Light guide and surface light emitting device

Abstract

The invention provides a light guide and a surface light emitting device. The light guide body includes: a light guide plate configured so that light from a light source is introduced into the light guide plate and transmitted; a recess provided on one side of the light guide plate in the thickness direction, the light source being provided on the inner side of the recess; a wall portion protruding toward the one side with respect to the light guide plate, the wall portion having the recessed portion provided on the inner side thereof; a first reflection portion provided on the other side of the light guide plate in the thickness direction so as to face the light source, the first reflection portion having a conical recess so that a first portion of the light from the light source is reflected into the light guide plate; and a second reflection portion provided on the wall portion on the one side of the light guide plate in the thickness direction so that a second portion of the light from the light source is reflected into the light guide plate. According to the light guide body and the surface light-emitting device, the light incidence efficiency can be improved, and periodical unevenness can be reduced.

Description

Technical Field

[0001] The present invention relates to a light guide and a surface light-emitting device, and more particularly to a light guide and a surface light-emitting device capable of improving light input efficiency and reducing periodic non-uniformity of surface light emission. Background Art

[0002] In recent years, efforts have been made to provide sustainable transportation systems to include the elderly and children who are in a disadvantaged position as traffic participants. To achieve the above-mentioned purpose, research and development related to visibility technology is being conducted to further improve the safety and convenience of traffic.

[0003] In the technology related to visibility, Patent Document 1 discloses a surface luminous device having a light source and a light guide; wherein the light guide has: a funnel-shaped concave portion (total reflection portion) and a light guide plate adjacent to the concave portion. Light from the light source is reflected in the funnel-shaped concave portion and then enters the light guide plate for transmission to perform surface luminescence.

[0004] [Prior art literature]

[0005] [Patent Document]

[0006] [Patent Document 1]: Japanese Patent Laid-Open No. 2013-165044 Summary of the invention

[0007] [Problems to be solved by the invention]

[0008] However, in Patent Document 1, the light-collecting angle of the light guide is limited, so a portion of the light from the light source cannot be captured by the light-entering portion of the light guide, which reduces the light-entering efficiency. In addition, since the light is uniformly reflected in the funnel-shaped concave portion, the periodicity of the surface light emission is uneven, making it difficult to uniformly diffuse the light. In addition, in order to improve the light-entering efficiency, the thickness of the light guide plate needs to be increased and the funnel-shaped concave portion (total reflection portion) must be enlarged, which will increase the cost and weight of the light guide plate.

[0009] [Technical means to solve the problem]

[0010] In order to achieve the above-mentioned purpose, the light guide body and the surface light emitting device of the present invention change the shape of the light input portion without increasing the thickness of the light guide plate, thereby improving the light input efficiency, and reducing the periodic non-uniformity through the multiple light guide paths of the light input portion. Furthermore, the thickness of the light guide plate is relatively thin, which can effectively reduce the cost and weight of the light guide plate.

[0011] According to the technical solution of one embodiment of the present invention, the present invention provides a light guide, including: a light guide plate, configured such that: light from a light source is introduced into the light guide plate for transmission; a recessed portion, arranged on one side in the thickness direction of the light guide plate, and the light source is arranged on the inner side of the recessed portion; a wall portion, which protrudes toward the one side compared to the light guide plate, and the recessed portion is arranged on the inner side of the wall portion; a first reflecting portion, arranged on the other side in the thickness direction of the light guide plate and opposite to the light source, the first reflecting portion having a conical recess so that a first part of the light from the light source is reflected into the interior of the light guide plate; and a second reflecting portion, arranged on the one side in the thickness direction of the light guide plate and located on the wall portion, so that a second part of the light from the light source is reflected into the interior of the light guide plate.

[0012] In one embodiment of the present invention, the wall portion is configured to protrude to the same horizontal plane as the light emitting surface of the light source.

[0013] In one embodiment of the present invention, the wall portion is configured to protrude in a circular shape with the light source as the center.

[0014] In one embodiment of the present invention, the light guide further includes: a plurality of dot portions, which are arranged on the back side of the light emitting portion of the light guide plate.

[0015] In one embodiment of the present invention, the recess includes: a planar portion; and a curved portion connected to the planar portion, wherein the wall portion surrounds the curved portion; and a third portion of the light from the light source is transmitted to the interior of the light guide plate via the curved portion.

[0016] The present invention also provides a surface light emitting device, comprising: a light source; and the above-mentioned light guide body, which guides and emits the light from the light source.

[0017] [Effects of the Invention]

[0018] The light guide and the surface light emitting device of the embodiment of the present invention change the shape of the light input portion of the light guide, thereby being able to increase the light collection angle to take in light in a wider angle range, thereby improving the light entry efficiency. Through the multiple light guide paths of the light guide, multiple lights from the light source can be taken in, thus reducing the periodic unevenness phenomenon to achieve uniform lighting. The light guide and the surface light emitting device of the present invention can achieve a thinner light guide plate and more uniform surface light emission, thereby reducing cost and weight.

[0019] In order to make the above features and advantages of the present invention more clearly understood, embodiments are given below with reference to the accompanying drawings for detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 FIG. 1 is a schematic diagram of the front surface of a light guide according to an embodiment of the present invention.

[0021] Figure 2 It is a schematic diagram of the back side of a light guide according to an embodiment of the present invention.

[0022] Figure 3 is a cross-sectional schematic diagram of a surface light-emitting device according to an embodiment of the present invention, showing Figure 1 The cross section of the light guide along line AA.

[0023] Figure 4 It is a schematic diagram of the front side of a surface light-emitting device according to an embodiment of the present invention.

[0024] Figure 5 FIG. 1 is a schematic diagram of the back side of a surface light-emitting device according to an embodiment of the present invention.

[0025] Figure 6 It is along Figure 5 Schematic diagram of the cross section of line BB.

[0026] Figure 7 It is a schematic cross-sectional view of a conventional light guide.

[0027] Figure 8 FIG. 1 is a schematic cross-sectional view of a light guide according to an embodiment of the present invention.

[0028] Fig. 9 This is a schematic cross-sectional view of a conventional light guide having a relatively thick thickness.

[0029] Fig.10 It is a cross-sectional schematic diagram of a light guide having a relatively thin thickness according to an embodiment of the present invention.

[0030] Description of reference numerals:

[0031] 100A: Conventional light guide

[0032] 100: Light guide body of an embodiment of the present invention

[0033] 110: Light guide plate

[0034] 112: Luminous part

[0035] 120: concave part

[0036] 122: Plane part

[0037] 124: Surface part

[0038] 130: Wall

[0039] 140: First reflection part

[0040] 142: Depression

[0041] 150: Second reflection part

[0042] 160: Dot

[0043] 200: Light source

[0044] 200A: Luminous surface

[0045] 200S: Substrate

[0046] 210: The First Part of Light

[0047] 220: The Second Part of Light

[0048] 230: The Third Part of Light

[0049] 300: Surface luminous device

[0050] AA, BB: hatching

[0051] A1, A2: Arrow

[0052] D: Thickness direction

[0053] D1: One side in the thickness direction

[0054] D2: The other side in the thickness direction

[0055] F1, F2: Box

[0056] H: Horizontal plane

[0057] LA, LB, L1, L2: Light

[0058] TA, TB, T1, T2: thickness

[0059] θ1, θ2: angle DETAILED DESCRIPTION

[0060] Hereinafter, exemplary embodiments of the present invention will be described based on the accompanying drawings. It should be noted that in each embodiment described below, the same reference numerals are used for common parts, and repeated descriptions are omitted. Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0061] Figure 1 Schematic diagram of the front of a light guide according to an embodiment of the present invention. Figure 1 The light guide 100 has a light guide plate 110. The light guide 100 has a conical recess 142 (facing Figure 1The first reflector 140 is formed by the conical recess 142. Specifically, according to Snell's Law, the first portion 210 of the light from the light source 200 (see the following) Figure 3 ) The incident angle of the conical recess 142 is greater than the critical angle and satisfies the total reflection condition. As a result, the first part 210 of the light from the light source 200 is reflected by the first reflecting portion 140 and enters the light guide plate 110.

[0062] Figure 2 Schematic diagram of the back side of a light guide according to an embodiment of the present invention. Figure 2 The light guide 100 comprises a light guide plate 110, a recess 120 (facing Figure 2 The second reflecting portion 150 is formed by the wall portion 130. In detail, according to Snell's law, the second portion 220 of the light from the light source 200 (see the subsequent Figure 3 ) The incident angle of the light on the wall portion 130 is greater than the critical angle and satisfies the total reflection condition. Then, the second portion 220 of the light from the light source 200 is reflected by the second reflecting portion 150 and enters the light guide plate 110.

[0063] Figure 3 is a cross-sectional schematic diagram of a surface light-emitting device according to an embodiment of the present invention, showing Figure 1 The cross section of the light guide along line AA. Please also refer to Figure 1 to Figure 3 , in order to more clearly understand the overall structure of the light guide 100 according to the embodiment of the present invention. Figure 1 and Figure 2 In FIG. 1 , only the structure of the light guide 100 is shown. Figure 3 In the surface light-emitting device 300 shown in FIG. 1 , structures of a light guide 100 , a light source 200 , and a substrate 200S for arranging the light source 200 are shown.

[0064] Please refer to Figure 3The light guide 100 may include: a light guide plate 110, which is configured such that: light 210, 220, and 230 from a light source 200 is introduced into the light guide plate 110 for transmission; a recess 120, which is arranged on one side D1 in a thickness direction D of the light guide plate 110, and the light source 200 is arranged on the inner side of the recess 120; a wall 130, which protrudes toward the one side D1 compared to the light guide plate 110, and the recess 120 is arranged on the inner side of the wall 130; a first reflective portion 140, which is arranged The first reflecting portion 140 is arranged on the other side D2 of the thickness direction D of the light guide plate 110 and is opposite to the light source 200. The first reflecting portion 140 has a conical recess 142 so that the first part 210 of the light from the light source 200 is reflected into the interior of the light guide plate 110; and the second reflecting portion 150 is arranged on the one side D1 of the thickness direction D of the light guide plate 110 and is located on the wall portion 130 so that the second part 220 of the light from the light source 200 is reflected into the interior of the light guide plate 110.

[0065] Figure 3 The surface light-emitting device 300 may include: a light source 200; and a light guide 100 for guiding and emitting the light 210, 220, 230 from the light source 200. In this way, the surface light-emitting device 300 may emit surface light.

[0066] The light guide 100 and the surface light emitting device 300 of the embodiment of the present invention change the shape of the light input portion of the light guide 100, thereby being able to increase the light collection angle to take in light in a wider angle range, thereby improving the light collection efficiency and reducing the periodic non-uniformity of the surface light emission. The following will continue to explain the implementation of each component of the light guide 100.

[0067] The light guide plate 110 may be made of a transparent material, for example, an organic material such as acrylic resin, polycarbonate, or an inorganic material such as multi-component glass, quartz glass, etc. The light 210, 220, 230 from the light source 200 may be totally reflected and transmitted inside the light guide plate 110 to perform surface luminescence.

[0068] Please refer to Figure 3 The recess 120 is a space for accommodating the light source 200. In one embodiment, the recess 120 may include: a plane portion 122; and a curved portion 124, connected to the plane portion 122, wherein the wall portion 130 surrounds the curved portion 124; the third portion 230 of the light from the light source 200 is transmitted to the inside of the light guide plate 110 via the curved portion 124. In this way, in the light guide 100, through the plane portion 122 and the curved portion 124 of the recess 120, the wall portion 130, the first reflective portion 140 and the second reflective portion 150, multiple angle ranges of light 210, 220, 230 from the light source 200 can be taken in, thereby improving the light entry efficiency.

[0069] The light source 200 may be a surface light source composed of light emitting diodes, a light bulb or other suitable light sources. The light source 200 may also be composed of red light emitting diodes, green light emitting diodes and blue light emitting diodes. The type of the light source 200 is not limited here. Figure 3 In the light guide 100, the first portion 210 of light from the light source 200 is reflected by the first reflective portion 140 and transmitted to the inside of the light guide plate 110. The second portion 220 of light from the light source 200 is reflected by the second reflective portion 150 and transmitted to the inside of the light guide plate 110. The third portion 230 of light from the light source 200 is transmitted to the inside of the light guide plate 110 via the curved portion 124.

[0070] Please refer to Figure 3 The wall portion 130 surrounds the outer side of the recess 120; and the wall portion 130 protrudes toward one side D1 in the thickness direction D compared to the light guide plate 110. The wall portion 130 may be configured to protrude to the same horizontal plane H as the light emitting surface 200A of the light source 200. In this way, the wall portion 130 can effectively take in the light 210, 220, 230 from the light source 200.

[0071] In addition, since the wall portion 130 protrudes toward one side D1 in the thickness direction D compared to the light guide plate 110, the light guide body 100 has a thickness TB at the position where the wall portion 130 is provided. The provision of the wall portion 130 can improve the light input efficiency, so there is no need to increase the thickness of the light guide plate 110, and the light guide plate 110 can have a thinner thickness TA.

[0072] Furthermore, please also refer to Figure 2 and Figure 3 The wall portion 130 may be configured to protrude in a circular shape with the light source 200 as the center. In this way, the circular shape of the wall portion 130 can take in light in a wider range, thereby improving light entry efficiency.

[0073] As described above, by changing the shape of the light guide 100, the light input efficiency can be increased, and the optical system of the light guide 100 can have multiple light guide paths for transmitting the first part 210 of light, the second part 220 of light, and the third part 230 of light. In this way, the light-collecting angle range of the light guide 100 can be increased, thereby improving the light input efficiency. In addition, since the light collected contains various angular components, the periodic unevenness of the surface light emission can be reduced, making it easier for the light guide 100 to be evenly illuminated. Therefore, compared with previous light guides, the light guide 100 of the present invention can achieve thinner and more uniform surface light emission, thereby reducing cost and weight, and can improve the periodic unevenness of the surface light emission.

[0074] Figure 4This is a schematic diagram of the front of a surface light-emitting device according to an embodiment of the present invention. Figure 4 The surface luminous device 300 is provided with a plurality of light guides 100, which can transmit light in a light guide plate 110 to emit surface light. The light guide plate 110 has a light emitting portion 112, which can display the light emitting character H.

[0075] Figure 5 FIG. 1 is a schematic diagram of the back side of a surface light emitting device according to an embodiment of the present invention. Figure 5 In the figure, a partial enlarged view of the H character is shown. Figure 6 It is along Figure 5 Please also refer to Figure 5 and Figure 6 The light guide 100 may further include: a plurality of dot portions 160 disposed on the back side of the light emitting portion 112 of the light guide plate 110 .

[0076] Please refer to Figure 6 , the light LA ​​does not enter the point portion 160 , but continues to be totally reflected and transmitted in the light guide plate 110 . The light LB enters the point portion 160 , and the traveling direction of the light LB is changed, and the light LB is emitted toward the outside of the light guide plate 110 .

[0077] The light LB transmitted in the light guide plate 110 can be extracted through the dot portion 160, and as Figure 5 As shown, the luminous character H can be displayed. In other embodiments, the position and number of the dot portion 160 can be controlled to display any luminous characters (such as 26 English letters, etc.) or geometric patterns, etc.

[0078] [Comparison between Conventional Light Guide 100A and Light Guide 100 of Embodiment of the Invention]

[0079] Figure 7 This is a cross-sectional diagram of a conventional light guide. Figure 7 In the conventional light guide 100A, the light receiving angle θ1 of the light source 200 as shown in the box F1 is limited, resulting in poor light entry efficiency. Therefore, in order to improve the light entry efficiency, it is necessary to increase the thickness of the light guide 100A (eg Figure 7 As shown by arrow A1 in FIG. 1 , the total reflection portion must be enlarged (as shown in FIG. Figure 7 As a result, the thickness T1 of the light guide 100A will increase, resulting in an increase in both cost and weight.

[0080] And, if Figure 7 The conventional light guide 100A shown can only take in one type of light, making it difficult to mix the light, which easily leads to periodic uneven surface emission. Furthermore, since the light-taking angle θ1 is limited, even if light can be taken in, it is difficult to control the surface emission.

[0081] Figure 8 FIG. 1 is a cross-sectional schematic diagram of a light guide body according to an embodiment of the present invention. Figure 8 In the light guide 100 of the embodiment of the present invention, the light angle θ2 of the light source 200 as shown in the box F2 can be maximized, so that the light input efficiency is good. Therefore, in order to improve the light input efficiency, it is not necessary to increase the thickness T2 of the light guide 100. As a result, the thickness T2 of the light guide 100 is thinner, which can reduce the cost and weight.

[0082] And, if Figure 8 The light guide 100 of the embodiment of the present invention shown in FIG. 1 can take in three kinds of light (i.e., Figure 3 The first part 210, the second part 220 and the third part 230 of the light shown in the figure make it easy to mix the light, so that it is difficult to produce periodic unevenness of surface light emission; furthermore, since the light-taking angle θ2 can be maximized, it is easy to control the surface light emission.

[0083] Based on the above, compared with Figure 7 The conventional light guide 100A shown in FIG. Figure 8 The light guide 100 of the embodiment of the present invention shown in FIG. 1 changes the shape of the light input portion, and can take in light 210, 220, 230 in a wider range of angles; in particular, it can take in light that the conventional light guide 100A cannot take in (i.e., Figure 3 As a result, the light-incoming efficiency, cost, weight, and uniformity of surface light emission of the light guide 100 of the embodiment of the present invention are greatly improved.

[0084] [Explanation of periodic unevenness due to thickness differences]:

[0085] Fig. 9 This is a cross-sectional view of a conventional thicker light guide. Fig. 9 The conventional light guide 100A has a relatively thick thickness T1, so the reflection period of the light L1 in the light guide 100A is relatively long, and the number of times the light L1 is incident on the cross section of the light guide 100A is relatively small, which easily causes periodic unevenness in surface light emission.

[0086] Fig.10 FIG. 1 is a cross-sectional schematic diagram of a thin light guide according to an embodiment of the present invention. Fig.10 The light guide 100 of the embodiment of the present invention has a thinner thickness T2. Therefore, the reflection period of the light L2 in the light guide 100 is shorter, and the number of times the light L2 is incident on the cross-section of the light guide 100 is greater. The light L2 is more likely to be incident on the cross-section of the light guide 100. Therefore, it is difficult to produce periodic unevenness of surface luminescence.

[0087] In summary, the light guide and the surface light emitting device of the embodiments of the present invention have at least the following technical effects:

[0088] The shape of the light-entering portion of the light guide is changed, and the light-entering angle can be increased to take in light in a wider angle range, thereby improving the light-entering efficiency. Through the multiple light-guiding paths of the light guide, multiple lights from the light source can be taken in, so that the periodic unevenness can be reduced to achieve uniform lighting. The light guide and the surface light-emitting device of the present invention can achieve a thinner light guide plate and more uniform surface light emission, thereby reducing cost and weight.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A light guide, characterized in that: include: The light guide plate is configured such that: light from a light source is guided into the light guide plate for transmission; A concave portion is arranged on one side of the light guide plate in a thickness direction, and the light source is arranged inside the concave portion; a wall portion protruding toward the one side compared to the light guide plate, and the recessed portion is provided on the inner side of the wall portion; a first reflecting portion, arranged at the other side of the light guide plate in the thickness direction and facing the light source, the first reflecting portion having a conical recess so that a first portion of the light from the light source is reflected into the interior of the light guide plate; as well as The second reflecting portion is provided on the one side in the thickness direction of the light guide plate and is located on the wall portion so as to reflect a second portion of the light from the light source into the interior of the light guide plate.

2. The light guide according to claim 1, characterized in that: The wall portion is configured to protrude to the same level as a light emitting surface of the light source.

3. The light guide according to claim 1, characterized in that: The wall portion is configured to protrude in a circular shape with the light source as the center.

4. The light guide according to claim 1, characterized in that: Also includes: A plurality of dot portions are provided on the back side of the light emitting portion of the light guide plate.

5. The light guide according to claim 1, characterized in that: The recess includes: Planar parts; and The curved surface part connects the flat surface part. wherein the wall portion surrounds the curved surface portion, A third portion of the light from the light source is transmitted to the interior of the light guide plate via the curved portion.

6. A surface light emitting device, characterized in that: include: light source; as well as The light guide according to any one of claims 1 to 5 guides and emits the light from the light source.

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