JP3973865B2 - Light guide, light source device and flat illumination device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a light guide for a light source device used in a liquid crystal display device and the like, and light having the same shape as the light guide.deflectionThe present invention relates to a flat illumination device using a sheet. In particular, the present invention relates to a light guide, a light source device, and a planar illumination device that can obtain bright and spotless outgoing light even with a small number of light sources.
[0002]
[Prior art]
  Conventionally, as this type of light guide, there is known a light guide that emits light from the exit surface by applying a concave / convex shape such as knurling to the surfaces other than the incident end surface portion that guides light from the light source and the exit surface that emits light. ing.
[0003]
  In addition, as a conventional light guide, a convex or concave shape is randomly provided by a prism, a blast, or the like on the front surface or back surface of the light guide to reflect incident light incident from a light source, and light is emitted from an output surface. What is emitted is known.
[0004]
[Problems to be solved by the invention]
  Thus, as a conventional light guide, in a configuration in which light is emitted from the exit surface by providing a concave / convex shape such as knurling on the surfaces other than the incident end surface portion that guides light from the light source and the exit surface that emits light, However, it is difficult to control the light, and there is an effect such as reflection in some parts of the uneven shape, but the light cannot be reliably controlled, and there is a problem in the light deflection efficiency.
[0005]
  In addition, in the configuration in which convex or concave shapes are randomly provided on the front surface portion and the back surface portion of the light guide by prisms, blasts, etc., the incident light incident from the light source is reflected and the light is emitted from the output surface. A convex or concave shape is randomly provided on the front surface portion or the back surface portion of the light guide by blasting or the like. For this reason, even if the incident light incident from the light source is reflected, refracted, condensed, or the like, the emitted energy is not evenly distributed, and there is a problem that the emitted light has spots and brightness decreases.
[0006]
  The present invention has been made in order to solve such a problem. The light guide is formed in a quadrangular prism shape or a cylindrical shape, and the light exiting surface has a convex shape concentric with the center position of the incident end surface portion. Light having an arcuate prism shape having a concave ridge and a symmetric positional relationship with the ridge of the light guidedeflectionA sheet is provided to emit light in a substantially vertical direction with an equal light energy at an arbitrary distance corresponding to the ridge from the light source, and an incident surface of the light guide plate is provided in the substantially vertical direction so that the light enters the light guide plate.deflectionAn object of the present invention is to provide a light guide body, a light source device, and a flat illumination device that can efficiently guide outgoing light from a sheet and obtain bright outgoing light without luminance spots from the surface portion of the light guide plate.
[0007]
[Means for Solving the Problems]
  In order to solve the above-mentioned problem, the light guide according to claim 1 has a quadrangular prism shape and is concentric with the center position of the incident end face on the exit surface.Radially continuous or discontinuousHave convex or / and concave edges,Total reflection and refraction by convex and concave edges,Any distance corresponding to the edge from the light sourceInThe light energy is equally emitted.
[0008]
  The light guide according to claim 1 has a quadrangular prism shape and is concentric with the center position of the incident end surface portion on the exit surface.Radially continuous or discontinuousHave convex or / and concave edges,Total reflection and refraction by convex and concave edges,Any distance corresponding to the edge from the light sourceInIn this case, since the light energy is emitted equally, the light can be emitted with uniform brightness anywhere on the light exit surface of the light guide.Further, since the ridge is continuous or non-continuous, the emitted light can be emitted from the emission surface to the entire region along the ridge, and can also be emitted partially to a target position.
[0009]
  Moreover, the light guide according to claim 2 has a cylindrical shape.Cut out to have a rectangular surface in the longitudinal direction of the rectangular surface as the exit surfaceConcentric with the center position of the incident end faceRadially continuous or discontinuousHave convex or / and concave edges,Total reflection and refraction by convex and concave edges,The light energy is emitted equally at an arbitrary distance corresponding to the edge from the light source.
[0010]
  The light guide according to claim 2 has a cylindrical shape.Cut out to have a rectangular surface in the longitudinal direction of the rectangular surface as the exit surfaceConcentric with the center position of the incident end faceRadially continuous or discontinuousHave convex or / and concave edges,Total reflection and refraction by convex and concave edges,Since the light energy is emitted equally at an arbitrary distance corresponding to the ridge from the light source, it can be emitted with uniform brightness anywhere without any spots on the exit surface of the light guide.
[0011]
  Furthermore, the light guide according to claim 3 is characterized in that the cross section in the direction perpendicular to the normal line between the center and the ridge is always triangular.
[0012]
  In the light guide according to claim 3, since the cross section in the direction perpendicular to the normal line with the center position and the concentric ridge is always triangular, it is possible to obtain outgoing light having substantially the same outgoing angle from the outgoing face. it can.
[0013]
  And claims4The light guide according to the present invention is characterized in that a triangular ridge is cut out flat.
0014]
  Claim4Since the triangular ridge portion of the light guide according to the present invention is cut out flat, for example, when a reflector is provided in the vicinity of the opposite side surface of the emission surface, the light totally reflected by the flat portion of the emission surface is emitted. The light beam that travels in the direction opposite to the surface and exits the light guide is reflected by the reflector and enters the light guide again, and this light beam is reflected and refracted on the slope of the ridge of the exit surface. In the flat part in this claim, it can radiate | emit from an output surface substantially straight.
0015]
  Claims5The light guide according to the present invention is characterized in that adjacent surfaces of triangular ridges are curved or arcuate.
0016]
  Claim5In the light guide according to the present invention, the adjacent surfaces of the triangular ridges are curved or arc-shaped, and therefore, when the curved or arc-shaped surface is an indented ridge surface, the light is diffused and the curved surface is curved. Alternatively, in the case of a ridge surface having an arcuate bulge outward, light can be condensed at a location that matches the curvature, and the outgoing angle of the outgoing light can be varied so as to diffuse the light further away.
0017]
  And claims6A light source device according to the present invention includes a light source,
  At least one end is an incident end surface that guides light from the light source and has an exit surface that emits light, and the exit surface is concentric with the center position of the incident end surfaceRadially continuous or discontinuousAn elongated quadrangular prism shape with convex or / and concave edges orAbbreviation with a plane in the longitudinal directionA cylindrical light guide,
  The positional relationship to correspond to the ridge on the light exit surface of the light guideradiationLight with a prismatic shapedeflectionA sheet,
  Light guide edge angle and lightdeflectionThe angle of the sheet ridge is always the same angle.
0018]
  Claim6The light source device according to the present invention has a light source, and at least one end portion as an incident end surface portion that guides a light beam from the light source and has an exit surface that emits light, and the exit surface is concentric with the center position of the incident end surface portion.Radially continuous or discontinuousAn elongated quadrangular prism shape with convex or / and concave edges orAbbreviation with a plane in the longitudinal directionA cylindrical light guide and a positional relationship corresponding to a ridge on the light exit surface of the light guideradiationLight with a prismatic shapedeflectionA light guide with a ridge angle and lightdeflectionSince the angle of the edge of the sheet is always the same angle, the angle of light and the light before emitting from the edge of the light guidedeflectionThe angle of the light beam after entering the edge of the sheet can be made equal, and the light emitted from the edge of the light guide plate can be completely emitted at the shortest distance.deflectionEfficiently guides light to the edge of the sheetdeflectioncan do.
0019]
  Claims7The light source device according todeflectionThe sheet has a convex or / and concave ridge corresponding to a center position and a position concentric with the ridge of the light guide from the incident end face of the light guide.
0020]
  Claim7The light source device according todeflectionSince the sheet has a convex or / and concave ridge corresponding to the center position and the concentric position with the ridge of the light guide from the incident end surface of the light guide, the sheet protrudes from the convex or concave ridge of the light guide. Fully shine light in the shortest distancedeflectionIt can be guided to the convex or concave edge of the sheet.
0021]
  And claims8The light source device according todeflectionA cross section in a direction perpendicular to a normal to a ridge corresponding to a center position and a concentric position is always a triangular shape.
0022]
  Claim8The light source device according todeflectionSince the cross-section in the direction perpendicular to the normal to the ridge corresponding to the center position and the concentric position is always triangular, the light emitted from the light guidedeflectioncan do.
0023]
  Claims9The light source device according todeflectionThe sheet is characterized by being continuous or discontinuous.
0024]
  Claim9The light source device according todeflectionBecause the sheet is continuous or non-continuous, the light emitted from the light guidedeflectionSelect the part that needsdeflectioncan do.
0025]
  And claims10A flat illumination device according to the present invention includes a light source,
  At least one end is an incident end surface that guides light from the light source and has an exit surface that emits light, and the exit surface is concentric with the center position of the incident end surfaceRadially continuous or discontinuousAn elongated quadrangular prismatic light guide with convex or / and concave ridges;
  The positional relationship to correspond to the ridge on the light exit surface of the light guideradiationLight with a prismatic shapedeflectionSheet,
  lightdeflectionLight at the position facing the sheetdeflectionAn incident surface portion that guides light from the sheet, and a light guide plate having a front surface portion and / or a back surface portion that emits light;
  The light energy is equal at an arbitrary distance corresponding to the edge from the light source, and the light emitted from the light guide isdeflectionThe sheet is emitted in a direction substantially perpendicular to the emission surface, and the emitted light is guided from the incident surface portion of the light guide plate and emitted from the front surface portion and / or the back surface portion.
0026]
  Claim10The flat illumination device according to the present invention has a light source, an incident end surface portion that guides light from the light source at least one end portion, and an output surface that emits light, and is concentric with the center position of the incident end surface portion on the output surface.Radially continuous or discontinuousA long rectangular prismatic light guide having convex or / and concave ridges and a positional relationship corresponding to the ridges on the light exit surface of the light guideradiationLight with a prismatic shapedeflectionSheet and lightdeflectionLight at the position facing the sheetdeflectionA light guide plate having an incident surface portion that guides light from the sheet and a light guide plate having a front surface portion and / or a back surface portion that emits light, and the light energy is equal at an arbitrary distance corresponding to the ridge from the light source; Light emitted fromdeflectionThe sheet is emitted in a direction substantially perpendicular to the emission surface, and the emitted light is guided from the incident surface portion of the light guide plate and emitted from the front surface portion and / or the back surface portion. You can get light.
0027]
  Claims11A flat illumination device according to the present invention includes a light source,
  Has an elongated cylindrical shapeAt least one end is used as an incident end surface that guides light from the light source.Cut out to have a rectangular surface in the longitudinal direction of the cylindrical shape,It has an exit surface that emits light and is concentric with the center position of the incident end face on the exit surfaceRadially continuous or discontinuousAn elongated cylindrical light guide having convex or / and concave ridges;
  The positional relationship to correspond to the ridge on the light exit surface of the light guideradiationLight with a prismatic shapedeflectionSheet,
  lightdeflectionLight at the position facing the sheetdeflectionAn incident surface portion that guides light from the sheet, and a light guide plate having a front surface portion and / or a back surface portion that emits light;
  The light energy is equal at an arbitrary distance corresponding to the edge from the light source, and the light emitted from the light guide isdeflectionThe sheet is emitted in a direction substantially perpendicular to the emission surface, and the emitted light is guided from the incident surface portion of the light guide plate and emitted from the front surface portion and / or the back surface portion.
0028]
  Claim11A flat illumination device according to the present invention includes a light source,Has an elongated cylindrical shapeAt least one end is used as an incident end surface that guides light from the light source.Cut out to have a rectangular surface in the longitudinal direction of the cylindrical shape,It has an exit surface that emits light and is concentric with the center position of the incident end face on the exit surfaceRadially continuous or discontinuousThe elongated cylindrical light guide having convex or / and concave ridges and a positional relationship corresponding to the ridges on the light exit surface of the light guideradiationLight with a prismatic shapedeflectionSheet and lightdeflectionLight at the position facing the sheetdeflectionA light guide plate having an incident surface portion that guides light from the sheet and a light guide plate having a front surface portion and / or a back surface portion that emits light, and the light energy is equal at an arbitrary distance corresponding to the ridge from the light source; Light emitted fromdeflectionThe sheet is emitted in a direction substantially perpendicular to the emission surface, and the emitted light is guided from the incident surface portion of the light guide plate and emitted from the front surface portion and / or the back surface portion. You can get light.
0029]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
  In the present invention, at least one surface portion of the light guide body is an incident end surface portion, and the exit surface and the back surface are concentric with the center position of the incident end surface portion.ConvexA ridge with a triangular or concave triangular cross section is provided continuously or discontinuously to emit light energy equally from the light source at an arbitrary distance corresponding to the ridge, and light is emitted to the shape and symmetry provided on the light guidedeflectionLightdeflectionA sheet is placed on the top of the light guide to emit light from the light guide in a substantially vertical direction.deflectionThe light guide body, the light source device, and the planar illumination that project the emitted light from the light source device that emits light onto the incident surface of the light guide plate, and obtain bright emitted light that is uniform and free from luminance spots from the front and back surfaces of the light guide plate A device is provided.
0030]
  FIG. 1 is an overall perspective view showing a schematic configuration of a flat illumination device according to the present invention, FIG. 2 is a plan view schematically showing an exit surface of a light guide according to the present invention, and FIGS. 3 and 4 are guides according to the present invention. FIG. 5 is a partially enlarged side cross-sectional view of the light body, and is a cross-sectional view of P1-A that connects a point P1 and a point P1 of the light guide shown in FIG. FIG. 7 is a partially enlarged perspective view of the light guide according to the present invention, and FIG. 8 shows the light according to the present invention.deflectionFIG. 9 is a schematic sectional view of a sheet, and FIG.deflectionFIG. 10 is a schematic view of a sheet, and FIG. 10 is a light locus diagram of the light source device according to the present invention.
0031]
  In the present invention, the light source, light guide, lightdeflectionThe light source device is composed of sheets, and the light source, light guide, and lightdeflectionA flat illumination device is composed of a sheet and a light guide plate (which may further include a reflector).
0032]
  A flat illumination device 1 shown in FIG. 1 includes a light source 2, a light guide 3, and light.deflectionA sheet 8, a light guide plate 9, and a reflector 15 are provided and schematically configured.
0033]
  The light source 2 is a semiconductor light emitting element, which is composed of an LED, a laser, or the like, and uses white light made by monochromatic light, white light made of RGB (red, green, blue), or wavelength conversion using a fluorescent material. It is done. Although not shown here, the light source 2 may be integrated such that the light emitting surface 2a of the light source 2 is directly connected to the incident end surface 4 of the light guide 3.
0034]
  The light guide 3 is formed of a transparent acrylic resin (PMMA), polycarbonate (PC), or the like. The light guide 3 includes an incident end face 4 that guides light from the light source 2 at at least one end, an end face 4b opposite to the incident end face 4, and an exit face 5 that emits light incident from the incident end face 4. The back surface 6 on the opposite side and the side surfaces 7a and 7b surrounded by the incident end surface portion 4, the end surface portion 4b, the exit surface 5 and the back surface 6 have a substantially rectangular bar shape.
0035]
  As shown in FIGS. 2 and 3, the light guide 3 has a concave ridge 5 a and a convex ridge 5 b concentric with the center position P <b> 1 of the incident end face portion 4.
0036]
  This is because the convex ridges 5b in FIG. 3 are provided radially like the line S1 and concentric about the point P1, which is the center position of the incident end face part 4 of the exit surface 5, and the concave shape in FIG. Ridges 5a are provided in a radial pattern as shown by line S2.
0037]
  In the example of FIG. 3, the convex ridges 5b are shown as lines S1 and S3 (odd numbers), and the concave ridges 5a are shown as lines S2 and S4 (even numbers), and the convex and concave shapes are shown alternately or continuously (line Sn). . Although not shown in the figure, a convex ridge 5b is provided in the jump, a plane is formed between the convex ridge 5b and the ridge 5b, a concave ridge 5a is provided in the jump, and the concave ridge 5a and the ridge 5a are It is also possible to make the space flat.
0038]
  With the above configuration, the light beams incident from the light source 2 and reaching the ridge 5b and the ridge 5a are at the same distance from the light source 2 of the emitted radiation light, so that the light energy is emitted equally at any distance corresponding thereto. is doing.
0039]
  Although the description is repeated here, FIG. 3 uses the central position P1 of the incident end face 4 in FIG. 2 as the incident part P, and the normal line of the ridge concentric with the central position P1 of the incident part P and the perpendicular direction A The cross section of the line P1-A which connects is shown.
0040]
  The convex ridge 5b and the concave ridge 5a provided radially on the exit surface 5 from the incident end face portion 4 have a triangular cross section..
0041]
  FigureAs shown in FIG. 4, the light beam incident on the light guide 3 from the center position P1 of the incident portion P is, for example, when the material of the light guide 3 is polycarbonate (PC) resin, the refractive index n = 1. 59, it enters the light guide 3 from the air layer. The light beam L0 that enters the light guide 3 and exists in the light guide is 0 ≦ | α | ≦ sin.^-1From the equation (1 / n) (where n is an air layer and the refractive index is n = 1), the angle of refraction is approximately in the range of α = ± 38.997 °.
0042]
  In addition, the light incident on the light guide 3 within the range of the refraction angle α = ± 38.997 ° is sin γ = (1 at the boundary surface between the light guide 3 and the air layer (refractive index n = 1). The critical angle can be expressed by the equation / n). For example, since the refractive index of polycarbonate resin which is a resin material used for the general light guide 3 is about n = 1.59, the critical angle γ is about γ = 38.97 °. When an acrylic resin (PMMA) material is used as the material of the light guide 3, the refractive index n of the acrylic resin is about n = 1.49, and the refraction angle α is about α = 42.38 °. Therefore, the critical angle γ is also about γ = 42.38 °.
0043]
  3 is a diagram in which convex ridges 5b and concave ridges 5a are provided only on the light exit surface 5 of the light guide 3. However, as shown in FIG. By providing the convex ridge 6b and the concave ridge 6a equivalent to the ridge 5b and the concave ridge 5a, the light beam directed toward the back surface 6 can also be used.
0044]
  Further, in FIG. 3, a plane portion is drawn on the exit surface 5 and the back surface 6 on the incident end surface portion 4 side of the light guide 3, but this represents the basic plane of the exit surface 5 and the back surface 6. In general, a triangular shape of a convex ridge 5b or ridge 6b or a concave ridge 5a or ridge 6a is provided from the center position P1, which is the incident end face portion 4.
0045]
  Therefore, as shown in FIG. 4, the light rays L1 and L1 ′ that have traveled in the direction of the exit surface 5 with the maximum refraction angle α are the angles (incidents) formed with the perpendiculars of the sides 5d and 6d formed by the virtual horizontal planes 1c and 1d and the angle θ3. The angle) is smaller than the critical angle γ, breaks the critical angle γ, and is refracted and emitted as light rays L12 and L12 ′ along the emission surface 5 and the back surface 6.
0046]
  For example, in the case of a light beam having a small refraction angle α such as the light beam L2 or L2 ′, the angle (incident angle) formed with the perpendicular of the side 5d or the side 6d is larger than the critical angle γ, and thus the light beam L3 or the light beam L3. 'As a total reflection. Then, the light beam L3 and the light beam L3 ′ travel in opposite surface directions to reach the side 6d and the side 5d again, and the angle (incident angle) formed with the perpendicular of the side 6d and the side 5d is smaller than the critical angle γ. The critical angle γ is broken and refracted to be emitted from the back surface 6 and the exit surface 5 along the exit surface 5 and the back surface 6 at a certain angle as the light beam L4 and the light beam L4 ′.
0047]
  As described above, the triangular shape of the cross section perpendicular to the normal line of the convex ridge 5b and ridge 6b and the concave ridge 5a and ridge 6a provided radially on the output surface 5 and the back surface 6 from the incident end face portion 4 of the present invention. In the angle range, most of the light rays emitted from the emission surface 5 are light rays totally reflected by the side 6d of the convex ridge 6b provided on the back surface 6. Further, most of the light rays emitted from the back surface 6 are light rays totally reflected by the side 5 d of the convex ridge 5 b provided on the emission surface 5.
0048]
  Of the light rays existing in the light guide 3 (substantially within the range of refraction angle α = ± 38.9971 °), the smaller the refraction angle α, the greater the energy of the light. The light beam totally reflected by the side 6d of the ridge 6b can be used effectively.
0049]
  Further, as the distance from the light source 2 increases, the pitch between the convex ridges 5b and ridges 6b, the concave ridges 5a and ridges 6a, and the like, the height of the ridges of the convex ridges 5b and ridges 6b and the concave shape are increased. It is also possible to set the depth of the ridges 5a and 6a. Thereby, the amount of light reaching the side 5d, the side 6d, and the like can be changed, and the amount of emitted light can be changed.
0050]
  In addition, as shown in FIG. 5A, the light guide 3 is incident from the light source 2 when the convex ridges 5 b and ridges 6 b and the concave ridges 5 a and ridges 6 a are continuous. The light beams that have reached 6b, the ridge 5a, and the ridge 6a are at the same distance from the light source 2 of the emitted radiation light, and the light energy of all the ridges at arbitrary distances corresponding thereto is emitted equally.
0051]
  Furthermore, as shown in FIG. 5B, the light guide 3 is incident from the light source 2 when the convex ridges 5b and ridges 6b and the concave ridges 5a and ridges 6a are discontinuous. The light beams reaching the ridge 6b, the ridge 5a, and the ridge 6a are at the same distance from the light source 2 of the emitted radiation light, but only the ridges at arbitrary distances corresponding thereto emit light equally. Thereby, the emitted light from the emission surface 5 and the back surface 6 can be partially emitted to a target position.
0052]
  Further, as shown in FIG. 6, the light guide 3 may be provided with a flat portion 511 and a flat portion 521 in which triangular ridges are cut out flat. Furthermore, although not shown, for example, a flat portion 511 that is notched flat on the ridge 5b may be provided only on the emission surface 5. Thereby, when a reflector is provided in the vicinity of the back surface 6, the light totally reflected by the emission surface 5 travels in the direction of the back surface 6, and the light beam emitted from the back surface 6 to the outside is reflected by the reflector and is again guided to the light guide. 3 is reflected or refracted on the slope (side) of the ridge 5b of the emission surface 5, but can be emitted from the emission surface 5 in a substantially straight manner in the flat portion 511.
0053]
  Although not shown here, by providing a flat portion on the back surface 6 in the same manner, the light can be emitted substantially straight from the flat portion provided on the back surface 6 by the same action.
0054]
  Furthermore, as shown in FIG. 7, the adjacent faces (sides) of the triangular ridges of the light guide 3 may be curved or arcuate. FIG. 7 shows ridge surfaces 51a and 51b with curved or arcuate indentations. As a result, when the light existing in the light guide 3 reaches the surface 51a of the concave concave ridge, the emission angle becomes larger than the straight ridge with respect to the normal of the surface 51a, so It becomes a diffused state.
0055]
  Further, although not shown, in the case of a curved or arcuate ridge surface bulging outward, the light existing in the light guide 3 reaches the surface of the bulging convex ridge when the normal of the surface is reached. In contrast, the emission angle is smaller than that of the straight ridge, and the light becomes inward, condensing light at a location matching the curvature, and diffusing the light further away.
0056]
  Thus, when the adjacent surfaces (sides) of the triangular ridges of the light guide 3 are curved or arcuate, the emission angle of the emitted light can be varied.
0057]
  Here, the convex ridges 5b and ridges 6b and the concave ridges 5a and ridges 6a have the sides 5c and 5d and the sides 6c and 6d equal in shape. 3 may be emitted from the incident end surface portion 4 direction of the exit surface 5 of the light guide 3 in the direction opposite to the incident end surface portion 4. Therefore, it does not have to be an isosceles triangle, and for example, it may have a shape of a right triangle having only the sides 5d and 6d and having the sides 5c and 6c vertical.
0058]
  Although not shown here, when the light source 2 is provided at both ends of the light guide 3, the exit surface 5 of the light guide 3 is directed to the center position of the exit surface 5 that is the same distance from both ends 4, 4 b. 2 and 3 are provided with a convex ridge 5b and a concave ridge 5a. Thereby, the light beam of the light source 2 from both ends is efficiently emitted.
0059]
  Further, although not shown here, the light guide 3 has a cylindrical shape and is provided with an emission surface 5 having a rectangular surface in the longitudinal direction, and the incident end face portion 4 is the same as shown in FIGS. 2 and 3 described above. Alternatively, a convex ridge 5b or a concave ridge 5a may be provided concentrically with the center position P1.
0060]
  In this case, ridges 5b and ridges 5a are provided only on the exit surface 5, and the other cylindrical portions always repeat total reflection, and finally exit from the exit surface 5, which is the same effect as in the case of a quadrangular prism shape. Can be obtained.
0061]
  FIG. 8 shows the light of the flat illumination device according to the present invention.deflection9 is a partially enlarged cross-sectional view of the sheet. FIG. 9 shows light when the light source 2 is disposed at the center position of the incident end face portion 4 corresponding to the light guide 3.deflection3 is a plan view of a sheet 8. FIG.
0062]
  lightdeflectionThe sheet 8 is formed from a transparent resin such as acrylic resin (PMMA) or polycarbonate (PC). lightdeflectionThe sheet 8 has a shape corresponding to the light guide 3, has a triangular cross section, and has a convex ridge 8a and a concave ridge 8b. lightdeflectionDepending on the usage of the light guide 3, the sheet 8 is provided with a convex ridge 8 a that is not shown, a concave ridge 8 b that is skipped, or between the convex ridge 8 a and the ridge 8 a or a concave shape. It is also possible to make a plane between the ridge 8b and the ridge 8b.
0063]
  Also,lightdeflectionWhen the light source 2 is provided facing the incident portion P of the incident end face portion 4 of the light guide 3 so as to correspond to the light guide 3, the sheet 8 radiates from the incident portion P as shown in FIG. 9. In this case, a line P− connecting a convex ridge 8a and a concave ridge 8b provided on the back side of the front surface portion 8 ′ to the normal position of the ridge concentric with the center position P1 of the incident portion P and the perpendicular direction a. 8a is provided with a triangular cross section as shown in FIG.
0064]
  In addition, lightdeflectionSimilarly to the light guide 3, the sheet 8 is provided with convex ridges 8 a as lines S 1 and S (odd numbers) and concave ridges 8 b as lines S 2 and S 4 (even numbers) in a radial pattern. 8a and concave ridges 8b can be formed alternately or continuously (line Sn).
0065]
  Here, the side 8d and the side 8c of the convex ridge 8a and the concave ridge 8b have the same shape, but the shape may not be an isosceles triangle according to the light emitted from the light emission surface 5 of the light guide 3.
0066]
  Next, FIG. 10 shows the light guide 3 and light according to the present invention.deflectionIt is a partial top view of the light source device which consists of a sheet | seat 8 grade | etc.,.
0067]
  Light source devicedeflectionThe sheet 8 is provided on the upper surface of the light exit surface 5 of the light guide 3, and light is provided so as to face the convex ridge 5 b provided on the light guide 3.deflectionThe convex ridge 8 a of the sheet 8 is disposed toward the light exit surface 5 side of the light guide 3, and the light source 2 is disposed in the vicinity of the incident end surface portion 4 of the light guide 3.
0068]
  Here, the light guide 3 and lightdeflectionThe description of the sheet 8 is omitted because it overlaps with the description above, and the locus of light as the light source device will be described.
0069]
  In FIG. 10, the light ray L0 that has entered the light guide 3 from the incident portion P and has traveled in the direction of the exit surface 5 with the maximum refraction angle α reaches the side 5d of the convex ridge 5b of the exit surface 5. To do. When the exit surface 5 is flat with respect to the light ray L0, the light is totally reflected and proceeds in the direction of the back surface 6. However, the incident angle with respect to the side 5d is smaller than the critical angle γ = 38.97 °. Then, the critical angle γ is broken and refracted, and the light beam L1 is emitted to the air layer. The light beam L1 at this time is emitted at a large emission angle along the emission surface 5 of the light guide 3.
0070]
  Next, the light beam L1 is light.deflectionIt reaches the side 8c of the convex ridge 8a of the sheet 8, and here also the light guide 3 and the lightdeflectionLight that is the same material as the sheet 8 (polycarbonate (PC)) and has a higher refractive index than air from the air layerdeflectionThe light ray L1 with respect to the side 8c of the sheet 8 is refracted at the side 8c and is light.deflectionThe light beam L11 travels into the sheet 8.
0071]
  Further, the light beam L11 is light.deflectionSince it reaches the side 8d in the sheet 8 and the incident angle here is larger than the critical angle γ = 38.97 °, total reflection is performed at the side 8d, and the light ray L12 is reflected by light.deflectionProceed in the direction of the surface portion 8 ′ of the sheet 8.
0072]
  Ray L12 is lightdeflectionSince the incident angle at the surface portion 8 ′ of the sheet 8 is smaller than the critical angle γ = 38.97 °, the light is emitted from the surface portion 8 ′ substantially perpendicularly.
0073]
  In this way, lightdeflectionThe sheet 8 emits light rays from the light guide 3 that are low along the light guide 3 using total reflection.deflectionLight can be emitted in a direction substantially perpendicular to the sheet 8. For this reason, the exit surface 5 of the light guide 3 and the lightdeflectionLight can be projected substantially perpendicularly to the incident surface portion 10 of the light guide plate 9 placed opposite to the sheet 8.
0074]
  The light guide plate 9 includes an incident surface portion 10 for guiding light, a reflection end surface portion 11 located on the opposite side, side surfaces 14 a and 14 b connected to the incidence surface portion 10 and the reflection end surface portion 11 at right angles, and the incident surface portion 10. It has a front surface portion 12 and a back surface portion 13 for emitting light, and is configured in a rectangular shape or a wedge shape.
0075]
  The light guide plate 9 is formed of a transparent acrylic resin (PMMA), polycarbonate (PC), or the like. The light guide plate 9 includes a light source 2, a light guide 3, and light.deflectionA light beam from the light source device comprising the sheet 8 is guided into the light guide plate 9 by the incident surface portion 10 and is formed of a fine arc shape, an ellipse, a polygonal column, a polygonal pyramid and the like applied to the front surface portion 12 and the back surface portion 13 (not shown). The light incident from the light source 2 is refracted, diffused, reflected, and scattered by the shape or convex shape, dot pattern, and prism shape, and the light is emitted from the front surface portion 12 and the back surface portion 13.
0076]
  The reflector 15 is a sheet in which a white material such as titanium oxide is mixed in a thermoplastic resin for portions other than the incident end face portion 4 where light from the light source 2 is incident on the light guide 3 and the exit surface 5 where light is emitted. The thermoplastic resin sheet is subjected to metal deposition such as aluminum, or is covered with metal foil or a sheet metal, and the light from the light source 2 reflects or irregularly reflects light other than that emitted from the light guide 3. All the light from the light source 2 is emitted from the emission surface 5 of the light guide 3 by being incident on the light guide 3.
0077]
  Therefore, the light guide 3 and light of the present inventiondeflectionThe light source device composed of the sheet 8 or the like gives a constant light energy everywhere even with a small number of point light sources, by providing radial edges on the exit surface 5 and the back surface 6 of the light guide 3 from the location of the light source. Then, among the light rays incident on the light guide 3, a light ray having a large energy is emitted from the light guide 3 at an arbitrary angle, and this light ray is emitted as light.deflectionWith the sheet 8, in a substantially vertical directiondeflectionTherefore, the light can be reliably projected onto the light guide plate 9.
0078]
  Then, the flat illumination device of the present invention has light on the upper portion of the light guide 3.deflectionBy providing the sheet 8, the light emitted from the light guide 3 along the light guide 3 can be emitted as light.deflectionThe sheet 8 as a whole can efficiently emit light to the incident surface portion 10 of the light guide plate 9, and can emit light with higher brightness and no spots than the surface portion of the light guide plate 9.
0079]
【The invention's effect】
  As described above, the light guide according to claim 1 has a quadrangular prism shape, and is concentric with the center position of the incident end surface on the exit surface.Radially continuous or discontinuousHave convex or / and concave edges,Total reflection and refraction by convex and concave edges,Any distance corresponding to the edge from the light sourceInIn this case, since the light energy is equally emitted, the light can be emitted with uniform brightness anywhere on the light exit surface of the light guide, and high quality light can be provided to the light entrance surface of the light guide plate.Further, since the ridge is continuous or non-continuous, the emitted light can be emitted from the emission surface to the entire region along the ridge, and can also be emitted partially to a target position. Therefore, it is possible to control the spread of the light cone of the emitted light, control the brightness, and the like.
0080]
  Moreover, the light guide according to claim 2 has a cylindrical shape.Cut out to have a rectangular surface in the longitudinal direction of the rectangular surface as the exit surfaceConcentric with the center position of the incident end faceRadially continuous or discontinuousHave convex or / and concave edges,Total reflection and refraction by convex and concave edges,Since the light energy is emitted equally at any distance corresponding to the ridge from the light source, it can be emitted with uniform brightness anywhere without any spots on the exit surface of the light guide, and the quality of the incident surface of the light guide plate is high. Can provide good light.
0081]
  Furthermore, since the light guide according to claim 3 has a triangular cross section in a direction perpendicular to the normal line with the ridge centered and concentric, the light emitted from the light exit surface is made substantially the same. It is possible to provide high-quality light to the incident surface of the light guide plate.
0082]
  And claims4Since the triangular ridge portion of the light guide according to the present invention is cut out flat, for example, when a reflector is provided in the vicinity of the opposite side surface of the emission surface, the light totally reflected by the flat portion of the emission surface is emitted. The light beam that travels in the direction opposite to the surface and exits the light guide is reflected by the reflector and enters the light guide again, and this light beam is reflected and refracted on the slope of the ridge of the exit surface. In the flat portion of the present invention, since the light can be emitted from the light exit surface substantially straight, the brightness of the light emitted can be controlled.
0083]
  Claims5In the light guide according to the present invention, the adjacent surfaces of the triangular ridges are curved or arc-shaped, and therefore, when the curved or arc-shaped surface is an indented ridge surface, the light is diffused and the curved surface is curved. Or, in the case of a ridge surface that bulges outward, the light can be condensed at a location that matches the curvature, and the exit angle of the emitted light can be varied to diffuse the light further away. , Can be designed to suit the purpose.
0084]
  And claims6The light source device according to the present invention has a light source, and at least one end portion as an incident end surface portion that guides a light beam from the light source and has an exit surface that emits light, and the exit surface is concentric with the center position of the incident end surface portion.Radially continuous or discontinuousAn elongated quadrangular prism shape with convex or / and concave edges orAbbreviation with a plane in the longitudinal directionA cylindrical light guide and a positional relationship corresponding to a ridge on the light exit surface of the light guideradiationLight with a prismatic shapedeflectionA light guide with a ridge angle and lightdeflectionSince the angle of the edge of the sheet is always the same angle, the angle of light and the light before emitting from the edge of the light guidedeflectionThe angle of the light beam after entering the edge of the sheet can be made equal, and the light emitted from the edge of the light guide plate can be completely emitted at the shortest distance.deflectionEfficiently guides light to the edge of the sheetdeflectioncan do. This makes it possible to obtain bright, uniform and uniform outgoing light, and even when the light emitted from the light guide emits along the light guide side, it rises almost vertically, and the incident surface of the light guide plate The light from the light source can be projected efficiently.
0085]
  Claims7The light source device according todeflectionSince the sheet has a convex or / and concave ridge corresponding to the center position and the concentric position with the ridge of the light guide from the incident end surface of the light guide, the sheet protrudes from the convex or concave ridge of the light guide. Fully shine light in the shortest distancedeflectionThis light can be guided to the convex or concave edge of the sheet.deflectionLight emitted from the light guide by the sheetdeflectioncan do.
[0086]
  And claims8The light source device according todeflectionSince the cross-section in the direction perpendicular to the normal to the ridge corresponding to the center position and the concentric position is always triangular, the light emitted from the light guidedeflectioncan do. For example, even when light emitted from the light guide exits along the light guide,deflectioncan do.
[0087]
  Claims9The light source device according todeflectionBecause the sheet is continuous or non-continuous, the light emitted from the light guidedeflectionSelect the part that needsdeflectioncan do. For this reason, the design suitable for the purpose can be performed.
[0088]
  And claims10The flat illumination device according to the present invention has a light source, an incident end surface portion that guides light from the light source at least one end portion, and an output surface that emits light, and is concentric with the center position of the incident end surface portion on the output surface.Radially continuous or discontinuousA long rectangular prismatic light guide having convex or / and concave ridges and a positional relationship corresponding to the ridges on the light exit surface of the light guideradiationLight with a prismatic shapedeflectionSheet and lightdeflectionLight at the position facing the sheetdeflectionA light guide plate having an incident surface portion that guides light from the sheet and a light guide plate having a front surface portion and / or a back surface portion that emits light, and the light energy is equal at an arbitrary distance corresponding to the ridge from the light source; Light emitted fromdeflectionThe sheet is emitted in a direction substantially perpendicular to the emission surface, and the emitted light is guided from the incident surface portion of the light guide plate and emitted from the front surface portion and / or the back surface portion. You can get light. As a result, when used in a liquid crystal display device or the like, an appropriate viewing angle can be obtained with no bright spots.
[0089]
  Claims11A flat illumination device according to the present invention includes a light source,Has an elongated cylindrical shapeAt least one end is used as an incident end surface that guides light from the light source.Cut out to have a rectangular surface in the longitudinal direction of the cylindrical shape,It has an exit surface that emits light and is concentric with the center position of the incident end face on the exit surfaceRadially continuous or discontinuousThe elongated cylindrical light guide having convex or / and concave ridges and a positional relationship corresponding to the ridges on the light exit surface of the light guideradiationLight with a prismatic shapedeflectionSheet and lightdeflectionLight at the position facing the sheetdeflectionA light guide plate having an incident surface portion that guides light from the sheet and a light guide plate having a front surface portion and / or a back surface portion that emits light, and the light energy is equal at an arbitrary distance corresponding to the ridge from the light source; Light emitted fromdeflectionThe sheet is emitted in a direction substantially perpendicular to the emission surface, and the emitted light is guided from the incident surface portion of the light guide plate and emitted from the front surface portion and / or the back surface portion. You can get light. As a result, when used in a liquid crystal display device or the like, an appropriate viewing angle can be obtained with no bright spots.
[Brief description of the drawings]
FIG. 1 is an overall perspective view showing a schematic configuration of a flat illumination device according to the present invention.
FIG. 2 is a plan view schematically showing an exit surface of a light guide according to the present invention.
FIG. 3 is a partially enlarged side sectional view of a light guide according to the present invention.
FIG. 4 is a partially enlarged side sectional view of a light guide according to the present invention.
5A and 5B are partially enlarged perspective views of a light guide according to the present invention.
FIG. 6 is a partially enlarged perspective view of a light guide according to the present invention.
FIG. 7 is a partially enlarged perspective view of a light guide according to the present invention.
FIG. 8 is a view showing light provided in the flat illumination device according to the present invention.deflectionSchematic side view of seat
FIG. 9 is a view showing the light provided in the flat illumination device according to the present invention.deflectionSchematic plan view of the sheet
FIG. 10 is a light locus diagram of the light source device according to the present invention.
[Explanation of symbols]
  DESCRIPTION OF SYMBOLS 1 ... Plane illumination apparatus, 2 ... Light source, 2a ... Light-emitting surface, 3 ... Light guide, 4 ... Incident end surface part, 4b ... End surface part, 5 ... Outgoing surface, 5b ... Convex ridge, 5a ... Concave ridge, 6 ... Back, 7a, 7b ... side, 8 ... lightdeflectionSheet, 9: Light guide plate, n: Refractive index, 8b: Convex ridge, 8a: Concave ridge, 1c, 1d, 11a ... Virtual horizontal line, A, a ... Vertical point of normal line concentric with light source, 511 521 ... Flat part, 51a, 52a ... Curved edge, 5c, 5d, 8c, 8d ... Side, P ... Incident part, P1 ... Center position, S1 ... Convex ridge line, S2 ... Concave ridge line, Sn ... Line, α ... Refraction angle, θ1, θ5, convex ridge angle, θ2, θ6, concave ridge angle, θ3, θ7, angle formed with virtual horizontal line, γ, critical angle, L0, L1, L2, L1 ′, L2 ′, L3 , L3 ′, L4, L4 ′, L12, L12 ′, L11, L13, L31, L32, L33, L34.

Claims (11)

An elongated light guide made of a translucent material, a point light source located at at least one end of the light guide, an exit surface for emitting light from one longitudinal direction of the light guide, and an incident end surface facing the light source In the light guide used in the light source device composed of a reflector that covers other than the part,
The light guide has a quadrangular prism shape, and has a convex or concave ridge that is radially continuous or discontinuous concentrically with the center position of the incident end surface portion on the exit surface . A light guide which is totally reflected and refracted by a ridge, and emits light energy equally at an arbitrary distance corresponding to the ridge from the light source. An elongated light guide made of a translucent material, a point light source located at at least one end of the light guide, an exit surface for emitting light from one longitudinal direction of the light guide, and an incident end surface facing the light source In the light guide used in the light source device composed of a reflector that covers other than the part,
The light guide is notched so as to have a rectangular surface in the longitudinal direction of the columnar shape , and the convex surface is a continuous or non-continuous radial shape concentrically with the center position of the incident end surface portion with the rectangular surface as an exit surface. And / or a concave ridge that is totally reflected and refracted by the convex and concave ridges so that light energy is equally emitted from the light source at an arbitrary distance corresponding to the ridge. body.   The light guide according to claim 1 or 2, wherein a cross section of the ridge in a direction perpendicular to a normal line between the center position and the concentricity is always triangular.   The light guide according to claim 1, wherein the triangular shape has the ridge portion cut out flat.   3. The light guide according to claim 1, wherein the triangular shape is such that adjacent surfaces of the ridge are curved or arcuate. A light source;
At least one end portion is an incident end surface portion that guides a light beam from the light source, and has an exit surface that emits light, and the exit surface has a convex shape that is continuous or discontinuous radially concentrically with the center position of the incident end surface portion. Or / and an elongated quadrangular prism shape having a concave ridge or a substantially cylindrical light guide having a plane in the longitudinal direction ;
; And a light deflection sheet having a radiation prismatic shape corresponding such positional relation to the ridge on the exit surface of the light guide,
The light source device characterized in that the ridge angle of the light guide and the ridge angle of the light deflection sheet are always the same angle. The light deflection sheet has a radial convex or / and concave ridge corresponding to the center position and a position concentric with the ridge of the light guide from the incident end surface portion of the light guide. The light source device according to claim 6 . The light source device according to claim 6 , wherein the ridge of the light deflection sheet is always triangular in cross section in a direction perpendicular to a normal line between the center position and the ridge corresponding to the concentric position. The light source device according to claim 6 , wherein the light deflection sheet is continuous or discontinuous. A light source;
At least one end portion is an incident end surface portion that guides a light beam from the light source, and has an exit surface that emits light, and the exit surface has a convex shape that is continuous or discontinuous radially concentrically with the center position of the incident end surface portion. Or / and an elongated quadrangular prismatic light guide with concave ridges;
A light deflection sheet having a radiation prismatic shape corresponding such positional relation to the ridge on the exit surface of the light guide,
Comprising a surface portion and / or has a back surface light guide plate for emitting incident face and the light guiding light from the light deflection sheet at a position opposed to the light deflection sheet,
The light energy is equal at an arbitrary distance corresponding to the ridge from the light source, the light emitted from the light guide is emitted in a direction substantially perpendicular to the emission surface by the light deflection sheet, and the emitted light is A flat illumination device characterized in that light is emitted from the incident surface portion of the light guide plate and from the front surface portion and / or the back surface portion. A light source;
It has an elongated cylindrical shape, and at least one end portion is used as an incident end surface portion that guides light from the light source, and is cut out so as to have a rectangular surface in the longitudinal direction of the cylindrical shape, and light is emitted from the rectangular surface. An elongated cylindrical light guide having an exit surface and having a convex or / and concave ridge that is continuous or discontinuous radially concentrically with the center position of the incident end surface on the exit surface;
A light deflection sheet having a radiation prismatic shape corresponding such positional relation to the ridge on the exit surface of the light guide,
Comprising a surface portion and / or has a back surface light guide plate for emitting incident face and the light guiding light from the light deflection sheet at a position opposed to the light deflection sheet,
The light energy is equal at an arbitrary distance corresponding to the ridge from the light source, the light emitted from the light guide is emitted in a direction substantially perpendicular to the emission surface by the light deflection sheet, and the emitted light is A flat illumination device characterized in that light is emitted from the incident surface portion of the light guide plate and from the front surface portion and / or the back surface portion.

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