a direction perpendicular thereto. The fourth prism array 84 includes a third substrate 74A and a plurality of microprisms 84B. The third and fourth prism arrays 74 and 84 may share a third substrate 74A. The third substrate 74A may be formed by bonding two substrates. At this time, one of the two substrates may be included in the third prism array 74, and the other substrate may be included in the fourth prism array 84. The micro prisms 84B of the fourth prism array 84 may be the same as the micro prisms 74B of the third prism array 74. [ The micro prism 84B of the fourth prism array 84 is attached to the light emitting surface 74AT of the third substrate 74A. The inclined surface of the micro prism 84B is brought into contact with the light emitting surface 74AT of the third substrate 74A. The light emitting surface 84S1 of the micro prism 84B corresponds to the light incident surface 74S1 of the micro prism 74B and the micro prism 84B is attached such that the two surfaces 74S1 and 84S1 are parallel to each other. The micro prisms 84B of the fourth prism array 84 correspond to the micro prisms 74B of the third prism array 74 in a one-to-one correspondence. The incident light 40L passes through the micro prisms 74B of the third prism array 74, the third substrate 74A and the micro prisms 84B of the fourth prism array 84, The incident light 40L is not different from the process in which the incident light 40L passes through the total reflection prism 40, the gap 50 and the third prism 48 and is perpendicularly incident on the image sensor 42 in FIG.

When the non-parallel light is used as the incident light in the optical shutter of FIG. 16, the incident light path changing means 90 is provided in front of the third prism array 74 as shown in FIG. 17 so that the non-parallel incident light 68L is incident on parallel incident light (40L). The incident light path changing means 90 may be the same as the incident light path changing means 80 described with reference to FIG.

18 shows another embodiment of an optical shutter including a prism array. For the members described above, use the same reference number as used.

Referring to Fig. 18 (A), the optical shutter includes a fourth prism array 94. The fourth prism array 94 may be another embodiment of the total square modulation medium 30 of FIG. The fourth prism array 94 includes a fourth substrate 94A and a plurality of microprisms 94B. The fourth substrate 94A may be parallel to the image sensor 42. [ However, the image sensor 42 may be arranged such that the incident light 46T coming from the fourth prism array 94 is incident perpendicularly thereto. In this case, the image sensor 42 is parallel to the fourth substrate 94A . The micro prism 94B is provided on the light incident surface of the fourth substrate 94A. The process of forming the micro prisms 94B on the incident surface of the fourth substrate 94A may be basically the same as the process of forming the first prism array 60 of FIG. The micro prism 94B may be the same as the second prism 46 of FIG. 3 only in size. Therefore, the process in which the incident light 46L passes through the microprism 94B and becomes the refracted light 46T in FIG. 18 or the total reflection process may be as described in the second prism 46 in FIG.

The fourth substrate 94A is a substrate transparent to the incident light 46L. The fourth substrate 94A is a material having the same electro-optical characteristic as the micro prism 94B and has a function of externally acting, for example, in a state in which the electric field 46E is applied, The refractive index can be changed in the same manner. (B) is a plan view of the fourth prism array 94. FIG. (A) is a cross-sectional view of the fourth prism array 84 taken along the line 18A-18A in FIG.

Next, FIG. 19 shows another embodiment of an optical shutter having a prism array.

19, the optical shutter shown in FIG. 19 is a case in which a fifth prism array 98 is further provided between the image sensor 42 and the fourth prism array 94 in the optical shutter of FIG. The fifth prism array 98 is merely an example of the optical path changing means. Therefore, instead of the fifth prism array 98, other optical path changing means having an equivalent function thereto may be provided. The fifth prism array 98 is arranged such that the traveling direction of the light 46T traveling from the fourth prism array 94 to the image sensor 42 in the shutter-on state is perpendicular to the image sensor 42, ). By the provision of the fifth prism array 98, the image sensor 42 and the fourth prism array 94 in the optical shutter of FIG. 19 can be located on the same vertical optical axis. Accordingly, the horizontal size of the optical shutter can be reduced, and light can be incident on the image sensor 42 in a direction perpendicular to the optical axis, thereby enhancing the optical sensing efficiency of the image sensor 42.

Subsequently, a gap 100 is present between the fourth prism array 94 and the fifth prism array 98. The gap 100 may be, for example, 10 mu m or less. The thickness of the gap 100 is uniform. The gap 100 may be filled with an optical medium having a predetermined refractive index. The refractive index of the optical medium filling the gap 100 is smaller than that of the fourth and fifth prism arrays 94 and 98. The optical medium filling the gap 100 may be, for example, air or other material having a lower refractive index than the substrates 94A and 98A. Thus, the light passing through the gap 100 is simply moved horizontally in proportion to the thickness of the gap 100 in the direction of travel. Therefore, the thickness of the gap 100 can be appropriately determined in consideration of the position of the image sensor 42. [

The fifth prism array 98 includes a plurality of microprisms 98B together with a fifth substrate 98A. The fifth substrate 98A may be the same electro-optical material as the fourth substrate 94A. Further, the fifth substrate 98A may have the same thickness as the fourth substrate 94A. The fifth substrate 98A and the fourth substrate 94A are parallel to each other and face the gap 100 therebetween. Each microprism 98B may have the same electro-optical characteristic as the micro prism 94B of the fourth prism array 94 except for the direction of arrangement. In the fifth prism array 98, the micro prisms 98B are attached on the light emitting surface 98AS2 of the fifth substrate 98A. Each microprism 98B corresponds to the microprism 94B of the fourth prism array 94 in one-to-one correspondence. Each micro prism 98B has the same arrangement as the micro prisms 94B of the fourth prism array 94 rotated 180 degrees around the y axis and then rotated 180 degrees around the x axis. The light absorbing means 44 is provided on the surface of the fourth prism array 94 through which the totally-reflected light is emitted from the micro prism 94B. The micro prisms 98B Is also provided on the surface of the light absorbing member 98C. At this time, the light absorbing means 98C may not be provided as an option. The traveling direction of the incident light 46L is substantially changed by the two microprisms 94B and 98B and the shapes and the electro-optical characteristics of the two microprisms 94B and 98B are the same as those of the second and fourth prisms 46 , 52). Therefore, the process in which the light 46L incident on the optical shutter of FIG. 19 in the shutter-on state passes through the fourth and fifth prism arrays 94 and 98 and is incident on the image sensor 42 is shown in FIGS. 4 prisms 46 and 52 and incident on the image sensor 42. [0060] FIG.

The light 46L incident on the optical shutter of Fig. 18 is parallel light. However, non-planar light such as a divergent spherical wave can be incident on the optical shutter. In such a case, the incident light path changing means 110 may be provided in front of the third prism array 94, as in the case of the optical shutter shown in FIG. The incident light path changing means 110 may be, for example, a Fresnel lens. The incident light path changing means 110 changes the incident spherical wave light 68L into parallel light 46L.

19. In this case, the incident light path changing means 120 is provided in front of the third prism array 94 as in the example of the optical shutter shown in Fig. 21, . The incident light path changing means 120 shown in FIG. 21 may be the same as the incident light path changing means 110 shown in FIG.

In the optical shutters illustrated in FIGS. 20 and 21, the incident light path changing means 110 and 120 may be arranged to be in direct contact with the third prism array 94. However, a transparent flat plate having a uniform thickness may be further provided between the third prism array 94 and the incident light path changing means 110, 120.

22 shows an optical shutter according to another embodiment of the present invention.

Referring to FIG. 22, the optical shutter includes a sixth prism array and a seventh prism array. The seventh prism array 140 and the sixth prism array 130 are sequentially arranged above the image sensor 42. The sixth and seventh prism arrays 130 and 140 and the image sensor 42 are aligned on the same optical axis. A gap G2 exists between the sixth and seventh prism arrays 130 and 140. This gap G2 is a gap between specific surfaces of the sixth and seventh prism arrays 130 and 140, and is not as large as shown in Fig. In FIG. 22, the convenience gap G2 is markedly enlarged to facilitate understanding of the drawings and the drawings. Gap G2 is actually a gap existing between the inclined surface of the first annular microprism 130B and the inclined surface of the second annular microprism 140B as shown in FIG. The interval of the gap G2 may be, for example, 10 mu m or less.

 The sixth prism array 130 allows the incident light L1 to proceed to the seventh prism array 140 (shutter-on) according to the external action, for example, the intensity of the applied electric field E1 or the magnitude of the applied voltage. Or shutting off (shutter-off) function. The seventh prism array 140 has a function of changing the light path from the sixth prism array 130 to make the light enter the image sensor 42 vertically when the optical shutter is in the shutter-on state. The sixth prism array 130 includes a sixth substrate 130A and a plurality of first annular microprisms 130B. The sixth substrate 130A may be a transparent material that changes in accordance with a material having the same electro-optical characteristic as the first annular micro-prism 130B, for example, an electric field E1 to which a refractive index is applied. The sixth substrate 130A may be the same as the first substrate 62 of FIG. The first annular microprisms 130B have different sizes.

FIG. 22B is a bottom view of the sixth prism array 130. FIG.

(B), an array of the first annular microprisms 130B has annular micro-prisms having the smallest diameter at the center, and annular micro-prisms sequentially surround the peripheries in order of diameter. The cross section of the first annular microprism 130B is a rectangular prism like the microprism 60A of the first prism array 60 of FIG. 10 as seen in FIG. Therefore, the process of passing the incident light L1 through the annular microprism 130B of the sixth prism array 130 (the process of being totally reflected or refracted in the total reflection plane) may be the same as that described in FIG. 2 or FIG. A light absorbing means 135 is attached to a surface of the sixth prism array 130 on which the light RL1 reflected from the total reflection surface 130S1 of each first annular micro prism 130B is incident. The light absorbing means 135 may be the same as the light absorbing means 44 described in Fig. The seventh prism array 140 includes a seventh substrate 140A and a plurality of second annular microprisms 140B.

The seventh substrate 140A may be a substrate having the same electro-optical characteristics as the sixth substrate 130A. The sixth and seventh substrates 130A and 140A may be parallel to each other and have a uniform thickness. The second annular microprism 140B serves as a counterpart of the first annular microprism 130B. The second annular microprism 140B is the same as the microprism 64A of the second prism array 64 of FIG. Therefore, the arrangement relationship in which the first and second annular microprisms 130B and 140B correspond one-to-one is the same as the arrangement relationship of the first and second prism arrays 60 and 64 shown in FIG. Therefore, in the process in which the incident light L1 passes through the first and second annular micro prisms 130B and 140B and becomes the light TL1 incident perpendicularly to the image sensor 42, And is not different from the process of passing through the micro prisms 60A and 64A of the arrays 60 and 64. [

On the other hand, when the light incident on the optical shutter of FIG. 22 is nonparallel light, incident light path changing means 150 may be provided in front of the sixth prism array 130 as shown in FIG. The incident light path changing means 150 may be the same as the incident light path changing means 80, 90, 110 and 120 described above. The incident light path changing means 150 changes the path of the incident non-parallel light NL1 and emits it as parallel light.

24 shows an optical shutter according to still another embodiment of the present invention.

Referring to FIG. 24, the optical shutter includes eighth and ninth prism arrays 160 and 170. And the incident light L1 is incident on the eighth prism array 160. The ninth prism array 170 is provided between the eighth prism array 160 and the image sensor 42. The eighth and ninth prism arrays 160 and 170 and the image sensor 42 are arranged on the same optical axis. The eighth prism array 160 blocks or passes the incident light L1 according to an external action. The ninth prism array 170 is an example of the optical path changing means and changes the path of the light from the eighth prism array 160 so that light enters the image sensor 42 vertically. The eighth and ninth prism arrays 160 and 170 and the image sensor 42 are arranged in parallel as a whole. The eighth and ninth prism arrays 160 and 170 are spaced apart from each other. Therefore, a gap G3 exists between the eighth and ninth prism arrays 160 and 170. [ The gap G3 is filled with a predetermined optical material. At this time, the refractive index of the optical material is smaller than that of the eighth and ninth prism arrays 160 and 170. The optical material may be air or other material. The eighth prism array 160 includes an eighth substrate 160A and a plurality of third annular microprisms 160B. The eighth substrate 160A may be a material having the same electro-optical characteristic as the third annular microprism 160B. The eighth substrate 160A may be the same as the first substrate 62 of Fig. The eighth substrate 160A may be parallel to the image sensor 42. [ The third annular microprism 160B is attached on the light incident surface of the eighth substrate 160A. The third annular microprism 160B may be an electro-optic material whose refractive index changes according to an external action to change the total reflection angle. In the arrangement of the plurality of third annular microprisms 160B, as shown in FIG. 24B, there is an annular microprism having the smallest diameter in the center. And the remaining annular microprisms surround the smallest annular microprism in order of decreasing diameter. The light absorption means 180 is provided on the surface of the third annular micro prism 160B on which the light RL2 totally reflected is emitted. The light absorbing means 180 may be the same as the light absorbing means 44 described above.

The ninth prism array 170 includes a ninth substrate 170A and a plurality of fourth annular microprisms 170B. The ninth substrate 170A faces the eighth substrate 160A with the gap G3 interposed therebetween. The ninth substrate 170A may be parallel to the eighth substrate 160A and the image sensor 42. [ The ninth substrate 170A may be a substrate having the same electro-optical characteristics as the eighth substrate 160A. The ninth substrate 170A may have the same electro-optical characteristic as the fourth annular microprism 170B. Further, the ninth substrate 170A is not a substrate having electro-optical characteristics, but may be a substrate which is transparent and whose refractive index is close to the refractive index of the fourth annular microprism 170B. The fourth annular microprism 170B may correspond to or be arranged in a similar manner to the third annular microprism 160B. The fourth annular microprism 170B is attached to the light emitting surface of the ninth substrate 170A.

24A, the cross sections of the third and fourth annular microprisms 160B and 170B correspond to the micro prisms 94B and the fourth prism arrays 94B of the third prism array 94 of FIG. And the micro prism 98B of FIG. The incident light L1 passes through the fourth annular microprism 170B from the third annular microprism 160B in the shutter-on state, basically, the incident light 46L in the optical shutter of FIG. It may be the same as the process of passing through the micro prism 94B of the prism array 94 and the micro prism 98B of the fifth prism array 98. [ Therefore, the light TL2 passing through the ninth prism array 170 in the shutter-on state toward the image sensor 42 is incident on the image sensor 42 in a direction perpendicular thereto. The end face of the fourth annular microprism 170B is the same as the end face of the third annular microprism 160B rotated 180 degrees around the y axis and then rotated 180 degrees around the x axis. The light absorbing means 190 is attached to the surface of the fourth annular microprism 170B corresponding to the exit surface of the totally reflected light RL2 of the third annular micro prism 160B. The light incident on the fourth annular microprism 170B in the shutter-on state is refracted by the refracting surface 170S2 and is incident on the image sensor 42. [ In this process, some reflected light (not shown) may be generated on the refracting surface 170S2. The reflected light thus generated can interfere with the neighboring fourth annular microprism. The light absorbing means 190 absorbs the reflected light reflected by the refracting surface 170S2. Therefore, by providing the light absorbing means 190, optical interference between the fourth annular microprisms 170B can be prevented. When the light amount of the reflected light is small, the provision of the light absorbing means 190 may be omitted.

On the other hand, when the light L1 incident on the optical shutter of FIG. 24 is nonparallel light, the incident light path changing means 200 may be provided in front of the eighth prism array 160 as shown in FIG. The incident light path changing means 200 may be, for example, a Fresnel lens. The non-parallel light NL1 incident on the incident light path changing means 200 is incident on the eighth prism array 160 as the parallel light L1 while passing through the incident light path changing means 200.

Next, a simulation model for the optical shutter will be described, and operational characteristics obtained from the simulation model will be described.

26 shows an example of the simulation model. Such a simulation model may be used in a camera optical system.

Referring to FIG. 26, the lower electrode 212, the lower prism array 214, the upper prism array 216, the upper electrode 218, and the incident light path changing means 220 are sequentially stacked in the simulation model. The stacked elements can be contacted at the interface. Under the simulation model, a CCD image sensor 210 is provided immediately below the lower electrode 212. As a result, the stacks of the simulation model are on the CCD image sensor 210. On the CCD image sensor 210 is provided an adjusting frame 222 which is in contact with the side surface of the laminate including the lower electrode 212, the lower prism array 214, the upper prism array 216 and the upper electrode 218, Respectively. The adjustment frame 222 adjusts the separation distance of the upper and lower prism arrays 216 and 214. The gap G4 between the opposing slopes of the micro prisms 216B and 214B of the upper and lower prism arrays 216 and 214 can be adjusted to less than 10 mu m using the adjustment frame 222. [ The upper prism array 216 includes a plurality of annular microprisms 216B whose cross section is a right angle prism. A light absorbing means 224 is provided on a surface of the annular micro prism 216B on which the light totally reflected from the vertical surface, that is, the inclined surface which is the total reflection surface, is emitted. The lower prism array 214 is a light path changing means for changing the path of light incident from the upper prism array 216. The light incident on the CCD image sensor 210 is vertically incident on the CCD image sensor 210 do. The lower prism array 214 is a counterpart of the upper prism array 216 and includes a plurality of annular microprisms 214B. The annular micro prisms 214B of the lower prism array 214 are counterparts of the annular micro prisms 216B of the upper prism array 216 and correspond to the annular micro prisms 214B and 216B in a one-to-one correspondence. The incident light path changing means 220 may be a Fresnel lens. In the simulation model, the material of the upper and lower prism arrays 216 and 214 may be KTN. The upper and lower electrodes 218 and 212 are transparent electrodes, and a voltage of about 0 to 250 V may be applied between both electrodes, and this voltage can be changed continuously. The width of the simulation model may be about 1 cm, and the total height of the upper and lower prism arrays 216 and 214 may be 10 micrometers. The overall thickness of the simulation model is about 1 mm.

27 shows an equivalent circuit for the simulation model of Fig. In Fig. 27, Vshutter represents a voltage applied to the upper and lower prism arrays 216 and 214 in Fig. And C shutter represents the capacitance of the upper and lower prism arrays 216 and 214. Also, Ru represents a load resistance on the circuit. V represents the voltage applied to the optical device including the optical shutter of Fig.

FIG. 28 shows the applied voltage-transmittance specification for the simulation model of FIG. In FIG. 28, the abscissa represents the voltage applied to the upper and lower prism arrays 216 and 214 through the upper and lower electrodes 218 and 212 in the simulation model. And the vertical axis represents the transmittance of the upper and lower prism arrays 216 and 214 according to the applied voltage.

The total reflection angle of the microprisms 216B in the KTN upper prism array 216 is about 26 degrees. The upper prism array 216 is regarded as formed to have a smaller total reflection angle depending on an external action, that is, an applied voltage. The angle of incidence of the image light incident on the inclined plane of the micro prism 216B of the upper prism array 216, that is, the total reflection plane, is smaller than 26 degrees and is constantly maintained in a range larger than the minimum overall angle of incidence . For example, if the minimum total reflection angle is 24 °, the incident angle of the image light can be maintained at 25 °.

Referring to FIG. 28, when the applied voltage is 0 (when the intensity of the applied electric field is 0), the transmittance of the simulation model becomes close to 100%. Therefore, it can be seen that the simulation model is in the shutter-on state. As the applied voltage increases (the intensity of the applied electric field increases), the transmittance of the simulation model is close to 0%. As the applied voltage increases, the total reflection angle of the upper prism array 216 starts to become smaller than the fixed total reflection angle of 26 degrees and becomes smaller than the incident angle of the image light. Thus, all of the image light incident on the upper prism array 216 is totally reflected. As a result, the simulation model becomes a shutter-off state. In Fig. 28, the transmittance varies continuously depending on the applied voltage. According to these results, it is possible to continuously control the transmittance by changing the applied voltage continuously in a given applied voltage range.

On the other hand, in the simulation model, if the upper prism array 216 is formed so as to increase the total reflection angle depending on the external action, that is, the applied voltage, the influence of the applied voltage is reversed from FIG. That is, when the applied voltage is 0, the simulation model is in the shutter-off state, and the simulation model becomes the shutter-on state as the applied voltage increases.

FIG. 29 shows the time response to the applied voltage, that is, the rate of change of the shuttering state, when a voltage is applied to the simulation model.

Referring to FIG. 29, it can be seen that the transmittance is greater than 80% in 1 ns after the voltage is applied. This result means that applying the voltage only takes about 1 ns to change the simulation model in the shutter-off state to the shutter-on state. Since the change in the shuttering state is reversible, the result in Fig. 29 means that the time for changing the shutter-on state to the shutter-off state is also about 1 ns. A shutter speed of about 1 ns is much faster than a conventional high speed shutter for image processing. Thus, images can be deformed or modulated at high speed.

30 to 35 show the shutter speed according to the type of voltage applied to the simulation model.

FIGS. 30 to 32 show the transmittance change when the waveform of the applied voltage is a rectangular file, and FIGS. 33 to 35 show the transmittance change when the waveform of the applied voltage is a sine file. The waveform of the voltage is not limited to a square wave or a sine wave.

Referring to FIGS. 30 to 32, when the applied voltage is a rectangular file, the transmittance change is stable up to 10 MHz and the transmittance change is distorted at 1 GHz. 33 to 35, it can be seen that the transmittance change is stable up to 1 GHz when the applied voltage is a sine file.

36 is an example of an optical device including the optical shutter described above, and may be a camera system for distance measurement.

36, the optical device includes a light source 710, a light source driver 720, a camera controller 730, an optical image sensor 750, first and second lenses LZ1 and LZ2, a filter 780, And an optical shutter 770. The first lens LZ1, the filter 780, the optical shutter 770, the second lens LZ2, and the optical image sensor 750 are arranged in a line and may be on the same optical axis. The irradiation light TL irradiated to the object 700 is emitted from the light source 710. [ At this time, the irradiation light TL may be light having a predetermined wavelength, for example, infrared rays. The irradiation light TL can be irradiated in the form of a pulse wave or a sine wave. The light source 710 is controlled by the light source driver 720. The operation of the light source driver 720 is controlled by the camera controller 730. The camera controller 730 controls the operation of the optical shutter 770 and the optical image sensor 750. The optical image sensor 750 may be, for example, a CCD or a CMOS. The first lens LZ1 collects the reflected light RL reflected from the subject 700 to be incident on the filter 780 in a suitable manner. The filter 780 is a band filter for removing the irregular light except for the irradiated light TL from the reflected light RL, and may be, for example, an IR band filter. The second lens LZ2 serves to condense the light emitted from the optical shutter 770 to the optical image sensor 750. [ The optical shutter 770 may be any one of the optical shutters according to the embodiments of the present invention described above.

The optical shutters according to the embodiments of the present invention can be applied to a LADAR or a display device such as a liquid crystal display device (LCD) in addition to a 3D camera. In addition, the optical shutters can be applied to devices requiring an optical element for controlling transmission / Can be applied.

Although a number of matters have been specifically described in the above description, they should be interpreted as examples of preferred embodiments rather than limiting the scope of the invention. Therefore, the scope of the present invention is not to be determined by the described embodiments but should be determined by the technical idea described in the claims.

1 is a cross-sectional view showing a configuration concept of an optical shutter according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the optical shutter configuration when the total reflection recording medium 30 of FIG. 1 is a total reflection prism.

3 is a sectional view of an optical shutter using another type of prism in place of the right angle prism 40 in Fig.

4 is a cross-sectional view showing the case where the optical path changing means is provided in the optical shutter shown in Fig.

5 is a cross-sectional view showing a case where the optical path changing means is provided in the optical shutter of FIG.

6 is a cross-sectional view showing an embodiment of an optical shutter including means for changing the optical path of incident light so that the light incident on the incident surface of the total reflection medium is parallel light.

FIG. 7 is a cross-sectional view showing an embodiment of an optical shutter including the incident light path changing means in the case of FIG. 4;

8 is a cross-sectional view showing an example in which the optical shutters shown in Fig. 3 are further provided with an incident light path changing means.

9 is a cross-sectional view showing an example in which the optical shutters shown in Fig. 5 are further provided with an incident light path changing means.

10A is a cross-sectional view showing an embodiment of an optical shutter including an array in which the total reflection prism 40 of FIG. 2 is used as a unit total square control medium, and FIG. 10B is a plan view.

11 is a cross-sectional view illustrating a case where a second prism array 64 is provided between the image sensor 42 and the first prism array 60 in FIG.

12 is a cross-sectional view of an optical shutter having an incident light path changing means on the light incident surface of the first substrate in FIG.

FIG. 13 is a cross-sectional view of an optical shutter having an incident light path changing means on the light incident surface of the first substrate in FIG. 11; FIG.

14 is a cross-sectional view showing another embodiment of an optical shutter including a prism array composed of a plurality of microprisms.

Fig. 15 is a cross-sectional view showing a case in which a means for changing the path of incident light is provided in front of the third prism array in the optical shutter of Fig. 14;

FIG. 16 is a sectional view showing a case where a fourth prism array is further provided between the third prism array and the image sensor in the optical shutter of FIG. 14;

17 is a cross-sectional view showing a case in which an incident light path changing means is provided in front of the third prism array 74 in the optical shutter of FIG.

18 is a sectional view showing still another embodiment of the optical shutter including the prism array.

19 is a cross-sectional view showing still another embodiment of an optical shutter having a prism array.

20 is a cross-sectional view showing an optical shutter including an incident light path changing means in front of the third prism array in the optical shutter of FIG. 18;

 FIG. 21 is a cross-sectional view showing a case in which an incident light path changing means is provided in front of the third prism array in the optical shutter shown in FIG. 19;

22 is a cross-sectional view and a bottom view showing an optical shutter according to still another embodiment of the present invention.

23 is a cross-sectional view showing the case where the incident light path changing means 150 is provided in front of the sixth prism array in the optical shutter of FIG.

24 is a cross-sectional view showing an optical shutter according to still another embodiment of the present invention.

25 is a cross-sectional view showing the case where the light path changing means is provided in front of the eighth prism array in the optical shutter of FIG.

26 is a cross-sectional view showing a simulation model of an optical shutter according to the embodiment of the present invention.

27 shows an equivalent circuit for the simulation model of Fig.

28 is a graph showing the applied voltage-transmittance specification for the simulation model of Fig.

FIG. 29 is a graph showing a time response, that is, a rising time, with respect to an applied voltage when a voltage is applied to the simulation model of FIG.

FIGS. 30 to 35 show the shutter speed according to the type of voltage applied to the simulation model of FIG.

36 shows a configuration of an optical device including an optical shutter according to an embodiment of the present invention.

Description of the Related Art [0002]

30: total reflection angle adjustment medium 40: total reflection prism

35, 42, 210: image sensors 44, 98C, 135, 190: light absorbing means

46, 48, 52: second to fourth prisms 50, 54, 72, 100, G2, G3, G4:

60, 64, 76, 94, 98, 130, 140, 160, 170: first to ninth prism arrays

The first to ninth substrates 100a, 100b, 100c, 100d,

68, 70, 80, 90, 110, 120, 150, 200, 220:

76: Cabinet 212: Lower electrode

214: lower prism array 216: upper prism array

218: upper electrode 222: adjusting frame

216B: annular microprism

710: Light source 720: Light source driver

730: Camera controller 750: Optical image sensor

780: Filter 770: Optical shutter

40A, 46B: Incident angle

40S1, 46S1, 52S1, 58S1, 74AS, 74S1:

40L, 46L, 68L, L1: incident light 40T, 46T, 74T, TL2: refracted light

40R, 46R, RL1: Total reflected light 40DL: Spherical wave incident light

40E, 46E, E1: electric field 42P: pixel (pixel)

40S2, 46S2, S1, 60S2, 74S2, and 130S1:

48T, 52S2, 58S2, 74AT, 98AS2: light emitting side

52T: light emitted from the light emitting surface 52S2

58: collimating means

60a, 64A, 74B, 84B, 94B, 98B:

68L, NL1: Non-parallel incident light

130B, 140B, 160B, and 170B: first to fourth annular microprisms

170S2: refracting surface

L: an incident light incident on the total reflection angle adjusting medium 30

Lt: refracted light LZ1, LZ2: first and second lenses

t1: thickness of the first prism array 60

Claims (33)

Optical medium having a total reflection surface whose total reflection angle is changed by an external action, wherein one surface of the electro-optic medium is covered with a light absorbing film, An optical shutter that is not on the path of light passing through. The method according to claim 1, Further comprising optical path changing means for causing the light to be vertically incident on an object to which light having passed through the electro-optical medium is incident. 3. The method of claim 2, And an incident light path changing means in front of the electro-optical medium. 3. The method of claim 2, Wherein the electro-optical medium and the optical path changing means comprise a prism or a prism array. 5. The method of claim 4, Optical printers of the electro-optic medium and the optical path changing means are arranged so as to have the same shape but have mutual symmetry. 5. The method of claim 4, Wherein the prism array of the electro-optical medium and the optical path changing means includes a plurality of micro-prisms, and the cross-section of the micro-prisms of the electro- An optical shutter in which an electro-optic medium and a prism array of said optical path changing means are arranged. The optical shutter according to claim 6, wherein the micro-prism is an annular micro-prism. The method of claim 3, Wherein the incident light path changing means is a lens unit that emits light incident on the light path changing means in parallel to the electro-optic medium. 5. The method of claim 4, Wherein a gap of a uniform thickness exists between the electro-optic medium and the optical path changing means on the optical path. The method according to claim 6, Wherein the light absorbing film is attached to one surface of the prism of the electro-optical medium or one surface of the micro prism, and the one surface is a surface to which the totally reflected light is incident. 10. The method of claim 9, Wherein the gap is filled with air or an optical medium having a refractive index lower than that of the prism or the prism array. The method according to claim 1, Further comprising an incident light path changing means in front of the electro-optic medium. 13. The method of claim 12, Wherein the incident light path changing means is a prism or a prism array. 13. The method of claim 12, Wherein the incident light path changing means changes the path of the incident light so that incident light incident on the light path changing means is incident on the electro-optic medium as parallel light. The method according to claim 1, Wherein the electro-optical medium is a prism or prism array in which incident light is totally reflected or transmitted according to the external action. 16. The method of claim 15, Wherein a light incident surface of the prism or a light incident surface of a microprism included in the prism array is inclined with incident light. 16. The method according to claim 13 or 15, Wherein the prism array is a plurality of micro prisms or annular micro prisms in the form of strips. The method according to claim 1, Wherein the external action is an electric field generated by applying a voltage. 16. The method of claim 15, Wherein the light absorbing film is attached to one surface of the prism or one surface of a microprism included in the prism array, and the one surface is a surface through which the totally reflected light is incident. 3. The method of claim 2, Wherein the light path changing means includes a prism or a prism array and a light absorbing film is attached to one surface of the prism or one surface of the prism array and the light absorbing film is on a path of light passing through the prism or the prism array Unknown optical shutter. The method according to claim 1, Wherein the electro-optic medium itself is inclined with respect to an object to which light emitted from the electro-optic medium is incident. In a camera including an optical shutter, Wherein the optical shutter is the optical shutter according to claim 1 or claim 2. 23. The method of claim 22, Wherein the electro-optic medium further comprises an incident light path changing means in front of the electro-optic medium. 23. The method of claim 22, Wherein the electro-optical medium and the optical path changing means comprise a prism or a prism array when the optical shutter is the optical shutter of claim 2. In a display device including an optical shutter, Wherein the optical shutter is the optical shutter according to claim 1 or claim 2. 26. The method of claim 25, Wherein the electro-optical medium further comprises an incident light path changing means. 26. The method of claim 25, Wherein the electro-optical medium and the optical path changing means comprise a prism or a prism array when the optical shutter is the optical shutter of claim 2. A method of operating an optical shutter comprising the electro-optic medium of claim 1, And applying a voltage to the electro-optic medium to vary the total reflection angle of the electro-optic medium. 29. The method of claim 28, Wherein the voltage is continuously applied to continuously change the total reflection angle of the electro-optic medium. 29. The method of claim 28, Wherein the total reflection angle of the electro-optic medium is reduced according to the application of the voltage. 29. The method of claim 28, Wherein the total reflection angle of the electro-optic medium increases as the voltage is applied. 29. The method of claim 28, Wherein the incident angle of the incident light incident on the electro-optic medium is smaller than the fixed total square of the electro-optic medium and greater than the minimum total square by the voltage application. 29. The method of claim 28, Wherein the incident angle of the incident light incident on the electro-optic medium is greater than the fixed total square of the electro-optic medium and less than the maximum total square by applying the voltage.

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