JP6540486B2 - Light emitting device - Google Patents

Description

  The present invention relates to a light emitting device using a light guide plate.

  In recent years, vehicles have been fitted with an emblem indicating a vehicle type, a manufacturer name and the like. The emblem is designed to emit light at night to improve the appearance. For example, Patent Literatures 1 and 2 disclose one in which a light guide plate is disposed on the back side of an emblem and light is emitted from the LED to the light guide plate. The light guide plate emits light by leaking part of the light while internally reflecting the incident light. In Patent Document 1, by surrounding the surface and the back surface of the light guide plate with a reflective material, the reflection of light inside the light guide plate is further repeated to make the light emission intensity uniform. In Patent Document 2, light is made incident from the LED to the surface in the thickness direction of the light guide plate, and light emitted from the LED is made to emit light uniformly so as to be directed to the outer peripheral curved surface of the light guide plate.

JP, 2013-205530, A Patent No. 5005109

  However, in Patent Document 1, since the LED is disposed at the center of the light guide plate, the light emission intensity of the portion of the light guide away from the LED is low. In patent document 2, LED is installed so that the optical axis of the light which injected into the light-guide plate through LED from a LED may turn to the direction along a surrounding surface. For this reason, light emitted from the LED strikes the peripheral surface and is likely to leak light from the peripheral surface. For this reason, it is difficult to cause the light guide plate of Patent Document 2 to emit light efficiently.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a light emitting device capable of causing a light guide to emit light uniformly.

A light emitting device according to the present invention is provided in a light guide plate having a front surface, a back surface, and a circumferential surface, a plurality of light entrance portions provided at mutually opposing positions on the circumferential surface, and a plurality of the light entrance portions. Equipped with multiple light sources,
The optical axis of one light incident from one of the light entrances of the pair of light entrances facing each other and the optical axis of the other light incident from the other light entrances are in front of one Pass through the area on the opposite side across the straight line between the light entrances connecting the light entry and the other light entrances,
The wide-area angle centered on a bisector dividing a wide-area angle formed by a critical angle straight line that passes through the light entrance and forms a critical angle with respect to the circumferential surface and a straight line between the light entrances When an area formed between two straight lines that make an angle of 50% when 100% is defined as a light area, an optical axis of light incident from the light entrance passes through the light area The light entrance portion is set.

  In the above configuration, a plurality of light entrances are provided on the circumferential surface of the light guide plate, and light is incident on the light guide plate from the plurality of light entrances.

  The plurality of light entrance portions are disposed at positions facing each other on the circumferential surface. The optical axis of one light incident from one of the light entrances of the pair of light entrances facing each other and the optical axis of the other light incident from the other light entrances are in front of one It passes through the area on the opposite side across a straight line between the light entrances connecting the writing light and the other light entrances. For this reason, when light is incident on the light guide plate from the plurality of light entrance portions, different regions can be illuminated with light incident from the light entrance portions, and light can be emitted over a wide range of the light guide plate.

  Here, the critical angle refers to the smallest incident angle at which total reflection occurs when light travels from a portion having a large refractive index to a portion having a small refractive index. When light incident from the light entrance portion travels to the circumferential surface, a straight line connecting the light entrance portion and a portion forming a critical angle on the circumferential surface is referred to as a critical angle straight line. When light incident from the light entrance portion travels at an angle larger than the critical angle with respect to the circumferential surface, the light is totally reflected on the circumferential surface, and thus does not leak from the light guide plate to the outside, but is reflected on the circumferential surface The light intensity is maintained before and after. On the other hand, when light incident from the light entrance portion travels at an angle smaller than the critical angle with respect to the circumferential surface, part of the light leaks from the light guide plate to the outside on the circumferential surface and is reflected on the circumferential surface The intensity of the light after being made is weaker than the intensity of the light before being reflected by the circumferential surface. That is, since light passing through a wide area between the critical angle straight line and the straight line between the light entrance portions is incident at an angle smaller than the critical angle with respect to the circumferential surface, light leaks to the outside at the circumferential surface. Light intensity is weakened.

  Therefore, in the present invention, the light entrance portion is set so that the optical axis of the light incident from the light entrance portion travels along the approximate center line of the wide area between the critical angle straight line and the straight line between the light entrance portions. There is. That is, it is formed between two straight lines that form an angle of 50% when the wide-area angle is 100% centering on a bisector dividing the wide-area angle formed by the critical angle straight line and the straight line between light entrances into two. Area is the light area. The light entrance portion is set such that the optical axis of the light incident from the light entrance portion passes through the inside of the light region. In this way, the light incident from the light entrance portion travels in a wide range of the wide area before it strikes the circumferential surface, and leaks uniformly from the front and back surfaces. Therefore, the light guide plate can emit light uniformly.

  As described above, according to the present invention, it is possible to provide a light emitting device capable of causing the light guide to emit light uniformly.

It is an AA arrow line sectional view of Drawing 2 for explaining a light emitting device of a 1st embodiment of the present invention. It is a top view of the light-emitting device of 1st Embodiment. It is a disassembled perspective view of the light-emitting device of 1st Embodiment. It is a top view of the light-guide plate which shows the optical axis of the light which injected from the light-incidence part of 1st Embodiment. It is an enlarged plan view of the light entrance part of Drawing 4A. It is a top view of a light guide plate for explaining the direction of an optical axis of a 1st embodiment. It is plane explanatory drawing of the surrounding surface vicinity of a light-guide plate for showing the case where an incident angle is larger than a critical angle. It is plane explanatory drawing of the surrounding surface vicinity of a light-guide plate for showing the case where an incident angle is smaller than a critical angle. It is a BB arrow directional cross-sectional view of FIG. 8 for demonstrating the hollow provided in the back surface of the light-guide plate of 1st Embodiment. It is a top view of a light guide plate for explaining the height of a hollow of a 1st embodiment. It is a top view of a light guide plate for explaining a central field, a border field, and a peripheral field of a 1st embodiment. It is a BB arrow sectional view of Drawing 8 for explaining the density of a hollow as a modification of a 1st embodiment. It is CC arrow sectional drawing of FIG. 3 for demonstrating the refractive member of 1st Embodiment. It is the plane enlarged view of the refraction | bending area | region in the refraction | bending member of 1st Embodiment. It is a perspective view of a prism sheet of a 1st embodiment. It is explanatory drawing which shows the sequence direction of a hollow of 1st Embodiment. It is a top view of a refraction member which has arranged a light guide plate in the back in order to explain a relation between an arrangement direction of hollows and an extension direction of a refraction field of a 1st embodiment. It is explanatory drawing of the design when a refraction | bending area | region is seen from the surface of a refraction | bending member of 1st Embodiment. It is a top view of the refraction member which has arranged a light guide plate in the back in order to explain the relation between the arrangement direction of hollows, and the extension direction of a refraction field as a modification of a 1st embodiment. It is explanatory drawing of the design when a refraction | bending area | region is seen from the surface as a modification of 1st Embodiment. It is the DD arrow directional cross-sectional view of FIG. 3 for showing the emblem of 1st Embodiment. It is explanatory drawing of a design when a light-emitting device is seen when the light source is OFF of 1st Embodiment. It is explanatory drawing of a design when a light-emitting device is seen when the light source is ON of 1st Embodiment. In 2nd Embodiment, it is a top view of the light-guide plate for demonstrating the direction of the optical axis in case a light-guide plate is circular. In 2nd Embodiment, it is a top view of a light-guide plate for demonstrating a peripheral area | region, a boundary area | region, and a center area | region. In 3rd Embodiment, it is a top view of the light-guide plate for demonstrating the direction of the optical axis in case a light-guide plate is a rectangle. In 3rd Embodiment, it is a top view of a light-guide plate for demonstrating a peripheral area | region, a boundary area | region, and a center area | region. In 4th Embodiment, it is a top view of the light-guide plate for demonstrating the direction of the optical axis in case a light-guide plate is a square. It is a top view of a light guide plate for explaining a peripheral field, a border field, and a central field in a 4th embodiment. In 5th Embodiment, a refraction | bending area | region is plane explanatory drawing of the refraction | bending area | region which has the extending part extended in 3 directions. In 5th Embodiment, it is a top view of the light-guide plate for showing the sequence direction of a hollow. It is a top view of a refraction member which has arranged a light guide plate in the back in order to explain a relation between an arrangement direction of hollows and an extension direction of a refraction field of a 5th embodiment. It is explanatory drawing of the design when a refractive area | region is seen from the surface of 5th Embodiment. It is sectional drawing which cut | disconnected the light-emitting device in the position of the AA arrow of FIG. 2 in order to demonstrate the light-emitting device of 6th Embodiment. It is sectional drawing which cut | disconnected the light-emitting device in the position of the AA arrow of FIG. 2 in order to demonstrate the light-emitting device of 7th Embodiment.

First Embodiment
Embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the light emitting device of the present embodiment includes a case 9, a reflector 8, a light guide plate 1, a light source 2, a refracting member 3, and a decorative member 5.

  As shown in FIG. 2, the overall shape of the light emitting device is elliptical. In FIG. 2 and other figures, “long” and “short” indicate the major axis direction and the minor axis direction of an ellipse which is the overall shape of the light emitting device.

  As shown in FIGS. 1 and 3, the case 9 has a bottom wall 91 having a substantially elliptical shape, and a peripheral wall 92 provided upright from the periphery of the bottom wall 91. A pair of holding walls 93 are provided upright on both sides of the center of the case 9 in the long axis direction. A light source 2 is fixed to one end of one holding wall 93 and the other end of the other holding wall 93. The holding wall 93 extends in parallel to the short axis direction, and both ends of the holding wall 93 are fixed to the peripheral wall 92.

  Case 9 is an injection-molded article made of a synthetic resin material. Examples of synthetic resin materials used in Case 9 include ASA (acrylate-styrene-acrylonitrile), AES (acrylonitrile-ethylene-styrene), ABS (acrylonitrile-butadiene-styrene), PC (polycarbonate) and the like. In the present embodiment, AES is used.

  The light guide plate 1 is a thin plate having an elliptical shape. The light guide plate 1 has a major axis of 148 mm, a minor axis of 69 mm, and a thickness of 3 mm. The light guide plate 1 has an elliptical surface 1a, a back surface 1b opposite to the surface 1a, and a circumferential surface 1c provided between the periphery of the surface 1a and the periphery of the back surface 1b. The light incident on the light guide plate 1 travels while being reflected by the front surface 1a, the back surface 1b, and the circumferential surface 1c. When light traveling to the front surface 1a, the back surface 1b or the circumferential surface 1c exceeds the critical angle while light travels inside the light guide plate 1, the light leaks little by little from the front surface 1a, the back surface 1b or the circumferential surface 1c The light guide plate 1 emits light.

  As a material of the light guide plate 1, it is preferable to use a glass material, a synthetic resin material, or the like. Examples of synthetic resin materials include PMMA (polymethyl methacrylate) and PC. In the present embodiment, PMMA is used as the material of the light guide plate 1.

  The surface 1a of the light guide plate 1 is a flat surface.

  The back surface 1b of the light guide plate 1 is provided with a large number of recesses 11 described later. The back surface 1 b of the light guide plate 1 is covered with a reflective material 8. The reflector 8 has the same shape and size as the light guide plate 1. For example, it is made of a highly reflective metal such as aluminum. Since the reflective material 8 covers the back surface 1 b of the light guide plate 1, the light traveling toward the back surface 1 b of the light guide plate 1 is reflected to the front surface 1 a side. The light guide plate 1 and the reflector 8 are accommodated in the case 9 and fixed on the holding wall 93 of the case 9.

  As shown in FIG. 4A, on the circumferential surface 1c of the light guide plate 1, a pair of light entrance sections 15, 15 are provided. The pair of light entrance portions 15 are disposed at positions facing each other on the circumferential surface 1c. The pair of light incident portions 15, 15 are not located on the major axis G and the minor axis H of the elliptical shape of the light guide plate 1, but are disposed on the opposite sides of the major axis G and the minor axis H. In addition, the light guide plate 1 is disposed at a point-symmetrical position with respect to the intersection (center) of the major axis G and the minor axis H of the ellipse of the light guide plate 1.

  As shown in FIG. 5, an optical axis L of a certain light incident from one light entrance portion 15 and an optical axis of another light incident from another light entrance portion 15 facing the one light entrance portion 15 L passes through regions opposite to each other across a straight line D between light entrances connecting one light entrance 15 and the other light entrance 15.

  In the present embodiment, the light guide plate 1 has a pair of (two) light incident portions 15 and 15, but a plurality of light incident portions, for example, four or six light incident portions are provided. It is also good. Also in this case, the light entrances of each pair may have the above-mentioned relationship.

  As shown in FIG. 3, the light entrance part 15 is the step part 17 which notched part of the surrounding surface 1c in step shape. The light entrance portion 15 is directed in the vertical direction with respect to the front surface 1 a and the back surface 1 b of the light guide plate 1. The light entrance unit 15 causes the light emitted from the light source 2 to be incident in the direction perpendicular to the surface 1 a which is the exit surface of the light guide plate 1.

  As shown in FIG. 4B, the light input unit 15 is provided with the light source 2. An LED is used as the light source 2. LEDs are thin chip scale packages. The emission part 20 of the light source 2 is disposed close to and opposed to the light input part 15. The light source 2 may use a semiconductor light emitting element such as EL (Electro Luminescence) or LD (Laser Diode) instead of the LED.

  The emission part 20 of the light source 2 irradiates light to the irradiation area | region where the irradiation angle (alpha) is the range of 90 degrees-150 degrees. The emitting unit 20 may emit light having a spread over the irradiation area. The irradiation area is an area where the light incident from the light entrance section 15 is oriented, and the light spreads from the light entrance section 15 at the irradiation angle α. The emitting unit 20 of the light source 2 used in the present embodiment emits light with an irradiation angle α of 120 °.

Here, the critical angle refers to the smallest incident angle at which total reflection occurs when light travels from a portion having a large refractive index to a portion having a small refractive index. As shown in FIG. 5, when light incident from the light entrance portion 15 travels to the circumferential surface 1c, a straight line forming a critical angle with the circumferential surface 1c is referred to as a critical angle straight line E. As shown in FIGS. 5 and 6A, when the light Z travels from the light entrance portion 15 to the circumferential surface 1c, all light Z is incident on the circumferential surface 1c at an angle θ larger than the critical angle θ _0. Because the light is reflected, the light intensity is maintained without leaking to the outside. A region closer to the circumferential surface 1 c than the critical angle straight line E is referred to as a circumferential surface near region A. The light Z passing through the peripheral surface close region A is totally reflected on the peripheral surface 1c because it travels to the peripheral surface 1c at an angle larger than the critical angle.

On the other hand, as shown in FIG. 5 and FIG. 6B, when the light Z from the light entrance section 15 is directed to the circumferential surface 1c, the light Z is incident on the circumferential surface 1c at an angle θ smaller than the critical angle θ _0. In the peripheral surface 1c, a part of the light leaks to the outside, and the light intensity weakens. That is, the light passing through the wide area B between the critical angle straight line E and the light entrance part straight line D (hatched portion in the upper right hatching and cross hatching portions in FIG. 5) is smaller than the critical angle θ ₀ Incident at an angle. For this reason, a part of the light Z leaks to the outside on the circumferential surface 1c, and the light emission intensity is weakened.

  Therefore, in the present embodiment, the optical axis L of the light incident from the light entrance section 15 travels along the approximate center line of the wide area B between the critical angle straight line E and the light entrance section straight line D. The light unit 15 is set. The optical axis L refers to a virtual ray representing a light flux passing through the entire system. More specifically, the optical axis L is a center line of the irradiation range, and coincides with a straight line that bisects the irradiation angle α formed by the irradiation range at the light entrance unit 15.

  That is, a 50% angle is formed when the wide-range angle β is 100% with a bisector F bisecting the wide-angle angle β formed by the critical angle straight line E and the light-into-light straight line D 2 An area formed between the straight lines F1 and F1 is a light area C (cross hatched portion in FIG. 5). The light region C extends on the critical angle straight line E side and the light entrance part straight line D side with the bisector F as a center. More preferably, the light region C is a region formed between two straight lines that make an angle of 40% when the wide angle β is 100%, and formed between two straight lines that make an angle of 30% It is desirable that the region be The light entrance unit 15 is set such that the optical axis L of the light incident from the light entrance unit 15 passes through the light region C.

  In order to set the light entrance portion 15 in this manner, for example, it is preferable to adjust the direction of the light entrance portion 15 and the direction of the emission portion 20 of the light source 2. By doing this, the light incident from the light entrance portion 15 travels in the wide area B before hitting the circumferential surface 1 c and leaks uniformly from the front surface 1 a and the back surface 1 b of the light guide plate 1. Therefore, the light guide plate 1 can emit light uniformly.

  Further, as shown in FIG. 4A, the optical axis L of the light incident on the light guide plate 1 from the light entrance portion 15 passes through the light region C, and the light entrance portion 15 and the end G1 of the major axis G of the elliptical shape. It is preferable that the light travels in the traveling region Q between two straight lines intersecting at an angle of 30 ° in the light entrance portion 15 with the straight line T between the light entrance end portions connecting the centers. It is preferable to pass within a traveling region Q between two intersecting straight lines at an angle of 20 °. In the present embodiment, the optical axis L of the light incident on the light guide plate 1 from the light entrance portion 15 is directed to the end G 1 of the major axis G of the elliptical shape of the light guide plate 1 in the traveling region Q. For this reason, the light incident from the light entrance portion 15 travels in a long and wide range until it hits the circumferential surface 1 c. Therefore, the entire light guide plate 1 can emit light uniformly.

  When light is made incident from the light source 2 to the inside of the light guide plate 1 through the pair of light entrance portions 15, the central region X of the light guide plate 1 is irradiated with light incident from the pair of light entrance portions 15 together. In the peripheral region Y located on the periphery of X, the light incident from one of the light entrance portions 15 is irradiated. The peripheral region Y tends to have a lower emission intensity than the central region X. Therefore, the unit projected area of the peripheral region Y can be obtained by interspersing a plurality of recesses 11 on the back surface 1 b of the light guide plate 1 and making the depth of the recesses 11 in the peripheral region Y deeper than the depth of the recesses 11 in the central region X The area of the light striking surface is made larger than the area of the light striking surface per unit projected area of the central region X. Thereby, the light emission unevenness of central region X and peripheral region Y can be further reduced.

  It will be described in more detail. FIG. 8 is a plan view of the light guide plate 1 for showing the depression area K, where the largest cross hatching in FIG. 8 shows the central area X, the smallest cross hatching shows the peripheral area Y, and the middle size The cross hatching of indicates the boundary area P. FIG. 7 is a cross-sectional view taken along the line B-B in FIG. 8 for explaining the depression provided on the back surface of the light guide plate.

  As shown in FIGS. 7 and 8, a large number of depressions 11 are scattered on the back surface 1 b of the light guide plate 1. The back surface 1b of the light guide plate 1 has a flat area J with a predetermined width from the peripheral edge and no depressions 11 and a depression area K in which the depressions 11 are scattered. The depression area K is a central area X disposed between the pair of light sources 2, a peripheral area Y disposed in a portion other than the central area X, and a boundary area interposed between the central area X and the peripheral area Y And P.

  As shown in FIG. 8, the central region X is positioned at the center of the light guide plate 1, and the boundary region P is positioned on both sides of the central region X and extends in a strip shape. The peripheral region Y is located further outside the boundary region P in the depression region K.

  As shown in FIG. 9, the central area X has a dual optical path area M in which the irradiation areas where light is incident from the light source 2 through the pair of light incident sections 15 overlap. In the present embodiment, the irradiation area is an area having an irradiation angle α of 120 ° around the optical axis L of the light emitted from the light source 2 (FIG. 4B). The irradiation area of the light source 2 positioned on the right side of the drawing in FIG. 9 is an area indicated by hatching upward to the right, and the irradiation area of the light source 2 positioned on the left side of the drawing of FIG. The both-optical path area M corresponds to a portion in which the rightward hatching and the leftward hatching overlap, that is, a cross hatching portion. In FIG. 9, in the area shown by the upper left hatching and the area shown by the upper right hatching, an area in which both hatchings are not overlapped is the one optical path area N where light is incident through one light entrance portion 15.

  As shown to FIG. 4B, the light entrance part 15 has the bending part 16 in the vicinity of the output part 20 of the light source 2. As shown in FIG. In the bending portion 16, light incident from the light source 2 is scattered and incident, so that the vicinity of the bending portion 16 emits light relatively strongly. Even if the vicinity of the bending portion 16 exists in the optical path region N, the light is relatively strongly emitted. In FIG. 9, a near-bending region R that emits strong light in the vicinity of the bending portion 16 is indicated by dot hatching. As described above, when there is the near-bending region R, the central region X consists of the two optical path regions M and the near-bending region R. The peripheral area Y is an area other than the central area X of the recessed area K, that is, an area excluding the bending near area R from the one optical path area N.

  As shown in FIGS. 8 and 9, a point Q2 at which the boundary line Q1 between the dual optical path area M and the one optical path area N intersects the boundary line between the depressed area K and the flat area J is a point Q2. Of the boundaries with J, the line along the circumferential surface 1c on the short axis H side of the light guide plate 1 is taken as the short axis side line K1. In this case, the central region X forms a substantially parallelogram surrounded by a straight line QR connecting the point Q2 and the bending near region R and the short axis side straight line K1.

  The boundary area P is a band-like area located on both sides of the central area X and extending along the straight line QR. The width of the boundary area P is preferably 3 to 10 mm, and is 5 mm in this embodiment.

  The peripheral area Y has an optical path area N, and is located closer to the end G1 of the major axis G than the boundary area P in the recessed area K.

  In the case where the light incident portion 15 does not have the bent portion 16, the bent vicinity region R does not emit light strongly, and the light emission intensity is about the same as the light path region N. In this case, the central region X does not include the near-bending region R and is formed of only the two optical path regions M. The peripheral area Y consists of an optical path area N.

  As shown in FIG. 7, the ratio T3 / T1 of the depth T3 of the recess 11 in the central region X to the depth T1 of the recess 11 in the peripheral region Y is preferably 0.1 to 0.9, and 0 0.2 to 0.75 and 0.3 to 0.7 are preferable. In this case, the difference between the light emission intensities of the central region X and the peripheral region Y can be hardly recognized visually.

  In this embodiment, the depth T3 of the recess 11 formed in the central region X is 0.3 mm, the depth T2 of the recess 11 formed in the boundary region P is 0.4 mm, and the recess 11 is formed in the peripheral region Y The depth T1 of the recess 11 is 0.5 mm. The depressions 11 formed in any of the regions are scattered at the same density (pitch).

  Moreover, in the present embodiment, the depressions 11 have the same shape in all the depression regions K. The shape of the recess 11 is not particularly limited, but may be a cone shape or a column shape. The cone shape includes a cone and a pyramid, and the column shape includes a cylinder and a prism. Among these, the cone is preferred. As shown in FIG. 7, the elevation 11 a surrounding the conical recess 11 is inclined toward the surface of the light guide plate 1, so when light traveling inside the light guide 1 strikes the elevation 11 a, the light is surface 1 a Because it is easy to turn to the side. In the present embodiment, the shape of the recess 11 is a cone. In addition, the depressions 11 are arranged in a grid shape at equal intervals in the major axis direction and the minor axis direction over the entire depression area K.

  The peripheral region Y has one optical path region N through which light incident from one light entrance portion 15 passes, and the central region X is both optical path regions M through which light incident from both light entrance portions 15 and scattered light And a near-flexure region R to be irradiated. For this reason, when the depths of the depressions 11 are the same, the light emission intensity in the one optical path region N of the light guide plate 1 becomes smaller than the light emission intensity of the both optical path regions M.

  In the present embodiment, the depth of the depressions 11 scattered in the peripheral region Y is made deeper than the depth of the depressions 11 scattered in the central region X. As a result, the light incident surface per unit projected area of the peripheral region Y is larger than the light incident surface per unit projected area of the central region X. In the peripheral region Y, light leaks more easily than the central region X. The intensity of light emitted from the peripheral region Y is approximately the same as the intensity of light emitted from the central region X, and the entire light guide plate 1 emits light uniformly.

  Further, by setting the depth of the depressions 11 scattered in the boundary region P to be intermediate between the depth of the depressions 11 in the central region X and the depth of the depressions 11 in the peripheral region Y, the depths of the depressions 11 in both regions sharply. The boundary between the central area X and the peripheral area Y is less likely to be recognized as compared with the case where the height is changed. The light guide plate 1 can emit light more uniformly.

  The light traveling inside the light guide plate 1 is reflected or scattered by the raised surface 11 a of the recess 11. For example, when the depth of the recess 11 is large, when the light guide plate 1 is viewed from the surface 1 a side, the recess 11 may be seen as a light emitting point that emits light more strongly than other portions. In the present embodiment, the depressions 11 of the light guide plate 1 are arranged at equal intervals in all of the depression regions K. When the light guide plate 1 is viewed from the front surface 1 a, the light emitting points resulting from the depressions 11 appear uniformly in the entire light guide plate 1. The entire light guide plate 1 can emit light with uniform light emission intensity due to the uniform light emission point.

  On the other hand, as shown in FIG. 10, the pitch P1 between the depressions 11 in the peripheral region Y may be smaller than the pitch P3 between the depressions 11 in the central region X. That is, the density of the depressions 11 in the peripheral area Y may be larger than the density of the depressions 11 in the central area X. The surface on which the light per unit projected area of the peripheral region Y hits is larger than the surface on which the light per unit projected area on the central region X hits, and the entire light guide plate 1 can emit light uniformly. On the other hand, when the pitch P1 between the depressions 11 in the peripheral region Y is smaller than the pitch P3 between the depressions 11 in the central region X, the light emitting points per unit projected area of the peripheral region Y are the unit projection of the central region X The number of light emission points is larger than the light emission point per area, and the appearance of light emission differs between the peripheral region Y and the central region X. When the boundary area P is provided, the pitch P2 of the depressions 11 in the boundary area P may be a size between the pitch P1 of the depressions 11 in the peripheral area Y and the pitch P3 of the depressions 11 in the central area X.

  As shown in FIG. 11, the refraction member 3 has a refraction area 36 and a background area 37. The refraction area 36 refracts the light incident from the light guide plate 1. The refractive area 36 has an extending portion 36 b which is long in the extending direction I. In the refractive area 36, one or more extending portions 36b are provided. When the plurality of extending portions 36 b are provided, the plurality of extending portions 36 b may be arranged radially around the central portion 36 a. In the present embodiment, in the refractive area 36, four extending portions 36b extend in four directions centering on the central portion 36a. The width of each extending portion 36b may be shaped to change in the extending direction I, and may be the same in any part in the extending direction I. In the present embodiment, the width of each extending portion 36 b is gradually narrowed in the extending direction I.

  The refractive member 3 has a transparent substrate 31, a background layer 32, a half mirror layer 33, and a prism sheet 34. The transparent substrate 31 is a transparent thin plate. The peripheral edge of the transparent base 31 is locked to a step 94 provided on the peripheral wall 92 of the case 9 (FIG. 3). The transparent substrate 31 is made of, for example, a synthetic resin such as PMMA, PC, PC / ABS alloy or the like. Among these, PMMA is most preferable because of its high transparency and excellent injection moldability.

  As shown in FIGS. 11 and 3, the back surface 31 b of the transparent base 31 has a flat portion 35 and a central recess 30 which is recessed from the flat portion 35. The recess 30 is a portion corresponding to the refractive area 36, and has a radial shape in a plane arrow. The flat portion 35 is a portion other than the concave portion 30 in the back surface 31 b of the transparent base 31 and corresponds to the background region 37. The refractive area 36 is recessed on the surface side of the background area 37 on the back surface 31 b of the transparent base material 31. Therefore, when the refractive member 3 is viewed from the surface, the refractive area 36 is on the front side with respect to the background area 37 It looks three-dimensional as if jumping out.

  The refractive area 36 may protrude to the back side with respect to the background area 37. In this case, it appears that the refraction area 36 is located behind the background area 37. The refractive area 36 may be at the same height with respect to the background area 37.

  As shown in FIG. 12, in the present embodiment, the radial shape of the refracting region 36 in the planar arrow direction is a central portion 36 a and four extension portions 36 b extending in four directions at equal angles (90 °) from the central portion 36 a It consists of Two of the four extensions 36 b extend in the longitudinal direction, and the other two extend in the short axis direction.

  As shown in FIG. 11, the background layer 32 covers the back surface 31 b of the transparent substrate 31 with a portion other than the refraction area 36, that is, the background area 37. The background layer 32 is white translucent. The background layer 32 may be formed by a painting method or a printing method. The background layer 32 may be made of a colored or non-colored light transmitting synthetic resin material. As such a synthetic resin material, it is preferable to use PMMA, PC, PET (polyethylene terephthalate), PVC (polyvinyl chloride) or the like.

  The half mirror layer 33 covers the entire back surface 31 b side of the transparent base 31. The half mirror layer 33 reflects light from the outside, but transmits light from the light guide plate 1 disposed on the back surface side. The half mirror layer 33 is more likely to transmit light from the light guide plate 1 than the background layer 32. The half mirror layer 33 is made of a thin metal layer having a thickness of about 1 μm or less. Examples of the metal used for the half mirror layer 33 include tin, silver, gold, titanium, aluminum, chromium and indium. In the present embodiment, aluminum is used for the half mirror layer 33. The half mirror layer 33 is formed by vapor deposition, plating or the like.

  As shown in FIG. 13, in the prism sheet 34, a plurality of grooves 34a are formed at the same pitch. The plurality of grooves 34a are arranged in a straight line at equal intervals in four extending directions I at equal angles (90 °) from the center 34b of the refractive area 36. The prism sheet 34 forms a prism pattern (linear Fresnel lens) in which the thickness is reduced by cutting the cylindrical lens surface into sections at predetermined intervals. Each groove 34a is a boundary of the section of the cylindrical lens surface. The cylindrical lens surface is a cylindrical surface, which has a curvature in one direction but does not have a curvature in a direction orthogonal to the one direction. Therefore, the prism sheet 34 diffuses the light incident on the sheet surface to the entire sheet surface while refracting the light in the extension direction I of the refractive area 36. The pitch of the grooves 34 a is preferably 5 μm to 100 μm, and is 10 μm in the present embodiment. The prism pattern formed on the prism sheet 34 is a pattern for refracting the light incident from the light guide plate 1 in the refraction area 36, and provided with a plurality of grooves 34a arranged in the extension direction I of the extension portion 36b. As long as the lens is used, it may be a Fresnel lens other than the cylindrical lens pattern.

  The prism sheet 34 is made of a translucent synthetic resin material. As a synthetic resin material used for the prism sheet 34, PMMA, PC, PET or the like may be used. The prism sheet 34 may be formed by extrusion molding or calendar molding. Further, the prism sheet 34 may be a two-layered sheet material in which a prism layer having each groove 34 a is formed on one surface side of the base film.

  As shown in FIGS. 3 and 11, the entire rear surface of the transparent base 31 is covered with a half mirror layer 33. In the background area 37 of the back surface 31 b of the transparent substrate 31, the background layer 32 is disposed between the transparent substrate 31 and the half mirror layer 33. Therefore, as shown in FIG. 12, when the light is irradiated from the back surface to the front surface of the refractive member 3 and the refractive member 3 is viewed from the front surface, the groove 34a of the prism sheet 34 can be visually recognized in the refractive region 36. In the background area 37, the groove 34a can not be visually recognized because it is blocked by the background layer 32.

  Here, as shown in FIG. 14, on the back surface 1 b of the light guide plate 1, a large number of depressions 11 are arranged in a lattice at equal intervals in the long axis direction and the short axis direction. The pitch S1 of the depressions 11 adjacent to each other in the long axis direction and the short axis direction is shorter than the pitch between the depressions 11 adjacent to each other in the other direction.

  In the present embodiment, as shown in FIG. 15, the extending direction I of the extending portion 36 b of the refraction area 36 of the refraction member 3 coincides with the arrangement direction S of the depressions 11. In the arrangement direction S of the depressions 11, the pitch S1 between the depressions 11 is the narrowest. The light reflected and diffused by the recess 11 is further reflected and diffused by the groove 34a. In this case, as shown in FIG. 16, when the refracting member 3 and the light guide plate 1 are viewed from the surface of the refracting member 3, many straight streaks extend in the extending direction I of the extending portion 36b, and the extending portion 36b are viewed as being highlighted in the extension direction I. This is because the light reflected and scattered by the depression 11 is most emphasized in the arrangement direction S of the depressions 11, so that many lines extend in the extension direction I of the extending portion 36 b parallel to the arrangement direction of the depressions 11. It is considered to have been visually recognized.

  On the other hand, as shown in FIG. 17, it is assumed that the extending direction I of the extending portion 36 b of the refractive area 36 of the refractive member 3 is inclined 45 ° with respect to the arrangement direction S of the depressions 11. In this case, as shown in FIG. 18, when the refracting member 3 and the light guide plate 1 are viewed from the surface of the refracting member 3, a large number of lines inclined at 45.degree. As viewed. This is because the light reflected and scattered by the depression 11 is most emphasized in the arrangement direction of the depressions 11, and the arrangement direction S of the depressions 11 is inclined at 45 ° with respect to the extension direction I of the extending portion 36b. It is considered that many lines are viewed as extending in the inclination direction.

  As shown in FIG. 19, the decorative member 5 is an emblem having a display area 56 displaying a car type, a manufacturer name and the like. The decorative member 5 has a cover member 51, a decorative layer 52 and a half mirror layer 53. As shown in FIGS. 19 and 3, the cover member 51 has a flat portion 55 and a central recess 50 recessed from the flat portion 55. The recess 50 is a portion to be the display area 56 where the half mirror layer 53 is visually recognized. The flat portion 55 is a portion to be the decoration area 57 in which the decoration layer 52 is visually recognized. The cover material 51 is transparent, and is made of, for example, a synthetic resin such as PMMA, PC, or PC / ABS alloy. Among these, PMMA is most preferable because of its high transparency and excellent injection moldability.

  The decorative layer 52 of the decorative member 5 covers the decorative area 57 on the back surface of the cover member 51. The decorative layer 52 may be formed by a painting method or a printing method. The decorative layer 52 may be made of a colored or non-colored light transmitting synthetic resin material. In the case of coloring, a coloring material is added to the synthetic resin material. As such a synthetic resin material, it is preferable to use PMMA, PC, PET (polyethylene terephthalate), PVC (polyvinyl chloride) or the like. In the present embodiment, the decorative layer 52 exhibits blue translucency.

  The half mirror layer 53 of the decorative member 5 covers the entire back surface side of the cover member 51. The half mirror layer 53 is made of a thin metal layer, like the half mirror layer 33 of the refractive member 3. As a metal used for the half mirror layer 53 of the decoration member 5, the thing similar to what is used for the half mirror layer 33 of the refraction member 3 can be used. In the present embodiment, the half mirror layer 53 uses aluminum.

  The shape of the display area 56 of the cover member 51 as viewed in plan view is a rhombus. Although the entire back surface of the cover member 51 is covered with the half mirror layer 53, the decorative layer 52 is disposed between the cover member 51 and the half mirror layer 53 in the decoration area 57 of the back surface of the cover member 51 . Therefore, the metal color of the half mirror layer 53 is visually recognized in the display area 36, and the blue color of the decorative layer 52 is visually recognized in the decorative area 37.

  In the light emitting device of the present embodiment, when the light source 2 is turned off when viewed from the front surface side, as shown in FIG. 20, a rhombic metallic display area 56 of the half mirror layer 53; The blue color of the decorative layer 52 can be seen in the decorative area 57 around it. At this time, the refracting region 36 on the back surface side can not be seen by the half mirror layer 53 of the decorative member 5.

  As shown in FIG. 21, when the light source 2 is viewed from the front side with the switch of the light source 2 turned on, the rhombic metallic display area 56 of the half mirror layer 53 and the surrounding decoration layer 52 are provided. The blue decorative area 57 is visible. Then, the half mirror layer 53 of the decorative member 5 is seen through to see the refractive area 36 of the refractive member 3 on the back surface side. The refractive area 36 appears bright in the half mirror layer 53. Furthermore, in the refraction area 36, many straight streaks are seen in the extension direction of the extending portion 36b, and the extending portion 36b is emphasized and visually recognized in the extension direction.

  When the light emitting device is viewed in a dark environment such as nighttime, in addition to the light emission pattern of the decoration area 56, the light emission pattern of the refraction area 36 is clearly seen. Unlike when viewed in a bright environment such as daytime, it is possible to visually recognize a complex and highly aesthetic luminous design.

  Further, since the light guide plate 1 emits light uniformly, the light is uniformly irradiated from the light guide plate 1 to the refractive member 3. Therefore, the decorative member 5 can emit light without unevenness through the refractive member 3.

  In the present embodiment, the light entrance portion 15 is provided in the step 17 which is recessed inward in the radial direction from the outer peripheral edge of the light guide plate 1, and the light source 2 is disposed in the step 17. Therefore, both the light guide plate 1 and the light source 2 are accommodated in the elliptical case 9 and the appearance is good. On the other hand, the light entrance portion 15 of the light guide plate 1 may be provided at a portion projecting radially outward from the outer peripheral edge of the light guide plate 1. In this case, the entire elliptical portion of the light guide plate 1 can emit light.

Second Embodiment
The light emitting device of the present embodiment differs from that of the first embodiment in that the planar arrow shape of the light guide plate 1 is circular as shown in FIG.

  In the present embodiment, the light axis L of one light incident on the light guide plate 1 from one of the light incident portions 15 of the pair of light incident portions 15 facing each other and the light incident on the light guide plate 1 from the other light incident portion 15 The optical axis L of the other light passes through mutually opposite areas across the straight line D between the light entrances. The light incident from each light entrance 15 passes through the inside of the light region C as in the first embodiment. For this reason, the light which injected from a pair of light-incidence part 15 travels the wide range area | region B wide area, before striking the surrounding surface 1c. Therefore, the light guide plate 1 can be made to emit light uniformly.

  As shown in FIG. 23, even when the planar light guide plate 1 has a circular shape in the arrow direction, the height of the recess 11 in the peripheral region Y is made larger than the height of the recess 11 in the central region X. The depth of the depression 11 may be an intermediate size between the depth of the depression 11 in the central region X and the depth of the depression 11 in the peripheral region Y. Thereby, light can be emitted with uniform light emission intensity in the central region X and the peripheral region Y of the light guide plate 1.

Third Embodiment
The light emitting device of the present embodiment is different from that of the first embodiment in that the light guide plate 1 has a rectangular shape in a plan view, as shown in FIG.

  In the present embodiment, the pair of light incident portions 15 is disposed on the opposite side of the center line U1 of the long sides of the rectangular shape of the light guide plate 1 and the center line U2 of the short sides of the light guide plate 1. When the planar arrow shape of the light guide plate 1 is rectangular, as shown in FIG. 24, the light entrance portion 15 is disposed in the middle of the long side of the circumferential surface 1 c but disposed at the corner 18 of the circumferential surface 1 c You may. In any case, the optical axis L of one light incident from one of the light entrances 15 of the pair of light entrances 15 facing each other and the optical axis L of the other light incident from the other light entrances 15 The light passes through the light regions C present on the opposite sides of the straight line D between the light entrances, and passes through the end U3 of the center line U1 present in each light region C. For this reason, the light which injected from both the light-incidence parts 15 travels the wide range area | region B wide area, before striking the surrounding surface 1c. Therefore, the light guide plate 1 can emit light uniformly. In addition, when the planar arrow shape of the light guide plate 1 is rectangular, the critical angle straight line E is a straight line connecting the light incident portion 15 and the corner portion 18.

  As shown in FIG. 25, even when the light guide plate 1 has a rectangular shape in plan view, the depressions 11 scattered on the back surface 1 b of the light guide plate 1 are in the order of the central region X, the boundary region P, and the peripheral region Y. Then, it is good to make it deeper gradually.

Fourth Embodiment
The light emitting device of the present embodiment is different from the third embodiment in that the light guide plate 1 has a square shape in plan view as shown in FIG.

  In the present embodiment, the pair of light entrance sections 15 sandwiches the center line V1 of one pair of sides of the square pair of sides of the light guide plate 1 and the center line V2 of the other pair of sides. They are arranged opposite to each other. When the planar arrow shape of the light guide plate 1 is a square, as shown in FIG. 26, the light entrance portion 15 is disposed at the corner 18 of the circumferential surface 1c, but is disposed halfway along the circumferential surface 1c. May be In any case, the optical axis L of one light incident from one of the light entrances 15 of the pair of light entrances 15 facing each other and the optical axis L of the other light incident from the other light entrances 15 The light passes through the light regions C present on the opposite sides of the straight line D between the light entrance portions, and passes through the end V3 of the center line V1 of the sides present in each light region C. The light incident from both light entrances 15 travels in a wide range of the wide area B before hitting the circumferential surface 1 c. Therefore, the light guide plate 1 can be made to emit light uniformly.

  As shown in FIG. 27, even when the light guide plate 1 has a square shape in plan view, the depressions 11 scattered on the back surface 1b of the light guide plate 1 are in the order of the central region X, the boundary region P, and the peripheral region Y. Then, it is good to make it deeper gradually.

Fifth Embodiment
As shown in FIGS. 28 and 29, the light emitting device of the present embodiment is provided on the back surface 1 b of the light guide plate 1 in that the shape of the refracting region 36 of the refracting member 3 has a radiation shape extending in three directions. The second embodiment is different from the first embodiment in that the recesses 11 are arranged in the arrangement direction S in three directions.

  As shown in FIG. 28, the refractive area 36 has an extending portion 36 b extending in three directions at equal angles (120 °) from the central portion 36 a. In the refractive area 36, the prism sheet 34 has a plurality of grooves 34a formed at equal intervals from the center 34b.

  As shown in FIG. 29, the depressions 11 provided on the back surface 1b of the light guide plate 1 are arrayed in three directions: a short axis direction and two directions inclined 120 ° to the right and left with respect to the short axis direction. The arrangement directions S form equal angles (120 °) with each other.

  As shown in FIG. 30, the refractive member 3 and the light guide plate 1 are arranged such that the extension direction of the refractive area 36 coincides with the arrangement direction S of the depressions 11 of the light guide plate 1. When the light source 2 is turned off and the refracting member 3 and the light guide plate 1 thus arranged are viewed from the surface side of the refracting member 3, as shown in FIG. 31, similar to the refracting region 36 of the first embodiment. A plurality of straight streaks can be seen along the extension direction of the extension portion 36b of the refractive area 36, and the extension direction of the extension portion 36b can be seen to be emphasized.

Sixth Embodiment
The light emitting device of the present embodiment is different from that of the first embodiment in that the decorative member 5 is not provided as shown in FIG.

  The light emitting device of the present embodiment includes the light guide plate 1, the reflective material 8, and the refractive member 3. The entire refractive member 3 can be seen from the surface side of the light emitting device. The refractive area 36 can be seen both when the light source 2 is on and when it is off. When the light source 2 is ON, the refractive area 36 is visible, and furthermore, a straight line due to the coordination between the groove 34a and the recess 11 is visible in the refractive area 36 (see FIG. 21). When the light source 2 is off, the refraction area 36 is visible but the straight line is not visible.

Seventh Embodiment
The light emitting device of the present embodiment is different from that of the first embodiment in that the refracting member 3 is not provided as shown in FIG.

  The light emitting device of the present embodiment includes the light guide plate 1, the reflective member 8, and the decorative member 5, and the refractive member 3 is not provided. For this reason, when the light source 2 is turned ON, the light guide plate 1 emits light uniformly, and the decorative member 5 is illuminated with light of uniform intensity. The decorative member 5 can exhibit a light emission design without light emission unevenness.

  In the above embodiment, the decoration member 5 is an emblem, but may be a radio wave transmission member such as a millimeter wave cover.

  In the above embodiment, in the light guide plate 1, the optical axis L of the light incident from one of the light entrances 15 of the light entrances 15 facing each other and the optical axis L of the light incident from the other light entrances 15 are And an end portion of the light entrance portion passing through the light region C which exists in mutually opposite regions across the straight line D between the light entrance portions and connecting between the light entrance portion 15 and the end portion G1 of the major axis G of the elliptical shape. It passes through the inside of the traveling region Q between the two straight lines which make an angle of 20 ° at the light entrance portion 15 with the center straight line T at the center. However, the optical axis may pass through the light region C but not the traveling region Q, and conversely, it may pass through the traveling region Q but not the light region C.

  As a modification, regardless of whether the optical axis passes through the optical area C and the traveling area Q, the depth of the recess 11 in the back surface 1b may be lower in the peripheral area Y than in the central area X. The refractive member 3 and / or the decoration member 5 may be provided.

  In the light emitting device of the above embodiment, the planar arrow shape of the light guide plate 1 is an ellipse, a circle, a rectangle or a square, but the invention is not limited to this. The planar arrow shape of the light guide plate 1 may be, for example, another polygonal shape such as a triangle, a pentagon, or a hexagon.

(1) The light emitting device of the above embodiment includes the light guide plate 1 having the front surface 1a, the back surface 1b, and the circumferential surface 1c, the plurality of light entrance sections 15 provided at mutually opposing positions on the circumferential surface 1c, and the plurality of light entrances. And a plurality of light sources 2 respectively disposed in the light unit 15;
The optical axis L of one light incident from one of the light entrances 15 of the pair of light entrances 15 facing each other, and the optical axis L of the other light incident from the other light entrances 15 , Passing through the area on the opposite side across a straight line D between the light entrances connecting one light entrance 15 and the other light entrance 15,
Centering on bisector F bisecting wide-area angle β formed by critical angle straight line E passing through light entrance portion 15 and forming critical angle θ 0 with respect to circumferential surface 1 c and straight line between light entrance portions D The optical axis L of light incident from the light entrance portion 15 when a region formed between the two straight lines F1 and F1 forming an angle of 50% when the wide angle β is 100% is the light region C. Is characterized in that the light entrance section 15 is set so that the light passes through the inside of the light area C.

  In the above configuration, the plurality of light entrance sections 15 are arranged at positions facing each other on the circumferential surface 1c. An optical axis L of light incident from the light entrance section 15 is a region on the opposite side across a straight line D between the light entrance sections connecting the light entrance section 15 and the other light entrance section 15 facing the light entrance section 15 Pass through. For this reason, when light injects into the light-guide plate 1 from several light-incidence part 15, the wide range of the light-guide plate 1 can be light-emitted.

Here, the critical angle θ ₀ refers to the smallest incident angle at which total reflection occurs when light travels from a portion having a large refractive index to a portion having a small refractive index. When the light incident from the light incident portion 15 is directed toward the circumferential surface 1c, and a straight line connecting the portion forming the critical angle theta ₀ at the light incident portion 15 and the peripheral surface 1c of the critical angle linearly E. When light from the light entrance portion 15 is incident on the circumferential surface 1c at an angle larger than the critical angle θ ₀ , the light is totally reflected. The light intensity is maintained before and after being On the other hand, when light enters from the light entrance portion 15 at an angle smaller than the critical angle θ ₀ with respect to the circumferential surface 1c, part of the light leaks to the outside at the circumferential surface 1c, and the light intensity weakens. . That is, the light passing through the wide area B between the straight line D between the critical angle linear E and the light input portion is incident at an angle smaller than the critical angle theta ₀ with respect to the circumferential surface 1c. A part of the light leaks from the light guide plate 1 to the outside on the peripheral surface 1c, and the light intensity traveling through the light guide plate 1 becomes weaker after being reflected by the peripheral surface 1c than before being reflected.

  Therefore, in the present embodiment, the light axis L of the light incident from the light entrance section 15 travels along the approximate center line of the wide area B between the critical angle straight line D and the light entrance straight line E. The light unit 15 is set. That is, a 50% angle is formed when the wide-range angle β is 100% with a bisector F bisecting the wide-angle angle β formed by the critical angle straight line E and the light-into-light straight line D 2 A region formed between the straight lines F1 and F1 is a light region C. At this time, the light entrance portion 15 is set such that the optical axis L of the light incident from the light entrance portion 15 passes through the inside of the light region C. In this way, the light incident from the light entrance portion 15 travels in a wide range of the wide area B before a part of the light strikes the peripheral surface 1c and leaks to the outside, and leaks light uniformly from the front surface 1a and the back surface 1b. Do. Therefore, the light guide plate 1 can emit light uniformly.

  As mentioned above, according to the said embodiment, the light-emitting device which can light-emit a light guide uniformly can be provided.

  (2) In the above (1), the planar shape of the light guide plate 1 is preferably elliptical.

  (3) In the above (1) or (2), the optical axis L of the light incident from the light entrance section 15 is a straight line connecting the light entrance section 15 and the end G1 of the major axis G of the elliptical shape. It is preferable that the light entrance section 15 be set so as to pass through the area (traveling area Q) between two straight lines that make an angle of 30 ° at the light entrance section 15 and cross at the center.

  In this case, the light incident from the light entrance portion 15 travels to a distant place before hitting the circumferential surface 1c. For this reason, the wide range of the light guide plate 1 emits light by the light incident from the light entrance portion 15 before hitting the circumferential surface 1 c. Therefore, the light guide plate 1 can efficiently emit light uniformly.

  (4) In any one of the above (1) to (3), the back surface 1b of the light guide plate 1 is located between the pair of light entrances 15, 15 facing each other, and from the pair of light entrances 15, 15. A central region X having a region through which incident light passes (both optical path regions M) and a peripheral region Y (including one optical path region N) located in a portion other than the central region X A plurality of depressions 11 are dispersed in X, and the depth of the depressions 11 located in the peripheral region Y is preferably larger than the depth of the depressions 11 located in the central region X.

  When light is incident from the light source 2 to the inside of the light guide plate 1 through the pair of light entrance portions 15, the light incident from the pair of light entrance portions 15 is both irradiated to the central region X of the light guide plate 1. The light which injected from one light-incidence part 15 is irradiated to the peripheral area | region Y located in the periphery also. The peripheral region Y tends to have a lower emission intensity than the central region X.

  Therefore, in the above embodiment, a plurality of depressions 11 are scattered on the back surface 1b of the light guide plate 1, and the depth of the depressions 11 in the peripheral region Y is made deeper than the depressions 11 in the central region X. Increase the area of the hit surface. Thereby, the light emission unevenness of central region X and peripheral region Y can be further reduced.

  (5) In said (4), the light entrance part 15 may have the bending part 18 in some cases. In this case, it is preferable that the central region X further include a near-bending region R through which light scattered in the bent portion 18 of the light entrance portion 15 passes.

  The near-bending region R is a portion where the light scattered by the bent portion 18 strongly emits light. For this reason, the light guide plate 1 can be made to emit light with more uniform emission intensity by setting the depth of the depression to be lower than that of the central region X for the depression 11 in the region R near the bending.

  (6) In the above (4) or (5), the back surface 1b of the light guide plate 1 is positioned between the central area X and the peripheral area Y, the depth of the recess 11 located in the peripheral area Y, and the central area X It is preferable to have the boundary area P where the hollows having a depth between the depth of the hollow 11 and the hollow are dotted.

  The boundary between the central region X and the peripheral region Y becomes less visible as compared with the case where the depth of the recess 11 is changed rapidly at the boundary between the central region X and the peripheral region Y. The light guide plate 1 can emit light more uniformly.

(7) In any of the above (4) to (6), the refracting member 3 is disposed on the surface side of the light guide plate 1,
The refracting member 3 has a transparent base 31, a background layer 32, a half mirror layer 33, and a prism sheet 34, which are sequentially stacked on the back surface 31b of the transparent base 31.
The half mirror layer 33 and the prism sheet 34 cover the refractive area 36 having at least one or more extending portions 36 b extending in the extending direction I on the side of the back surface 31 b of the transparent substrate 31,
The background layer 32 covers the background area 37 excluding the refractive area 36 on the back surface 31 b of the transparent substrate 31,
The prism sheet 34 is provided with a plurality of grooves 34 a arranged in the extending direction I of the extending portion 36 b,
It is preferable that the arrangement direction S of the depressions 11 of the light guide plate coincide with the extension direction I of the extending portion 36 b.

  In this case, when light is irradiated from the back surface to the front surface of the refractive member 3 and the refractive member 3 is viewed from the front surface, the refractive region 36 can clearly recognize the groove 34 a of the prism sheet 34.

  Here, on the back surface 1 b of the light guide plate 1, a large number of depressions 11 are arranged at equal intervals in a plurality of arrangement directions S. The pitch S1 of the depressions 11 adjacent to each other in the arrangement direction S is shorter than the pitch of the depressions 11 adjacent to each other at another angle. The arrangement direction of the depressions 11 coincides with the extension direction I of the extension portion 36 b of the refractive area 36. The light reflected and diffused by the recess 11 is further reflected and diffused by the groove 34a. In this case, when the refracting member 3 and the light guide plate 1 are viewed from the surface of the refracting member 3, many straight streaks extend in the extending direction of the extending portion 36b of the refracting region 36, and the refracting region 36 extends in the extending direction I It is viewed as highlighted.

(8) In the above (7), the decorative member 5 is disposed on the surface side of the refractive member 3;
The decorative member 5 has a transparent cover material 51 and a decorative layer 52 and a half mirror layer 53 sequentially stacked on the back surface of the cover material 51,
The decoration layer 52 covers the decoration area 57 other than the display area 56 on the back surface of the cover material 51,
The half mirror layer 53 preferably covers at least the display area 56 on the back surface side of the cover material 51.

  In this case, the half mirror layer 53 is visually recognized in the display area 56 of the cover member 51 of the decorative member 5, and the decorative layer 52 is visually recognized in the decorative area 57.

  When the light source 2 is turned off and the light emitting device is viewed from the front side, the blue color of the decorative layer 52 can be seen in the metallic display area 56 of the half mirror layer 53 and the surrounding decorative area 57. At this time, the refracting region 36 on the back surface side can not be seen by the half mirror layer 53 of the decorative member 5.

  When the light source 2 is turned on and the light emitting device is viewed from the front side, the color of the half mirror layer 53 can be seen in the display area 56 and the color of the decoration layer 52 can be seen in the decoration area 57. Then, the refractive area 36 of the refractive member 3 is seen through the half mirror layer 53. Furthermore, in the refraction area 36, a number of straight streaks are visible in the extension direction, and the refraction area 36 is highlighted and visually recognized in the extension direction I.

  When the light emitting device is viewed in a dark environment such as nighttime, in addition to the light emission pattern of the decoration area 56, the light emission pattern of the refraction area 36 is clearly seen. Unlike when viewed in a bright environment such as daytime, it is possible to visually recognize a complex and highly aesthetic luminous design.

  The decorative member 5 can be directly disposed on the surface side of the light guide plate 1 instead of being disposed on the surface side of the refractive member 3.

  (9) In any one of the above (1) to (8), the back surface 1 b of the light guide plate 1 is preferably covered with the reflective material 8. Since light is reflected and scattered by the reflective material 8 on the back surface 1b of the light guide plate 1, light leakage from the back surface 1b can be prevented.

(10) The light emitting device of the above embodiment includes the light guide plate 1 having the elliptical surface 1a and the back surface 1b, and the peripheral surface 1c, and a plurality of light entrance sections 15 provided at mutually opposing positions on the peripheral surface 1c. A plurality of light sources 2 respectively disposed in the plurality of light entrance sections 15;
The optical axis L of one light incident from one of the light entrances 15 of the pair of light entrances 15 facing each other, and the optical axis L of the other light incident from the other light entrances 15 , Passing through the area on the opposite side across a straight line D between the light entrances connecting one light entrance 15 and the other light entrance 15,
The optical axis L of the light incident from the light entrance portion 15 is centered on a straight line connecting the light entrance portion 15 and the end G1 of the major axis G of the elliptical shape (straight line T between the light entrance end), It is characterized in that the light entrance section 15 is set to pass through the area (traveling area Q) between two straight lines which make an angle of 30 ° and intersect in the light entrance section.

  According to the above configuration, the light incident from the light entrance section 15 travels in a long and wide range until it strikes the circumferential surface 1c. A wide range of the light guide plate 1 can be advanced before the light intensity is weakened by the leaked light from the circumferential surface 1c. Therefore, the entire light guide plate 1 can emit light uniformly.

  In said (10), either of said (2) and (4)-(9) can be combined.

(11) A light emitting device according to a modification of the present invention includes a light guide plate 1 having a front surface 1a, a back surface 1b, and a circumferential surface 1c, and a plurality of light entrance sections 15 provided at mutually opposing positions on the circumferential surface 1c. A plurality of light sources 2 respectively disposed in the plurality of light entrance sections 15;
The back surface 1 b of the light guide plate 1 is located between a pair of light entrances 15 facing each other, and has a central area X having an area through which light incident from the pair of light entrances 15 passes and a central area X And the surrounding area Y located in
The peripheral region Y and the central region X are dotted with a plurality of depressions 11,
The depth of the recess 11 located in the peripheral region Y is characterized by being larger than the depth of the recess 11 located in the central region X.

  The above (11) can be combined with any of the above (1) to (3) and (5) to (10).

(12) A refractive member 3 according to a modified embodiment of the present invention includes a transparent base 31, a background layer 32, a half mirror layer 33, and a prism sheet 34 sequentially stacked on the back surface 31b of the transparent base 31.
The half mirror layer 33 and the prism sheet 34 cover the refracting region 36 having at least one extending portion 36 b extending in the extending direction I on the back surface side of the transparent substrate 31,
The background layer 32 covers the background area 37 excluding the refractive area 36 on the back surface 31 b of the transparent substrate 31,
The prism sheet 34 is characterized in that a plurality of grooves 34a arranged in the extension direction I of the extending portion 36b are provided.

  It is preferable that the arrangement direction S of the depressions 11 of the light guide plate 1 coincide with the extension direction I of the extending portion 36 b.

  The above (12) can be combined with any of the above (1) to (6) and (8) to (11).

1: light guide plate 1a: front surface 1b: back surface 1c: circumferential surface 11: hollow 15: light incident portion 16: bent portion 2: light source 3: refractive member 31: transparent base material 32: background layer 33: half mirror layer 34: prism Sheet 34a: Groove 36: Refraction area 36b: Extension section 37: Background area 5: Decorative member 51: Cover material 52: Decorative layer 53: Half mirror layer 56: Display area 57: Decorative area 8: Reflective material A : Peripheral area proximity area B: Large area area C: Light area D: Straight line between light entrances E: Critical angle line F: Bisection line G: Long axis H: Short axis G1: End of long axis I: Extension direction K: hollow area L: optical axis M: both optical path area N: one optical path area P: boundary area Q: advancing area R: near bending area S: arrangement direction T: straight line between light entrance end X: central area Y: Peripheral area β: Wide angle

Claims (9)

A light guide plate having a front surface, a back surface, and a circumferential surface, a plurality of light incident portions provided at positions facing each other on the circumferential surface, and a plurality of light sources respectively disposed in the plurality of light incident portions;
The optical axis of one light incident from one of the light entrances of the pair of light entrances facing each other and the optical axis of the other light incident from the other light entrances are in front of one Pass through the area on the opposite side across the straight line between the light entrances connecting the light entry and the other light entrances,
The wide-area angle centered on a bisector dividing a wide-area angle formed by a critical angle straight line that passes through the light entrance and forms a critical angle with respect to the circumferential surface and a straight line between the light entrances When an area formed between two straight lines that make an angle of 50% when 100% is defined as a light area, an optical axis of light incident from the light entrance passes through the light area The light entrance portion is set ,
The back surface of the light guide plate is located between a pair of the light incident portions facing each other, and a central region having a region through which light incident from the pair of light incident portions passes, and a portion other than the central region Have surrounding areas and
The peripheral area and the central area are dotted with a plurality of depressions,
The depth of the recess located in the peripheral region is greater than the depth of the recess located in the central region,
The light entrance portion has a bending portion,
The light emitting device according to claim 1, wherein the central region further includes a region near a bend through which light scattered in the bent portion of the light entrance part passes . The back surface of the light guide plate has a depth between the central region and the peripheral region, between the depth of the recess located in the peripheral region and the depth of the recess located in the central region. The light emitting device according to claim 1 , wherein the light emitting device has a boundary area in which the depressions are scattered. A refracting member is disposed on the surface side of the light guide plate,
The refracting member includes a transparent substrate, and a background layer, a half mirror layer, and a prism sheet sequentially stacked on the back surface of the transparent substrate.
The half mirror layer and the prism sheet cover a refractive area having at least one extending portion extending in the extending direction on the back surface side of the transparent substrate,
The background layer covers a background area excluding the refractive area on the back surface of the transparent substrate,
The prism sheet is provided with a plurality of grooves arranged in the extending direction of the extending portion of the refractive area;
The light emitting device according to claim 1 or 2 , wherein the arrangement direction of the depressions of the light guide plate coincides with the extension direction of the extending portion. A light guide plate having a front surface, a back surface, and a circumferential surface, a plurality of light incident portions provided at positions facing each other on the circumferential surface, and a plurality of light sources respectively disposed in the plurality of light incident portions;
The optical axis of one light incident from one of the light entrances of the pair of light entrances facing each other and the optical axis of the other light incident from the other light entrances are in front of one Pass through the area on the opposite side across the straight line between the light entrances connecting the light entry and the other light entrances,
The wide-area angle centered on a bisector dividing a wide-area angle formed by a critical angle straight line that passes through the light entrance and forms a critical angle with respect to the circumferential surface and a straight line between the light entrances When an area formed between two straight lines that make an angle of 50% when 100% is defined as a light area, an optical axis of light incident from the light entrance passes through the light area The light entrance portion is set ,
The back surface of the light guide plate is located between a pair of the light incident portions facing each other, and a central region having a region through which light incident from the pair of light incident portions passes, and a portion other than the central region Have surrounding areas and
The peripheral area and the central area are dotted with a plurality of depressions,
The depth of the recess located in the peripheral region is greater than the depth of the recess located in the central region,
A refracting member is disposed on the surface side of the light guide plate,
The refracting member includes a transparent substrate, and a background layer, a half mirror layer, and a prism sheet sequentially stacked on the back surface of the transparent substrate.
The half mirror layer and the prism sheet cover a refractive area having at least one extending portion extending in the extending direction on the back surface side of the transparent substrate,
The background layer covers a background area excluding the refractive area on the back surface of the transparent substrate,
The prism sheet is provided with a plurality of grooves arranged in the extending direction of the extending portion of the refractive area;
The arrangement direction of the hollow of the light guide plate is coincident with the extending direction of the extending portion . The back surface of the light guide plate has a depth between the central region and the peripheral region, between the depth of the recess located in the peripheral region and the depth of the recess located in the central region. The light emitting device according to claim 4 , having a boundary area in which the depressions are scattered. A decorative member is disposed on the surface side of the refracting member,
The decorative member has a transparent cover material, and a decorative layer and a half mirror layer sequentially laminated on the back surface of the cover material,
The said decoration layer covers the decoration area other than the display area on the back surface of the cover material, and the half mirror layer covers at least the display area on the back surface side of the cover material. The light-emitting device in any one of 3-5 . The light emitting device according to any one of claims 1 to 6, wherein a planar shape of the light guide plate is an elliptical shape. The optical axis of the light incident from the light entrance forms an angle of 30 ° in the light entrance, centering on a straight line connecting between the light entrance and the end of the major axis of the elliptical shape The light emitting device according to claim 7 , wherein the light entrance portion is set to pass in a region between two intersecting straight lines.   The light emitting device according to any one of claims 1 to 8, wherein the back surface of the light guide plate is covered with a reflective material.

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