Waveguide for effective condensing of divergent light source

Abstract

The present invention relates to a waveguide for switching an optical path and, more particularly, a waveguide in which, when a light source incident from a light source-incident port is reflected by a reflector, wherein a surface of the reflector is a curved surface in the longitudinal direction, and a cross section vertically cut based on the longitudinal center line of the curved surface is a parabolic shaped surface, and thus the light source can be switched to an optical path oriented in a constant direction and emitted through a light source-emission port, thereby increasing light efficiency.

Description

Waveguide for effective concentration of diverging light sources

[0001] The present invention relates to a waveguide for switching optical paths, and more specifically, to a waveguide with high light efficiency in which, when a light source incident from a light source entrance is reflected by a reflector, the optical path is switched toward the direction of a light source exit port so that the light is emitted in a constant direction regardless of the angle of incidence of the original light source.

[0002] A light source exists at a point in space and can propagate in all directions.

[0003] In this case, the path along which the light source travels is called the optical path, and according to the principle of the rectilinear propagation of light, that path is in a straight direction.

[0004] Therefore, a waveguide, a special optical device, is required to change the direction of the optical path.

[0005] A waveguide is a device that collects and efficiently transmits light by limiting the divergence of a light source that diverges in all directions, thereby ensuring that the light source's optical path follows a specific direction.

[0006] These waveguides can be constructed based on various principles.

[0007] For example, an optical fiber, a type of optical waveguide, forms a reflector with a structure in which a dielectric material with a high refractive index is surrounded by a material with a low refractive index, thereby causing a series of total internal reflections.

[0008] In these optical fibers, when an incident light source is incident to satisfy the critical angle, which is the requirement for total internal reflection, the light source propagates while maintaining a constant path.

[0009] In this case, when the light source enters the narrow entrance of the optical fiber, the path is switched and propagation becomes possible only when the angle of incidence is greater than the critical angle.

[0010] However, light sources incident at an angle smaller than the critical angle have difficulty propagating.

[0011] As such, depending on the angle of incidence of the light source incident inside the waveguide, there are cases where the optical path cannot be switched and the light cannot be emitted from the waveguide.

[0012] As such, there is a problem in that the light efficiency of the waveguide decreases as the number of light sources that cannot be emitted increases.

[0013] Since the incident direction of a light source cannot be physically limited and results in an infinite number of possibilities, a new waveguide design is required to converge and convert them into a single direction.

[0014] In other words, since the angle at which a light source is reflected by a reflector inside a waveguide varies depending on the direction in which the optical path enters the waveguide from the outside, and the optical path is switched accordingly, the structure of the reflector's surface is an important requirement to ensure that the light exits from a single outlet.

[0015] If the optical path of a light source reflected from a reflector is diverted to a path that bypasses the exit and remains in the waveguide without exiting, the optical efficiency decreases; therefore, there is a need for research on methods to maximize optical efficiency in the waveguide.

[0016] The present invention has been devised to solve the aforementioned problems, and the objective of the present invention is to provide a waveguide that enables a light source incident through a light source entrance to be reflected by a reflector, wherein the surface of the reflector is a curved surface in the longitudinal direction, and the cross-section cut perpendicularly with respect to the longitudinal centerline of the curved surface is a parabolic surface, thereby converting the light source into an optical path directed in a certain direction and allowing it to be emitted from a light source exit port.

[0017] To achieve the above objective, the present invention comprises: a light source inlet opening into which a light source is incident; and

[0018] A waveguide for switching an optical path is provided, comprising: a first reflector positioned spaced apart from the light source inlet and positioned to switch the optical path of the incident light source; wherein the first reflector includes a first reflective surface that reflects the light source, and the first reflective surface is a curved surface in the longitudinal direction, and the cross-section cut perpendicularly with respect to the longitudinal centerline of the curved surface is a parabolic shape.

[0019] In a preferred embodiment, the apparatus may further comprise: a second reflector positioned in contact with one side of the first reflector and spaced apart from the other side, and positioned to re-reflect by switching the optical path of a light source reflected from the parabolic surface of the first reflector; a third reflector positioned facing and spaced apart from the second reflector and positioned to switch the optical path of a light source re-reflected from the second reflector; and a light source outlet positioned in contact with one side of the third reflector and spaced apart from the other side, through which a light source with a switched optical path from the third reflector is emitted.

[0020] In a preferred embodiment, the second reflector includes a second reflective surface that re-reflects a reflected light source, and the second reflective surface may be characterized as being a curved surface in the longitudinal direction and having a parabolic shape in the cross-section cut perpendicularly with respect to the longitudinal centerline of the curved surface.

[0021] In a preferred embodiment, the third reflector includes a third reflective surface for emitting a light source that is re-reflected from the second reflective surface, and the third reflective surface may be characterized as being a curved surface in the longitudinal direction and having a parabolic shape in the cross-section cut perpendicularly with respect to the longitudinal centerline of the curved surface.

[0022] The present invention has the following excellent effects.

[0023] The waveguide for optical path switching according to the present invention has the advantage that when a light source incident through a light source entrance is reflected by a reflector, the optical path is switched and emitted in a constant direction regardless of the angle of incidence of the light source incident within the waveguide, and accordingly, the light source is emitted with high light efficiency.

[0024] FIG. 1 is a drawing illustrating a waveguide for optical path switching according to an embodiment of the present invention, and

[0025] FIG. 2 is a cross-sectional view of a waveguide for optical path switching according to an embodiment of the present invention, and

[0026] FIG. 3 is a drawing illustrating a waveguide for optical path switching according to a comparative example of the present invention, and

[0027] FIG. 4 is a cross-sectional view of a waveguide for optical path switching according to a comparative example of the present invention, and

[0028] FIG. 5 is a diagram showing the optical path of a light source incident at the light source inlet port of a waveguide according to one embodiment of the present invention and the distribution of a light source emitted at the light source outlet port by simulation.

[0029] Figure 6 is a diagram showing the optical path of a light source incident at the light source inlet port and the distribution of a light source emitted at the light source outlet port of a waveguide according to one comparative example of the present invention by simulation.

[0030] [Explanation of the symbol]

[0031] 110: Light source entrance

[0032] 120: First reflector

[0033] 120a: First reflective surface

[0034] 130: Second reflector

[0035] 130a: Second reflective surface

[0036] 140: Third reflector

[0037] 140a: Third reflective surface

[0038] 150: Light source exit point

[0039] The terms used in this invention have been selected to be as widely used as possible; however, in specific cases, terms have been arbitrarily selected by the applicant. In such cases, the meaning should be understood by considering the meaning described or used in the detailed description of the invention, rather than merely the name of the term.

[0040] Hereinafter, the technical configuration of the present invention will be described in detail with reference to preferred embodiments illustrated in the attached drawings.

[0041] However, the present invention is not limited to the embodiments described herein and may be embodied in other forms.

[0042] Identical reference numbers throughout the specification represent identical components.

[0043] FIG. 1 is a drawing showing a waveguide for optical path switching according to one embodiment of the present invention, and FIG. 2 is a drawing showing a cross-section of a waveguide for optical path switching according to one embodiment of the present invention.

[0044] Referring to FIGS. 1 and 2, the waveguide (100) according to the present invention is a device for switching the optical path of an incident light source, and performs the function of switching the optical path so that the light source is emitted in a certain direction when the incident light source enters the waveguide, regardless of the initial angle of incidence.

[0045] In addition, the waveguide (100) may be configured as shown in FIG. 1 or may be configured as a waveguide having various other external shapes.

[0046] Additionally, it can be confirmed that the waveguide (100(A-A')) is formed by including a light source inlet (110) and a first reflector (120) from a cross-section of the waveguide cut in the AA' direction as shown in FIG. 2.

[0047] The above light source inlet (110) is the entrance of a waveguide into which a light source is incident.

[0048] In this case, the incident light source corresponds to light emitted as energy generated through heat, chemical reactions, mass conversion, or electromagnetic waves, and the angle of incidence, which is the angle at which the light enters the waveguide, can be incident in any direction without restriction as long as it is an angle that allows entry into the waveguide.

[0049] In addition, devices capable of generating an incident light source, such as light-emitting diodes (LEDs) and infrared emitters (Emitter), can be used.

[0050] The first reflector (120) is positioned spaced apart from the light source inlet (110) and is positioned to switch the light path of the incident light source.

[0051] This is to ensure that the optical path of the light source incident in the x-axis direction through the light source inlet (110) is converted into an optical path in the z-axis direction when reflected by the first reflector (120).

[0052] At this time, as shown in FIG. 2, it is preferable that the first reflector (120) has a portion that is close and a portion that is far from the light source incident port (110), so that it forms an oblique angle when separated from the light source incident port (110).

[0053] In addition, the x, y, and z axes correspond to virtual axes that define the three-dimensional space in which the waveguide exists, and in the present invention, as illustrated in FIG. 1 and the same applies below.

[0054] In addition, the first reflector (120) includes a first reflective surface (120a) that reflects a light source.

[0055] In addition, the structure of the first reflective surface (120a) can be confirmed in detail from an enlarged view (200(a)) in which only the first reflector (120) is cut and enlarged from the waveguide (100).

[0056] Additionally, the first reflective surface (120a) is a curved surface in the longitudinal direction, and the cross-section (200(b)) cut in the vertical direction (B-B') with respect to the longitudinal centerline (120b) of the curved surface is a parabolic surface in the shape of a parabola.

[0057] This is to ensure that the light path of the light source reflected from the first reflector (120) is not radiated in the xy plane but is consistently switched in the z-axis direction.

[0058] Additionally, the waveguide (100(A-A')) may be configured to further include a second reflector (130), a third reflector (140), and a light source outlet (150) as shown in FIG. 2.

[0059] The second reflector (130) is positioned to re-reflect the light path of the light source reflected from the parabolic surface of the first reflector (120).

[0060] This is to convert the light path of the light source reflected in the z-axis direction from the first reflector (120) back into a light path in the x-axis direction and reflect it again.

[0061] Additionally, the second reflector (130) may be positioned in contact with one side of the first reflector (120) and spaced apart from the other side.

[0062] At this time, as shown in FIG. 2, it is preferable that the distance between the first reflector (120) and the second reflector (130) gradually increases from one side in contact with the first reflector (120) to the other side that is spaced apart.

[0063] Additionally, the second reflector (130) includes a second reflective surface (130a) that reflects the reflected light source back.

[0064] Additionally, the second reflective surface (130a) is a curved surface in the longitudinal direction and is formed as a parabolic surface in which the cross-section cut perpendicularly with respect to the longitudinal centerline of the curved surface is in the shape of a parabola.

[0065] That is, it is desirable to have a single focus as a parabolic surface, like the first reflector (120) above.

[0066] This is to redirect the light source reflected from the first reflective surface (120a) so that it is directed back toward the x-axis direction, as many of the light sources are radiated in the yz plane.

[0067] The third reflector (140) is positioned to divert the light path of the light source reflected back from the parabolic surface of the second reflector (130).

[0068] This is to convert the light path of the light source reflected in the x-axis direction from the second reflector (130) back into a light path in the z-axis direction and reflect it again.

[0069] Additionally, the third reflector (140) may be spaced apart from and facing the second reflector (130), and may be arranged in various ways to switch the light path of the light source.

[0070] Additionally, the third reflector (140) includes a third reflective surface (140a) for emitting a light source that is reflected back from the second reflective surface (130a).

[0071] Additionally, the third reflective surface (140a) is a curved surface in the longitudinal direction and is formed as a parabolic surface in which the cross-section cut perpendicularly with respect to the longitudinal centerline of the curved surface is in the shape of a parabola.

[0072] That is, it is desirable to have a single focus as a parabolic surface, like the first reflector (120) above.

[0073] This is to prevent the light path of the light source from radiating in a direction other than the z-axis direction when the light source is emitted from the third reflective surface (140a), and to change the direction so that it faces the z-axis direction.

[0074] The light source emission port (150) emits a light source whose light path has been switched at the third reflector (140).

[0075] Additionally, the light source outlet (150) may be positioned without restriction as long as it is in contact with one side of the third reflector (140) as shown in FIG. 2 and spaced apart from the other side, or in a structure where a light source can be emitted in various embodiments.

[0076] Therefore, it can be confirmed that the light path (A1) of the light source incident in the x-axis direction through the light source inlet (110) is switched to the z-axis direction at the light source outlet (150).

[0077]

[0078] In the following, to explain the effect of the waveguide according to the present invention, a waveguide according to a comparative example will first be described with reference to FIGS. 3 and 4.

[0079] FIG. 3 is a drawing showing a waveguide for optical path switching according to one comparative example of the present invention, and FIG. 4 is a drawing showing a cross-section of a waveguide for optical path switching according to one comparative example of the present invention.

[0080] Referring to FIG. 3, a waveguide (10) according to one comparative example of the present invention is designed to function as a device for switching the optical path of an incident light source, in the same way as the waveguide (100) in the present invention.

[0081] Additionally, it can be seen that the waveguide (10(C-C')) is configured to include a light source inlet (11) and a fourth reflector (12) from a cross-section of the waveguide cut in the CC' direction as shown in FIG. 4, and may additionally include a fifth reflector (13), a sixth reflector (14), and a light source outlet (15).

[0082] The light source inlet (11) and the light source outlet (15) are configured in a physical form that allows a light source to be incident and emitted, identical or similar to an embodiment of the present invention.

[0083] However, in the waveguide (10) according to one comparative example of the present invention, both the optical path (B1) of the light source emitted through the light source output port (15) and the optical path (C2) of the light source that was not emitted exist.

[0084] This is because the structure of the fourth reflector (12), the fifth reflector (13), and the sixth reflector (14) is different from the first reflector (120), the second reflector (130), and the third reflector (140) in the waveguide according to the present invention.

[0085] The above-mentioned fourth reflector (12) is spaced apart from the light source inlet (11) and is positioned to change the path of the light source incident in the x-axis direction.

[0086] This is to ensure that when a light source incident in the x-axis direction through the light source inlet (11) is reflected by the fourth reflector, the light path is switched to the z-axis direction.

[0087] In addition, as shown in FIG. 3, it is preferable that the fourth reflector (12) has a portion that is close and a portion that is far from the light source incident port (11).

[0088] Additionally, referring to the enlarged view (20(a)) in which only the fourth reflector (12) is cut out and enlarged, the fourth reflector (12) includes a fourth reflective surface (12a) that reflects a light source.

[0089] In addition, the fourth reflective surface (12a) is a curved surface that is curved in the longitudinal direction.

[0090] Additionally, the fourth reflective surface (12a) is formed as a flat plane in which the cross-section (20(b)) cut in the vertical direction (D-D') with respect to the longitudinal centerline (12b) of the curved surface is rectangular.

[0091] At this time, the light source reflected from the fourth reflector (12) is divided into a light path (B) of a light source that is incident in the x-axis direction and then converted in the z-axis direction, and a light path (C) of a light source that is radiated in the xy plane and cannot be converted in the z-axis direction.

[0092] This is because, since the radius of curvature in the plane is infinite, the focal length also becomes infinite, so the light source reflected in the y-axis direction from the fourth reflective surface (12a) cannot be converged into a single focal point.

[0093] The above-mentioned fifth reflector (13) and sixth reflector (14) each include a fifth reflective surface (13a) and a sixth reflective surface (14a), and may be identical to the arrangement between the first reflector (120), second reflector (130), and third reflector (140) in one embodiment of the present invention.

[0094] However, the fifth reflective surface (13a) and the sixth reflective surface (14a) are curved surfaces that are bent in the longitudinal direction, just like the fourth reflective surface (12a), and are formed as flat planes in which the cross-section cut vertically with respect to the longitudinal centerline of the curved surfaces is in the shape of a straight line.

[0095] Therefore, at the fifth reflective surface (13a), the light source radiating in the yz plane is not converted into a light path in the x-axis direction, and at the sixth reflective surface (14a), the light source (C1) is not converted into a light path in the z-axis direction and thus cannot be emitted.

[0096] That is, in the waveguide according to one comparative example of the present invention, there is a light source that is not emitted, thereby lowering the light efficiency.

[0097] Hereinafter, with reference to FIGS. 5 and 6, the effects according to one embodiment of the present invention and one comparative example are compared as experimental results through simulation.

[0098] Figure 5 is a diagram showing the optical path of a light source incident at the light source entrance of a waveguide according to one embodiment of the present invention and the distribution of a light source emitted at the light source exit.

[0099] Referring to FIG. 5, the light source distribution (16a) can be confirmed when a light source emitted by simulating a waveguide (100a) according to one embodiment of the present invention is detected through a detector (16).

[0100] At this time, the light source was generated using a laser, and the simulation was performed under the condition that 10,000 optical paths of the incident light source were generated.

[0101] In addition, when the entire path of the light source is checked in the plan view (100b), it can be seen that the light path (A2) of the light source converges at the light source exit port (150).

[0102] At this time, according to the simulation results, the optical path of the light source reaching the detector is 6030, which corresponds to about 60% of the ratio of the optical path of the emitted light source to the optical path of the incident light source.

[0103] Figure 6 is a diagram showing the optical path of a light source incident at the light source inlet port and the distribution of a light source emitted at the light source outlet port of a waveguide according to one comparative example of the present invention by simulation.

[0104] At this time, the light source was generated using a laser, and 10,000 optical paths of the incident light source were generated, so the simulation conditions are the same as in one embodiment according to the present invention.

[0105] Referring to FIG. 6, when a light source emitted by simulating a waveguide (10a) according to one comparative example of the present invention is detected through a detector (16), the light source distribution (16b) is small, unlike FIG. 5.

[0106] Additionally, when the entire path of the light source is checked in the plan view (10b), it can be seen that the optical path (B2) of some light sources reaches the light source exit port (15), but the optical path (C2) of some light sources does not converge and remains inside the waveguide.

[0107] At this time, according to the simulation results, the optical paths of the light source reaching the detector are 765, which corresponds to about 7% of the ratio of the optical paths of the emitted light source to the optical paths of the incident light source.

[0108] That is, when the optical path is switched using the waveguide according to the present invention, the optical efficiency can be increased by about 10 times compared to the waveguide according to the comparative example.

[0109] As described above, the present invention has been illustrated and explained with reference to preferred embodiments, but it is not limited to the aforementioned embodiments, and various changes and modifications may be made by those skilled in the art within the scope of the invention without departing from the spirit of the invention.

Claims

1. A light source entrance into which a light source is incident; and It includes a first reflector positioned spaced apart from the light source inlet and positioned to switch the optical path of the incident light source; A waveguide for optical path switching, characterized in that the first reflector includes a first reflective surface that reflects a light source, the first reflective surface is a curved surface in the longitudinal direction, and the cross-section cut perpendicularly with respect to the longitudinal centerline of the curved surface is a parabolic shape.

2. In Paragraph 1, A second reflector positioned in contact with one side of the first reflector and spaced apart from the other side, and positioned to re-reflect by switching the light path of a light source reflected from the parabolic surface of the first reflector; A third reflector positioned spaced apart from and facing the second reflector, and positioned to switch the light path of a light source reflected back from the second reflector; and A waveguide for optical path switching, further comprising: a light source output port positioned in contact with one side of the third reflector and spaced apart from the other side, through which a light source with an optical path switched from the third reflector is emitted.

3. In Paragraph 2, A waveguide for optical path switching, characterized in that the second reflector includes a second reflective surface that re-reflects a reflected light source, and the second reflective surface is a curved surface in the longitudinal direction, and the cross-section cut perpendicularly with respect to the longitudinal centerline of the curved surface is a parabolic shape.

4. In Paragraph 3, A waveguide for optical path switching, characterized in that the third reflector includes a third reflective surface for emitting a light source re-reflected from the second reflective surface, and the third reflective surface is a curved surface in the longitudinal direction, and the cross-section cut perpendicularly with respect to the longitudinal centerline of the curved surface is parabolic in shape.

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