Light guide device

Abstract

A light guide device according to an embodiment of the present invention comprises: a plate part in which light is totally reflected; a first diffraction part which is disposed on the plate part and on which the light is incident; a second diffraction part which is disposed on the plate part and in which the light is emitted from the inside of the plate part to the outside; and at least one third diffraction part which is disposed on the plate part and located between the first diffraction part and the second diffraction part, wherein the first diffraction part diffracts the light incident on the plate part toward the second diffraction part, and the third diffraction part diffracts, toward the second diffraction part, the light that is totally reflected in the plate part.

Description

Light guide device

[0001] The present invention relates to a light guide device.

[0002] The camera module can sense light reflected from an object and generate an image based on the sensed light.

[0003] However, since camera modules generate images using light incident on the image sensor, they generally sense the image in the direction they are facing. If the camera module cannot reach the desired shooting location, this can be overcome through various methods, such as using a drone, utilizing a separate support structure, or employing a miniature camera module.

[0004] Nevertheless, the use of a light guide device is being devised in which, for design or aesthetic reasons, the camera module is not exposed externally, and the incident light is diffracted and the diffracted light is totally reflected so that the position of incidence and the position where the light is sensed are different.

[0005] However, due to the distance between the input where light is incident and the output where light is emitted toward the image sensor of the camera module, the light undergoing total internal reflection converges toward the output, which may cause a problem of slightly reducing the field of view of the light incident from the input.

[0006] This may result in the disadvantage of utilizing only an image angle smaller than the angle of view of the image to be captured.

[0007] The present invention is an invention devised to solve the problems of the aforementioned prior art, and has the objective of maintaining the angle of view of incident light.

[0008] The problems that the present invention aims to solve are not limited to those mentioned above, and other problems not mentioned herein will be clearly understood by those skilled in the art from the description below.

[0009] A light guide device according to an embodiment of the present invention for achieving the above-described purpose comprises a plate portion in which light is totally reflected internally, a first diffraction portion disposed on the plate portion and into which the light is incident, a second diffraction portion disposed on the plate portion and into which the light is emitted from the inside of the plate portion to the outside, and at least one third diffraction portion disposed on the plate portion and disposed between the first diffraction portion and the second diffraction portion, wherein the first diffraction portion diffracts the light incident on the inside of the plate portion toward the second diffraction portion, and the third diffraction portion diffracts the light totally reflected internally within the plate portion toward the second diffraction portion.

[0010] According to an embodiment of the present invention, the distance in the first direction between the first diffraction part and the third diffraction part is greater than the distance in the first direction between the second diffraction part and the third diffraction part, and the first direction may be a direction from the first diffraction part toward the second diffraction part.

[0011] According to an embodiment of the present invention, a first virtual line and a second virtual line connecting both ends of the first diffraction section in a second direction perpendicular to the first direction and both ends of the third diffraction section in the second direction may have a first intersection point where they intersect each other.

[0012] According to an embodiment of the present invention, the first distance from the first intersection point to the third diffraction part in the first direction may be the focal length of the third diffraction part.

[0013] According to an embodiment of the present invention, the first distance may be the same as the second distance from the first intersection point to the first diffraction part in the first direction.

[0014] According to an embodiment of the present invention, the angle between the third virtual line and the fourth virtual line connecting both ends of the third diffraction part and the center of the second diffraction part in the second direction may be the same as the angle between the first virtual line and the second virtual line at the first intersection point.

[0015] According to an embodiment of the present invention, the angle between the first virtual line and the second virtual line may correspond to the angle of view at the first diffraction section.

[0016] According to an embodiment of the present invention, the third diffraction section may include a third-1 diffraction section disposed adjacent to the first diffraction section and a third-2 diffraction section disposed adjacent to the second diffraction section.

[0017] According to an embodiment of the present invention, a fifth virtual line and a sixth virtual line connecting both ends of the third-1 diffraction section and both ends of the third-2 diffraction section in the second direction may have a second intersection point that intersects each other.

[0018] According to an embodiment of the present invention, the third distance from the second intersection point to the third-1 diffraction section may be the focal length of the third-1 diffraction section.

[0019] According to an embodiment of the present invention, the fourth distance from the second intersection point to the third-2 diffraction section may be the focal length of the third-2 diffraction section.

[0020] According to an embodiment of the present invention, the distance in the first direction between the third-1 diffraction part and the third-2 diffraction part may correspond to the sum of the focal length of the third-1 diffraction part and the focal length of the third-2 diffraction part.

[0021] According to an embodiment of the present invention, the third diffraction part includes a diffraction pattern, and the diffraction pattern includes a plurality of protrusions that diffract the light, and the plurality of protrusions may be spaced apart from each other in the second direction.

[0022] According to an embodiment of the present invention, the plurality of protrusions may have different refractive indices.

[0023] According to an embodiment of the present invention, the shortest distance in the second direction between adjacent protrusions can be increased in the second direction away from the center of the third diffraction part.

[0024] A light guide device according to an embodiment of the present invention for solving the above problem may have the effect of maintaining the angle of view of the incident light.

[0025] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description in the claims.

[0026] The summary described above, as well as the detailed description of the preferred embodiments of the present application described below, will be better understood when read in conjunction with the accompanying drawings.

[0027] Preferred embodiments are illustrated in the drawings for the purpose of illustrating the present invention.

[0028] However, it should be understood that the present application is not limited to the exact arrangement and means depicted.

[0029] FIG. 1 is a drawing illustrated for the overall explanation of a light guide device according to an embodiment of the present invention;

[0030] FIG. 2 is a drawing showing a light guide device according to an embodiment of the present invention as viewed from V1 in FIG. 1;

[0031] FIG. 3 is a drawing showing the view of a light guide device according to a modified embodiment of the present invention as seen from V1 in FIG. 1;

[0032] FIG. 4 is a drawing showing the view of a light guide device according to an embodiment of the present invention as seen from V2 in FIG. 1;

[0033] FIG. 5 is a drawing illustrating a third diffraction section of a light guide device according to an embodiment of the present invention;

[0034] FIG. 6 is a drawing illustrating the focal length of a light guide device according to an embodiment of the present invention;

[0035] FIG. 7 is a drawing illustrating the configuration of a diffraction section of a light guide device according to an embodiment of the present invention;

[0036] FIG. 8 is a drawing illustrating a light guide device according to another embodiment of the present invention; and

[0037] FIG. 9 is a drawing illustrating the features of a light guide device according to another embodiment of the present invention.

[0038] The present invention is capable of various modifications and may have various embodiments, and specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to specific embodiments, and it should be understood that it includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the present invention. In describing the present invention, detailed descriptions of related prior art are omitted if it is determined that such detailed descriptions may obscure the essence of the present invention.

[0039] Terms such as "first," "second," etc., may be used to describe various components, but said components should not be limited by said terms. These terms are used solely for the purpose of distinguishing one component from another.

[0040] The terms used in this application are used merely to describe specific embodiments and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, terms such as "comprising" or "having" are intended to indicate the presence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0041] Furthermore, throughout the specification, when the term "connected" is used, it does not mean only that two or more components are directly connected, but may also mean that two or more components are indirectly connected through other components, that they are connected not only physically but also electrically, or that they are a single unit although referred to by different names depending on their location or function.

[0042] Furthermore, when described as being formed or placed on the “top or bottom” of each component, “top or bottom” includes not only cases where two components are in direct contact with each other, but also cases where one or more other components are formed or placed between the two components. Additionally, when expressed as “top or bottom,” it may include the meaning of a downward direction as well as an upward direction relative to a single component.

[0043] Furthermore, when describing objects as "identical" or "similar" based on numerically or geometrically comparable properties such as length, inner diameter, diameter, or area, this may imply that there is a margin of error. For example, if it is stated that the lengths of components A and B are identical, it may be advisable to interpret this to mean that the length of B falls within the margin of error of the length of A. This takes into account the margin of error that occurs during the injection molding and manufacturing processes; since this is a matter that can occur physically and is self-evident, it is advisable to understand the description as "identical" or "similar" by considering the margin of error as described above. In this case, the margin of error may be within the range of -5% to +5% of the mentioned numerical value or shape, but this is merely an example of the margin of error and may not necessarily be limited to the stated range.

[0044] A preferred embodiment of the present invention, in which the objective of the present invention can be specifically realized, will be described below with reference to the attached FIGS. 1 to 7.

[0045] Specifically, FIG. 1 is a drawing illustrating an overall description of a light guide device according to an embodiment of the present invention, FIG. 2 is a drawing illustrating a view of a light guide device according to an embodiment of the present invention as seen from V1 in FIG. 1, FIG. 3 is a drawing illustrating a view of a light guide device according to a modified embodiment of the present invention as seen from V1 in FIG. 1, FIG. 4 is a drawing illustrating a view of a light guide device according to an embodiment of the present invention as seen from V2 in FIG. 1, FIG. 5 is a drawing illustrating a third diffraction section of a light guide device according to an embodiment of the present invention, FIG. 6 is a drawing illustrating a focal length of a light guide device according to an embodiment of the present invention, FIG. 7 is a drawing illustrating a configuration of a diffraction section of a light guide device according to an embodiment of the present invention.

[0046] First, the light guide device according to an embodiment of the present invention includes, as shown in FIG. 1, a plate portion (100) in which light is totally reflected from within, a first diffraction portion (200) disposed on the plate portion (100) and into which light is incident, a second diffraction portion (300) into which light is emitted from the inside of the plate portion (100) to the outside, and at least one third diffraction portion (400) disposed on the plate portion (100) and disposed between the first diffraction portion (200) and the second diffraction portion (300).

[0047] Here, the first diffraction section (200) can diffract light incident on the inside of the plate section (100) toward the second diffraction section (300), and the third diffraction section (400) can diffract light totally reflected inside the plate section (100) toward the second diffraction section (300).

[0048] Specifically, the first diffraction section (200), the second diffraction section (300), and the third diffraction section (400) each include a diffraction pattern, and the first diffraction section (200) diffracts light so that incident light is totally reflected from the inside of the plate section (100) toward the second diffraction section (300), and the second diffraction section (300) can diffract light that is totally reflected from the inside of the plate section (100) toward a camera module (C) or image sensor disposed on the outside of the plate section (100).

[0049] Here, the third diffraction section (400) is positioned between the first diffraction section (200) and the second diffraction section (300), and the third diffraction section (400) can diffract light that is diffracted from the first diffraction section (200) and moved to the second diffraction section (300). At this time, if the direction from the first diffraction section (200) toward the second diffraction section (300) or the direction from the second diffraction section (300) toward the first diffraction section (200) is defined as the first direction, the third diffraction section (400) can be positioned between the first diffraction section (200) and the second diffraction section (300) in the first direction.

[0050] At this time, the light diffracted from the first diffraction section (200) toward the second diffraction section (300) is not accumulated in a form that gathers toward the second diffraction section (300), but rather only the path of the light is changed toward the second diffraction section (300), and is radiated in a second direction perpendicular to the first direction toward the second diffraction section (300), and can be moved in the first direction. Among them, the light incident on the second diffraction section (300) can be diffracted by the second diffraction section (300) and incident on an external image sensor.

[0051] However, since the light incident on the second diffraction section (300) among the light radiated and moving from the first diffraction section (200) toward the second diffraction section (300) is incident on the image sensor, the field of view (FOV; Field Of View) of the light guide device according to the embodiment of the present invention may be the angle between the virtual lines connecting the two ends of the first diffraction section (200) to the second diffraction section (300). This may be because the light incident on the second diffraction section (300) among the light diffracted, radiated, and moving from the first diffraction section (200) is only a part of it.

[0052] As described above, since the angle between the virtual lines connecting the two ends of the first diffraction section (200) to the second diffraction section (300) becomes the angle of view of the light guide device, it can be determined by the first length (W1) in the first direction from the first diffraction section (200) to the second diffraction section (300). However, in such a case, as the first length (W1) increases, the angle of view of the light guide device gradually decreases; therefore, if the first length (W1) between the first diffraction section (200) and the second diffraction section (300) must be formed longer according to design conditions or needs, the reduction in the angle of view of the light guide device must be accepted.

[0053] The light guide device according to an embodiment of the present invention places a third diffraction section (400) between a first diffraction section (200) and a second diffraction section (300), and because the third diffraction section (400) diffracts the light that is radiated and moved by the first diffraction section (200) again toward the second diffraction section (300), the problem of the angle of view decreasing as the first length (W1) increases can be effectively solved.

[0054] As illustrated in FIG. 2, when viewed from V1 in FIG. 1, light incident on the first diffraction section (200) is diffracted in a first direction toward the second diffraction section (300) inside the plate section (100), and due to the characteristics of the light, it can move while being radiated in a second direction. In the process described above, since the third diffraction section (400) is located between the first diffraction section (200) and the second diffraction section (300), there may be an advantage of increasing the amount of light incident on the second diffraction section (300) by diffracting the light again, and at the same time increasing the maximum angle of view of the incident light.

[0055] Additionally, as shown in FIG. 2, the camera module (C) is positioned adjacent to the second diffraction section (300) so that light diffracted from the second diffraction section (300) is incident thereon, and the second diffraction section (300) may be positioned on the same plane as the first diffraction section (200) and the plate section (100), or may be positioned on different planes as shown in FIG. 3.

[0056] However, due to the reflection characteristics of light, it may be preferable for the second diffraction unit (300) and the camera module (C) to be positioned so as to face one side of the plate unit (100) where the first diffraction unit (200) is positioned, or to face the other side opposite to the one side of the plate unit (100) where the first diffraction unit (200) is positioned. In FIGS. 2 and 3, the first diffraction unit (200) and the second diffraction unit (300) are shown as being positioned on the outside of the plate unit (100), but they may be positioned on the inside of the plate unit (100) depending on the design, and are not necessarily limited to what is mentioned.

[0057] Additionally, although the first diffraction section (200) and the second diffraction section (300) are depicted as a type through which incident light is transmitted, if they are provided as a type that diffracts and reflects incident light, based on FIG. 2, the first diffraction section (200) may be positioned on a surface opposite to the plate section (100) in a third direction perpendicular to the first and second directions, and the second diffraction section (300) may also be positioned on a surface opposite to the plate section (100) in a third direction. Furthermore, the camera module (C) may be positioned with the second diffraction section (300) and the plate section (100) in between in a third direction.

[0058] When the first diffraction section (200) and the second diffraction section (300) are arranged in a reflection type based on FIG. 3, the first diffraction section (200) is arranged on the opposite side of the plate section (100) in the third direction, and the second diffraction section (300) is also arranged on the opposite side of the plate section (100) in the third direction, and the camera module (C) may be arranged with the second diffraction section (300) and the plate section (100) in the third direction in between.

[0059] That is, the transmission type is as shown in FIGS. 2 and 3, and the reflection type is such that the arrangement of the first diffraction part (200) and the second diffraction part (300) is arranged on the opposite side of the plate part (100) in the third direction based on FIGS. 2 and 3, and the arrangement of the camera module (C) may be the same.

[0060] However, since the third diffraction section (400) collects light that is radiated in the second direction from the first diffraction section (200) toward the second diffraction section (300) in the second direction, it may be preferable to provide it as a reflection type. Additionally, the third diffraction section (400) may be placed on the same plane as the first diffraction section (200) and the plate section (100) as shown in FIG. 2, but since the third diffraction section (400) performs the function of diffracting light and collecting light reaching the second diffraction section (300), it may be placed on a different plane from the first diffraction section (200).

[0061] Meanwhile, as illustrated in FIG. 4, when viewed from the direction of V2 in FIG. 1, the angle of view (A3) of light incident on the plate portion (100) increases with the second length (W2) in the second direction of the first diffraction portion (200), and since the angle between the virtual lines from both ends of the first diffraction portion (200) toward the second diffraction portion (300) corresponds to the angle of view of the light guide device, the second length (W2) in the second direction of the first diffraction portion (200) can correspond to the angle of view of the light guide device. Additionally, the angle of view of the light guide device can correspond to the angle of view in the first diffraction portion (200).

[0062] That is, when the third diffraction section (400) is not installed, the second length (W2) in the second direction of the first diffraction section (200) may increase as it increases, and the first length (W1) spaced apart in the first direction of the first diffraction section (200) and the second diffraction section (300) may decrease as it increases.

[0063] Referring to FIG. 5 to describe in detail the light guide device according to an embodiment of the present invention, as shown in FIG. 5, a first virtual line (L1) and a second virtual line (L2) connecting the ends of the first diffraction section (200) in the second direction to the ends of the third diffraction section (400) in the second direction intersect each other to form a first intersection point (C1), and at the first intersection point (C1), the first virtual line (L1) and the second virtual line (L2) may intersect with a first angle (A1). In addition, a third virtual line (L3) and a fourth virtual line (L4) connecting the ends of the third diffraction section (400) in the second direction to the center of the second diffraction section (300) may have a second angle (A2) at the center of the second diffraction section (300).

[0064] Here, assuming that the end forming the starting point of the first virtual line (L1) and the third virtual line (L3) in the second direction is the first end, and the end forming the starting point of the second virtual line (L2) and the fourth virtual line (L4) in the second direction is the other end, the virtual line connecting the first end of the first diffraction section (200) to the other end of the third diffraction section (400) may be the first virtual line (L1), the virtual line connecting the other end of the first diffraction section (200) to the first end of the third diffraction section (400) may be the second virtual line (L2), the virtual line connecting the first end of the third diffraction section (400) to the center of the second diffraction section (300) may be the third virtual line (L3), and the virtual line connecting the other end of the third diffraction section (400) to the center of the second diffraction section (300) may be the fourth virtual line (L4).

[0065] As described above, the first virtual line (L1) and the second virtual line (L2) intersect each other to form a first intersection point (C1), and at the first intersection point (C1), the first virtual line (L1) and the second virtual line (L2) may have a first angle (A1). In addition, as described above, the third virtual line (L3) and the fourth virtual line (L4) meet at the center of the second diffraction section (300), and the third virtual line (L3) and the fourth virtual line (L4) may have a second angle (A2).

[0066] At this time, in the light guide device according to the embodiment of the present invention, since the second angle (A2) at the second diffraction unit (300) is diffracted to the camera module (C) through the second diffraction unit (300), the second angle (A2) corresponds to the angle of view of the light guide device, and this may be the same as the first angle (A1). That is, the first virtual line (L1) and the third virtual line (L3) are parallel to each other, the second virtual line (L2) and the fourth virtual line (L4) are parallel to each other, the first angle (A1) and the second angle (A2) are the same to each other, and the first angle (A1) and the second angle (A2) may correspond to the angle of view of the light guide device.

[0067] In this way, when the third diffraction section (400) is not present, the path of light that could not go toward the second diffraction section (300) is diffracted toward the second diffraction section (300) through the third diffraction section (400), thereby maintaining the angle of view of the light guide device that decreases as the first distance (S1) increases.

[0068] Here, the first angle (A1) and the second angle (A2) are described in planar terms, but as illustrated in FIGS. 2 and FIGS. 3, the light path moves while undergoing total reflection between one side and the other side of the plate portion (100), so the above-described angle of view can be based on the plate surface (100) adjacent to the camera module (C). For example, if based on FIGS. 2 and FIGS. 5, the first angle (A1) in FIGS. 5 is the angle on one side of the plate portion (100) adjacent to the camera module (C) between the first diffraction portion (200) and the third diffraction portion (400) in FIGS. 2, and the second angle (A2) at the second diffraction portion (300) is the angle on one side of the plate portion (100) adjacent to the camera module (C).

[0069] That is, the first angle (A1) and the second angle (A2) described above may be angles based on the plane of the same plate portion (100).

[0070] At this time, as shown in FIG. 6, the first distance (S1) in the first direction from the first intersection point (C1) to the center of the first diffraction section (200) is the same as the second distance (S2) in the first direction from the first intersection point (C1) to the center of the third diffraction section (400), and the second distance (S2) may correspond to the focal length of the third diffraction section (400).

[0071] In order to maintain the angle of view of the first angle (A1) and the second angle (A2), the first virtual line (L1) and the second virtual line (L2) must form a first intersection point (C1) where the first distance (S1) and the second distance (S2) are the same, which is the same as the distance in the first direction from the third diffraction section (400) to the second diffraction section (300), and through this, the first angle (A1) and the second angle (A2) become the same, thereby allowing the angle of view of the light guide device to be maintained at the second diffraction section (300).

[0072] Meanwhile, the third diffraction section (400) includes a diffraction pattern as shown in FIG. 7, and the diffraction pattern includes a plurality of protrusions (402) that diffract light, and the plurality of protrusions (402) may be spaced apart from each other in a second direction. Additionally, although not shown, the plurality of protrusions (402) may be inclined in a first direction.

[0073] Here, the diffraction pattern is formed through a plurality of protrusions (402), and the third diffraction section (400) may include a body section (401) in which a plurality of protrusions (402) are arranged and a curing section (403) arranged between the plurality of protrusions (402). At this time, the body section (401) is configured to form a diffraction pattern by arranging a plurality of protrusions (402), and the curing section (403) arranged between the plurality of protrusions (402) may be, for example, epoxy. The curing section (403) can prevent foreign substances from entering between the plurality of protrusions (402) and interfering with the process of light diffraction.

[0074] Additionally, the spacing between the plurality of protrusions (402) can be arranged to gradually increase in the direction from both ends of the third diffraction section (400) toward the center in the second direction. For example, if the spacing between the plurality of protrusions (402) adjacent to both ends of the third diffraction section (400) in the second direction is defined as the third length (W3), and the spacing between the plurality of protrusions (402) adjacent to the center of the third diffraction section (400) in the second direction is defined as the fourth length (W4), then the fourth length (W4) may be larger than the third length (W3). Furthermore, the spacing between the plurality of protrusions (402) arranged between the plurality of protrusions (402) forming the third length (W3) and the fourth length (W4) may have a length between the third length (W3) and the fourth length (W4).

[0075] Meanwhile, to explain a light guide device according to another embodiment of the present invention, reference may be made to FIGS. 8 and FIGS. 9.

[0076] Specifically, FIG. 8 is a drawing illustrating a light guide device according to another embodiment of the present invention, and FIG. 9 is a drawing illustrating a feature of a light guide device according to another embodiment of the present invention.

[0077] A light guide device according to another embodiment of the present invention comprises a plate portion (100), a first diffraction portion (200), a second diffraction portion, and a third diffraction portion (400). The third diffraction portion (400) may include a third-1 diffraction portion (410) adjacent to the first diffraction portion (200) in a first direction and a third-2 diffraction portion (420) adjacent to the second diffraction portion (300) in a first direction. Alternatively, the first diffraction portion (200), the third-1 diffraction portion (410), the third-2 diffraction portion (420), and the second diffraction portion (300) may be arranged sequentially in a first direction.

[0078] To explain this in detail, refer to FIG. 9. As shown in FIG. 9, the first virtual line (L1) and the second virtual line (L2) connecting the ends of the first diffraction section (200) in the second direction to the ends of the third-1 diffraction section (410) in the second direction intersect each other to form a first intersection point (C1), and at the first intersection point (C1), the first virtual line (L1) and the second virtual line (L2) may intersect at a first angle (A1). Additionally, the third virtual line (L3) and the fourth virtual line (L4) connecting the ends of the third-2 diffraction section (420) in the second direction to the center of the second diffraction section (300) may have a second angle (A2) at the center of the second diffraction section (300).

[0079] Here, the fifth virtual line (L5) and the sixth virtual line (L6) connecting the ends of the third-1 diffraction section (410) in the second direction to the ends of the third-2 diffraction section (420) in the second direction intersect each other to form a second intersection point (C2), and at the second intersection point (C2), the fifth virtual line (L5) and the sixth virtual line (L6) may intersect at a second angle (A2).

[0080] Assuming that the end forming the starting point of the first virtual line (L1), the third virtual line (L3), and the fifth virtual line (L5) in the second direction is the first end, and the end forming the starting point of the second virtual line (L2), the fourth virtual line (L4), and the sixth virtual line (L6) in the second direction is the other end, then the virtual line connecting the first end of the first diffraction section (200) to the other end of the third-1 diffraction section (410) is the first virtual line (L1), the virtual line connecting the other end of the first diffraction section (200) to the first end of the third-1 diffraction section (410) is the second virtual line (L2), the virtual line connecting the first end of the third-2 diffraction section (420) to the center of the second diffraction section (300) is the third virtual line (L3), and the virtual line connecting the other end of the third-2 diffraction section (420) to the center of the second diffraction section (300) The virtual line is the fourth virtual line (L4), the virtual line connecting one end of the third-1 diffraction section (410) to the other end of the third-2 diffraction section (420) is the fifth virtual line (L5), and the virtual line connecting the other end of the third-1 diffraction section (410) to one end of the third-2 diffraction section (420) may be the sixth virtual line (L6).

[0081] As described above, the first virtual line (L1) and the second virtual line (L2) intersect each other to form a first intersection point (C1), and at the first intersection point (C1), the first virtual line (L1) and the second virtual line (L2) may have a first angle (A1). Additionally, as described above, the third virtual line (L3) and the fourth virtual line (L4) meet at the center of the second diffraction section (300), and the third virtual line (L3) and the fourth virtual line (L4) may have a second angle (A2). Furthermore, the fifth virtual line (L5) and the sixth virtual line (L6) form a second intersection point (C2), and at the second intersection point (C2), the fifth virtual line (L5) and the sixth virtual line (L6) may have a second angle (A2).

[0082] At this time, in the light guide device according to the embodiment of the present invention, since the second angle (A2) at the second diffraction unit (300) is diffracted to the camera module (C) through the second diffraction unit (300), the second angle (A2) corresponds to the angle of view of the light guide device, and this may be the same as the first angle (A1) and the fourth angle (A4). That is, the first virtual line (L1), the third virtual line (L3), and the fifth virtual line (L5) are parallel to each other, the second virtual line (L2), the fourth virtual line (L4), and the sixth virtual line (L6) are parallel to each other, the first angle (A1), the second angle (A2), and the fourth angle (A4) are the same to each other, and the first angle (A1), the second angle (A2), and the fourth angle (A4) may correspond to the angle of view of the light guide device.

[0083] Accordingly, the light path is diffracted toward the second diffraction section (300) through the third-1 diffraction section (410) and the third-2 diffraction section (420), thereby maintaining the angle of view of the light guide device, which decreases as the first distance (S1) increases.

[0084] At this time, the first distance (S1) in the first direction from the first intersection point (C1) to the center of the first diffraction section (200) is the same as the second distance (S2) in the first direction from the first intersection point (C1) to the center of the third-1 diffraction section (410), and the second distance (S2) may correspond to the focal length of the third-1 diffraction section (410). Additionally, the third distance (S3) in the first direction from the second intersection point (C2) to the center of the third-1 diffraction section (410) is the same as the fourth distance (S4) in the first direction from the second intersection point (C2) to the center of the third-2 diffraction section (420), and the third distance (S3) may correspond to the focal length of the third-1 diffraction section (410), and the fourth distance (S4) may correspond to the focal length of the third-2 diffraction section (420).

[0085] Additionally, since the first virtual line (L1), the third virtual line (L3), and the fifth virtual line (L5) are parallel, and the second virtual line (L2), the fourth virtual line (L4), and the sixth virtual line (L6) are parallel to each other, the first angle (A1) at the first intersection point (C1) is the same as the fourth angle (A4) at the second intersection point (C2), and the fourth angle (A4) at the second intersection point (C2) can be the same as the second angle (A2) at the second diffraction section (300). As a result, the field of view of the light guide device can be maintained at the second diffraction section (300).

[0086] We have examined preferred embodiments according to the invention, and it is obvious to those skilled in the art that, in addition to the embodiments described above, the invention may be embodied in other specific forms without departing from the spirit or scope thereof.

[0087] Therefore, the embodiments described above should be regarded as exemplary rather than limiting, and accordingly, the present invention is not limited to the description above but may be modified within the scope of the appended claims and their equivalents.

Claims

1. A plate portion in which light is totally reflected internally; A first diffraction section disposed on the above plate portion and upon which the light is incident; A second diffraction section disposed on the plate portion and through which the light is emitted from the inside of the plate portion to the outside; and It includes at least one third diffraction section disposed on the plate portion and disposed between the first diffraction section and the second diffraction section, and The first diffraction part diffracts the light incident on the inside of the plate part toward the second diffraction part, and The above third diffraction section is a light guide device that diffracts the light totally reflected inside the plate section toward the second diffraction section.

2. In Paragraph 1, The distance in the first direction between the first diffraction part and the third diffraction part is greater than the distance in the first direction between the second diffraction part and the third diffraction part, and A light guide device in which the first direction is a direction from the first diffraction section toward the second diffraction section.

3. In Paragraph 2, A light guide device having a first virtual line and a second virtual line that intersect each other at a first intersection point, connecting both ends of the first diffraction section in a second direction perpendicular to the first direction and both ends of the third diffraction section in the second direction.

4. In Paragraph 3, A light guide device in which the first distance from the first intersection point to the third diffraction section in the first direction is the focal length of the third diffraction section.

5. In Paragraph 4, A light guide device in which the first distance is equal to the second distance from the first intersection point to the first diffraction section in the first direction.

6. In Paragraph 3, A light guide device in which the angle between the third virtual line and the fourth virtual line connecting both ends of the third diffraction section and the center of the second diffraction section in the second direction is the same as the angle between the first virtual line and the second virtual line at the first intersection.

7. In Paragraph 6, An optical guide device in which the angle between the first virtual line and the second virtual line corresponds to the angle of view in the first diffraction section.

8. In Paragraph 3, The above third diffraction section includes a diffraction pattern, and The above diffraction pattern includes a plurality of protrusions that diffract the light, and A light guide device in which the plurality of protrusions are spaced apart from each other in the second direction.

9. In Paragraph 8, The above plurality of protrusions are light guide devices with different refractive indices.

10. In Paragraph 8, A light guide device in which the shortest distance in the second direction between adjacent protrusions increases in the second direction away from the center of the third diffraction part.

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